WTNT41 KNHC 192042
TCDAT1
 
TROPICAL STORM ALBERTO DISCUSSION NUMBER   1
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL012012
500 PM EDT SAT MAY 19 2012
 
SATELLITE...RADAR...AND SURFACE DATA INDICATE THAT THE SMALL SURFACE
LOW LOCATED OFF THE COAST OF SOUTH CAROLINA HAS ACQUIRED THE
CHARACTERISTICS OF A TROPICAL CYCLONE.  ORGANIZED DEEP CONVECTION
HAS BEEN PERSISTENT OVER THE CENTER FOR MORE THAN 18 HOURS...AND
THE CIRCULATION CENTER HAS BEEN MOVING SOUTH AWAY FROM AN AIRMASS
BOUNDARY THAT EXTENDS ROUGHLY ALONG 33N.  BASED ON AN ASCAT PASS
FROM AROUND 1530 UTC...THE INITIAL INTENSITY IS SET AT 40 KT.
ALBERTO IS SITUATED IN A MARGINAL THERMODYNAMIC ENVIRONMENT FOR
STRENGTHENING...WITH A MARKEDLY DRY CONTINENTAL AIRMASS TO ITS NORTH
AND WEST OVER THE EASTERN CAROLINAS.  GIVEN THIS...ONLY MODEST
INTENSIFICATION IS EXPECTED DESPITE THE CYCLONE BEING OVER
THE RELATIVELY WARM GULF STREAM.  ALBERTO IS EXPECTED TO BECOME
EXTRATROPICAL BY 96 HOURS...AND SHOULD DISSIPATE BY DAY 5.  THE NHC
INTENSITY FORECAST IS A BLEND OF THE MORE AGGRESSIVE STATISTICAL
GUIDANCE AND THE WEAKER DYNAMICAL MODELS.
 
THE LOW-LEVEL CIRCULATION IS A BIT TO THE EAST OF THE COLDEST CLOUD
TOPS AND THE CIRCULATION CENTER SEEN ON RADAR...AND THE INITIAL
MOTION ESTIMATE IS 220/03. THE SYNOPTIC ENVIRONMENT IS COMPLEX...AS
ALBERTO IS IN A REGION OF WEAK STEERING FLOW WITHIN A BROAD
MID/UPPER-LEVEL TROUGH. THE NHC FORECAST SHOWS A SLOW SOUTHWESTWARD
MOTION OVER THE NEXT DAY OR SO DUE TO THE STRONG NORTHEASTERLY FLOW
BETWEEN A SURFACE RIDGE EAST OF THE APPALACHIANS AND A LARGER
EXTRATROPICAL LOW CENTERED NEAR 36N/72W. AS THAT LOW MOVES WESTWARD
AND WEAKENS BY SUNDAY NIGHT...ALBERTO IS EXPECTED TO TURN NORTHWARD
AND THEN ACCELERATE NORTHEASTWARD AFTER 48 HOURS AS A SHORTWAVE
TROUGH MOVES INTO THE EASTERN UNITED STATES AND THE STEERING FLOW
BECOMES SOUTHWESTERLY. GIVEN THE SMALL SIZE OF ALBERTO AND THE
COMPLEX STEERING PATTERN...IT IS NOT SURPRISING THAT THE TRACK
MODEL GUIDANCE SHOWS A LARGE AMOUNT OF SPREAD...BOTH IN TERMS OF
HOW FAR SOUTH AND WEST ALBERTO WILL MOVE...AND HOW SHARP THE TURN
TOWARD THE NORTHEAST WILL BE. THE NHC TRACK FORECAST IS GENERALLY
CLOSE TO THE TVCA MULTI-MODEL CONSENSUS...AND IS OF VERY LOW
CONFIDENCE.

A TROPICAL STORM WATCH COULD BE REQUIRED FOR A PORTION OF THE COAST
OF THE CAROLINAS THIS EVENING.

ALBERTO IS EARLIEST-FORMING TROPICAL STORM IN THE ATLANTIC BASIN
SINCE ANA IN 2003.  THIS IS ALSO THE FIRST TIME THAT A TROPICAL
STORM HAS FORMED BEFORE THE OFFICIAL START OF THE HURRICANE SEASON
IN BOTH THE ATLANTIC AND EAST PACIFIC BASINS.
 

FORECAST POSITIONS AND MAX WINDS
 
INIT  19/2100Z 32.2N  77.7W   40 KT  45 MPH
 12H  20/0600Z 31.9N  78.1W   45 KT  50 MPH
 24H  20/1800Z 31.7N  78.5W   45 KT  50 MPH
 36H  21/0600Z 31.9N  78.9W   45 KT  50 MPH
 48H  21/1800Z 32.7N  78.5W   45 KT  50 MPH
 72H  22/1800Z 34.5N  75.5W   45 KT  50 MPH
 96H  23/1800Z 37.5N  72.0W   40 KT  45 MPH...POST-TROP/EXTRATROP
120H  24/1800Z...DISSIPATED
 
$$
FORECASTER BRENNAN
 

WTNT41 KNHC 200254
TCDAT1
 
TROPICAL STORM ALBERTO DISCUSSION NUMBER   2
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL012012
1100 PM EDT SAT MAY 19 2012
 
THE INTENSITY OF ALBERTO HAS BEEN DIFFICULT TO DECIPHER THIS
EVENING. WHILE AN EARLIER SHIP REPORT SUGGESTED THE STORM WAS
STRONGER...THE SATELLITE AND RADAR PRESENTATION HAS BEEN ON THE
DECLINE SINCE THEN...WITH A NOTABLE DECREASE IN WINDS FROM THE
COASTAL DOPPLER RADARS. THE INITIAL INTENSITY OF 45 KT IS A
COMPROMISE BETWEEN THE SHIP REPORT AND THE LOWER SATELLITE/RADAR
ESTIMATES. ALTHOUGH THE CYCLONE IS EXPECTED TO MOVE NEAR THE WARM
GULF STREAM WATERS FOR THE NEXT DAY OR TWO...MODERATE SHEAR ALONG
WITH PROBABLE ENTRAINMENT OF A DRY AIRMASS TO THE NORTH OF THE
SYSTEM COULD PREVENT SIGNIFICANT STRENGTHENING. THE INTENSITY
GUIDANCE REMAINS SPLIT WITH THE DYNAMICAL GUIDANCE SUGGESTING SOME
WEAKENING...AND THE STATISTICAL TOOLS SHOWING STRENGTHENING. THE
OFFICIAL FORECAST IS UNCHANGED FROM THE PREVIOUS ONE AND LIES NEAR
THE CONSENSUS.
 
ALBERTO APPEARS TO BE MOVING SOUTHWESTWARD AT ABOUT 5 KT...AS IT IS
BEING STEERED PRIMARILY BY A LOW- TO MID-LEVEL RIDGE OVER THE
EASTERN UNITED STATES.  THIS RIDGE IS EXPECTED TO BREAK DOWN IN A
DAY OR SO...WITH A COMPLEX STEERING FLOW PROBABLY CAUSING THE
CYCLONE TO TURN TOWARD THE NORTHEAST IN A COUPLE OF DAYS.  THE
GUIDANCE ENVELOPE HAS SHIFTED SOMEWHAT TO THE SOUTHWEST IN THIS
MODEL CYCLE...THOUGH MOST OF THE RELIABLE MODELS STILL KEEP THE
STORM OFFSHORE.  THE NHC FORECAST IS SHIFTED SOUTHWEST OF THE
PREVIOUS ONE THROUGH THE FIRST 36 HOURS...AND IS NEAR THE TVCA
MULTI-MODEL CONSENSUS.
 
ALTHOUGH THE OFFICIAL FORECAST CALLS FOR THE TROPICAL-STORM-FORCE
WINDS TO REMAIN JUST OFFSHORE...THERE IS TOO LITTLE MARGIN FOR
ERROR TO NOT ISSUE A TROPICAL STORM WATCH AT THIS TIME.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  20/0300Z 31.8N  78.5W   45 KT  50 MPH
 12H  20/1200Z 31.6N  79.0W   45 KT  50 MPH
 24H  21/0000Z 31.4N  79.5W   45 KT  50 MPH
 36H  21/1200Z 31.8N  79.4W   45 KT  50 MPH
 48H  22/0000Z 32.7N  78.2W   45 KT  50 MPH
 72H  23/0000Z 35.0N  75.0W   45 KT  50 MPH
 96H  24/0000Z 38.0N  70.0W   35 KT  40 MPH...POST-TROP/EXTRATROP
120H  25/0000Z...DISSIPATED
 
$$
FORECASTER BLAKE/FRANKLIN
 

WTNT41 KNHC 200848
TCDAT1
 
TROPICAL STORM ALBERTO DISCUSSION NUMBER   3
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL012012
500 AM EDT SUN MAY 20 2012
 
ALBERTO APPEARS TO BE MAINTAINING ITS STRENGTH. SATELLITE AND RADAR
IMAGES SHOW THAT DEEP CONVECTION REFORMED NEAR THE CENTER OF THE
TROPICAL STORM OVERNIGHT WITH A BROKEN BAND OF THUNDERSTORM
ACTIVITY REMAINING TO THE NORTH OF THE CENTER. AN ASCAT PASS AROUND
0300 UTC SHOWED MAXIMUM WINDS NEAR 40 KT. BASED ON THE
SCATTEROMETER DATA AND THE RECENT INCREASE IN THUNDERSTORM
ACTIVITY...THE INITIAL INTENSITY IS HELD AT 45 KT. ALTHOUGH ALBERTO
LIES OVER THE RELATIVELY WARM WATERS OF THE GULF STREAM...DRY AIR
IN THE VICINITY OF THE CYCLONE AND STRONG WEST-SOUTHWESTERLY SHEAR
SHOULD LIMIT THE INTENSIFICATION PROCESS. THE OFFICIAL INTENSITY
FORECAST IS SIMILAR TO THE PREVIOUS ONE AND SHOWS ALBERTO REMAINING
STEADY STATE FOR THE NEXT COUPLE OF DAYS. WEAKENING AND A
TRANSITION TO A POST-TROPICAL CYCLONE IS FORECAST BEYOND THAT TIME
WHEN ALBERTO MOVES OVER COOLER WATERS AND INTO AN AREA OF VERY
STRONG UPPER-LEVEL WINDS.
 
ALBERTO IS CURRENTLY MOVING WEST-SOUTHWESTWARD AT ABOUT 5 KT. THIS
GENERAL HEADING WITH A DECREASE IN FORWARD SPEED IS EXPECTED TODAY 
AS A DEEP-LAYER RIDGE OVER THE EASTERN UNITED STATES WEAKENS. THE
TROPICAL CYCLONE IS EXPECTED TO STALL OFF THE SOUTHEAST UNITED
STATES COAST TONIGHT AND EARLY MONDAY AS IT INTERACTIONS WITH AN
AREA OF LOW PRESSURE TO ITS NORTH NEAR THE MID-ATLANTIC STATES AND
A DEVELOPING LOW TO ITS SOUTHEAST.  THEREAFTER...A MID-TO
UPPER-LEVEL TROUGH MOVING ACROSS THE EASTERN UNITED STATES SHOULD
CAUSE ALBERTO...OR ITS POST-TROPICAL REMNANTS...TO ACCELERATE
NORTHEASTWARD OVER THE WESTERN ATLANTIC.  THE OFFICIAL TRACK
FORECAST HAS BEEN ADJUSTED SLIGHTLY EASTWARD TO BE IN BETTER
AGREEMENT WITH THE LATEST GUIDANCE. FUTURE ADJUSTMENTS IN THAT
DIRECTION MAY BE NECESSARY IF THE RECENT MODEL TRENDS CONTINUE.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  20/0900Z 31.7N  78.9W   45 KT  50 MPH
 12H  20/1800Z 31.4N  79.3W   45 KT  50 MPH
 24H  21/0600Z 31.2N  79.5W   45 KT  50 MPH
 36H  21/1800Z 31.6N  78.8W   45 KT  50 MPH
 48H  22/0600Z 32.8N  77.1W   45 KT  50 MPH
 72H  23/0600Z 36.2N  72.6W   40 KT  45 MPH...POST-TROPICAL
 96H  24/0600Z 39.0N  68.5W   35 KT  40 MPH...POST-TROPICAL
120H  25/0600Z...DISSIPATED
 
$$
FORECASTER CANGIALOSI/BROWN
 

WTNT41 KNHC 201450
TCDAT1
 
TROPICAL STORM ALBERTO DISCUSSION NUMBER   4
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL012012
1100 AM EDT SUN MAY 20 2012
 
THE CENTER OF ALBERTO HAS BECOME MORE EXPOSED THIS MORNING...AND THE
DEEPEST CONVECTION APPEARS TO BE MOVING WESTWARD AWAY FROM THE
SYSTEM.  OBJECTIVE AND SUBJECTIVE INTENSITY ESTIMATES ARE ALL
SUGGESTING AN INTENSITY AROUND 35 KT...BUT THE ADVISORY INTENSITY
IS ONLY BEING LOWERED TO 40 KT FOR NOW.  AN AIR FORCE HURRICANE
HUNTER IS SCHEDULED TO INVESTIGATE THE SYSTEM THIS AFTERNOON...AT
WHICH TIME ADDITIONAL ADJUSTMENTS CAN BE MADE.
 
ALBERTO APPEARS TO HAVE AT LEAST THREE STRIKES AGAINST ANY
RE-INTENSIFICATION.  FIRST...DEWPOINTS OVER SOUTHEASTERN U.S. ARE
ROUGHLY 50 DEGREES FAHRENHEIT...AND THE CYCLONE IS LIKELY INGESTING
SOME OF THIS DRY AIR.  SECOND...THE CENTER IS MOVING WEST OF THE
GULF STREAM OVER COOLER SHELF WATERS NEAR THE SOUTH CAROLINA/
GEORGIA COAST.  AND THIRD...UPPER-LEVEL WESTERLY WINDS ARE EXPECTED
TO INCREASE OVER THE SYSTEM DURING THE NEXT 24 HOURS.  THE OFFICIAL
FORECAST THEREFORE KEEPS ALBERTO AT LOW-END TROPICAL-STORM STRENGTH
THROUGH WEDNESDAY WITH WEAKENING AND DISSIPATION OCCURRING ON
THURSDAY.  THIS SCENARIO IS SUPPORTED BY VIRTUALLY ALL OF THE
INTENSITY GUIDANCE.  ALBERTO IS FORECAST TO BECOME POST-TROPICAL BY
72 HOURS...ALTHOUGH THERE IS CONSIDERABLE UNCERTAINTY ON THE EXACT
TIMING OF THAT TRANSITION.
 
A BLOCKING PATTERN OVER THE EASTERN UNITED STATES HAS CAUSED ALBERTO
TO MOVE SLOWLY WEST-SOUTHWESTWARD SINCE YESTERDAY...AND THE CURRENT
MOTION IS 250/5 KT.  THE BLOCKING ANTICYCLONE CURRENTLY POSITIONED
OVER WESTERN NEW ENGLAND IS EXPECTED TO BEGIN SLIDING EASTWARD
TODAY WITH A PROGRESSIVE MID-LATITUDE TROUGH APPROACHING FROM THE
UPPER MIDWEST.  ALBERTO SHOULD CONTINUE TO MOVE LITTLE THROUGH
TONIGHT...BUT THE EVOLVING STEERING PATTERN IS EXPECTED TO
ACCELERATE THE STORM NORTHEASTWARD BEGINNING ON MONDAY.  THERE IS
VERY LITTLE SPREAD IN THE TRACK GUIDANCE THROUGH THE NEXT 48 HOURS.
THEREAFTER...THE ECMWF DIVERGES FROM THE CLUSTER OF OTHER MODELS
AND SHOWS A SLOWER...MORE SOUTHERN SOLUTION.  THE OFFICIAL FORECAST
IS THEREFORE A LITTLE SLOWER AND FARTHER SOUTH THAN THE MULTI-MODEL
CONSENSUS ON DAYS 3 AND 4.
  
FORECAST POSITIONS AND MAX WINDS
 
INIT  20/1500Z 31.5N  79.7W   40 KT  45 MPH
 12H  21/0000Z 31.2N  79.7W   35 KT  40 MPH
 24H  21/1200Z 31.4N  79.1W   35 KT  40 MPH
 36H  22/0000Z 32.3N  77.6W   35 KT  40 MPH
 48H  22/1200Z 34.2N  75.4W   35 KT  40 MPH
 72H  23/1200Z 38.0N  70.5W   35 KT  40 MPH...POST-TROPICAL
 96H  24/1200Z 39.5N  66.5W   30 KT  35 MPH...POST-TROPICAL
120H  25/1200Z...DISSIPATED
 
$$
FORECASTER BERG/PASCH
 

WTNT41 KNHC 202045
TCDAT1
 
TROPICAL STORM ALBERTO DISCUSSION NUMBER   5
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL012012
500 PM EDT SUN MAY 20 2012
 
ALBERTO DOES NOT HAVE THE TYPICAL VERTICAL WIND PROFILE OF A HEALTHY
TROPICAL CYCLONE.  THE AIR FORCE PLANE THAT SAMPLED THE STORM ONLY
MEASURED MAXIMUM 850-MB FLIGHT-LEVEL WINDS OF 37 KT...YET SFMR
VALUES WERE AS HIGH AS ABOUT 50 KT.  THE SFMR ESTIMATES ARE LIKELY
TOO HIGH BASED ON COINCIDENT SPIKES IN THE RAIN RATE AND A
WELL-DOCUMENTED HIGH BIAS AT LOW-END TROPICAL STORM WIND SPEEDS. 
IN ADDITION...DROPSONDE DATA FROM THE AIRCRAFT DO NOT SUPPORT WINDS
OF 50 KT NEAR THE SURFACE.  THE INTENSITY IS THEREFORE BEING HELD
AT 40 KT.  THE AIRCRAFT DATA SUGGEST THAT THE BOUNDARY LAYER HAS
DECOUPLED...AND THE SURFACE CIRCULATION MAY NOW BE TAKING SOME TIME
TO SPIN DOWN.
 
ALBERTO IS INGESTING DRY AIR...AND IT HAS MOVED OVER SHELF WATERS
THAT ARE COLDER THAN 26C.  IN ADDITION...WESTERLY VERTICAL WIND
SHEAR IS EXPECTED TO INCREASE MARKEDLY DURING THE NEXT 24 HOURS. 
ALTHOUGH THE CYCLONE WILL TRAVERSE THE GULF STREAM AGAIN WHEN IT
ACCELERATES NORTHEASTWARD ON MONDAY...THE OTHERWISE HOSTILE
CONDITIONS SUGGEST THAT SIGNIFICANT INTENSIFICATION IS UNLIKELY. 
SMALL FLUCTUATIONS IN INTENSITY ARE POSSIBLE THROUGH TUESDAY
DEPENDING ON THE BEHAVIOR OF DEEP CONVECTION...BUT OVERALL LITTLE
CHANGE IN STRENGTH IS ANTICIPATED.  THIS SCENARIO IS SUPPORTED BY
THE BULK OF THE INTENSITY GUIDANCE.  ALBERTO COULD BECOME POST- 
TROPICAL BY WEDNESDAY AS IT MOVES TOWARDS EVEN COLDER WATER...WITH
DISSIPATION POSSIBLE BY THURSDAY.
 
THE MOTION HAS BECOME SOUTHWESTWARD DURING THE DAY...AND IT APPEARS
THAT ALBERTO IS BEGINNING ITS ANTICIPATED COUNTER-CLOCKWISE LOOP.
THE BLOCKING PATTERN IN PLACE OVER THE EASTERN U.S. IS STILL
EXPECTED TO BREAKDOWN THROUGH MONDAY...AND ALBERTO WILL RESPOND BY
ACCELERATING NORTHEASTWARD AHEAD OF AN APPROACHING LONGWAVE TROUGH.
THE 12Z ECMWF MODEL RUN...LIKE THE PREVIOUS ONE...IS STILL A LITTLE
SOUTH OF THE REST OF THE TRACK GUIDANCE ENVELOPE.  THE OFFICIAL
FORECAST IS CLOSE TO THE VARIOUS CONSENSUS MODELS THROUGH 48 HOURS
BUT A LITTLE FARTHER SOUTH AT 72 HOURS...HEDGING TOWARD THE ECMWF
SOLUTION.
 

FORECAST POSITIONS AND MAX WINDS
 
INIT  20/2100Z 30.9N  80.0W   40 KT  45 MPH
 12H  21/0600Z 30.8N  79.8W   40 KT  45 MPH
 24H  21/1800Z 31.2N  78.6W   40 KT  45 MPH
 36H  22/0600Z 32.5N  76.6W   40 KT  45 MPH
 48H  22/1800Z 34.7N  73.8W   40 KT  45 MPH
 72H  23/1800Z 38.0N  66.5W   35 KT  40 MPH...POST-TROP/EXTRATROP
 96H  24/1800Z...DISSIPATED
 
$$
FORECASTER BERG
 

WTNT41 KNHC 210238
TCDAT1
 
TROPICAL STORM ALBERTO DISCUSSION NUMBER   6
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL012012
1100 PM EDT SUN MAY 20 2012
 
ALBERTO HAS BEEN STRUGGLING TO PRODUCE DEEP CONVECTION THIS
EVENING...ALTHOUGH THERE ARE STILL BANDING FEATURES PRESENT ON THE
JACKSONVILLE DOPPLER RADAR. SATELLITE CLASSIFICATIONS AND DOPPLER
WIND DATA SUGGEST THE STORM HAS WEAKENED...AND THE INITIAL WIND
SPEED IS REDUCED TO 35 KT FOR THIS ADVISORY. LITTLE CHANGE IN
INTENSITY IS FORECAST BY MUCH OF THE GUIDANCE DUE TO ALBERTO MOVING
OVER WARM WATERS ALONG THE GULF STREAM...BUT IN A MODERATE-TO-
STRONG VERTICAL SHEAR ENVIRONMENT. THE NHC FORECAST SHOWS NO CHANGE
IN INTENSITY FOR THE NEXT COUPLE OF DAYS AND THEN WEAKENING AS THE
CYCLONE MOVES OVER MUCH COOLER WATERS. A PLAUSIBLE ALTERNATE
SCENARIO IS THAT THE STORM LOSES ALL DEEP CONVECTION DUE TO
MARGINAL THERMODYNAMIC CONDITIONS...AND BECOMES A REMNANT LOW IN A
DAY OR TWO.
 
ALBERTO HAS TURNED SOUTHWARD AND IS MOVING 180/4.  THE SYSTEM IS
EMBEDDED IN A PECULIAR PLACE WITHIN THE SOUTH SIDE OF A MID- TO
UPPER-LEVEL LOW.  THIS LOW IS EXPECTED TO WEAKEN AND MOVE
NORTHEASTWARD AS ANOTHER TROUGH MOVES INTO THE SOUTHEASTERN UNITED
STATES.  THE MODEL GUIDANCE IS IN VERY GOOD AGREEMENT ON ALBERTO
MOVING SOUTHEASTWARD AND EASTWARD DURING THE NEXT 12 HOURS OR
SO...THEN TURNING TO THE NORTHEAST WITH INCREASING FORWARD SPEED. 
THE OFFICIAL FORECAST IS CLOSE TO THE PREVIOUS ONE BUT HAS BEEN
ADJUSTED A BIT TO THE SOUTHEAST TO ACCOUNT FOR THE LATEST MODEL
TRENDS.
  
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  21/0300Z 30.5N  80.1W   35 KT  40 MPH
 12H  21/1200Z 30.6N  79.4W   35 KT  40 MPH
 24H  22/0000Z 31.5N  77.8W   35 KT  40 MPH
 36H  22/1200Z 33.2N  75.3W   35 KT  40 MPH
 48H  23/0000Z 35.5N  72.2W   35 KT  40 MPH
 72H  24/0000Z 39.0N  66.0W   30 KT  35 MPH...POST-TROP/EXTRATROP
 96H  25/0000Z...DISSIPATED
 
$$
FORECASTER BLAKE
 

WTNT41 KNHC 210841
TCDAT1
 
TROPICAL STORM ALBERTO DISCUSSION NUMBER   7
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL012012
500 AM EDT MON MAY 21 2012
 
DEEP CONVECTION HAS REFORMED NEAR THE CENTER OF ALBERTO AGAIN THIS
MORNING WITH BROKEN RAINBANDS CONTINUING AROUND THE CENTER. THE
INITIAL WIND SPEED IS HELD AT 35 KT...ALTHOUGH SATELLITE INTENSITY
ESTIMATES SUGGEST THAT ALBERTO COULD BE WEAKER. THE TROPICAL STORM
IS QUITE COMPACT WITH ITS ASSOCIATED CLOUDINESS EXTENDING NO MORE
THAN 150 N MI ACROSS. EVEN THOUGH ALBERTO HAS MOVED BACK OVER THE
GULF STREAM...WHERE SEA SURFACE TEMPERATURES ARE RELATIVELY
WARM...VERY DRY AIR AROUND THE CYCLONE AND STRONG
WEST-SOUTHWESTERLY SHEAR SHOULD SUPPRESS SIGNIFICANT STRENGTHENING.
THE OFFICIAL FORECAST...THEREFORE...KEEPS ALBERTO AT THE SAME
INTENSITY FOR THE NEXT DAY OR TWO...IN AGREEMENT WITH ALL OF THE
INTENSITY GUIDANCE. ALTHOUGH NOT EXPLICITLY SHOWN BELOW...ALBERTO
IS EXPECTED TO TRANSITION TO A POST-TROPICAL CYCLONE AFTER 48 HOURS
AND BEFORE DISSIPATION IN ABOUT THREE DAYS.
 
THE TROPICAL STORM IS MOVING SLOWLY SOUTHEASTWARD OFF THE
NORTHEAST FLORIDA COAST...NEARLY COMPLETING THE ANTICIPATED
COUNTER-CLOCKWISE LOOP. AN EASTWARD MOTION IS EXPECTED TO BEGIN
TODAY AS AN AMPLIFYING MID- TO UPPER-LEVEL TROUGH APPROACHES THE
CYCLONE. A TURN TO THE NORTHEAST WITH AN INCREASE IN FORWARD SPEED
IS FORECAST TO OCCUR TONIGHT AND TUESDAY...TAKING THE COMPACT
TROPICAL STORM PARALLEL TO...BUT OFFSHORE...OF THE SOUTHEAST UNITED
STATES COASTLINE. THE NHC TRACK FORECAST HAS BEEN ADJUSTED SLIGHTLY
TO THE EAST AND LIES BETWEEN THE GFS AND ECMWF SOLUTIONS.
  
FORECAST POSITIONS AND MAX WINDS
 
INIT  21/0900Z 30.4N  79.7W   35 KT  40 MPH
 12H  21/1800Z 30.6N  78.7W   35 KT  40 MPH
 24H  22/0600Z 31.8N  76.8W   35 KT  40 MPH
 36H  22/1800Z 33.5N  74.3W   35 KT  40 MPH
 48H  23/0600Z 35.5N  71.5W   30 KT  35 MPH
 72H  24/0600Z...DISSIPATED
 
$$
FORECASTER CANGIALOSI
 

WTNT41 KNHC 211449
TCDAT1
 
TROPICAL STORM ALBERTO DISCUSSION NUMBER   8
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL012012
1100 AM EDT MON MAY 21 2012
 
ALBERTO CONTINUES TO GENERATE SOME DEEP CONVECTION...BUT THE CLOUD
PATTERN OF THE STORM IS BEGINNING TO BECOME ELONGATED EAST-
NORTHEASTWARD...WHICH IS INDICATIVE OF INCREASING SHEAR.  THE
CURRENT INTENSITY IS HELD AT 35 KT FOR THIS ADVISORY...ALTHOUGH
DVORAK ESTIMATES SUGGEST A SLIGHTLY LOWER VALUE.  AN AIR FORCE
HURRICANE HUNTER AIRCRAFT SHOULD PROVIDE A BETTER ESTIMATE OF THE
STRENGTH OF ALBERTO.  GLOBAL MODEL PREDICTIONS SHOW A SUBSTANTIAL
INCREASE IN SHEAR OVER THE NEXT 48 HOURS AND THIS...ALONG WITH DRY
AIR SEEN IN WATER VAPOR IMAGERY...SHOULD LEAD TO WEAKENING AND
DISSIPATION IN 2-3 DAYS.  THE OFFICIAL WIND SPEED FORECAST IS
SIMILAR TO THAT FROM THE PREVIOUS ADVISORY AND IS CLOSE TO THE LGEM
GUIDANCE.  IT IS CERTAINLY POSSIBLE THAT ALBERTO COULD BECOME A
POST-TROPICAL CYCLONE IN 48 HOURS. 

THE TROPICAL CYCLONE HAS TURNED TOWARD THE EAST...AND THE MOTION IS
NOW ABOUT 090/6.  THERE IS LITTLE CHANGE TO THE TRACK FORECAST AND
REASONING FROM THE PREVIOUS ADVISORY. AN AMPLIFYING MID-LEVEL
TROUGH TO THE WEST OF ALBERTO SHOULD ACCELERATE THE SYSTEM TOWARD
THE NORTHEAST OVER THE NEXT 48 HOURS.  THE OFFICIAL FORECAST IS
VERY CLOSE TO THE PREVIOUS NHC FORECAST TRACK AND ROUGHLY IN THE
MIDDLE OF THE DYNAMICAL MODEL GUIDANCE.  THIS TRACK KEEPS THE SMALL
CYCLONE WELL OFFSHORE OF THE U.S. EAST COAST.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  21/1500Z 30.4N  78.8W   35 KT  40 MPH
 12H  22/0000Z 31.0N  77.5W   35 KT  40 MPH
 24H  22/1200Z 32.5N  75.4W   35 KT  40 MPH
 36H  23/0000Z 34.3N  73.2W   30 KT  35 MPH
 48H  23/1200Z 36.3N  70.8W   30 KT  35 MPH
 72H  24/1200Z...DISSIPATED
 
$$
FORECASTER PASCH
 

WTNT41 KNHC 212036
TCDAT1
 
TROPICAL STORM ALBERTO DISCUSSION NUMBER   9
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL012012
500 PM EDT MON MAY 21 2012
 
DATA FROM AN AIR FORCE HURRICANE HUNTER AIRCRAFT CONFIRM THAT
ALBERTO IS STILL A TROPICAL STORM.  MAXIMUM SFMR-OBSERVED SURFACE
WINDS WERE 37 KT AND PEAK 1000 FT FLIGHT-LEVEL WINDS WERE 39 KT.  IT
SHOULD ALSO BE NOTED THAT SEVERAL YACHTS FROM THE VOLVO OCEAN RACE
HAVE BEEN SAILING NOT FAR FROM...OR THROUGH...THE CENTER OF
ALBERTO...AND HAVE ALSO MEASURED WINDS OF TROPICAL STORM FORCE.
ONE OF THE YACHTS MEASURED A PRESSURE VERY CLOSE TO THE ESTIMATED
CENTRAL PRESSURE OF THE STORM.  THE CLOUD PATTERN IS BECOMING
INCREASINGLY SHEARED WITH THE LOW-LEVEL CENTER NOW EXPOSED TO THE
SOUTHWEST OF THE DEEP CONVECTION.  A CONTINUED INCREASE IN VERTICAL
SHEAR IS FORECAST BY THE GLOBAL MODELS...AND THIS SHOULD RESULT IN
ALBERTO WEAKENING TO DISSIPATION IN ABOUT 2 DAYS.  GLOBAL
MODELS...HOWEVER...SUGGEST THAT THE CYCLONE COULD DISSIPATE SOONER
THAN THAT.
 
ALBERTO CONTINUES TO MOVE EASTWARD...OR 080/7.  THERE IS ESSENTIALLY
NO CHANGE TO THE TRACK FORECAST FROM THE PREVIOUS ADVISORY.  AN
AMPLIFYING MID-LEVEL TROUGH TO THE WEST OF THE TROPICAL CYCLONE
SHOULD CAUSE THE SYSTEM TO ACCELERATE NORTHEASTWARD OVER THE NEXT
COUPLE OF DAYS.  THE OFFICIAL FORECAST IS AN EXTENSION OF THE
PREVIOUS ONE AND IS MORE OR LESS IN THE MIDDLE OF THE DYNAMICAL
TRACK MODEL GUIDANCE.  THIS FORECAST TRACK KEEPS THE COMPACT
CYCLONE WELL OFFSHORE OF THE U.S. EAST COAST. 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  21/2100Z 30.5N  77.9W   35 KT  40 MPH
 12H  22/0600Z 31.7N  76.4W   35 KT  40 MPH
 24H  22/1800Z 33.4N  74.3W   30 KT  35 MPH
 36H  23/0600Z 35.4N  71.7W   30 KT  35 MPH
 48H  23/1800Z 37.5N  69.0W   25 KT  30 MPH...POST-TROP/EXTRATROP
 72H  24/1800Z...DISSIPATED
 
$$
FORECASTER PASCH
 

WTNT41 KNHC 220232
TCDAT1
 
TROPICAL DEPRESSION ALBERTO DISCUSSION NUMBER  10
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL012012
1100 PM EDT MON MAY 21 2012
 
STRONG SOUTHWESTERLY VERTICAL WIND SHEAR IS FINALLY TAKING ITS TOLL
ON ALBERTO. THE ONLY DEEP CONVECTION REMAINING IS RESTRICTED TO THE
NORTHEAST QUADRANT OF THE DEPRESSION AND BARELY MEETS THE CRITERIA
TO KEEP ALBERTO CLASSIFIED AS A TROPICAL CYCLONE. THE INITIAL
INTENSITY IS LOWERED TO 30 KT BASED ON SATELLITE INTENSITY
ESTIMATES OF T2.0 FROM TAFB AND T1.5 FROM SAB. THE LAST RECON PASS
THROUGH ALBERTO AROUND 21Z INDICATED THE STRONGEST SURFACE AND
FLIGHT-LEVEL WINDS WERE LOCATED IN THE SOUTHEAST QUADRANT...AND THE
LACK OF CONVECTION IN THAT PART OF THE CYCLONE FURTHER JUSTIFIES 
DOWNGRADING ALBERTO TO DEPRESSION STATUS. NOAA BUOY 41002 DIRECTLY
AHEAD OF ALBERTO SHOULD PROVIDE SOME GROUND TRUTH LATER TONIGHT.

THE INITIAL MOTION ESTIMATE IS 065/11. ALTHOUGH ALBERTO HAS BEEN
MOVING MORE EASTWARD OVER THE PAST 6 HOURS...THE CYCLONE APPEARS TO
BE STARTING TO GAIN SOME LATITUDE. THE NEW TRACK FORECAST HAS BEEN
SHIFTED TO THE EAST OF THE PREVIOUS ADVISORY DUE TO THE MORE
EASTWARD INITIAL POSITION. OTHERWISE THERE IS NO CHANGE TO THE
PREVIOUS FORECAST REASONING. A DEEPENING MID-LEVEL TROUGH OVER THE
SOUTHEASTERN U.S. IS FORECAST TO MOVE TO THE MID-ATLANTIC REGION
DURING THE NEXT COUPLE OF DAYS...WHICH SHOULD CAUSE ALBERTO TO
GRADUALLY ACCELERATE TO THE NORTHEAST. THE OFFICIAL TRACK FORECAST
IS CLOSE TO A BLEND OF THE ECMWF...UKMET...AND GFS MODELS...WHICH
KEEP THE CYCLONE WELL OFFSHORE OF THE U.S. EAST COAST.
 
INCREASING VERTICAL WIND SHEAR OF MORE THAN 50 KT AHEAD OF THE
AFOREMENTIONED DEEPENING TROUGH...ALONG WITH SSTS DECREASING TO
LESS THAN 22C...SHOULD CONTINUE THE RECENT WEAKENING TREND...AND IT
IS POSSIBLE THAT ALBERTO COULD DEGENERATE INTO A POST-TROPICAL
CYCLONE SOONER THAN INDICATED IN THE OFFICIAL INTENSITY FORECAST.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  22/0300Z 30.9N  76.5W   30 KT  35 MPH
 12H  22/1200Z 32.1N  75.0W   30 KT  35 MPH
 24H  23/0000Z 34.2N  72.4W   30 KT  35 MPH
 36H  23/1200Z 36.3N  70.0W   25 KT  30 MPH...POST-TROP/EXTRATROP
 48H  24/0000Z 38.3N  67.2W   25 KT  30 MPH...POST-TROP/EXTRATROP
 72H  25/0000Z...DISSIPATED
 
$$
FORECASTER STEWART
 

WTNT41 KNHC 220843
TCDAT1
 
TROPICAL DEPRESSION ALBERTO DISCUSSION NUMBER  11
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL012012
500 AM EDT TUE MAY 22 2012
 
GOES-E SHORTWAVE AND ENHANCED BD-CURVE INFRARED IMAGERY SHOW BANDING
REDEVELOPMENT DURING THE PAST 6 HOURS OVER THE NORTHERN PORTION OF
THE CYCLONE.  ALTHOUGH THIS DEEP CONVECTIVE BAND IS MORE THAN
LIKELY TEMPORARY...GIVEN THE HOSTILE WIND SHEAR ENVIRONMENT...I
HAVE ELECTED TO MAINTAIN ALBERTO AS A TROPICAL DEPRESSION FOR THIS
ADVISORY.  NOAA BUOY 41002 LOCATED ABOUT 65 NMI EAST-NORTHEAST OF
THE CENTER OF CIRCULATION REPORTED A PEAK 1-MINUTE WIND OF 33 KT.
STRONG 50-60 KT VERTICAL WIND SHEAR AND DECREASING SEA SURFACE
TEMPERATURES OF 22 DEGREES CELSIUS OR LESS SHOULD PROMOTE FURTHER
WEAKENING AND ULTIMATELY DISSIPATION IN ABOUT 2 DAYS.
 
THE INITIAL MOTION ESTIMATE IS 045/13.  THE DEPRESSION IS EXPECTED
TO ACCELERATE NORTHEASTWARD DURING THE NEXT 36-48 HOURS BEFORE
DISSIPATION IN RESPONSE TO AN AMPLIFYING MID-LEVEL TROUGH OVER THE
EASTERN UNITED STATES.  THE OFFICIAL FORECAST IS CLOSE TO THE
PREVIOUS FORECAST TRACK AND THE GLOBAL MODEL CONSENSUS...ALL OF
WHICH SHOW DISSIPATION IN LESS THAN 48 HOURS.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  22/0900Z 32.0N  75.5W   30 KT  35 MPH
 12H  22/1800Z 33.4N  73.8W   30 KT  35 MPH
 24H  23/0600Z 35.5N  71.1W   30 KT  35 MPH...POST-TROP/REMNT LOW
 36H  23/1800Z 37.5N  68.0W   25 KT  30 MPH...POST-TROP/REMNT LOW
 48H  24/0600Z...DISSIPATED
 
$$
FORECASTER ROBERTS
 

