WTNT45 KNHC 221452
TCDAT5
 
TROPICAL DEPRESSION TEN DISCUSSION NUMBER   1
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL102012
1100 AM AST WED AUG 22 2012
 
SATELLITE DATA INDICATE THAT THE LOW PRESSURE AREA LOCATED OVER THE
EASTERN TROPICAL ATLANTIC HAS DEVELOPED A WELL-DEFINED SURFACE
CIRCULATION AND SUFFICIENT CONVECTIVE ORGANIZATION TO BE DESIGNATED
AS A TROPICAL DEPRESSION. SATELLITE INTENSITY ESTIMATES FROM TAFB
AND SAB ARE BOTH 2.0...AND THE INITIAL INTENSITY IS SET AT 30KT.
GIVEN THE FAVORABLE UPPER-AIR ENVIRONMENT AHEAD OF THE DEPRESSION
DURING THE NEXT 2-3 DAYS...SOME INTENSIFICATION IS EXPECTED. AFTER
THAT TIME...THE INTENSITY WILL DEPEND IN LARGE PART ON HOW MUCH THE
DEPRESSION BECOMES INVOLVED WITH AN UPPER-LEVEL LOW NORTHEAST OF
THE LESSER ANTILLES IN ABOUT 3 DAYS AND THE INFLUENCE OF THE
UPPER-LEVEL OUTFLOW FROM TROPICAL STORM ISAAC LATE IN THE FORECAST
PERIOD.  INTERACTIONS WITH EITHER WOULD RESULT IN AN INCREASE OF
VERTICAL WIND SHEAR OVER THE CYCLONE AND A POSSIBLE HALT IN
INTENSIFICATION. FOR NOW...THE OFFICIAL FORECAST FOLLOWS THE
INTENSITY CONSENSUS AIDS.
 
THE INITIAL MOTION ESTIMATE IS 295/14.  THE DEPRESSION IS EXPECTED
TO CONTINUE MOVING WEST-NORTHWESTWARD...NEARLY IN TANDEM WITH A
MID- TO UPPER-LEVEL IMPULSE ON THE SOUTH SIDE OF A SUBTROPICAL
RIDGE OVER EASTERN/CENTRAL ATLANTIC. AFTER ABOUT 3 DAYS...THE
CYCLONE SHOULD TURN NORTHWESTWARD AS IT REACHES THE WESTERN
PERIPHERY OF THE SUBTROPICAL RIDGE. THE SPREAD IN THE TRACK
GUIDANCE INCREASES CONSIDERABLY BY THE END OF THE FORECAST
PERIOD...WITH THE GFS FORECASTING A DEEPER SYSTEM THAT TURNS
MORE QUICKLY.  THE HWRF SHOWS A SHALLOWER VORTEX THAT MOVES ON A
MORE WESTWARD TRACK. THE OFFICIAL FORECAST LIES BETWEEN THESE TWO
EXTREMES...CLOSE TO THE ECMWF AND THE MODEL CONSENSUS TVCA.

 
FORECAST POSITIONS AND MAX WINDS
 
INIT  22/1500Z 12.4N  36.3W   30 KT  35 MPH
 12H  23/0000Z 13.3N  38.1W   40 KT  45 MPH
 24H  23/1200Z 14.3N  40.8W   45 KT  50 MPH
 36H  24/0000Z 15.2N  43.6W   50 KT  60 MPH
 48H  24/1200Z 16.2N  46.3W   55 KT  65 MPH
 72H  25/1200Z 18.5N  52.0W   55 KT  65 MPH
 96H  26/1200Z 21.8N  58.0W   55 KT  65 MPH
120H  27/1200Z 26.0N  64.0W   60 KT  70 MPH
 
$$
FORECASTER KIMBERLAIN/ZELINSKY
 

WTNT45 KNHC 222041
TCDAT5
 
TROPICAL DEPRESSION TEN DISCUSSION NUMBER   2
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL102012
500 PM AST WED AUG 22 2012
 
SATELLITE IMAGERY INDICATES THAT TROPICAL DEPRESSION TEN HAS NOT
BECOME ANY BETTER ORGANIZED...AND CLOUD TOPS ARE WARMING...POSSIBLY
COINCIDING WITH THE DIURNAL MINIMUM. FURTHERMORE...THE LOW-LEVEL
CENTER HAS BEEN DIFFICULT TO LOCATE AND MAY BE SOMEWHAT ELONGATED.
SATELLITE INTENSITY ESTIMATES FROM TAFB AND SAB REMAIN AT 2.0...AND
THE INITIAL INTENSITY IS HELD AT 30 KT.
 
THE TROPICAL CYCLONE CONTINUES TO MOVE TO THE WEST-NORTHWEST...AND
THE INITIAL MOTION ESTIMATE IS 295/14...HOWEVER THIS IS HIGHLY
UNCERTAIN DUE TO DIFFICULTY IN LOCATING THE LOW-LEVEL CENTER. THIS
GENERAL MOTION IS EXPECTED TO CONTINUE AS THE DEPRESSION MOVES
TOWARD A MID- TO UPPER-LEVEL WEAKNESS IN THE SUBTROPICAL RIDGE OVER
THE NEXT 3 DAYS. AFTER THAT TIME...A TURN TO THE NORTHWEST IS
EXPECTED AS A DEEP-LAYER TROUGH OVER THE EASTERN U.S. CAUSES THE
RIDGE TO RETREAT AND THE TROPICAL CYCLONE REACHES THE EDGE OF THE
RIDGE.  THE TRACK HAS BEEN ADJUSTED SLIGHTLY TO THE RIGHT...AND IS
CLOSE TO THE ECMWF AND THE DYNAMICAL MODEL CONSENSUS.
 
THE UPPER-LEVEL OUTFLOW FROM TROPICAL STORM ISAAC...AND THE FLOW
ASSOCIATED WITH AN UPPER-LEVEL TROUGH LOCATED OVER THE CENTRAL NORTH
ATLANTIC...ARE DISTORTING THE OUTFLOW OF TROPICAL DEPRESSION NINE
INTO A NORTH-SOUTH ORIENTATION.  IN THE SHORT TERM...THE VERTICAL
WIND SHEAR IS FORECAST TO REMAIN SOMEWHAT WEAK OVER THE SYSTEM. BY
DAY THREE THE TROPICAL CYCLONE IS EXPECTED TO CATCH UP TO THE
UPPER-LEVEL LOW...WHICH SHOULD RESULT IN A SUBSTANTIAL INCREASE IN
WIND SHEAR...AND A HALTING OF INTENSIFICATION. THE SHEAR MAY
DECREASE BY THE END OF THE FORECAST PERIOD AS THE CYCLONE BEGINS TO
MOVE AWAY FROM THE UPPER LOW. THE NHC INTENSITY FORECAST HAS BEEN
LOWERED SLIGHTLY...IN LARGE PART DUE TO THE CURRENT ORGANIZATION OF
THE STORM...AND IS CLOSE TO THE DECAY SHIPS AND LGEM MODELS.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  22/2100Z 13.1N  37.4W   30 KT  35 MPH
 12H  23/0600Z 14.0N  39.6W   40 KT  45 MPH
 24H  23/1800Z 15.0N  42.2W   45 KT  50 MPH
 36H  24/0600Z 16.0N  44.9W   45 KT  50 MPH
 48H  24/1800Z 17.1N  47.5W   50 KT  60 MPH
 72H  25/1800Z 19.9N  53.6W   50 KT  60 MPH
 96H  26/1800Z 23.5N  59.5W   55 KT  65 MPH
120H  27/1800Z 28.5N  64.5W   60 KT  70 MPH
 
$$
FORECASTER KIMBERLAIN/ZELINSKY
 

WTNT45 KNHC 230233
TCDAT5
 
TROPICAL DEPRESSION TEN DISCUSSION NUMBER   3
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL102012
1100 PM AST WED AUG 22 2012
 
TROPICAL DEPRESSION TEN HAS BEEN PRODUCING PULSES OF DEEP CONVECTION
DURING THE PAST FEW HOURS...AND RECENT MICROWAVE IMAGERY SUGGESTS
THAT THE LOW-LEVEL CLOUD PATTERN REMAINS SOMEWHAT DISORGANIZED. 
DVORAK CI NUMBERS ARE UNCHANGED AT 2.0 FROM TAFB AND SAB...AND THE
CYCLONE IS STILL BEING DESIGNATED AS A 30-KT DEPRESSION.

WATER VAPOR IMAGERY SUGGESTS THAT THE ROAD AHEAD IS SOMEWHAT OF AN
OBSTACLE COURSE.  THE DEPRESSION IS NOT TOO FAR FROM AN UPPER-LEVEL
LOW LOCATED TO ITS NORTHWEST...AND IT IS LIKELY TO INTERACT WITH
THIS FEATURE IN SOME FASHION FOR THE NEXT SEVERAL DAYS.  EVEN AFTER
THE DEPRESSION MOVES AWAY FROM THE UPPER-LOW ON DAYS 4 AND 5...THE
CYCLONE COULD THEN BE AFFECTED BY THE UPPER-LEVEL OUTFLOW OF
TROPICAL STORM ISAAC TO ITS WEST.  THE DYNAMICAL GFDL AND HWRF
MODELS HAVE NEVER SHOWN MUCH STRENGTHENING WITH THIS CYCLONE...AND
THE STATISTICAL SHIPS AND LGEM MODELS HAVE COME DOWN CONSIDERABLY
ON THIS FORECAST CYCLE.  THE NHC INTENSITY FORECAST HAS BEEN
ADJUSTED DOWNWARD FROM THE PREVIOUS ONE...LYING JUST ABOVE THE
GUIDANCE FOR THE FIRST 48 HOURS AND THEN VERY NEAR THE INTENSITY
CONSENSUS FOR DAYS 3 THROUGH 5.

THE DEPRESSION IS LOCATED TO THE SOUTH OF THE SUBTROPICAL RIDGE AND
HAS AN ESTIMATED MOTION OF 295/15 KT.  THE CYCLONE SHOULD CONTINUE
TO BE STEERED WEST-NORTHWESTWARD UNTIL IT REACHES THE WESTERN
PERIPHERY OF THE RIDGE ON DAY 3.  A TURN TOWARD THE NORTHWEST AND
NORTH-NORTHWEST IS THEN EXPECTED ON DAYS 4 AND 5.  THE TRACK
GUIDANCE ENVELOPE HAS SHIFTED TO THE WEST ON THIS CYCLE BUT IS
STILL IN RELATIVELY GOOD AGREEMENT.  THE NEW NHC FORECAST HAS
THEREFORE BEEN NUDGED WESTWARD ON DAYS 4 AND 5.  THIS TRACK ENDS UP
VERY CLOSE TO THE GFS AND ECMWF SOLUTIONS...WHICH ARE NEARLY
IDENTICAL ON DAY 5.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  23/0300Z 13.8N  39.5W   30 KT  35 MPH
 12H  23/1200Z 14.5N  41.5W   35 KT  40 MPH
 24H  24/0000Z 15.4N  44.1W   35 KT  40 MPH
 36H  24/1200Z 16.4N  46.7W   35 KT  40 MPH
 48H  25/0000Z 17.6N  49.5W   40 KT  45 MPH
 72H  26/0000Z 21.0N  55.5W   40 KT  45 MPH
 96H  27/0000Z 25.0N  62.0W   45 KT  50 MPH
120H  28/0000Z 30.0N  65.5W   50 KT  60 MPH
 
$$
FORECASTER BERG
 

WTNT45 KNHC 230858
TCDAT5
 
TROPICAL DEPRESSION TEN DISCUSSION NUMBER   4
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL102012
500 AM AST THU AUG 23 2012
 
DEEP CONVECTION WITH THE TROPICAL DEPRESSION CONTINUES TO BE
SPORADIC THOUGH WITH QUITE COLD CLOUD TOPS.  THE CENTER APPEARS TO
BE NEAR THE SOUTH SIDE OF THE CONVECTION SUGGESTING THAT THE
MODERATE SOUTHERLY VERTICAL SHEAR IS INHIBITING ITS DEVELOPMENT. 
AS A RESULT OF THE LACK OF IMPROVEMENT OF THE ORGANIZATION OF THE
DEEP CONVECTION...THE DVORAK CLASSIFICATIONS FROM TAFB AND SAB
REMAIN AT A 2.0...OR ABOUT 30 KT.  IN CONTRAST...TWO RECENT AMSU
SATELLITE PASSES SUGGEST THAT THE CYCLONE MAY BE A 35 TO 45 KT
TROPICAL STORM.  GIVEN THE UNIMPRESSIVE CONVECTIVE STRUCTURE...THE
SYSTEM REMAINS AS A 30-KT TROPICAL DEPRESSION.

A 0406Z AMSU IMAGE FROM THE NRL WEBSITE PROVIDES MODERATE CONFIDENCE
IN THE INITIAL POSITION OF THE TROPICAL DEPRESSION.  THE CURRENT
MOTION OF THE SYSTEM CONTINUES TOWARD THE WEST-NORTHWEST...295
DEGREES...AT 14 KT...AS THE CYCLONE IS BEING ADVECTED AROUND THE
SOUTHERN PERIPHERY OF A DEEP-LAYER SUBTROPICAL RIDGE.  THE SYSTEM
SHOULD GRADUALLY TURN TOWARD THE NORTH-NORTHWEST BY DAY FIVE AS IT
REACHES THE WESTERN SIDE OF THE RIDGE.  THE GLOBAL AND REGIONAL
TRACK GUIDANCE SHOWS RELATIVELY TIGHT CLUSTERING AND HAD LITTLE
CHANGE FROM THE PREVIOUS MODEL CYCLE.  THUS THE TRACK FORECAST IS
NEARLY IDENTICAL TO BOTH THE LAST ADVISORY AND THE HFIP TV15
CONSENSUS.

THE INTENSITY PREDICTION IS MORE PROBLEMATIC THAN THE TRACK
FORECAST.  THE AFOREMENTIONED MODERATE VERTICAL SHEAR IS PRIMARILY
BEING INDUCED BY AN UPPER LOW LOCATED ABOUT 600 NM NORTHWEST OF THE
CYCLONE.  THE TROPICAL DEPRESSION AND THE UPPER LOW SHOULD GET
CLOSER TOGETHER OVER THE NEXT THREE DAYS...WHICH WOULD CONTINUE
MODERATE SHEAR ACROSS THE CYCLONE.  ON DAYS FOUR AND FIVE...THE
VERTICAL SHEAR MAY INCREASE DUE TO THE OUTFLOW OF ISAAC. 
MOREOVER...THE THERMODYNAMICS ARE NOT CONDUCIVE FOR MUCH
INTENSIFICATION AS SOME DRY STABLE AIR ASSOCIATED WITH A SAHARAN
AIR LAYER...WORKING IN CONCERT WITH THE VERTICAL SHEAR...MAY BE
REACHING THE INNER CORE OF THE CYCLONE DURING THE NEXT TWO TO THREE
DAYS.  THUS ONLY VERY GRADUAL INTENSIFICATION IS SHOWN THROUGHOUT
THE FORECAST PERIOD IN BEST AGREEMENT WITH HWRF AND SHIPS MODELS. 
THE PREDICTED INTENSITIES ARE REDUCED SLIGHTLY FROM THE PREVIOUS
ADVISORY. AN ALTERNATIVE SCENARIO DEPICTED BY THE ECMWF AND GFDL
MODELS IS THAT THE CYCLONE COULD SUCCOMB TO THE HOSTILE ENVIRONMENT
AND DISSIPATE BEFORE THE END OF THE FORECAST PERIOD.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  23/0900Z 14.5N  40.6W   30 KT  35 MPH
 12H  23/1800Z 15.2N  42.5W   35 KT  40 MPH
 24H  24/0600Z 16.2N  45.0W   35 KT  40 MPH
 36H  24/1800Z 17.4N  47.7W   35 KT  40 MPH
 48H  25/0600Z 18.8N  50.8W   35 KT  40 MPH
 72H  26/0600Z 22.0N  57.0W   40 KT  45 MPH
 96H  27/0600Z 27.0N  63.0W   45 KT  50 MPH
120H  28/0600Z 31.0N  64.5W   45 KT  50 MPH
 
$$
FORECASTER LANDSEA
 

