[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 152330
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT SUN APR 15 2012

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF
SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE
EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE
IMAGERY...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL
ANALYSIS.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 2315 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM THE WEST AFRICAN COAST OF
LIBERIA NEAR 6N10W TO 3N17W...WHERE THE ITCZ CONTINUES ALONG THE
EQUATOR NEAR 30W TO THE COAST OF BRAZIL NEAR 3S40W. SCATTERED
WEAK TO ISOLATED MODERATE CONVECTIVE PRECIPITATION IS WITHIN
150-200 NM ON EITHER SIDE OF THE ITCZ.

...DISCUSSION...

GULF OF MEXICO...
WATER VAPOR IMAGERY DISPLAYS DRY AIR AND STRONG SUBSIDENCE ALOFT
ACROSS THE DISCUSSION AREA THIS EVENING...ANCHORED BY A STRONG
1029 MB CENTERED OVER THE WRN ATLC BASIN. THE SURFACE RIDGE AXIS
ASSOCIATED TO THIS HIGH PRESSURE SYSTEM EXTENDS WSW INTO THE
AREA...AND TOGETHER WITH A STRONG LOW PRESSURE SYSTEM OVER THE
GREAT PLAINS...IS GENERATING A MODERATE E-W PRESSURE GRADIENT
OVER THE GULF WITH 15-25 KT SSE WINDS ACROSS THE BASIN WITH JUST
A LINE OF HEAVY SHOWERS AND ISOLATED THUNDERSTORMS IS HEADING N
AGAINST THE COAST OF THE WRN FLORIDA PANHANDLE AND ALABAMA.
SHORT RANGE COMPUTER MODELS SUGGEST THE PRESSURE GRADIENT
BETWEEN THE STRONG SURFACE LOW AND RIDGE ACROSS THE GULF WILL
PERSIST UNTIL MONDAY WHEN THE GRADIENT WILL BEGIN TO RELAX
GRADUALLY DUE TO A WEAK FRONTAL BOUNDARY EMERGING OFF THE TEXAS
AND LOUISIANA COASTS. WEAK FRONTAL TROUGHING WILL REMAIN ACROSS
THE NORTHERN GULF THROUGH TUESDAY INTO WEDNESDAY WITH WINDS
GENERALLY IN THE RANGE OF 10 TO 15 KT.

CARIBBEAN SEA...
WATER VAPOR IMAGERY SHOWS MODERATE TO STRONG SUBSIDENCE AND DRY
AIR ALOFT OVER A GREAT PORTION OF THE DISCUSSION AREA THIS
EVENING. HOWEVER...THE SRN EXTENSION OF A COLD FRONT ENTERS THE
NE BASIN ACROSS THE LEEWARD ISLANDS THROUGH THE ISLAND OF
MONTSERRAT...AND QUICKLY BECOMES A SHEAR AXIS EXTENDING TO THE
NRN COASTAL WATERS OF COLOMBIA NEAR 13N74W. MODERATE TO HEAVY
SHOWERS AND ISOLATED THUNDERSTORMS ARE WITHIN 75 NM ON EITHER
SIDE OF THE AXIS. SIMILAR CONVECTION IS NOTICED S OF JAMAICA
FROM 14N TO THIS ISLAND BETWEEN 75W-81W. OTHERWISE...ENE
TRADEWIND FLOW OF 10-20 KTS IS REPORTED ACROSS THE AREA...WITH
STRONGER NE FLOW FILTERING THROUGH THE WINDWARD AND MONA
PASSAGES AS THE PRESSURE GRADIENT STRENGTHENS TO THE NORTH OVER
THE SW NORTH ATLC.

ATLANTIC OCEAN...
AN UPPER LEVEL TROUGH CONTINUES TO MOVE ACROSS THE CENTRAL ATLC
THIS EVENING. WATER VAPOR IMAGERY SHOWS A VIGOROUS SHORTWAVE
EMBEDDED AT THE BASE OF THE UPPER TROUGH SUPPORTING AN OCCLUDED
1012 MB LOW CENTERED NEAR 31N51W. A COLD FRONT EXTENDS SSW FROM
ITS TRIPLE POINT INTO THE DISCUSSION AREA ALONG 32N48W 24N51W
INTO THE FAR NE CENTRAL CARIBBEAN SEA ALONG THE ISLAND OF
MONTSERRAT. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS
WITHIN 80-150 NM AHEAD OF THE COLD FRONT...BECOMING STRONGER N
OF 23N WHERE LOW LEVEL CONVERGENCE AND UPPER LEVEL DIFFLUENCE IS
MAXIMIZED. HIGH PRESSURE CONTINUES TO BUILD BEHIND THE FRONT AS
A 1029 MB HIGH CENTERED NEAR 32N70W IS FORECAST TO REMAIN IN
CONTROL THROUGH WEDNESDAY. COMPUTER MODELS SUGGEST THE FRONT
WILL CONTINUE TO EXPAND E OVER THE NEXT 24 HOURS AND BEGIN TO
STALL DURING THE NEXT 24-48 HOURS. FAIR WEATHER CONDITIONS ARE
FOUND ELSEWHERE AHEAD OF THE FRONTAL CONVECTION...ASSOCIATED TO
A STRONG SURFACE RIDGE ANCHORED BY A 1033 MB HIGH CENTERED N OF
THE AZORES NEAR 40N27W.

FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE

$$

GARCIA



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