[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 251134
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST THU FEB 25 2010

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...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND
RADAR.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1115 UTC.

...ITCZ...
THE ITCZ AXIS IS CENTERED ALONG 7N11W 4N24W CROSSING THE EQUATOR
AT 38W THEN INLAND OVER NE BRAZIL NEAR 1S50W. SCATTERED MODERATE
TO ISOLATED STRONG CONVECTION IS WITHIN 140 NM S OF AXIS E OF
20W.

...DISCUSSION...

GULF OF MEXICO...
HIGH PRES CONTINUES TO BUILD ACROSS THE GULF REGION IN THE WAKE
OF A STRONG COLD FRONT CURRENTLY MOVING OVER EASTERN CUBA. FRESH
TO STRONG NLY WINDS ARE STILL NOTED OVER MOST OF THE AREA PER
SURFACE DATA AND A RECENT ASCAT PASS. CONVECTIVE CLOUDS STREETS
ARE FORMING PARALLEL TO THESE WINDS DUE TO THE ADVECTION OF COLD
AIR OVER RELATIVELY WARM WATERS. CLEARING IS ALREADY OCCURRING
OVER THE N WATERS PARTICULARLY N OF 28N. HIGH PRES WILL MOVE EWD
TODAY ALLOWING SLY RETURN FLOW TO SET UP OVER THE WESTERN GULF
THIS EVENING AHEAD OF THE NEXT COLD FRONT EXPECTED TO PUSH SE
OFF THE COAST OF TEXAS FRI AFTERNOON. NLY WINDS OF 20 TO 30 KT
WILL ALSO FOLLOW THE NEW COLD FRONT. A LOW MAY DEVELOP ALONG THE
FRONTAL BOUNDARY OVER THE N GULF WATERS EARLY SATURDAY AND MOVE
EWD TOWARD THE FLORIDA PENINSULA LATE SAT. A DEEP LAYER TROUGH
EXTENDING FROM THE GREAT LAKES REGION TO THE NW PORTION OF THE
GULF SUPPORTS THE ABOVE MENTIONED COLD FRONT. SWLY WINDS AHEAD
OF THIS UPPER-LEVEL TROUGH ARE ADVECTING MID TO UPPER LEVEL
MOISTURE FROM THE EPAC ACROSS SOUTHERN MEXICO AND THE YUCATAN
PENINSULA INTO SE FLORIDA AND THE W ATLC. MODERATE TO STRONG
SUBSIDENCE IS NOTED OVER MUCH OF THE GULF.

CARIBBEAN SEA...
AT 25/0900 UTC...A COLD FRONT EXTENDS FROM EASTERN CUBA...NEAR
THE CITY OF CAMAGUEY TO NE HONDURAS. NW WINDS OF 20 TO 30 KT ARE
OBSERVED OVER THE WESTERN CARIBBEAN BEHIND THE FRONT INCLUDING
THE YUCATAN CHANNEL. A PRE-FRONTAL TROUGH IS ANALYZED FROM NEAR
SANTA CRUZ DEL SUR CAMAGUEY TO NEAR 13N82W. A BAND OF SHOWERS
AND TSTMS IS WITHIN AROUND 90 NM JUST AHEAD OF THE TROUGH AXIS N
OF 17.5N. PART OF THIS CONVECTIVE ACTIVITY IS AFFECTING EASTERN
CUBA AND THE WESTERN PORTION OF JAMAICA. MONTEGO BAY REPORTED
+TSRA WITH GUSTY WINDS OF 31 KT. CONVECTION NEAR THE SOUTHERN
END OF THE TROUGH AXIS OVER HONDURAS HAS DIMINISHED...AND NOW
SOME SHOWERS WITH ISOLATED TSTMS ARE DEVELOPING OVER CENTRAL
NICARAGUA. A DIFFLUENT PATTERN ALOFT BETWEEN THE UPPER-LEVEL
TROUGH ACROSS THE NW GULF OF MEXICO AND AN UPPER-LEVEL HIGH
CENTERED OVER COLOMBIA EXTENDING A RIDGE NWD ALONG 69W-70W IS
HELPING TO INDUCE THIS CONVECTIVE ACTIVITY. DUE TO THE PRESENCE
OF THE COLD FRONT AND THE PRE-FRONTAL TROUGH OVER THE WESTERN-
CENTRAL CARIBBEAN...THE TRADE WINDS CONTINUE TO ABATE MAINLY
NEAR THE COAST OF COLOMBIA WHERE ONLY NE WINDS OF 10 KT ARE
SEEN. ELY WINDS OF 10 TO 15 KT ARE BLOWING ACROSS THE EASTERN
CARIBBEAN. THE COLD FRONT AND THE PRE-FRONTAL TROUGH WILL MERGE
AND THE COLD FRONT WILL MOVE TO A POSITION FROM THE WINDWARD
PASSAGE TO COSTA RICA EARLY THIS AFTERNOON THEN WILL CROSS
HISPANIOLA THIS EVENING AND TONIGHT AFFECTING PUERTO RICO ON
FRI. A SURFACE TROUGH... REMNANTS OF AN OLD FRONTAL BOUNDARY
EXTENDS FROM A 1009 MB LOW PRES LOCATED NEAR 22N56W TO NEAR
ANTIGUA IN THE LEEWARD ISLANDS. A NARROW BAND OF LOW TO MID
CLOUDS WITH EMBEDDED SHOWERS IS ASSOCIATED WITH THIS TROUGH. THE
LOW PRES WILL MOVE EWD AND DISSIPATE DRAGGING THE TROUGH AWAY
FROM THIS AREA LATE TODAY.

ATLANTIC OCEAN...
A COLD FRONT ENTERS THE FORECAST REGION NEAR 31N74W THEN
CONTINUES SW ACROSS THE CENTRAL BAHAMAS AND EASTERN CUBA INTO
THE CARIBBEAN SEA. HIGH PRES BUILDING OVER THE FLORIDA PENINSULA
AND THE NW BAHAMAS WILL BRING WITH IT MUCH COLDER TEMPERATURES
THROUGH FRIDAY. THE AREA OF SHOWERS WITH EMBEDDED TSTMS THAT WAS
PREVIOUSLY AFFECTING THE CENTRAL BAHAMAS HAS MOVED EWD AHEAD OF
THE FRONT AND NOW COVERS THE REGION FROM 24N-25.5N BETWEEN 71W
AND 73W. A WEAK 1015 MB HIGH IS EAST OF THE FRONT NEAR 25N64W.
THIS SYSTEM WILL DISSIPATE DURING THE NEXT 24 HOURS AS THE FRONT
CONTINUES TO MOVE SE ACROSS THE SW N ATLC AND THE SE BAHAMAS. A
1004 MB LOW PRES IS NEAR 31N55W WITH A TROUGH EXTENDING TO
ANOTHER LOW PRES SYSTEM LOCATED NEAR 22N56W. SEE THE CARIBBEAN
SECTION FOR MORE DETAILS. A MUCH EARLIER ASCAT PASS SHOWED VERY
WELL THE CYCLONIC CIRCULATION ASSOCIATED WITH THE LOW NEAR
31N55W WHICH IS FORECAST TO MOVE ESE TO NEAR 28N31W IN ABOUT 24
HOURS. THE GFS COMPUTER MODEL SUGGESTS SW TO W WINDS NEAR GALE
FORCE ASSOCIATED WITH THIS DEEPENING LOW PRES THAT WILL APPROACH
THE MADEIRA AND CANARY ISLANDS LATE FRI. A BROAD BUT WEAK
SURFACE RIDGE EXTENDS FROM OVER THE E ATLC INTO THE REMAINDER OF
THE CENTRAL ATLC ANCHORED BY A 1017 MB HIGH CENTERED JUST W OF
THE CANARY ISLANDS NEAR 26N21W. THIS FEATURE WILL MOVE NE IN THE
NEXT 24 HOURS. IN THE UPPER LEVELS...A RIDGE/TROUGH/RIDGE
PATTERN DOMINATES THE FORECAST AREA.

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

$$
GR







This weather bulletin was brought to you by:
www.nashvilleweather.net