Tropical Storm LISA Discussion 39 11PM EDT

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Tropical Storm LISA

 

 

000

WTNT43 KNHC 290229

TCDAT3

TROPICAL STORM LISA DISCUSSION NUMBER 39

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL

11 PM EDT TUE SEP 28 2004

 

VARIOUS SATELLITE SOURCES INDICATE LISA HAS BECOME A LITTLE BETTER

ORGANIZED AND HAS STRENGTHENED. A 28/1936Z TRMM OVERPASS INDCIATED

A NICE MID-LEVEL EYE FEATURE THAT WAS STILL SHEARED ABOUT 30 NMI TO

THE NORTHEAST OF THE LOW-LEVEL CENTER. A 28/2115Z HI-RES QUIKSCAT

OVERPASS REVEALED A SEVERAL RAINFLAGGED WINDS OF 60-70 KT AND A

28/1708Z CIRA/AMSU OVERPASS PROVIDED A PRESSURE OF 991 MB AND

SURFACE WIND ESTIMATE OF 59 KT. THE INITIAL INTENSITY OF 55 KT IS

BASED ON A COMBINATION OF THE MICROWAVE DATA AND A DVORAK SATELLITE

ESTIMATE OF T3.5...OR 55 KT FROM TAFB.

 

THE INITIAL MOTION ESTIMATE IS 360/11. LISA IS EXPECTED TO MOVE

NORTH TO NORTHWESTWARD FOR THE NEXT 36 HOURS OR SO AROUND THE

WESTERN PERIPHERY OF A SUBTROPICAL RIDGE LOCATED ALONG 30-32N

LATITUDE. BY 48-72 HOURS...AN APPROACHING MID-LEVEL SHORTWAVE

TROUGH IS EXPECTED TO TURN LISA MORE NORTHEASTWARD AND BRING ABOUT

RECURVATURE AROUND THE NORTH SIDE OF THE RIDGE. IN 96-120 HOURS...

LISA IS EXPECTED TO BE CAPTURED BY THE SHORTWAVE TROUGH AND BECOME

EXTRATROPICAL...OR EVEN MERGE WITH ANOTHER EXTRATROPICAL LOW. THE

NHC MODEL GUIDANCE IS IN GOOD AGREEMENT ON THIS EVOLVING SCENARIO.

 

LISA REMAINS A RATHER TENACIOUS TROPICAL CYCLONE BY DEVELOPING A

NICE MID-LEVEL EYE FEATURE DESPITE RATHER STRONG VERTICAL SHEAR.

THE VERTICAL SHEAR ACROSS LISA HAS BEEN SLOWLY DECREASING AND THE

SHIPS MODEL IS FORECASTING THE SHEAR TO DECREASE TO LESS THAN 5 KT

IN THE 24-72 HOUR PERIOD. LISA IS EXPECTED TO REMAIN OVER 26C OR

HIGHER SSTS THROUGH 36 HOURS...SO SOME SLOW STRENGTHENING IS

FORECAST. AFTER 36 HOURS...LISA IS EXPECTED TO MOVE OVER SUB-25C

SSTS AND SLOW WEAKENING IS FORECAST TO OCCUR. THE OFFICIAL

INTENSITY FORECAST IS SLIGHTLY LOWER THAN THE SHIPS MODEL FORECAST.

 

FORECASTER STEWART

 

FORECAST POSITIONS AND MAX WINDS

 

INITIAL 29/0300Z 27.0N 46.5W 55 KT

12HR VT 29/1200Z 28.7N 46.7W 55 KT

24HR VT 30/0000Z 30.5N 47.3W 60 KT

36HR VT 30/1200Z 32.3N 48.2W 65 KT

48HR VT 01/0000Z 34.0N 48.7W 60 KT

72HR VT 02/0000Z 38.0N 47.0W 60 KT

96HR VT 03/0000Z 41.0N 42.0W 55 KT...BECOMING EXTRATROPICAL

120HR VT 04/0000Z 43.5N 32.0W 50 KT...EXTRATROPICAL

 

 

$$