[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 272250
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT SUN APR 27 2008

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

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2230 UTC.

...THE ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 6N11W 3N20W 1N30W 1N40W...
CROSSING THE EQUATOR NEAR 44W...AND INTO NE BRAZIL NEAR 1S48W.
SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FROM 2S-4N
BETWEEN 19W-29W. SCATTERED MODERATE CONVECTION IS N OF THE AXIS
TO 3N W OF 44W AND INLAND OVER SOUTH AMERICA.

...DISCUSSION...

GULF OF MEXICO...
A COLD FRONT HAS ENTERED THE FAR NW GULF THIS AFTERNOON. AS OF
21Z...THE BOUNDARY EXTENDED FROM THE LOUISIANA COAST NEAR 30N93W
ALONG 28N95W TO THE TEXAS COAST SOUTH OF CORPUS CHRISTI NEAR
27N97W. SATELLITE IMAGERY...LIGHTNING DATA...AND DOPPLER RADAR
MOSAIC INDICATE NUMEROUS SHOWERS AND THUNDERSTORMS AHEAD OF THE
FRONT. A SECOND BAND OF CONVECTION WITH EMBEDDED THUNDERSTORMS
SURROUNDS A PRE-FRONTAL TROUGH THAT STRETCHES FROM THE
FLORIDA/ALABAMA BORDER ALONG 28N90W TO 26N94W. THE CONVECTION IS
CONFINED TO THE NW AND CENTRAL GULF NW OF A LINE FROM THE
TEXAS/MEXICO BORDER TO THE FLORIDA PANHANDLE NEAR APALACHICOLA.
THIS CONVECTIVE ACTIVITY IS ENHANCED BY A DIFFLUENT PATTERN
ALOFT BETWEEN AN UPPER RIDGE COVERING THE ENTIRE GULF AND AN
UPPER TROUGH OVER THE CENTRAL CONUS. BEHIND THE FRONT...WINDS
SHIFT N AND INCREASE TO 20 TO 30 KT...WITH GALE CONDITIONS
EXPECTED OFF THE MEXICAN COAST IN THE SW GULF LATER TONIGHT.
EXPECT THE FRONT TO MOVE SE OF THE AREA BY TUE. A 1009 MB SFC
LOW REMAINS OVER MEXICO JUST SOUTH OF THE BAY OF CAMPECHE WITH A
SFC TROUGH EXTENDING NORTHWARD TO NEAR 21N95W. THIS FEATURE IS
MAINLY DRY IN NATURE WITH THE TROUGH INDICATING A WIND SHIFT
BETWEEN LIGHT N WINDS TO THE WEST AND MODERATE SE WINDS TO THE
EAST. THE REMAINDER OF THE GULF IS UNDER MOSTLY CLEAR SKIES AND
MODERATE S TO SE RETURN FLOW AROUND A 1022 MB SFC HIGH IN THE W
ATLC.

CARIBBEAN SEA...
MULTILAYERED CLOUDS AND SHOWERS REMAIN OVER THE EASTERN
CARIBBEAN E OF 75W AND N OF 15N. THIS CONVECTION IS ASSOCIATED
WITH A WESTWARD MOVING SURFACE TROUGH...ANALYZED FROM THE MONA
PASSAGE TO THE NETHERLANDS ANTILLES ALONG 68W AT 18Z...AND A
MID/UPPER LEVEL TROUGH LOCATED OVER THE WEST-CENTRAL ATLC JUST N
OF PUERTO RICO. SAN JUAN DOPPLER RADAR INDICATES NUMEROUS
SHOWERS MOVING NORTHWESTWARD OVER PUERTO RICO AND THE VIRGIN
ISLANDS WITH MOST OF THE ACTIVITY OVER THE MONA PASSAGE AND N OF
THE ISLANDS. LIGHT TO MODERATE TRADEWINDS DOMINATE THE WESTERN
CARIBBEAN WITH MOSTLY FAIR WEATHER W OF 75W DUE TO THE PRESENCE
OF A MID/UPPER LEVEL RIDGE AND IMPLIED DRY AIR MASS. LOW-TOPPED
TRADE WIND SHOWERS CONTINUE TO MOVE ACROSS THE AREA. SWLY UPPER
FLOW IS ADVECTING UPPER LEVEL MOISTURE/HIGH CLOUDS FROM THE
TROPICAL PACIFIC OVER THE SW CARIBBEAN.

ATLANTIC OCEAN...
A 1022 MB SFC HIGH CENTERED NEAR 30N72W IS MAINTAINING TRANQUIL
CONDITIONS OVER THE W ATLC. THE CENTRAL ATLC IS DOMINATED BY A
DEEP LAYERED TROUGH WITH A COLD FRONT ENTERING THE REGION NEAR
31N46W AND EXTENDING ALONG 25N78W TO 21N54W WHERE IT CONTINUES
AS A SFC TROUGH TO NEAR 19N63W. A WIDE BAND OF ASSOCIATED
MULTILAYERED CLOUDS AND SCATTERED SHOWERS EXTENDS UP TO 230 NM
BEHIND THE BOUNDARY MOSTLY S OF 27N. WITHIN 180 NM AHEAD OF THE
FRONT AND N OF 27N...WINDS ARE S TO SW TO 20 KT. WINDS SHIFT W
20 TO 25 KT BEHIND THE FRONT N OF 28N. THE EAST ATLC IS
DOMINATED BY A SFC RIDGE ANCHORED BY A A 1029 MB SFC HIGH OVER
THE AZORES.

$$
WADDINGTON





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