[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 231043
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT MON APR 23 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1015 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS W AFRICA INTO THE E TROPICAL
ATLC NEAR 9N13W TO 5N16W WHERE THE ITCZ CONTINUES ALONG 2N23W
2N32W THEN S OF THE EQUATOR NEAR 40W. CLUSTERS OF SCATTERED
MODERATE/ISOLATED STRONG CONVECTION ARE FROM 5N TO JUST S OF THE
EQUATOR E OF 30W ACROSS THE PRIME MERIDIAN AND FROM 7N TO THE
EQUATOR BETWEEN 30W-40W.

...DISCUSSION...

GULF OF MEXICO...
BROAD UPPER TROUGH DOMINATES THE GULF INTO THE W ATLC SUPPORTING
A REINFORCING COLD FRONT THAT EXTENDS AT 23/0900 UTC FROM A 1009
MB LOW E OF TALLAHASSEE FLORIDA INTO THE GULF ALONG 27N90W TO
INLAND OVER TEXAS JUST N OF CORPUS CHRISTI. STRONG SUBSIDENCE A
DRY STABLE AIR ALSO DOMINATE THE GULF. HOWEVER...LOW LEVEL
MOISTURE IS GIVING THE NE GULF ISOLATED SHOWERS WITHIN 120 NM S
OF THE FRONT BETWEEN 85W-89W. A WEAK SURFACE RIDGE COVERS THE W
GULF ANCHORED BY A 1018 MB HIGH NEAR 24N97W LEAVING THE
REMAINDER OF THE GULF WITH MOSTLY CLEAR SKIES THIS MORNING. THE
DRY REINFORCING COLD FRONT WILL QUICKLY MOVE SE ACROSS THE GULF
THROUGH TONIGHT. FRESH TO STRONG NORTHERLY WINDS WILL PERSIST IN
THE WAKE OF THE FRONT OVER MUCH OF THE MID AND E PORTION THROUGH
TONIGHT. WINDS WILL SLOWLY DIMINISH OVER THE W GULF THROUGH
TONIGHT. INCREASING SE FLOW WILL RETURN TO THE FAR WESTERN
PORTION BEGINNING ON TUE AND SPREADING E ACROSS THE ENTIRE GULF
BY LATE WED AS A RIDGE DEVELOPS FROM CENTRAL FLORIDA TO THE
TEXAS COAST.

CARIBBEAN SEA...
THE UPPER TROUGH OVER THE GULF OF MEXICO AND W ATLC DIPS S OVER
THE NW CARIBBEAN SUPPORTING A COLD FRONT THAT EXTENDS FROM THE W
ATLC ACROSS E CUBA NEAR SANTIAGO DE CUBA THEN OVER JAMAICA TO
11N81W THEN W INTO COSTA RICA NEAR THE NICARAGUA BORDER.
SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE WITHIN
180 NM E OF THE FRONT N OF 17N INCLUDING PORTIONS OF JAMAICA...
CUBA...HAITI...AND THE WINDWARD PASSAGE. STRONG SUBSIDENCE AND
DRY AIR ALOFT ARE OVER THE NW CARIBBEAN W OF THE FRONT.
HOWEVER...LOW LEVEL MOISTURE IS GENERATING ISOLATED SHOWERS IN
THE GULF OF HONDURAS S OF 19N W OF 83W. A BROAD UPPER RIDGE
DOMINATES THE REMAINDER OF THE CARIBBEAN BASIN ANCHORED OVER E
VENEZUELA. THE CONVERGENCE OF UPPER AND LOWER LEVEL FLOW IS
GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS INLAND AND
WITHIN 75 NM OF THE COAST OF PANAMA AND COSTA RICA WITH
SCATTERED SHOWERS WITHIN 90 NM ALONG THE COAST OF VENEZUELA AND
COLOMBIA. THIS IS LEAVING THE REMAINDER OF THE CARIBBEAN E OF
74W WITH MOSTLY CLEAR SKIES THIS MORNING. THE COLD FRONT WILL
GRADUALLY WEAKEN REACHING FROM NEAR NW HAITI TO 12N79W EARLY
TONIGHT...AND FROM HAITI TO 12N79W BY EARLY TUE EVENING THEN
LINGER AS FRONTAL TROUGH OVER THE N CENTRAL WATERS THROUGH THU
AS IT BEGINS TO MOVE BACK W. FRESH TO STRONG NW TO N WINDS
BEHIND THE FRONT WILL DIMINISH TUE. WINDS BECOME NE AND E AND
INCREASE IN THE FAR NORTHERN WATERS W OF HISPANIOLA BEGINNING
TUE AFTERNOON AND INTO FRI AS THE PRES GRADIENT TIGHTENS.
ELSEWHERE LIGHT EASTERLY TRADES WILL CONTINUE THROUGH FRI.

ATLANTIC OCEAN...
THE BROAD UPPER TROUGH OVER THE GULF OF MEXICO EXTENDS INTO THE
W ATLC SUPPORTING A COMPLEX SYSTEM WITH A COLD FRONT ENTERING
THE W ATLC AT 23/0900 UTC NEAR 32N69W EXTENDING ALONG 27N69W
ACROSS CUBA NEAR SANTIAGO DE CUBA INTO THE W CARIBBEAN.
SCATTERED SHOWERS/THUNDERSTORMS ARE WITHIN 180 NM E OF THE FRONT
N OF 25N WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN
150 NM E OF THE REMINDER OF THE FRONT. A NEWLY DEVELOPED
REINFORCING COLD FRONT AT 23/0900 UTC IS TO THE NW ENTERING THE
REGION NEAR 32N75W TO 27N78W WITH ISOLATED SHOWERS WITHIN 75 NM
EITHER SIDE OF THIS REINFORCING FRONT. THE UPPER RIDGE OVER THE
CARIBBEAN EXTENDS A RIDGE AXIS ACROSS THE VIRGIN ISLANDS TO
BEYOND 32N60W FURTHER ENHANCING THE ACTIVITY ASSOCIATED WITH THE
LEADING COLD FRONT. A SURFACE RIDGE COVERS THE W/CENTRAL ATLC
ANCHORED BY A 1022 MB HIGH ABOUT 625 NM NE OF BERMUDA. AN UPPER
TROUGH DOMINATES THE REMAINDER OF THE CENTRAL ATLC N OF 10N
BETWEEN 35W-55W SUPPORTING A STATIONARY FRONT THAT EXTENDS TO
31N41W THEN DISSIPATES TO 24N46W GENERATING SCATTERED SHOWERS/
ISOLATED THUNDERSTORMS WITHIN 75 NM EITHER SIDE OF THIS FRONT. A
BROAD SURFACE RIDGE COVERS THE E ATLC ANCHORED BY A 1030 MB HIGH
OVER THE AZORES. THIS IS GIVING THE REMAINDER OF THE ATLC FAIR
WEATHER THIS MORNING. THE W ATLC COLD FRONT WILL REACH A
POSITION FROM NEAR 31N68W TO THE WINDWARD PASSAGE EARLY TONIGHT
AND FROM NEAR 26N65W TO HAITI BY EARLY TUE EVENING THEN BEGIN TO
WEAKEN INTO A TROUGH OVER THE CENTRAL ATLC LATE WED AND THU AS
IT BEGINS TO MOVE BACK W INTO FRI. THE DRY REINFORCING COLD
FRONT WILL QUICKLY MOVE FROM THE GULF OF MEXICO ACROSS THE N
WATERS THROUGH WED. HIGH PRESSURE WILL SHIFT E FROM FLORIDA
ACROSS THE CENTRAL WATERS WED AND THU...AND TO THE FAR NE
PORTION FRI. NE TO E WINDS INCREASE OVER THE SOUTHERN PORTION
BEGINNING LATE WED AND INTO FRI.


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

$$
PAW





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