WTNT43 KNHC 240243
TCDAT3
 
TROPICAL STORM RINA DISCUSSION NUMBER   2
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL182011
1100 PM EDT SUN OCT 23 2011
 
EARLIER REPORTS FROM AN AIR FORCE RESERVE RECONNAISSANCE AIRCRAFT
INDICATED BELIEVABLE SFMR WINDS OF 33-35 KT OUTSIDE OF THE
CONVECTION IN THE SOUTHWESTERN QUADRANT OF THE CYCLONE...BUT THESE
WINDS COULD HAVE BEEN GUSTS. THE AIRCRAFT ALSO HAD TO AVOID STRONG
THUNDERSTORMS TO THE NORTH OF THE CENTER AND WAS... THEREFORE...
UNABLE TO SAMPLE THE WINDS IN THAT AREA. SINCE THEN... HOWEVER...
DEEP CONVECTION HAS INCREASED MARKEDLY IN THE NORTHERN SEMICIRCLE
AND CONVECTION HAS ALSO DEVELOPED IN THE SOUTHWESTERN QUADRANT...
WHICH IS LIKELY HELPING TO SUSTAIN THE STRONGER WINDS IN THAT
REGION AS REPORTED PREVIOUSLY. UW-CIMSS ADT ESTIMATES HAVE BEEN
STEADILY INCREASING...AND THE MOST RECENT 2-HOUR AVERAGE IS T2.7/39
KT. AS A RESULT...THE DEPRESSION HAS BEEN UPGRADED TO TROPICAL
STORM RINA...THE SEVENTEENTH NAMED STORM OF THE SEASON.
 
RINA IS FORECAST TO REMAIN OVER SSTS OF NEAR 30C FOR THE NEXT 72-96
HOURS. IN ADDITION...DURING THE 24-48 HOUR TIME PERIOD...THE
CYCLONE WILL BE MOVING OVER SOME VERY HIGH UPPER-OCEAN CONTENT THAT
IS MORE THAN 10 TIMES THE VALUE THE STORM IS CURRENTLY TRAVERSING.
THE UPPER-LEVEL OUTFLOW HAS BEEN STEADILY INCREASING AND IS
EXPECTED TO IMPROVE EVEN MORE THROUGH 72 HOURS AS RINA MOVES UNDER
AN UPPER-LEVEL RIDGE AXIS THAT WILL PRODUCE OUTFLOW CHANNELS TO THE
NORTH AND SOUTH. SO THERE IS PLENTY OF HEAT AND VENTILATION
AVAILABLE FOR STRENGTHENING TO OCCUR. THE ONLY POSSIBLE INHIBITING
FACTOR IS VERY DRY MID-LEVEL AIR LOCATED OVER THE SOUTHERN GULF OF
MEXICO AND YUCATAN CHANNEL...WHICH COULD BE ENTRAINED INTO THE
CYCLONE AT 48 HOURS AND BEYOND. AS A RESULT...THE INTENSITY
FORECAST WILL REMAIN ON THE CONSERVATIVE SIDE AND LIES CLOSE TO THE
INTENSITY CONSENSUS MODEL ICON...AND THE STATISTICAL-DYNAMICAL
MODEL...LGEM.
 
THE INITIAL MOTION ESTIMATE IS 335/7 KT BASED ON RECON FIXES. THE
FORECAST TRACK DEPENDS HEAVILY ON THE INTENSITY FORECAST. SINCE THE
OFFICIAL INTENSITY FORECAST IS MUCH MORE ROBUST THAN WHAT THE
GFS...NOGAPS...CANADIAN...AND GFDL MODELS ARE FORECASTING FOR THE
NEXT 48 HOURS AND BEYOND...THOSE MODEL SOLUTIONS OF A WESTWARD OR
EVEN WEST-SOUTHWESTWARD MOTION FROM THE CURRENT POSITION HAVE BEEN
DISCOUNTED. IN CONTRAST...THE HWRF AND UKMET MODELS ARE FORECASTING
A STRONGER AND DEEPER CYCLONE THROUGHOUT THE THE FORECAST PERIOD...
WHICH LOOKS MORE LIKELY GIVEN THE RECENT UPWARD TRENDS IN SATELLITE
AND UPPER-AIR DATA. AS A RESULT...THE EXPECTED FORECAST SCENARIO
CALLS FOR RINA TO MOVE NORTHWESTWARD THROUGH A WEAKNESS IN THE
SUBTROPICAL RIDGE FOR THE NEXT 12 HOURS OR SO. AS A VIGOROUS
SHORTWAVE TROUGH CURRENTLY MOVING EASTWARD ACROSS THE CENTRAL AND
EASTERN GULF OF MEXICO PASSES EAST OF FLORIDA TOMORROW...THE RIDGE
SHOULD BUILD BACK IN TO THE NORTH OF RINA...FORCING THE CYCLONE ON
A SLOW WEST-NORTHWESTWARD TRACK UNTIL DAY 4. AFTER THAT...ANOTHER
STRONG SHORTWAVE TROUGH IS FORECAST TO DIG SOUTHEASTWARD FROM THE
SOUTHERN PLAINS AND INTO THE GULF OF MEXICO...WHICH IS EXPECTED TO
WEAKEN THE SUBTROPICAL RIDGE ONCE AGAIN AND ALLOW RINA TO TURN
NORTHWARD NEAR THE YUCATAN PENINSULA. THE OFFICIAL FORECAST TRACK
LIES TO THE RIGHT OF THE PREVIOUS ADVISORY TRACK AND THE CONSENSUS
MODELS..AND IS CLOSE TO A BLEND OF THE UKMET...HWRF...AND ECMWF
MODEL TRACKS.
 
IN THE SHORT TERM...HEAVY RAINFALL AND FLOODING WILL BE SIGNIFICANT
THREATS FOR NORTHERN HONDURAS WHERE 8-15 INCHES OF RAIN HAVE
ALREADY FALLEN DURING THE PAST 3 DAYS.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  24/0300Z 16.4N  82.2W   35 KT  40 MPH
 12H  24/1200Z 16.8N  82.6W   40 KT  45 MPH
 24H  25/0000Z 17.3N  83.4W   45 KT  50 MPH
 36H  25/1200Z 17.5N  84.3W   50 KT  60 MPH
 48H  26/0000Z 17.7N  85.1W   55 KT  65 MPH
 72H  27/0000Z 17.9N  86.2W   60 KT  70 MPH
 96H  28/0000Z 18.9N  87.4W   65 KT  75 MPH
120H  29/0000Z 20.0N  87.4W   65 KT  75 MPH
 
$$
FORECASTER STEWART
 

WTNT43 KNHC 240832
TCDAT3
 
TROPICAL STORM RINA DISCUSSION NUMBER   3
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL182011
500 AM EDT MON OCT 24 2011
 
THE CLOUD PATTERN OF RINA HAS NOT BECOME BETTER ORGANIZED OVER THE
PAST SEVERAL HOURS. THERE IS ONE LARGE CLUSTER OF DEEP CONVECTION
JUST TO THE NORTH OF THE ESTIMATED CENTER POSITION WITH A COUPLE OF
ADJACENT SMALLER CLUSTERS...BUT NOT MUCH EVIDENCE OF CURVED BANDS.
VERY LITTLE THUNDERSTORM ACTIVITY IS CURRENTLY OCCURRING OVER THE
SOUTHERN HALF OF THE CIRCULATION. THE INITIAL WIND SPEED IS HELD AT
35 KT IN AGREEMENT WITH THE LATEST OBJECTIVE DVORAK INTENSITY
ESTIMATES FROM UW/CIMSS. RINA IS IN AN ENVIRONMENT OF MODERATE
SOUTH-SOUTHEASTERLY VERTICAL BUT IS EXHIBITING FAIRLY WELL-DEFINED
UPPER-LEVEL OUTFLOW OVER ALL BUT THE SOUTHEASTERN QUADRANT OF THE
CIRCULATION. THE SHIPS GUIDANCE INDICATES THAT A SLIGHT LESSENING
OF THE SHEAR COULD OCCUR IN THE NEXT COUPLE OF DAYS. TOTAL
PRECIPITABLE WATER IMAGERY ALONG WITH SURFACE AND RADIOSONDE DATA
SHOW A SIGNIFICANTLY DRIER LOW- TO MID-TROPOSPHERIC AIR MASS EXISTS
JUST TO THE NORTH AND WEST OF THE STORM. GIVEN THESE MARGINALLY
CONDUCIVE ENVIRONMENTAL FACTORS...ONLY SLOW STRENGTHENING IS
FORECAST. THE OFFICIAL INTENSITY FORECAST IS VERY SIMILAR TO THE
LGEM GUIDANCE AND BELOW THE GFDL AND HWRF MODELS.
 
USING A COMBINATION OF CENTER FIXES FROM GEOSTATIONARY AND MICROWAVE
IMAGERY YIELDS AN INITIAL MOTION ESTIMATE OF 330/5.  A 500 MB SHORT
WAVE TROUGH IS CURRENTLY PASSING TO THE NORTH AND WILL SOON BYPASS
THE TROPICAL CYCLONE.  AFTER THE TROUGH DEPARTS THE AREA...A WEAK
RIDGE IS FORECAST TO DEVELOP TO THE NORTH OF RINA.  THIS STEERING
PATTERN SHOULD CAUSE THE CYCLONE TO TURN TOWARD THE WEST...BUT AT A
VERY SLOW RATE OF FORWARD SPEED...DURING THE NEXT 48 HOURS.  BY THE
END OF THE FORECAST PERIOD A STRONGER TROUGH MOVES INTO THE EASTERN
UNITED STATES...WHICH SHOULD INDUCE A NORTHWARD TURN.  THE OFFICIAL
TRACK FORECAST IS CLOSE TO A CONSENSUS OF THE GLOBAL MODELS...WHICH
ARE WELL TO THE SOUTH AND WEST OF THE GFDL AND HWRF.  THESE LATTER
MODELS ARE PREDICTING RINA TO BECOME A STRONG HURRICANE THAT WOULD
RESPOND TO THE DEEP-LAYER SOUTHWESTERLY FLOW OVER THE EASTERN GULF. 
GIVEN THE PREDICTED ATMOSPHERIC ENVIRONMENT...SUCH A SCENARIO SEEMS
UNLIKELY AT THIS TIME.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  24/0900Z 16.7N  82.3W   35 KT  40 MPH
 12H  24/1800Z 17.0N  82.9W   40 KT  45 MPH
 24H  25/0600Z 17.4N  83.6W   45 KT  50 MPH
 36H  25/1800Z 17.5N  84.3W   50 KT  60 MPH
 48H  26/0600Z 17.6N  85.0W   55 KT  65 MPH
 72H  27/0600Z 18.5N  86.5W   60 KT  70 MPH
 96H  28/0600Z 19.5N  87.0W   65 KT  75 MPH
120H  29/0600Z 20.5N  87.0W   65 KT  75 MPH
 
$$
FORECASTER PASCH/LANDSEA
 

WTNT43 KNHC 241438
TCDAT3
 
TROPICAL STORM RINA DISCUSSION NUMBER   4
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL182011
1100 AM EDT MON OCT 24 2011
 
VISIBLE SATELLITE IMAGES SHOW THAT RINA HAS BECOME BETTER
ORGANIZED WITH THE CENTER LOCATED WELL WITHIN THE LARGE AREA
OF DEEP CONVECTION.  THE LATEST DVORAK DATA T AND CI NUMBERS...
AND A RECENT AMSU INTENSITY ESTIMATE SUPPORT INCREASING THE 
INITIAL WIND SPEED TO 40 KT.  AN AIR FORCE RESERVE HURRICANE HUNTER
AIRCRAFT IS SCHEDULED TO INVESTIGATE THE CYCLONE THIS AFTERNOON AND
SHOULD PROVIDE A BETTER ASSESSMENT OF THE INTENSITY OF RINA. 
 
ALTHOUGH THERE IS SOME DRY AIR TO THE NORTHWEST OF THE CYCLONE...
AN INCREASINGLY FAVORABLE UPPER-LEVEL WIND PATTERN AND VERY WARM
WATERS OF THE NORTHWESTERN CARIBBEAN SEA SHOULD ALLOW FOR STEADY
STRENGTHENING DURING THE NEXT 48-72 HOURS.  IN 3 TO 4 DAYS...
SOUTHERLY SHEAR IS EXPECTED TO INCREASE...AND LATER IN THE
PERIOD...THE CYCLONE IS FORECAST TO INTERACT WITH A FRONTAL
BOUNDARY.  THESE CONDITIONS WILL LIKELY LEAD TO SOME WEAKENING OF
RINA BEFORE THE END OF THE FORECAST PERIOD.  THE UPDATED NHC
INTENSITY FORECAST IS ABOVE THE PREVIOUS ADVISORY AND LIES BETWEEN
THE STATISTICAL SHIPS/LGEM GUIDANCE AND THE MORE AGGRESSIVE
GFDL/HWRF MODELS.
 
RECENT GEOSTATIONARY AND MICROWAVE SATELLITE FIXES SUGGEST THAT RINA
IS BEGINNING ITS TURN TOWARD THE LEFT.  THE INITIAL MOTION ESTIMATE
IS 320/5.  THE CYCLONE SHOULD TURN WEST-NORTHWESTWARD TODAY AS A
MID-LEVEL RIDGE BUILDS OVER THE NORTHERN GULF OF MEXICO DURING THE
NEXT 24 HOURS.  AS THIS RIDGE SLIDES EASTWARD IN A COUPLE OF
DAYS...IT SHOULD ALLOW RINA TO TURN NORTHWESTWARD...THEN NORTHWARD.
NEAR THE END OF THE FORECAST PERIOD...RINA IS EXPECTED TO TURN
NORTHEASTWARD AS THE RIDGE RETREATS AND A BROAD TROUGH MOVES OVER
THE GULF OF MEXICO.  THE MODEL GUIDANCE IS IN SOMEWHAT BETTER
AGREEMENT THIS CYCLE...WITH THE GFDL AND HWRF SHIFTING SOUTHWARD
AND KEEPING RINA OVER THE NORTHWESTERN CARIBBEAN SEA DURING THE
FORECAST PERIOD.  THE NHC FORECAST IS VERY SIMILAR TO THE PREVIOUS
ADVISORY THROUGH 96 HOURS...BUT NOW SHOWS A SLOW NORTHEASTWARD
MOTION THEREAFTER.  THE NEW TRACK IS IN GOOD AGREEMENT WITH BOTH
THE TVCA AND HFIP MULTI-MODEL CONSENSUS.
 

FORECAST POSITIONS AND MAX WINDS
 
INIT  24/1500Z 17.1N  82.9W   40 KT  45 MPH
 12H  25/0000Z 17.4N  83.4W   50 KT  60 MPH
 24H  25/1200Z 17.6N  84.0W   60 KT  70 MPH
 36H  26/0000Z 17.8N  84.8W   70 KT  80 MPH
 48H  26/1200Z 18.1N  85.7W   80 KT  90 MPH
 72H  27/1200Z 19.2N  87.0W   75 KT  85 MPH
 96H  28/1200Z 20.5N  87.0W   65 KT  75 MPH
120H  29/1200Z 21.0N  86.0W   55 KT  65 MPH
 
$$
FORECASTER BROWN/ROBERTS
 

WTNT43 KNHC 241821
TCDAT3
 
HURRICANE RINA SPECIAL DISCUSSION NUMBER   5
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL182011
200 PM EDT MON OCT 24 2011
 
SATELLITE IMAGES AND REPORTS FROM AN AIR FORCE RESERVE HURRICANE
HUNTER AIRCRAFT INDICATE THAT RINA HAS RAPIDLY STRENGTHENED.  THE
AIRCRAFT REPORTED PEAK 850 MB FLIGHT-LEVEL WINDS OF 68 KT AND
BELIEVABLE SFMR WINDS AROUND 65 KT.  BASED ON THESE DATA THE
INITIAL INTENSITY IS INCREASED TO 65 KT...MAKING RINA THE 6TH
HURRICANE OF SEASON IN THE ATLANTIC BASIN.  THIS SPECIAL ADVISORY
HAS BEEN ISSUED TO INCREASE THE INITIAL AND FORECAST INTENSITIES
FROM THE PREVIOUS FORECAST...BUT NO CHANGE TO THE TRACK WAS
REQUIRED.

 
FORECAST POSITIONS AND MAX WINDS
 
INIT  24/1800Z 17.1N  83.0W   65 KT  75 MPH
 12H  25/0000Z 17.4N  83.4W   75 KT  85 MPH
 24H  25/1200Z 17.6N  84.0W   90 KT 105 MPH
 36H  26/0000Z 17.8N  84.8W  100 KT 115 MPH
 48H  26/1200Z 18.1N  85.7W  105 KT 120 MPH
 72H  27/1200Z 19.2N  87.0W  100 KT 115 MPH
 96H  28/1200Z 20.5N  87.0W   90 KT 105 MPH
120H  29/1200Z 21.0N  86.0W   80 KT  90 MPH
 
$$
FORECASTER BROWN/ROBERTS
 

WTNT43 KNHC 241821
TCDAT3
 
HURRICANE RINA SPECIAL DISCUSSION NUMBER   5
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL182011
200 PM EDT MON OCT 24 2011
 
SATELLITE IMAGES AND REPORTS FROM AN AIR FORCE RESERVE HURRICANE
HUNTER AIRCRAFT INDICATE THAT RINA HAS RAPIDLY STRENGTHENED.  THE
AIRCRAFT REPORTED PEAK 850 MB FLIGHT-LEVEL WINDS OF 68 KT AND
BELIEVABLE SFMR WINDS AROUND 65 KT.  BASED ON THESE DATA THE
INITIAL INTENSITY IS INCREASED TO 65 KT...MAKING RINA THE 6TH
HURRICANE OF SEASON IN THE ATLANTIC BASIN.  THIS SPECIAL ADVISORY
HAS BEEN ISSUED TO INCREASE THE INITIAL AND FORECAST INTENSITIES
FROM THE PREVIOUS FORECAST...BUT NO CHANGE TO THE TRACK WAS
REQUIRED.

 
FORECAST POSITIONS AND MAX WINDS
 
INIT  24/1800Z 17.1N  83.0W   65 KT  75 MPH
 12H  25/0000Z 17.4N  83.4W   75 KT  85 MPH
 24H  25/1200Z 17.6N  84.0W   90 KT 105 MPH
 36H  26/0000Z 17.8N  84.8W  100 KT 115 MPH
 48H  26/1200Z 18.1N  85.7W  105 KT 120 MPH
 72H  27/1200Z 19.2N  87.0W  100 KT 115 MPH
 96H  28/1200Z 20.5N  87.0W   90 KT 105 MPH
120H  29/1200Z 21.0N  86.0W   80 KT  90 MPH
 
$$
FORECASTER BROWN/ROBERTS
 

WTNT43 KNHC 242041
TCDAT3
 
HURRICANE RINA DISCUSSION NUMBER   6
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL182011
500 PM EDT MON OCT 24 2011
 
VISIBLE SATELLITE IMAGES SHOW SEVERAL BANDS OF DEEP CONVECTION
WRAPPING AROUND THE CENTER OF RINA AND A SMALL CENTRAL DENSE
OVERCAST FEATURE. THE HURRICANE HUNTER AIRCRAFT HAS NOT REPORTED
ANY STRONGER WINDS SINCE THEIR INITIAL PASS INTO THE CENTER JUST
BEFORE 1800 UTC...AND BASED ON THE EARLIER DATA THE INITIAL
INTENSITY WILL REMAIN 65 KT. 
 
RINA WILL BE TRAVERSING VERY WARM WATER AND REMAIN IN A LOW SHEAR
ENVIRONMENT DURING THE NEXT COUPLE OF DAYS. THE ONLY NEGATIVE
FACTOR FOR INTENSIFICATION IS AN AREA OF DRY AIR TO THE NORTHWEST
OF THE CYCLONE. SO FAR...RINA HAS REMAINED WELL INSULATED FROM THE
DRY AIR AND THE OFFICIAL FORECAST ASSUMES THAT THE DRY AIR WILL NOT
REACH THE CORE DURING THE NEXT COUPLE OF DAYS. AFTER THAT...
SOUTHERLY SHEAR IS FORECAST TO INCREASE AND RINA IS ALSO EXPECTED
TO INTERACT WITH A FRONTAL BOUNDARY THAT MOVES INTO THE
SOUTHEASTERN GULF OF MEXICO NEAR THE END OF THE FORECAST PERIOD.
THE INTENSITY FORECAST IS VERY SIMILAR TO THE ONE ISSUED IN THE
SPECIAL ADVISORY AND IS NEAR THE GFDL AND HWRF GUIDANCE THROUGH 48
HOURS. AFTER THAT TIME...IT IS CLOSER TO A BLEND OF THE STATISTICAL
AND DYNAMICAL MODEL GUIDANCE. GIVEN THE RELATIVELY SMALL SIZE OF
THE HURRICANE...IT WOULD NOT BE SURPRISING TO SEE RAPID CHANGES
BOTH UP AND DOWN IN ITS INTENSITY.
 
THE AIRCRAFT FIXES SHOW THAT THE HURRICANE HAS SLOWED DOWN.  A
BUILDING HIGH PRESSURE RIDGE OVER THE NORTHERN GULF OF MEXICO IS
EXPECTED TO STEER RINA WESTWARD DURING THE NEXT 24 TO 36 HOURS.
AS THE RIDGE SLIDES EASTWARD THE HURRICANE SHOULD TURN
NORTHWESTWARD...THEN NORTHWARD IN 2 TO 3 DAYS.  AFTER THAT...THE
TRACK GUIDANCE BECOMES QUITE DIVERGENT WITH THE GFDL AND HWRF
TAKING THE CYCLONE NORTHEASTWARD...AND THE GFS SHOWING AN
EASTWARD OR EAST-SOUTHEASTWARD MOTION.  FOR NOW...THE NHC FORECAST
REMAINS BETWEEN THESE TWO EXTREMES AND SHOWS A SLOW EAST-NORTHEAST
MOTION NEAR THE END OF THE PERIOD.
 
GIVEN THE EXTREMELY LARGE SPREAD IN THE GUIDANCE...AND THE POOR RUN
TO RUN CONSISTENCY...THERE IS MUCH LOWER THAN NORMAL CONFIDENCE IN
THE LONG-RANGE TRACK FORECAST OF RINA. 
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  24/2100Z 17.1N  83.1W   65 KT  75 MPH
 12H  25/0600Z 17.2N  83.7W   75 KT  85 MPH
 24H  25/1800Z 17.3N  84.4W   90 KT 105 MPH
 36H  26/0600Z 17.6N  85.2W  100 KT 115 MPH
 48H  26/1800Z 18.1N  86.0W  105 KT 120 MPH
 72H  27/1800Z 19.8N  87.2W   95 KT 110 MPH
 96H  28/1800Z 21.0N  87.0W   85 KT 100 MPH
120H  29/1800Z 21.5N  85.0W   75 KT  85 MPH
 
$$
FORECASTER BROWN
 

WTNT43 KNHC 250246
TCDAT3
 
HURRICANE RINA DISCUSSION NUMBER   7
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL182011
1100 PM EDT MON OCT 24 2011
 
RINA IS BECOMING BETTER ORGANIZED. THE HURRICANE HAS MAINTAINED A
NEARLY CIRCULAR CENTRAL DENSE OVERCAST THE LAST SEVERAL HOURS...
WITH A LARGE AREA OF CLOUD TEMPERATURES LOWER THAN -70C. A 0137 UTC
SSMIS OVERPASS ALSO SHOWED A CLOSED LOW- TO MID-LEVEL EYE IN THE
DEEPEST CONVECTION. WATER VAPOR IMAGERY INDICATES AN IMPRESSIVE
OUTFLOW CHANNEL TO THE NORTH...WITH GOOD OUTFLOW NOTED ELSEWHERE.
DVORAK INTENSITY ESTIMATES ARE 4.0 FROM TAFB AND SAB AND THE LATEST
ADT VALUE IS 4.3/73 KT. BASED UPON THESE DATA...THE INITIAL
INTENSITY IS SET AT 70 KT.
 
RINA IS LIKELY TO INTENSIFY FURTHER DURING THE NEXT COUPLE OF DAYS
AS IT TRAVERSES THE VERY WARM WATERS OF THE NORTHWEST CARIBBEAN SEA
IN AN ENVIRONMENT OF RELATIVELY LOW SHEAR. THE ONE CAVEAT TO THIS
FORECAST IS THAT DRY AIR LURKING IN THE NEAR-STORM ENVIRONMENT
COULD POTENTIALLY BE A LIMITING FACTOR. BEYOND 60 HOURS...THE
ATMOSPHERIC ENVIRONMENT IS FORECAST TO BECOME INCREASINGLY LESS
FAVORABLE AS RINA ENCOUNTERS STRONG SOUTHWESTERLY SHEAR AND
ADDITIONAL DRY AIR IMPINGES ON THE CIRCULATION. THE CYCLONE COULD
ALSO INTERACT WITH LAND AS IT PASSES NEAR OR OVER THE YUCATAN
PENINSULA IN 72-96 HOURS. THE OFFICIAL FORECAST FOLLOWS THE
PREVIOUS ONE AND CALLS FOR ADDITIONAL STRENGTHENING IN THE SHORT
TERM...FOLLOWED BY STEADY WEAKENING AFTER 48 HOURS. THE INTENSITY
FORECAST REMAINS ABOVE THE STATISTICAL-DYNAMICAL INTENSITY GUIDANCE
THROUGH 48 HOURS BUT IS IN GOOD AGREEMENT AFTER THIS TIME. IT
SHOULD BE NOTED THAT THE ECMWF CONTINUES TO FORECAST RINA TO
DISSIPATE IN THE 3 TO 5 DAY TIME FRAME...WHILE THE GFS/UKMET GLOBAL
MODELS IMPLY MORE WEAKENING THAN SHOWN IN THE OFFICIAL FORECAST.
 
THE LAST COUPLE OF AIRCRAFT AND SATELLITE FIXES INDICATE THAT RINA
HAS MOVED LITTLE AND THE INITIAL MOTION ESTIMATE IS 295/03. LITTLE
CHANGE HAS BEEN MADE TO THE PREVIOUS FORECAST TRACK. GLOBAL MODELS
ARE IN REASONABLY GOOD AGREEMENT THAT RINA WILL TURN TOWARD THE
NORTHWEST AND THEN THE NORTH-NORTHWEST IN 36-72 HOURS ON THE
WESTERN SIDE OF A MID-LEVEL RIDGE LOCATED OVER THE NORTHERN
CARIBBEAN. AFTER THIS TIME...THERE IS CONSIDERABLE SPREAD IN THE
TRACK GUIDANCE. THE HWRF/GFDL/UKMET ACCELERATE RINA NORTHEASTWARD
OVER OR NEAR SOUTH FLORIDA...WHEREAS THE GFS TURNS THE CYCLONE
SOUTHWARD IN THE NORTHWEST CARIBBEAN. THE MODEL SPREAD IS IN PART
RELATED TO THE PREDICTED VERTICAL DEPTH OF RINA. A STRONGER
CYCLONE...AS INDICATED BY THE GFDL/HWRF...WOULD LIKELY BE STEERED
BY THE DEEP-LAYER SOUTHWESTERLY FLOW...WHILE A WEAKER/SHALLOWER
SYSTEM WOULD BE PUSHED SOUTHWARD IN LOW-LEVEL NORTHERLY FLOW. SINCE
RINA IS FORECAST TO WEAKEN...PERHAPS MORE SIGNIFICANTLY THAN
FORECAST...THE OFFICIAL TRACK PLACES MORE WEIGHT ON THE WEAKER GFS
SOLUTION.

GIVEN THE LARGE SPREAD IN THE MODEL SOLUTIONS IN THE EXTENDED
RANGE...THE CONFIDENCE IN THE LATTER PART OF THE TRACK FORECAST
REMAINS LOW.

 
FORECAST POSITIONS AND MAX WINDS
 
INIT  25/0300Z 17.2N  83.3W   70 KT  80 MPH
 12H  25/1200Z 17.3N  83.9W   75 KT  85 MPH
 24H  26/0000Z 17.5N  84.8W   90 KT 105 MPH
 36H  26/1200Z 17.9N  85.6W  100 KT 115 MPH
 48H  27/0000Z 18.7N  86.3W  100 KT 115 MPH
 72H  28/0000Z 20.9N  87.2W   85 KT 100 MPH...INLAND
 96H  29/0000Z 22.2N  85.8W   75 KT  85 MPH
120H  30/0000Z 22.0N  84.0W   65 KT  75 MPH
 
$$
FORECASTER KIMBERLAIN
 

WTNT43 KNHC 250856
TCDAT3
 
HURRICANE RINA DISCUSSION NUMBER   8
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL182011
500 AM EDT TUE OCT 25 2011
 
RINA IS MAINTAINING A RATHER SYMMETRICAL CDO FEATURE WITH THE CENTER
LOCATED ABOUT IN THE MIDDLE OF A MASS OF VERY COLD CLOUD TOPS...BUT
AN EYE IS NOT YET DISCERNIBLE ON GEOSTATIONARY IMAGERY.  AN AIR
FORCE RECONNAISSANCE PLANE HAS BEEN INVESTIGATING THE HURRICANE
EARLY THIS MORNING.  THE HIGHEST UNFLAGGED SFMR WIND SPEED MEASURED
BY THE AIRCRAFT WAS 84 KT...THE PEAK FLIGHT-LEVEL WINDS WERE 89
KT...AND A GPS DROPSONDE MEASUREMENT IN THE WESTERN EYEWALL
SUPPORTED A SURFACE WIND SPEED OF AT LEAST 82 KT.  THE AIRCRAFT
DATA INDICATE THAT THIS SYSTEM IS MORE EFFECTIVE THAN USUAL IN
TRANSPORTING STRONG WINDS ALOFT TO THE SURFACE...WHICH IS
CONSISTENT WITH THE VIGOROUS DEEP CONVECTION OCCURRING NEAR THE
CENTER.  THE INITIAL WIND SPEED IS INCREASED TO 85 KT FOR THIS
ADVISORY.  RINA CONTINUES TO EXHIBIT STRONG UPPER-LEVEL OUTFLOW...
PARTICULARLY OVER THE NORTHERN SEMICIRCLE AND WILL CONTINUE TO
TRAVERSE WATERS OF HIGH OCEANIC HEAT CONTENT FOR THE NEXT COUPLE OF
DAYS.  ADDITIONAL STRENGTHENING SEEMS LIKELY UNTIL INCREASING
SOUTH-SOUTHWESTERLY SHEAR HALTS THE INTENSIFICATION PROCESS...WHICH
IS EXPECTED TO OCCUR IN ABOUT 48 HOURS.  THE OFFICIAL WIND SPEED
FORECAST IS ABOUT THE SAME AS IN THE PREVIOUS ADVISORY ALBEIT A
LITTLE LOWER NEAR THE END OF THE PERIOD.  THIS IS IN REASONABLE
AGREEMENT WITH THE CONSENSUS OF THE INTENSITY FORECAST MODELS.  IT
SHOULD BE NOTED THAT THE NORMALLY RELIABLE ECMWF MODEL SHOWS RINA
DISSIPATING OVER NORTHERN YUCATAN.
 
AIRCRAFT CENTER FIXES INDICATE THAT RINA CONTINUES TO MOVE VERY
SLOWLY OR ABOUT 290/3.  GLOBAL MODEL GUIDANCE SHOWS THAT THE WEAK
MID-TROPOSPHERIC RIDGE CURRENTLY TO THE NORTH OF RINA WILL
ESSENTIALLY DISSIPATE IN A COUPLE OF DAYS AND A BROAD TROUGH WILL
MOVE OVER THE U.S. EAST COAST NEAR THE END OF THE FORECAST PERIOD.
THESE CHANGES IN THE STEERING CURRENTS SHOULD CAUSE THE HURRICANE
TO TURN TOWARD THE NORTHWEST AND THEN NORTH IN 2 TO 3 DAYS.  BY
DAYS 4-5 THE CYCLONE IS EXPECTED TO TURN EASTWARD...BUT SINCE THE
SYSTEM SHOULD BE WEAKENING IT IS NOT EXPECTED TO FULLY RESPOND TO
THE MID-TROPOSPHERIC STEERING FLOW.  THE OFFICIAL FORECAST CALLS
FOR ONLY A VERY SLOW EASTWARD MOTION NEAR THE END OF THE FORECAST
PERIOD...AND IS SIMILAR TO THE GFS FORECAST AS WELL AS TO THE
PREVIOUS ADVISORY TRACK.  CONVERSELY...THE GFDL MODEL MAINTAINS
RINA AS A HURRICANE AND SHOWS A MUCH FASTER MOTION TOWARD THE
EAST-NORTHEAST IN THE LATTER PART OF THE FORECAST PERIOD.  HOWEVER
SINCE THIS IS NOW THE ONLY DYNAMICAL MODEL SHOWING SUCH BEHAVIOR...
IT IS AN OUTLIER THAT IS BEING DISREGARDED AT THIS TIME.
 
GIVEN THE LARGE SPREAD IN THE MODEL SOLUTIONS IN THE EXTENDED
RANGE...THE CONFIDENCE IN THE LATTER PART OF THE TRACK FORECAST
REMAINS LOW.
  
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  25/0900Z 17.3N  83.6W   85 KT 100 MPH
 12H  25/1800Z 17.4N  84.3W   90 KT 105 MPH
 24H  26/0600Z 17.8N  85.1W   95 KT 110 MPH
 36H  26/1800Z 18.3N  86.0W  100 KT 115 MPH
 48H  27/0600Z 19.3N  86.7W  100 KT 115 MPH
 72H  28/0600Z 21.5N  87.0W   80 KT  90 MPH...INLAND
 96H  29/0600Z 22.5N  85.0W   65 KT  75 MPH
120H  30/0600Z 22.5N  84.0W   55 KT  65 MPH...INLAND
 
$$
FORECASTER PASCH/LANDSEA
 

WTNT43 KNHC 251436
TCDAT3
 
HURRICANE RINA DISCUSSION NUMBER   9
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL182011
1100 AM EDT TUE OCT 25 2011

THE SATELLITE PRESENTATION OF RINA CONTINUES TO IMPROVE...WITH A
SMALL EYE SEEN IN AN 1128 UTC SSMIS PASS AND RECENT VISIBLE
IMAGERY. THE INITIAL INTENSITY IS INCREASED TO 90 KT FOR THIS
ADVISORY BASED 12Z DVORAK DATA-T NUMBERS FROM TAFB AND SAB. THE
HURRICANE IS SITUATED OVER A REGION OF VERY HIGH OCEAN HEAT CONTENT
AND THE UPPER-LEVEL OUTFLOW IS WELL ESTABLISHED...ESPECIALLY TO THE
NORTH. BASED ON THE FAVORABLE ENVIRONMENT...STRENGTHENING TO MAJOR
HURRICANE INTENSITY APPEARS LIKELY. THE NEW NHC FORECAST HAS BEEN
ADJUSTED UPWARD IN THE SHORT TERM AND IS IN GOOD AGREEMENT WITH THE
ICON INTENSITY CONSENSUS MODEL THROUGH 36 HOURS. AFTER 48 HOURS...
WEAKENING SHOULD BEGIN AS THE CYCLONE EXPERIENCES INCREASING
SOUTHWESTERLY VERTICAL WIND SHEAR. AT DAYS 4 AND 5 THE NEW NHC
FORECAST IS A LITTLE LOWER THAN THE PREVIOUS ONE...TRENDING TOWARD
THE LATEST RUN OF THE LGEM MODEL. 

THE INITIAL MOTION ESTIMATE IS 285/03...AS RINA CONTINUES TO MOVE
SLOWLY WEST-NORTHWESTWARD TO THE SOUTH OF A WEAKENING MID-LEVEL
RIDGE. IN ABOUT 3 DAYS A LARGE MID/UPPER-LEVEL TROUGH WILL MOVE
INTO THE EASTERN UNITED STATES...AND A RIDGE WILL STRENGTHEN TO THE
NORTHEAST OF PUERTO RICO. THIS EVOLUTION OF THE PATTERN SHOULD
RESULT IN RINA TURNING NORTHWESTWARD AND NORTHWARD AS IT APPROACHES
THE YUCATAN PENINSULA...AND THEN TURNING EASTWARD AS THE CYCLONE
WEAKENS LATE IN THE PERIOD. THE BIGGEST CHANGE TO THE TRACK FORECAST
IS A FASTER FORWARD SPEED THROUGH 48 HOURS...WITH THE NHC TRACK
LYING A LITTLE TO THE RIGHT OF THE CENTER OF THE GUIDANCE
ENVELOPE...BUT TO THE LEFT OF THE GFS. AT DAYS 3 THROUGH 5...LITTLE
CHANGE WAS MADE TO THE OFFICIAL FORECAST GIVEN THE LARGE SPREAD IN
THE TRACK GUIDANCE. AT THE END OF THE PERIOD THE NHC FORECAST IS
CLOSEST TO THE GFS ENSEMBLE MEAN AND A LITTLE NORTH OF THE FSU
SUPERENSEMBLE. GIVEN THE LARGE SPREAD IN THE MODEL SOLUTIONS IN THE
EXTENDED RANGE...THE CONFIDENCE IN THE LATTER PART OF THE TRACK
FORECAST REMAINS LOW.

BASED ON THE FASTER TRACK FORECAST...HURRICANE AND TROPICAL STORM
WARNINGS ARE NOW REQUIRED FOR A PORTION OF THE YUCATAN PENINSULA.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  25/1500Z 17.4N  83.9W   90 KT 105 MPH
 12H  26/0000Z 17.7N  84.7W  100 KT 115 MPH
 24H  26/1200Z 18.2N  85.6W  105 KT 120 MPH
 36H  27/0000Z 19.1N  86.5W  100 KT 115 MPH
 48H  27/1200Z 20.2N  87.0W  100 KT 115 MPH
 72H  28/1200Z 22.0N  86.5W   80 KT  90 MPH
 96H  29/1200Z 22.5N  84.5W   60 KT  70 MPH
120H  30/1200Z 22.5N  83.5W   50 KT  60 MPH...INLAND
 
$$
FORECASTER BRENNAN
 

WTNT43 KNHC 252054
TCDAT3
 
HURRICANE RINA DISCUSSION NUMBER  10
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL182011
500 PM EDT TUE OCT 25 2011
 
DATA FROM THE AIR FORCE HURRICANE HUNTER AIRCRAFT INDICATE THAT RINA
HAS INTENSIFIED A LITTLE THIS AFTERNOON. THE INITIAL
INTENSITY IS RAISED TO 95 KT BASED ON A PEAK SFMR WIND OF 94 KT AND
700-MB FLIGHT-LEVEL WIND MAXIMUM OF 106 KT. THE LATEST CENTRAL
PRESSURE MEASURED FROM THE PLANE WAS 970 MB...FALLING A LITTLE OVER
THE PAST FEW HOURS. THE ENVIRONMENT APPEARS FAVORABLE FOR SOME
ADDITIONAL INTENSIFICATION DURING THE NEXT DAY OR TWO AS THE
CYCLONE MOVES OVER VERY WARM WATERS IN A REGION OF LOW WIND SHEAR.
THE OFFICIAL FORECAST SHOWS A BROAD PEAK AT 100 KT FROM 12 TO 48
HOURS...A LITTLE ABOVE THE SHIPS AND LGEM MODELS. AFTER THAT
TIME...RINA WILL BE MOVING INTO A REGION OF INCREASING VERTICAL
SHEAR...WHICH SHOULD RESULT IN WEAKENING. THE NEW NHC FORECAST IS
SIMILAR TO THE PREVIOUS ONE AT DAYS 3 THROUGH 5...FOLLOWING THE
SHIPS AND LGEM. HOWEVER...IF RINA MOVES FARTHER INLAND OVER THE
YUCATAN PENINSULA THAN EXPECTED...IT COULD BE WEAKER THAN FORECAST
IN 2 OR 3 DAYS.
 
AIRCRAFT FIXES INDICATE THAT RINA HAS JOGGED TOWARD THE LEFT OVER
THE PAST FEW HOURS...WITH THE INITIAL MOTION NOW 270/04. THE TRACK
FORECAST REASONING REMAINS UNCHANGED IN THE SHORT TERM...AS RINA
SHOULD BEGIN TO TURN POLEWARD AROUND THE WESTERN EDGE OF THE
SUBTROPICAL RIDGE. THE TRACK GUIDANCE REMAINS IN GOOD AGREEMENT ON
THIS SCENARIO...AND ONLY A SLIGHT WESTWARD ADJUSTMENT WAS MADE TO
THE OFFICIAL FORECAST THROUGH 48 HOURS. AFTER THE CYCLONE PASSES BY
THE YUCATAN PENINSULA...SIGNIFICANT SPREAD DEVELOPS IN THE
GUIDANCE. THE TRACK AND INTENSITY FORECASTS ARE CLOSELY LINKED LATE
IN THE PERIOD. ON ONE EXTREME...THE ECMWF WEAKENS RINA AND
DISSIPATES IT OVER THE CENTRAL GULF OF MEXICO AFTER 72 HOURS...
WHILE THE GFS AND HWRF TAKE A STRONGER CYCLONE QUICKLY TOWARD THE
NORTHEAST AHEAD OF A BROAD MID/UPPER-LEVEL TROUGH. MUCH OF THE REST
OF THE GUIDANCE LIES BETWEEN THESE TWO CAMPS...BUT THE OVERALL
TREND IS NORTH OF THE PREVIOUS NHC FORECAST. THE NHC FORECAST HAS
BEEN ADJUSTED IN THAT DIRECTION...BUT A SLOW MOTION IS SHOWN AT
DAYS 4 AND 5 DUE TO THE LARGE SPREAD IN THE GUIDANCE. NEEDLESS TO
SAY...THE CONFIDENCE IN THE LATTER PART OF THE TRACK FORECAST
REMAINS VERY LOW.
 
   
FORECAST POSITIONS AND MAX WINDS
 
INIT  25/2100Z 17.4N  84.3W   95 KT 110 MPH
 12H  26/0600Z 17.5N  85.2W  100 KT 115 MPH
 24H  26/1800Z 18.3N  86.1W  100 KT 115 MPH
 36H  27/0600Z 19.4N  86.8W  100 KT 115 MPH
 48H  27/1800Z 20.8N  86.9W  100 KT 115 MPH
 72H  28/1800Z 22.5N  86.0W   80 KT  90 MPH
 96H  29/1800Z 23.5N  84.0W   60 KT  70 MPH
120H  30/1800Z 23.5N  82.5W   45 KT  50 MPH
 
$$
FORECASTER BRENNAN
 

WTNT43 KNHC 260249
TCDAT3
 
HURRICANE RINA DISCUSSION NUMBER  11
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL182011
1100 PM EDT TUE OCT 25 2011
 
THE EYE BECAME OBSCURED ON CONVENTIONAL SATELLITE IMAGERY...AND
CONSEQUENTLY T-NUMBERS FROM SAB AND TAFB HAVE DECREASED A LITTLE
BIT. HOWEVER...LATEST MICROWAVE DATA SHOW A DISTINCT EYE FEATURE
WHICH IS BETTER DEFINED THAN IN EARLIER DATA. A NOAA HURRICANE
HUNTER PLANE INVESTIGATING THE HURRICANE MEASURED A LOWER MINIMUM
PRESSURE OF 966 MB...BUT NEITHER SFMR OR FLIGHT-LEVEL WINDS
INDICATE THAT RINA IS STRONGER THAN A FEW HOURS AGO. THE INITIAL
INTENSITY IS KEPT AT 95 KNOTS IN THIS ADVISORY. GIVEN THE FAVORABLE
LOW-SHEAR ENVIRONMENT AND THE VERY HIGH OCEANIC HEAT CONTENT
PREVAILING IN THE NORTHWESTERN CARIBBEAN SEA...RINA COULD
BECOME A MAJOR HURRICANE AT ANY TIME BEFORE REACHING EASTERN
YUCATAN. THEREAFTER...RINA WILL FIND A VERY HOSTILE ENVIRONMENT OF
STRONG SHEAR OVER THE EXTREME SOUTHERN GULF OF MEXICO WHICH MOST
LIKELY WILL WEAKEN THE CYCLONE SIGNIFICANTLY.
 
RINA HAS BEEN DRIFTING WESTWARD ABOUT 3 KNOTS...TRAPPED SOUTH OF A
STRONG SUBTROPICAL HIGH PRESSURE RIDGE. BUT SOON...THE HIGH WILL
SHIFT EASTWARD...AND THE HURRICANE SHOULD BEGIN TO MOVE...STILL VERY
SLOWLY...TOWARD THE NORTHWEST AND NORTH AROUND THE PERIPHERY OF THE
RIDGE. THE CYCLONE IS FORECAST TO BE OVER THE NORTHWESTERN CARIBBEAN
SEA AND BE VERY NEAR NORTHEASTERN YUCATAN IN 48 HOURS. THERE IS
RELATIVELY HIGH CONFIDENCE IN THIS PORTION OF THE FORECAST SINCE
MOST OF THE GUIDANCE IS QUITE CONSISTENT WITH THIS MOTION.
BEYOND 48 HOURS...AS RINA BEGINS TO INTERACT WITH THE MID-LATITUDE
WESTERLY FLOW...THE FORECAST BECOMES HIGHLY UNCERTAIN SINCE THE
MODEL SPREAD INCREASES CONSIDERABLY. BY THEN...RINA EITHER RECURVES
OVER THE SOUTHEASTERN GULF OF MEXICO OR MEANDERS NEAR YUCATAN AS A
SHALLOW CYCLONE STEERED BY THE LOW-LEVEL FLOW. THE NHC FORECAST
CALLS FOR RECURVATURE AND BRINGS A WEAKENING RINA NEAR THE NORTH
COAST OF WESTERN CUBA. THIS IS CONSISTENT WITH THE PREVIOUS NHC
FORECAST.

 
FORECAST POSITIONS AND MAX WINDS
 
INIT  26/0300Z 17.5N  84.8W   95 KT 110 MPH
 12H  26/1200Z 17.9N  85.4W  100 KT 115 MPH
 24H  27/0000Z 19.0N  86.4W  100 KT 115 MPH
 36H  27/1200Z 20.2N  86.8W  100 KT 115 MPH
 48H  28/0000Z 21.3N  86.7W   85 KT 100 MPH
 72H  29/0000Z 23.0N  85.0W   75 KT  85 MPH
 96H  30/0000Z 23.5N  83.0W   60 KT  70 MPH
120H  31/0000Z 23.5N  82.5W   45 KT  50 MPH
 
$$
FORECASTER AVILA/BERG
 

WTNT43 KNHC 260845
TCDAT3
 
HURRICANE RINA DISCUSSION NUMBER  12
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL182011
400 AM CDT WED OCT 26 2011
 
THE EYE CONTINUES TO BE OBSCURED ON GEOSTATIONARY IMAGERY AND THE
ORGANIZATION OF THE HURRICANE HAS CHANGED LITTLE OVER THE PAST
SEVERAL HOURS.  AN AIR FORCE HURRICANE HUNTER PLANE MEASURED PEAK
700 MB FLIGHT-LEVEL WINDS OF 104 KT AND MAXIMUM BELIEVABLE
SFMR-OBSERVED SURFACE WINDS OF NEAR 90 KT...AND THE INITIAL WIND
SPEED IS HELD AT 95 KT FOR THIS ADVISORY.  WATER VAPOR IMAGERY
CONTINUES TO DEPICT A WELL-DEFINED UPPER-LEVEL OUTFLOW PATTERN...
AND ANALYSES FROM UW/CIMSS SUGGEST THAT STRONG VERTICAL SHEAR HAS
NOT YET REACHED THE CORE OF THE HURRICANE.  THEREFORE...RINA STILL
HAS AN OPPORTUNITY TO INTENSIFY INTO A MAJOR HURRICANE BEFORE IT
REACHES THE YUCATAN PENINSULA.  IT SHOULD BE NOTED...HOWEVER...THAT
THE OCEANIC HEAT CONTENT BELOW THE CYCLONE SHOULD DIMINISH FROM
THIS POINT ONWARD...WHICH COULD BE A MITIGATING FACTOR FOR
STRENGTHENING.  THE OFFICIAL WIND SPEED FORECAST CONTINUES TO SHOW
RINA INTENSIFYING TO CATEGORY 3 STATUS LATER TODAY.  SOME DECREASE
IN STRENGTH IS LIKELY TO OCCUR DUE TO THE INTERACTION WITH THE
YUCATAN PENINSULA.  BY DAYS 2-3...WHEN RINA IS FORECAST TO MOVE
OVER THE SOUTHEASTERN GULF OF MEXICO...SIGNIFICANTLY HIGHER SHEAR
DUE TO STRONG UPPER-LEVEL WESTERLIES SHOULD CAUSE A WEAKENING
TREND.  THE OFFICIAL INTENSITY FORECAST IS CLOSE TO THE NUMERICAL
CONSENSUS AND SLIGHTLY ABOVE THE STATISTICAL-DYNAMICAL GUIDANCE.
 
CENTER FIXES FROM THE HURRICANE HUNTERS INDICATE THAT RINA CONTINUES
TO MOVE VERY SLOWLY...OR 280/4.  AS A MID-TROPOSPHERIC RIDGE TO THE
NORTH SHIFTS EASTWARD DURING THE NEXT DAY OR TWO...THE HURRICANE
SHOULD TURN NORTHWESTWARD AND THEN NORTHWARD.  THE TRACK GUIDANCE
MODELS ARE IN REASONABLY GOOD AGREEMENT ON THIS SCENARIO FOR THE
FIRST 48 HOURS OF THE FORECAST PERIOD.  BY 3 TO 4 DAYS...A LARGE
500 MB TROUGH MOVES TO THE U.S. EAST COAST...RESULTING IN A
STRENGTHENING MID-TROPOSPHERIC WEST-SOUTHWESTERLY FLOW OVER THE
EASTERN GULF OF MEXICO.  IF RINA WERE TO MAINTAIN HURRICANE
INTENSITY BEYOND DAY 3 OR SO...AND THEREFORE REMAIN A DEEP-LAYER
VORTEX...IT WOULD LIKELY ACCELERATE EAST-NORTHEASTWARD.  HOWEVER
THE MAJORITY OF THE GUIDANCE...AND THE OFFICIAL FORECAST...SHOW
SIGNIFICANT WEAKENING IN THAT TIME FRAME.  THEREFORE THE OFFICIAL
TRACK FORECAST...LIKE THE PREVIOUS ONE...SHOWS ONLY A SLOW EASTWARD
MOTION NEAR THE END OF THE PERIOD.  THIS IS REASONABLY CLOSE TO THE
LATEST GFS TRACK.  IT IS WORTH REPEATING THAT THERE IS GREAT
UNCERTAINTY AS TO WHERE RINA WILL BE LOCATED BY THE WEEKEND.
  
FORECAST POSITIONS AND MAX WINDS
 
INIT  26/0900Z 17.5N  85.2W   95 KT 110 MPH
 12H  26/1800Z 18.2N  85.8W  100 KT 115 MPH
 24H  27/0600Z 19.2N  86.6W  100 KT 115 MPH
 36H  27/1800Z 20.5N  87.0W  100 KT 115 MPH
 48H  28/0600Z 21.8N  86.6W   85 KT 100 MPH
 72H  29/0600Z 23.5N  84.5W   70 KT  80 MPH
 96H  30/0600Z 23.5N  83.0W   60 KT  70 MPH
120H  31/0600Z 23.5N  82.0W   45 KT  50 MPH
 
$$
FORECASTER PASCH
 

WTNT43 KNHC 261457
TCDAT3
 
HURRICANE RINA DISCUSSION NUMBER  13
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL182011
1000 AM CDT WED OCT 26 2011

RINA HAS A SOMEWHAT RAGGED APPEARANCE THIS MORNING.  THE EYE IS NOT
APPARENT IN VISIBLE IMAGERY...AND DATA FROM THE RADARS AT BELIZE
CITY AND ON THE TRMM SATELLITE SUGGEST THE EYEWALL HAS LOST SOME
DEFINITION.  WHILE THE EYEWALL CLOUD TOP TEMPERATURES ARE COLDER
THAN -80C...THE OVERALL AMOUNT OF CONVECTION ASSOCIATED WITH THE
CYCLONE HAS DECREASED DURING THE PAST SEVERAL HOURS.  IN
ADDITION...THE OUTFLOW HAS DIMINISHED SINCE YESTERDAY...AND
ANALYSES FROM CIMSS AT THE UNIVERSITY OF WISCONSIN SUGGEST 15-20 KT
OF SOUTHERLY VERTICAL WIND SHEAR.  THE INITIAL INTENSITY IS KEPT AT
95 KT FOR THIS ADVISORY...BUT THIS COULD BE GENEROUS AND IT IS
QUITE POSSIBLE THAT THE NOAA HURRICANE HUNTER AIRCRAFT ABOUT TO
REACH THE STORM WILL FIND RINA HAS WEAKENED.
 
THE RECENT CENTER FIXES INDICATE THAT RINA HAS TURNED TOWARD THE
RIGHT DURING THE PAST SEVERAL HOURS WITH THE INITIAL MOTION NOW
290/4.  RINA IS CURRENTLY EMBEDDED IN A MID-LEVEL RIDGE...WITH A
STRONG LOW-LEVEL RIDGE NORTH OF THE HURRICANE AND AN UPPER-LEVEL
ANTICYCLONE TO ITS EAST OVER THE CENTRAL CARIBBEAN.  THE DYNAMICAL
MODELS FORECAST THE RIDGES TO THE NORTH AND WEST TO WEAKEN DURING
THE NEXT 48-72 HOURS AS A TROUGH IN THE WESTERLIES AND ASSOCIATED
COLD FRONT MOVE INTO THE GULF OF MEXICO.  THIS EVOLUTION SHOULD
CAUSE RINA TO GRADUALLY TURN NORTHWARD NEAR THE EAST COAST OF THE
YUCATAN PENINSULA.  THE TRACK GUIDANCE IS IN GOOD AGREEMENT ON THIS
PART OF THE FORECAST...AND THE NEW FORECAST TRACK IS SIMILAR TO THE
OLD ONE.  AFTER 72 HOURS...RINA IS EXPECTED TO MOVE INTO AN
ENVIRONMENT WHERE THE MID/UPPER-LEVEL FLOW TRIES TO STEER THE
CYCLONE NORTHEASTWARD WHILE THE LOW-LEVEL FLOW TRIES TO STEER IT
SOUTHWARD OR SOUTHWESTWARD.  THIS SHOULD CAUSE RINA TO SHEAR
APART...BUT THE MODELS DISAGREE ON WHEN THIS WILL HAPPEN AND THUS
ARE IN POOR AGREEMENT ON THE FORECAST TRACK.  THE ECMWF AND
CANADIAN WEAKEN RINA VERY QUICKLY AND KEEP THE LOW-LEVEL REMNANT
NEAR YUCATAN...WHILE THE GFDL FORECASTS A STRONGER CYCLONE TO CROSS
SOUTH FLORIDA INTO THE ATLANTIC.  THE OTHER MODELS ARE BETWEEN
THESE EXTREMES.  THE LATTER PORTION OF THE NEW FORECAST TRACK IS
SIMILAR TO THE PREVIOUS TRACK...IN BEST AGREEMENT WITH THE GFS AND
NOGAPS MODELS.  HOWEVER...THIS IS A LOW CONFIDENCE FORECAST.
 
SINCE THE OUTFLOW IS LESS IMPRESSIVE THAN 24 HOURS AGO AND THE SHEAR
IS FORECAST TO INCREASE FURTHER...IT APPEARS THAT RINA HAS RUN OUT
OF TIME TO INTENSIFY.  THE INTENSITY FORECAST NOW CALLS FOR THE
HURRICANE TO GRADUALLY WEAKEN DURING THE NEXT 12-24 HOURS...WITH A
FASTER WEAKENING AT 36-48 HOURS DUE TO LAND INTERACTION.  DUE TO
THE UNCERTAINTY OF JUST HOW QUICKLY RINA WILL SHEAR APART OVER THE
GULF OF MEXICO...THE FORECAST KEEPS RINA A HURRICANE THROUGH 72
HOURS AND A TROPICAL STORM THROUGH 120 HOURS IN BEST AGREEMENT WITH
THE SHIPS AND LGEM MODELS.  HOWEVER...IT IS POSSIBLE THAT THE
CYCLONE COULD WEAKEN MUCH FASTER THAN CURRENTLY FORECAST.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  26/1500Z 17.9N  85.5W   95 KT 110 MPH
 12H  27/0000Z 18.5N  86.2W   95 KT 110 MPH
 24H  27/1200Z 19.5N  87.0W   90 KT 105 MPH
 36H  28/0000Z 20.8N  87.1W   80 KT  90 MPH...INLAND
 48H  28/1200Z 22.0N  87.0W   75 KT  85 MPH...OVER WATER
 72H  29/1200Z 23.0N  85.0W   65 KT  75 MPH
 96H  30/1200Z 23.5N  83.0W   55 KT  65 MPH
120H  31/1200Z 23.5N  82.5W   45 KT  50 MPH
 
$$
FORECASTER BEVEN
 

WTNT43 KNHC 261736
TCDAT3
 
HURRICANE RINA SPECIAL DISCUSSION NUMBER  14
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL182011
1230 PM CDT WED OCT 26 2011

A NOAA HURRICANE HUNTER AIRCRAFT INVESTIGATING RINA REPORTED THAT
THE CENTRAL PRESSURE HAS RISEN TO 982 MB...WITH FLIGHT-LEVEL AND
SFMR WINDS THAT...AT THE MOST...SUPPORT AN INITIAL INTENSITY OF 75
KT.  THUS...A SPECIAL ADVISORY IS BEING ISSUED IN PLACE OF THE
REGULARLY SCHEDULED INTERMEDIATE ADVISORY TO SIGNIFICANTLY REDUCE
THE INTENSITY FORECAST.  THERE ARE A FEW MINOR CHANGES TO THE
PREVIOUS WIND RADII FORECAST AND NO CHANGE TO THE PREVIOUS TRACK
FORECAST.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  26/1730Z 18.1N  85.8W   75 KT  85 MPH
 12H  27/0000Z 18.5N  86.2W   70 KT  80 MPH
 24H  27/1200Z 19.5N  87.0W   70 KT  80 MPH
 36H  28/0000Z 20.8N  87.1W   65 KT  75 MPH...INLAND
 48H  28/1200Z 22.0N  87.0W   65 KT  75 MPH...OVER WATER
 72H  29/1200Z 23.0N  85.0W   55 KT  65 MPH
 96H  30/1200Z 23.5N  83.0W   45 KT  50 MPH
120H  31/1200Z 23.5N  82.5W   35 KT  40 MPH
 
$$
FORECASTER BEVEN
 

WTNT43 KNHC 262046
TCDAT3
 
HURRICANE RINA DISCUSSION NUMBER  15
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL182011
400 PM CDT WED OCT 26 2011
 
RECENT SATELLITE IMAGERY...DATA FROM THE BELIZE CITY RADAR...AND
REPORTS FROM AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT SUGGEST
THAT RINA HAS CHANGED LITTLE IN STRENGTH DURING THE PAST FEW HOURS.
THE AIRCRAFT HAS REPORTED 700 MB FLIGHT-LEVEL WINDS OF 79 KT AND
SFMR SURFACE WIND ESTIMATES OF 75-78 KT...WHILE AN EYEWALL
DROPSONDE SUGGESTS SURFACE WINDS NEAR 70 KT.  THE INITIAL INTENSITY
OF 75 KT IS A COMPROMISE BETWEEN THESE DATA. THE AIRCRAFT DATA
SUGGEST THE VORTEX IS TILTED WITH HEIGHT...AS DROPSONDES AT THE
FLIGHT-LEVEL CENTER HAVE CONSISTENTLY REPORTED 25-30 KT SURFACE
WINDS.  THIS TILT IS LIKELY DUE TO 20 KT OF SOUTHERLY VERTICAL WIND
SHEAR DEPICTED IN ANALYSES FROM CIMSS AT THE UNIVERSITY OF
WISCONSIN.
 
RITA HAS CONTINUED ITS SLOW RIGHT TURN...AND THE INITIAL MOTION IS
NOW 310/5.  THE FORECAST TRACK AND PHILOSOPHY ARE UNCHANGED FOR THE
FIRST 48 HOURS...WITH THE HURRICANE FORECAST TO MOVE SLOWLY
NORTHWARD AND THEN NORTH-NORTHEASTWARD NEAR OR OVER THE
NORTHEASTERN PORTION OF THE YUCATAN PENINSULA AS AN UPPER-LEVEL
TROUGH AND ASSOCIATED COLD FRONT MOVE ACROSS THE SOUTHEASTERN
UNITED STATES AND THE GULF OF MEXICO.  THE TRACK FORECAST BECOMES
VERY PROBLEMATIC AFTER 48 HOURS DUE TO UNCERTAINTIES OF HOW RINA
INTERACTS WITH THE TROUGH AND HOW LONG IT HOLDS TOGETHER
VERTICALLY.  THE GFDL AND GFDN MODELS CONTINUE TO FORECAST THE
SYSTEM TO MOVE EAST-NORTHEASTWARD OVER FLORIDA OR THE FLORIDA
STRAITS INTO THE ATLANTIC.  THE ECMWF...NOGAPS...UKMET...AND
CANADIAN MODELS NOW FORECAST RINA OR ITS REMNANTS TO MAKE A HAIRPIN
TURN AND MOVE SOUTHWARD NEAR THE EAST COAST OF YUCATAN.  THE
GFS...GFS ENSEMBLE MEAN...AND HWRF MODELS ARE BETWEEN THESE
EXTREMES...FORECASTING THE CYCLONE TO MOVE SLOWLY EASTWARD AND THEN
SOUTHEASTWARD NEAR OR OVER WESTERN CUBA.  THE NEW FORECAST TRACK
FOLLOWS THESE MODELS AND IS THUS SHIFTED SOUTH OF THE PREVIOUS
TRACK.  THIS LATTER PART OF THE FORECAST TRACK REMAINS A LOW
CONFIDENCE FORECAST.
 
RINA IS FORECAST TO BE IN A MODERATE SHEAR ENVIRONMENT FOR THE NEXT
24-36 HOURS.  THIS...COMBINED WITH EXPECTED LAND INTERACTION...
SUGGESTS IT SHOULD SLOWLY WEAKEN DURING THIS TIME.  AFTER 36
HOURS...THE CYCLONE SHOULD ENCOUNTER STRONG SHEAR AS THE
MID/UPPER-LEVEL FLOW TRIES TO STEER IT EAST-NORTHEASTWARD AND THE
LOW-LEVEL FLOW TRIES TO STEER IT SOUTHWARD OR SOUTHWESTWARD.  THIS
SHOULD CAUSE RINA TO WEAKEN IN AGREEMENT WITH ALL THE INTENSITY
GUIDANCE.  THE NEW INTENSITY FORECAST CALLS FOR A FASTER WEAKENING
THAN PREVIOUSLY SHOWN...IN BEST AGREEMENT WITH THE DECAY SHIPS
MODEL.  IT IS POSSIBLE THAT THIS RELATIVELY SMALL SYSTEM COULD
WEAKEN FASTER THAN CURRENTLY FORECAST AND BECOME A REMNANT LOW BY
120 HOURS OR EARLIER.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  26/2100Z 18.2N  85.9W   75 KT  85 MPH
 12H  27/0600Z 18.7N  86.5W   75 KT  85 MPH
 24H  27/1800Z 20.0N  86.9W   70 KT  80 MPH
 36H  28/0600Z 21.4N  86.9W   60 KT  70 MPH...INLAND
 48H  28/1800Z 22.5N  86.5W   60 KT  70 MPH...OVER WATER
 72H  29/1800Z 23.0N  84.5W   50 KT  60 MPH
 96H  30/1800Z 22.5N  83.0W   35 KT  40 MPH...INLAND
120H  31/1800Z 22.5N  83.0W   25 KT  30 MPH...INLAND
 
$$
FORECASTER BEVEN
 

WTNT43 KNHC 270242
TCDAT3
 
HURRICANE RINA DISCUSSION NUMBER  16
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL182011
1000 PM CDT WED OCT 26 2011
 
THE WEAKENING TREND OBSERVED EARLIER TODAY APPEARS TO HAVE LEVELED
OFF TONIGHT. ALTHOUGH THE EYE IS NOT DISCERNIBLE IN IR IMAGES...IT
IS EMBEDDED WITHIN A LARGE AREA OF VERY DEEP CONVECTION. IN
FACT...THE EYE FEATURE IS NOW QUITE DISTINCT IN VERY RECENT SSMIS
DATA. THIS WAS CONFIRMED BY A NOAA HURRICANE HUNTER PLANE WHICH
JUST TRAVERSED THE HURRICANE AND OBSERVED A CIRCULAR EYE OF 15 N MI
IN DIAMETER. ALTHOUGH THERE WAS A PEAK WIND OF 82 KNOTS MEASURED BY
THE SFMR...MOST OF THE WIND REPORTS YIELD AN INITIAL INTENSITY OF
75 KNOTS. MORE RECENT DATA SUGGEST THAT RITA COULD BE A LITTLE BIT
STRONGER. THE SHEAR IS NOT EXPECTED TO BE STRONG ENOUGH TO WEAKEN
RINA SIGNIFICANTLY DURING THE NEXT 12 TO 24 HOURS. AS RINA
APPROACHES THE EXTREME SOUTHERN GULF OF MEXICO...THE ENVIRONMENT IS
FORECAST TO BECOME VERY HOSTILE...AND A FASTER WEAKENING SHOULD
OCCUR...PROBABLY MORE THAN INDICATED IN THE NHC FORECAST.
 
RINA HAS ALREADY REACHED THE WESTERN SIDE OF THE SUBTROPICAL HIGH
AND IS MOVING TOWARD THE NORTHWEST OR 320 DEGREES AT 5 KNOTS. MOST
OF THE GUIDANCE IS VERY CONSISTENT IN MOVING RINA SLOWLY NORTHWARD
VERY NEAR OR OVER THE EAST COAST OF YUCATAN DURING THE NEXT 36 TO
48 HOURS. THEREAFTER...THE MODEL TREND IS TO KEEP RINA OR WHATEVER
IS LEFT OF THE CYCLONE MEANDERING BETWEEN WESTERN CUBA AND YUCATAN.
THERE ARE NO LONGER ANY RELIABLE DYNAMICAL MODELS THAT ACCELERATE
THE CYCLONE EASTWARD. LITTLE BY LITTLE...MODELS HAVE BEEN
CONVERGING ON THE SOLUTION GIVEN A COUPLE OF DAYS AGO BY THE
ECMWF...WHICH HAS BEEN SHOWING A WEAKENING RINA MEANDERING NEAR
YUCATAN. ALTHOUGH THE FORECAST IS HIGHLY UNCERTAIN...GIVEN THE
MODEL TREND...I HAVE NO CHOICE BUT TO ADJUST THE PREVIOUS FORECAST
A LITTLE BIT WESTWARD AT DAYS 4 AND 5 AND KEEP RINA BASICALLY
NEARLY STATIONARY OVER EXTREME WESTERN CUBA. BY THEN...THE CYCLONE
WILL LIKELY BE A TROPICAL DEPRESSION OR A REMNANT LOW.
 

 
FORECAST POSITIONS AND MAX WINDS
 
INIT  27/0300Z 18.5N  86.5W   75 KT  85 MPH
 12H  27/1200Z 19.2N  86.8W   75 KT  85 MPH
 24H  28/0000Z 20.4N  87.0W   70 KT  80 MPH
 36H  28/1200Z 21.5N  87.0W   65 KT  75 MPH
 48H  29/0000Z 22.0N  86.5W   55 KT  65 MPH
 72H  30/0000Z 22.5N  85.0W   50 KT  60 MPH
 96H  31/0000Z 22.0N  84.0W   35 KT  40 MPH
120H  01/0000Z 22.0N  84.0W   25 KT  30 MPH
 
$$
FORECASTER AVILA
 

WTNT43 KNHC 270835
TCDAT3
 
HURRICANE RINA DISCUSSION NUMBER  17
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL182011
400 AM CDT THU OCT 27 2011
 
RINA HAS BECOME LESS WELL ORGANIZED ON SATELLITE IMAGERY OVER THE
PAST SEVERAL HOURS...WITH THE EXTENT OF COLD CLOUD TOPS DIMINISHING
WITHIN A RAGGED-LOOKING CDO FEATURE. THIS SUGGESTS THAT SOME
WEAKENING HAS TAKEN PLACE...AND INDEED THE AIR FORCE HURRICANE
HUNTERS FOUND THAT THE CYCLONE IS NOW BARELY OF HURRICANE STRENGTH
WITH THE PEAK SFMR-OBSERVED SURFACE WINDS OF 62 KT.  THE INITIAL
WIND SPEED IS SET...PERHAPS GENEROUSLY...AT 65 KT.  SOUTH-
SOUTHWESTERLY SHEAR OVER RINA IS EXPECTED TO GRADUALLY INCREASE...
AND THIS ALONG WITH THE INTERACTION WITH THE YUCATAN PENINSULA AND
DRIER AIR SHOULD CAUSE THE SYSTEM TO WEAKEN THROUGHOUT THE FORECAST
PERIOD.  THE OFFICIAL INTENSITY FORECAST SHOWS MORE WEAKENING THEN
THE PREVIOUS ONE FOR DAYS 1-3 AND IS THE SAME AT DAYS 4-5.  THIS IS
SIMILAR TO THE STATISTICAL-DYNAMICAL DSHIPS MODEL FORECAST.
 
RINA IS MOVING ALONG THE WESTERN SIDE OF A MID-LEVEL HIGH PRESSURE
AREA AT ABOUT 325/5.  THE TRACK GUIDANCE IS IN GENERAL AGREEMENT ON
A NORTHWARD TURN DURING THE NEXT DAY OR SO.  IN 36-48 HOURS...THE
NORTHWARD MOTION IS EXPECTED TO END AS WEAK MID-LEVEL RIDGING
DEVELOPS TO THE WEST OF RINA.  BY THE END OF THE FORECAST
PERIOD...THE WEAKENING CYCLONE IS LIKELY TO BE DRIVEN SOUTHWARD BY
LOW-LEVEL NORTHERLY FLOW ASSOCIATED WITH A FRONT THAT PUSHES
THROUGH THE GULF OF MEXICO.  THE OFFICIAL TRACK FORECAST IS
SOMEWHAT TO THE SOUTH AND WEST OF THE PREVIOUS ONE...BUT NOT NEARLY
AS MUCH AS SHOWN BY THE PREPONDERANCE OF THE DYNAMICAL MODELS.
  
FORECAST POSITIONS AND MAX WINDS
 
INIT  27/0900Z 18.8N  86.9W   65 KT  75 MPH
 12H  27/1800Z 19.8N  87.0W   60 KT  70 MPH
 24H  28/0600Z 21.0N  87.1W   55 KT  65 MPH...INLAND
 36H  28/1800Z 21.6N  86.8W   50 KT  60 MPH
 48H  29/0600Z 21.9N  86.3W   45 KT  50 MPH
 72H  30/0600Z 22.0N  85.5W   40 KT  45 MPH
 96H  31/0600Z 21.5N  85.5W   35 KT  40 MPH
120H  01/0600Z 21.0N  85.5W   25 KT  30 MPH
 
$$
FORECASTER PASCH
 

WTNT43 KNHC 271445
TCDAT3
 
TROPICAL STORM RINA DISCUSSION NUMBER  18
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL182011
1000 AM CDT THU OCT 27 2011
 
A COMBINATION OF SOUTHERLY VERTICAL WIND SHEAR AND MID/UPPER-LEVEL
DRY AIR ENTRAINMENT APPEARS TO HAVE DISRUPTED THE CONVECTIVE
STRUCTURE OF RINA.  THE LOW-LEVEL CENTER IS NOW PARTIALLY EXPOSED AT
THE SOUTHERN EDGE OF A BURST OF DEEP CONVECTION...AND RADAR DATA
FROM BELIZE CITY AND CANCUN SHOWS LITTLE EVIDENCE OF BANDING IN THE
CONVECTION. A NOAA HURRICANE HUNTER AIRCRAFT INVESTIGATING THE
STORM IS REPORTING FLIGHT-LEVEL WINDS BELOW HURRICANE STRENGTH AND
SURFACE WIND ESTIMATES FROM THE STEPPED FREQUENCY MICROWAVE
RADIOMETER NEAR 60 KT.  BASED ON THESE DATA...RINA IS DOWNGRADED TO
A 60 KT TROPICAL STORM.
 
AFTER WOBBLING A LITTLE MORE WESTWARD...RINA APPEARS TO HAVE
RESUMED ITS RIGHT TURN WITH THE INITIAL MOTION NOW 330/5.  RINA
SHOULD MOVE SLOWLY NORTHWARD NEAR THE EAST COAST OF THE YUCATAN
PENINSULA FOR THE NEXT 24-36 HOURS ON THE WEST SIDE OF A
MID/UPPER-LEVEL RIDGE OVER THE CARIBBEAN SEA.  AFTER THAT...THE
DYNAMICAL MODELS ARE IN GOOD AGREEMENT THAT A COMBINATION OF RINA
WEAKENING TO A SHALLOW VORTEX AND RISING LOW-LEVEL PRESSURES TO ITS
NORTHWEST SHOULD CAUSE RINA TO TURN SOUTHWARD.  WHILE THERE ARE
DIFFERENCE IN THE DETAILS...THE GUIDANCE SUGGESTS THAT RINA OR ITS
REMNANTS WILL MEANDER OVER THE NORTHWEST CARIBBEAN SEA OR THE
YUCATAN PENINSULA FOR THE REST OF THE FORECAST PERIOD.  THE NEW
FORECAST TRACK SHOWS A SHARPER TURN AND A SLIGHTLY FASTER SOUTHWARD
MOTION THAN THE PREVIOUS FORECAST.  HOWEVER...IN DEFERENCE TO THE
PREVIOUS FORECAST...IT DOES NOT SHOW AS FAST OF A SOUTHWARD MOTION
AS MOST OF THE DYNAMICAL MODELS.

MODERATE TO STRONG SOUTHERLY VERTICAL WIND SHEAR IS LIKELY TO
PERSIST NEAR OR OVER RINA FOR THE NEXT 96 HOURS OR SO.  THIS...
ALONG WITH ADDITIONAL DRY AIR ENTRAINING INTO THE CYCLONE...SHOULD
CAUSE CONTINUED WEAKENING.  THE NEW INTENSITY FORECAST CALLS FOR A
FASTER WEAKENING THAN PREVIOUS...WITH RINA WEAKENING TO A TROPICAL
DEPRESSION IN ABOUT 72 HOURS AND DEGENERATING TO A REMNANT LOW BY
120 HOURS.  SINCE THE ENVIRONMENT IS HOSTILE AND THE CYCLONE IS
RELATIVELY SMALL...THIS DEGENERATION COULD OCCUR EARLIER THAN
FORECAST...ESPECIALLY IF THE CENTER MOVES BACK OVER THE YUCATAN
PENINSULA.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  27/1500Z 19.2N  87.0W   60 KT  70 MPH
 12H  28/0000Z 20.0N  87.1W   55 KT  65 MPH
 24H  28/1200Z 21.1N  87.1W   50 KT  60 MPH...INLAND
 36H  29/0000Z 21.6N  86.7W   45 KT  50 MPH...OVER WATER
 48H  29/1200Z 21.4N  86.2W   40 KT  45 MPH
 72H  30/1200Z 21.0N  86.0W   30 KT  35 MPH
 96H  31/1200Z 20.0N  86.0W   25 KT  30 MPH
120H  01/1200Z 19.0N  86.0W   20 KT  25 MPH...POST-TROP/REMNT LOW
 
$$
FORECASTER BEVEN
 

WTNT43 KNHC 272035
TCDAT3
 
TROPICAL STORM RINA DISCUSSION NUMBER  19
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL182011
400 PM CDT THU OCT 27 2011
 
SATELLITE IMAGERY...RADAR DATA...AND REPORTS FROM AN AIR FORCE
RESERVE HURRICANE HUNTER INDICATE THAT RINA CONTINUES TO WEAKEN.
THE PREVIOUSLY OBSERVED STRONG CONVECTIVE BURST HAS DISSIPATED...AND
THERE IS CURRENTLY LITTLE CONVECTION NEAR THE CENTER.  THE AIRCRAFT
HAS REPORTED MAXIMUM 850 MB FLIGHT-LEVEL WINDS OF 58 KT AND SURFACE
WIND ESTIMATES OF 48 KT FROM THE STEPPED FREQUENCY MICROWAVE
RADIOMETER.  BASED ON THESE DATA...THE INITIAL INTENSITY IS
DECREASED TO 50 KT.
 
THE INITIAL MOTION IS NOW 350/6.  THE TROPICAL CYCLONE SHOULD MOVE
SLOWLY NORTHWARD NEAR THE EAST COAST OF THE YUCATAN PENINSULA FOR
THE NEXT 12-24 HOURS ON THE WEST SIDE OF A MID/UPPER-LEVEL RIDGE
OVER THE CARIBBEAN SEA.  AFTER THAT...THE DYNAMICAL MODELS ARE IN
GOOD AGREEMENT THAT A COMBINATION OF RINA WEAKENING TO A SHALLOW
VORTEX AND RISING LOW-LEVEL PRESSURES TO ITS NORTHWEST SHOULD CAUSE
RINA TO TURN SOUTHWARD.  WHILE THERE REMAIN DIFFERENCES IN THE
DETAILS...THE GUIDANCE SUGGESTS THAT RINA OR ITS REMNANTS WILL
MEANDER OVER THE NORTHWEST CARIBBEAN SEA OR THE ADJACENT LAND AREAS
FOR THE REST OF THE FORECAST PERIOD.  THE FORECAST TRACK AFTER 48
HOURS SHOWS A SLIGHTLY FASTER SOUTHWARD AND THEN SOUTH-
SOUTHWESTWARD MOTION THAN THE OLD FORECAST.  WHILE THIS TRACK IS
NEAR THE CENTER OF THE TRACK GUIDANCE ENVELOPE...THE SOUTHWARD
MOTION IS SLOWER THAN THAT OF MOST OF THE DYNAMICAL GUIDANCE.
 
MODERATE TO STRONG SOUTHERLY VERTICAL WIND SHEAR IS LIKELY TO
PERSIST NEAR OR OVER RINA FOR THE NEXT 72 HOURS OR SO.  THIS...
ALONG WITH LAND INTERACTION AND DRY AIR ENTRAINING INTO THE
CYCLONE...SHOULD CAUSE CONTINUED WEAKENING.  BASED ON THIS AND THE
CURRENT TRENDS...THE NEW INTENSITY FORECAST CALLS FOR RINA TO MEET
AN EARLIER DEMISE THAN ON THE PREVIOUS ADVISORY...WITH THE CYCLONE
EXPECTED TO WEAKEN TO A TROPICAL DEPRESSION BY 48 HOURS AND TO
DEGENERATE TO A REMNANT LOW BY 72 HOURS.  THE DYNAMICAL MODELS
SUGGEST THE SHEAR MAY DECREASE AFTER 72 HOURS.  HOWEVER...GIVEN THE
UNCERTAINTIES OF THE STRUCTURE AND LOCATION OF THE REMNANTS OF RINA
THE FORECAST OF REMNANT LOW AT 120 HOURS WILL REMAIN UNCHANGED.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  27/2100Z 19.8N  87.2W   50 KT  60 MPH
 12H  28/0600Z 20.6N  87.2W   45 KT  50 MPH...INLAND
 24H  28/1800Z 21.3N  87.1W   40 KT  45 MPH...INLAND
 36H  29/0600Z 21.2N  86.5W   35 KT  40 MPH...OVER WATER
 48H  29/1800Z 20.9N  86.1W   30 KT  35 MPH
 72H  30/1800Z 20.0N  86.0W   25 KT  30 MPH...POST-TROP/REMNT LOW
 96H  31/1800Z 18.5N  86.5W   20 KT  25 MPH...POST-TROP/REMNT LOW
120H  01/1800Z 17.0N  87.0W   20 KT  25 MPH...POST-TROP/REMNT LOW
 
$$
FORECASTER BEVEN
 

WTNT43 KNHC 280241
TCDAT3
 
TROPICAL STORM RINA DISCUSSION NUMBER  20
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL182011
1000 PM CDT THU OCT 27 2011
 
RINA HAS BECOME A SHEARED CYCLONE WITH MOST OF THE STRONG
THUNDERSTORM ACTIVITY TO THE NORTH OF THE CENTER. THE CLOUD PATTERN
DETERIORATED SIGNIFICANTLY A FEW HOURS AGO...AND I WAS TEMPTED TO
LOWER THE WINDS. HOWEVER...THE AIR FORCE RECONNAISSANCE PLANE
CHECKING THE CYCLONE MEASURED SEVERAL FLIGHT-LEVEL WINDS WHICH
SUPPORT KEEPING THE INITIAL INTENSITY AT 50 KNOTS. THE SHEAR IS
EXPECTED TO INCREASE FURTHER...AND THE CYCLONE WILL INTERACT WITH
LAND AS WELL. ON THIS BASIS...RINA IS FORECAST TO WEAKEN...AND
THERE IS A STRONG LIKELIHOOD THAT IT COULD BECOME A TROPICAL
DEPRESSION EARLY SATURDAY IF NOT SOONER. RINA WILL LIKELY BECOME A
MEANDERING REMNANT LOW OVER THE NORTHWESTERN CARIBBEAN IN ABOUT 48
HOURS...WITH A SMALL CHANCE OF REGENERATION.
 
FIXES FROM A RECONNAISSANCE AIRCRAFT INDICATE THAT THE CYCLONE IS
MOVING TOWARD THE NORTH OR 360 DEGREES AT 6 KNOTS. THIS GENERAL
TRACK SHOULD CONTINUE DURING THE NEXT 12 TO 24 HOURS. A COLD FRONT
FOLLOWED BY A HIGH PRESSURE SYSTEM IS FORECAST TO INVADE THE GULF
OF MEXICO...AND THESE FEATURES WILL PUSH THE WEAKENING CYCLONE
SOUTHWARD BACK TO THE CARIBBEAN WHERE IT ALL BEGAN. MOST OF THE
TRACK MODELS PREFER THIS SOLUTION. DO NOT READ TOO MUCH INTO
THIS...IT HAS HAPPENED IN THE PAST WITH LATE SEASON CYCLONES. 
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  28/0300Z 20.5N  87.2W   50 KT  60 MPH
 12H  28/1200Z 21.5N  87.0W   40 KT  45 MPH...INLAND
 24H  29/0000Z 21.5N  86.5W   35 KT  40 MPH...OVER WATER
 36H  29/1200Z 21.0N  86.2W   30 KT  35 MPH
 48H  30/0000Z 20.0N  86.0W   25 KT  30 MPH...POST-TROP/REMNT LOW
 72H  31/0000Z 19.5N  86.2W   25 KT  30 MPH...POST-TROP/REMNT LOW
 96H  01/0000Z 18.0N  86.7W   20 KT  25 MPH...POST-TROP/REMNT LOW
120H  02/0000Z 17.0N  87.0W   20 KT  25 MPH...POST-TROP/REMNT LOW
 
$$
FORECASTER AVILA
 

WTNT43 KNHC 280836
TCDAT3
 
TROPICAL STORM RINA DISCUSSION NUMBER  21
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL182011
400 AM CDT FRI OCT 28 2011
 
AFTER AN EARLIER BURST OF VERY COLD-TOPPED CONVECTION OVER THE
LOW-LEVEL CENTER...WATER VAPOR IMAGERY INDICATES A SURGE OF 40-KT
SOUTHERLY UPPER-LEVEL WINDS HAS STARTED TO SHEAR AWAY THE
CONVECTION. AS A RESULT OF THE SHARP DEGRADATION IN THE CONVECTIVE
STRUCTURE...THE INITIAL INTENSITY HAS BEEN DECREASED TO 45 KT...
WHICH IS CONSISTENT WITH THE DOWNWARD TREND IN WIND SPEEDS NOTED IN
NEARBY SURFACE OBSERVATION SITES. 
 
THE INITIAL POSITION IS BASED ON A COUPLE OF SURFACE OBS AND POOR
RADAR SIGNATURES FROM BOTH CUBAN AND MEXICAN RADARS...WHICH MAKES
THE INITIAL MOTION ESTIMATE AN UNCERTAIN 015/04 KT. THE RAGGED
APPEARANCE IN RADAR IMAGERY SUGGESTS THAT THE SMALL CIRCULATION OF
RINA MAY ALREADY BE SUCCUMBING TO THE INCREASING SOUTHERLY VERTICAL
WIND SHEAR. SOME MID-LEVEL ROTATION HAS BECOME APPARENT JUST
NORTHEAST OF THE TIP OF YUCATAN...WHEREAS SURFACE OBS INDICATE THE
SURFACE CENTER IS STILL OVER LAND. WITH THE VERTICAL CIRCULATIONS
FORECAST TO COMPLETELY DECOUPLE DURING THE NEXT 12 HOURS OR SO...
THE LOW-LEVEL CENTER IS EXPECTED TO GRADUALLY TURN SLOWLY EASTWARD
AND THEN TURN SOUTHWARD BACK OVER THE NORTHWESTERN CARIBBEAN SEA BY
24 HOURS. THE OFFICIAL FORECAST TRACK IS SIMILAR TO THE PREVIOUS
ADVISORY AND IS WELL TO THE RIGHT OF THE CONSENSUS MODELS...TVCN
AND TVCA.

SINCE THE VERTICAL SHEAR IS FORECAST TO GRADUALLY INCREASE...THE
MID-/UPPER-LEVEL CIRCULATION IS EXPECTED TO DECOUPLE FROM THE
LOW-LEVEL CIRCULATION AND LIFT OUT TO THE NORTHEAST WHILE THE
LOW-LEVEL CIRCULATION REMAINS BEHIND OVER THE NORTHWESTERN
CARIBBEAN SEA. THIS STRONG SHEAR PATTERN SHOULD CAUSE RINA TO
STEADILY WEAKEN THROUGHOUT THE FORECAST PERIOD...AND THE CYCLONE
COULD BECOME A TROPICAL DEPRESSION BY LATER TODAY OR EARLY
SATURDAY. RINA IS EXPECTED TO BECOME A REMNANT LOW OVER THE
NORTHWESTERN CARIBBEAN BY 48 HOURS...BUT WITH A SLIGHT CHANCE OF
REGENERATING INTO A TROPICAL CYCLONE IF IT DOES NOT GET ABSORBED
INTO THE BROAD LOW PRESSURE SYSTEM LOCATED EAST OF NICARAGUA.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  28/0900Z 21.1N  87.0W   45 KT  50 MPH
 12H  28/1800Z 21.5N  86.8W   40 KT  45 MPH
 24H  29/0600Z 21.3N  86.4W   35 KT  40 MPH
 36H  29/1800Z 20.6N  86.1W   30 KT  35 MPH
 48H  30/0600Z 20.0N  86.1W   25 KT  30 MPH...POST-TROP/REMNT LOW
 72H  31/0600Z 19.2N  86.3W   25 KT  30 MPH...POST-TROP/REMNT LOW
 96H  01/0600Z 17.9N  86.8W   20 KT  25 MPH...POST-TROP/REMNT LOW
120H  02/0600Z 17.0N  87.1W   20 KT  25 MPH...POST-TROP/REMNT LOW
 
$$
FORECASTER STEWART
 

WTNT43 KNHC 281435
TCDAT3
 
TROPICAL DEPRESSION RINA DISCUSSION NUMBER  22
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL182011
1000 AM CDT FRI OCT 28 2011

STRONG VERTICAL WIND SHEAR...DRY AIR ENTRAINMENT...AND PASSAGE OVER
LAND HAVE TAKEN THEIR TOLL ON RINA. THE LOW-LEVEL CENTER IS EXPOSED
WELL TO THE SOUTH AND SOUTHWEST OF THE REMAINING DISORGANIZED
CONVECTION AND...BASED ON THE SATELLITE APPEARANCE AND OBSERVATIONS
FROM CANCUN MEXICO...APPEARS TO BE MUCH WEAKER THAN 24 HOURS AGO.
IN ADDITION...THE CIRCULATION IS ELONGATED NORTH TO SOUTH...AND A
SECOND LOW-LEVEL VORITICTY MAXIMUM HAS FORMED ABOUT 90 N MI
NORTH-NORTHWEST OF THE CENTER IN RESPONSE TO CONVECTION IN THAT
AREA. IT IS ESTIMATED THAT RINA HAS WEAKENED TO A TROPICAL
DEPRESSION WITH A 30-KT INITIAL INTENSITY.

THE INITIAL MOTION IS A SOMEWHAT UNCERTAIN 025/5. RINA IS CURRENTLY
IN AN AREA OF LIGHT LOW-LEVEL SOUTHWESTERLY TO WESTERLY FLOW AHEAD
OF A SOUTHEASTWARD-MOVING COLD FRONT OVER THE NORTHWESTERN GULF OF
MEXICO. HIGH PRESSURE IS FORECAST TO BUILD ACROSS THE GULF OF
MEXICO BEHIND THE FRONT...AND THIS IS EXPECTED TO TURN RINA
SOUTHWARD IN ABOUT 24-36 HOURS AND SOUTH-SOUTHWESTWARD BY 72 HOURS.
THE DYNAMICAL MODELS SHOW A LITTLE MORE EASTWARD MOTION BEFORE THE
SOUTHWARD TURN THAN PREVIOUSLY...SO THE FIRST 48 HOURS OF THE NEW
FORECAST TRACK IS SHIFTED A LITTLE TO THE EAST OF THE PREVIOUS
FORECAST. THE NEW TRACK LIES A LITTLE WEST OF THE VARIOUS CONSENSUS
MODELS THROUGH 48 HOURS AND NEAR THEM AFTER THAT.

THE DYNAMICAL MODELS FORECAST STRONG VERTICAL WIND SHEAR TO CONTINUE
OVER RINA FOR THE NEXT 48-72 HOURS. THUS...THE CYCLONE IS EXPECTED
TO DENEGENERATE INTO A REMNANT LOW IN ABOUT 36 HOURS...AND THIS
COULD OCCUR EARLIER IF ORGANIZED CONVECTION DOES NOT RE-DEVELOP
NEAR THE CENTER. ALL OF THE DYNAMICAL MODELS NOW FORECAST THE
REMNANTS OF RINA TO WEAKEN TO A TROUGH BY 120 HOURS...SO THE NEW
INTENSITY FORECAST CALLS FOR DISSIPATION AT THAT TIME.


FORECAST POSITIONS AND MAX WINDS
 
INIT  28/1500Z 21.8N  86.6W   30 KT  35 MPH
 12H  29/0000Z 22.1N  86.2W   30 KT  35 MPH
 24H  29/1200Z 22.1N  85.6W   25 KT  30 MPH
 36H  30/0000Z 21.4N  85.5W   25 KT  30 MPH...POST-TROP/REMNT LOW
 48H  30/1200Z 20.6N  85.5W   20 KT  25 MPH...POST-TROP/REMNT LOW
 72H  31/1200Z 19.5N  86.0W   20 KT  25 MPH...POST-TROP/REMNT LOW
 96H  01/1200Z 18.0N  87.0W   20 KT  25 MPH...POST-TROP/REMNT LOW
120H  02/1200Z...DISSIPATED
 
$$
FORECASTER BEVEN
 

