000
AXNT20 KNHC 221124
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST SUN FEB 22 2009

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...

ITCZ AXIS IS CENTERED ALONG 4N8W EQ20W 1N35W INTO NE BRAZIL NEAR 
2N48W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FROM 
2S-1N BETWEEN 42W-47W. ISOLATED MODERATE CONVECTION IS NEAR 
EQ28W...AND NEAR 1.5N15W. A CLUSTER OF MODERATE TO STRONG 
CONVECTION IS FROM EQ-3N BETWEEN THE PRIME MERIDIAN AND 4W.

...DISCUSSION...

GULF OF MEXICO...
A COLD FRONT MOVED OFF THE TEXAS COAST SATURDAY EVENING. AS OF 
09Z...THE FRONT EXTENDS ACROSS THE SE CONUS ENTERING THE GULF 
REGION THROUGH SE ALABAMA AND THE W FLORIDA PANHANDLE THEN 
CONTINUING SW TO JUST SOUTH OF TAMPICO MEXICO. THE CITY OF 
TAMPICO HAS REPORTED A WIND GUST OF 30 KT WITH THE PASSAGE OF 
THE FRONT. A WIDE BAND OF MULTI-LAYERED CLOUDS WITH EMBEDDED 
SHOWERS AND SCATTERED TSTMS IS ASSOCIATED WITH THE FRONTAL ZONE. 
FRESH TO STRONG NLY WINDS ARE BLOWING IN THE WAKE OF THE 
FRONT...EXPECTED TO REACH GALE FORCE OVER THE SW GULF AROUND 
1200 UTC. AN EARLIER ASCAT PASS SHOWED NORTH WINDS OF 20-30 KT 
BEHIND THE FRONT. THESE STRONG WINDS WILL FUNNEL THROUGH THE 
ISTHMUS OF TEHUANTEPEC PRODUCING A GAP WIND EVENT ON THE EPAC 
SIDE FORECAST TO LIKELY REACH STORM FORCE. THE COLD FRONT IS 
EXPECTED TO PASS THROUGH MUCH OF THE GULF TONIGHT WITH THE 
FRONTAL BOUNDARY EXTENDING FROM SOUTH FLORIDA THROUGH THE 
YUCATAN CHANNEL AND SE MEXICO AT 00Z MON. A 1024 MB HIGH 
SITUATED OVER THE EASTERN GULF NEAR 28N84W HAS A RIDGE EXTENDING 
SW TOWARDS THE YUCATAN PENINSULA. THIS RIDGE ALSO ENVELOPS THE 
FLORIDA PENINSULA. ALOFT...A LONG-WAVE TROUGH EXTENDING FROM 
GREAT LAKES REGION SOUTH ACROSS E TEXAS AND NE MEXICO SUPPORTS 
THE ABOVE MENTIONED COLD FRONT. THIS TROUGH WILL MOVE EWD ACROSS 
U.S. DIGGING INTO THE GULF WATERS...AND HELPING TO PUSH THE COLD 
FRONT SEWD. THIS TROUGH IS ALSO BRINGING ABUNDANT TROPICAL 
MOISTURE EMBEDDED IN 80 KT SW JET CORE FROM THE BAY OF CAMPECHE 
TO SE U.S. MODERATE TO STRONG SUBSIDENCE IS FOUND OVER THE 
YUCATAN PENINSULA AND THE SOUTHEAST PORTION OF THE GULF. 

CARIBBEAN SEA...
TIGHT PRESSURE GRADIENT BETWEEN HIGH PRES LOCATED N OF THE 
CARIBBEAN NEAR BERMUDA AND THE PANAMANIAN/COLOMBIAN LOW... 
ANALYZED 1007 MB...IS CAUSING TRADEWINDS TO INCREASE TO GALE 
FORCE ALONG THE COAST OF COLOMBIA. THESE GALE CONDITIONS 
ARE EXPECTED TO PERSIST INTO MON AS HIGH PRES SLIDES EWD ACROSS 
THE CENTRAL ATLC. SHALLOW MOISTURE EMBEDDED IN THE TRADE WIND 
FLOW WILL CONTINUE TO MOVE ACROSS THE REGION PRODUCING ISOLATED 
TO SCATTERED PASSING SHOWERS. THESE POCKETS OF LOW CLOUDS ARE 
MORE CONCENTRATED OVER THE EASTERN CARIBBEAN...AND BETWEEN 
JAMAICA AND CABO GRACIAS A DIOS NICARAGUA. IN THE UPPER 
LEVELS...A RIDGE FROM NORTHERN SOUTH AMERICA DOMINATES THE 
ENTIRE BASIN. SWLY FLOW ON THE WEST SIDE OF THE RIDGE IS 
TRANSPORTING SOME MID/UPPER LEVEL MOISTURE FROM THE EPAC REGION 
ACROSS N CENTRAL AMERICA INTO THE NW CARIBBEAN AND CUBA.  

ATLANTIC OCEAN...
A COLD FRONT ENTERS THE FORECAST AREA NEAR 31N53W THEN CONTINUES 
SW TO NEAR 27N62W WHERE IT BECOMES STATIONARY EXTENDING MAINLY 
WWD TO THE NW BAHAMAS NEAR NASSAU. THE WESTERNMOST PORTION OF 
THE FRONT IS SLOWLY SHIFTING NORTH AS SEEN ON SATELLITE IMAGERY. 
LOW LEVEL CONVERGENCE ALONG THE FRONTAL BOUNDARY IS PROMOTING 
THE DEVELOPMENT OF ISOLATED TO SCATTERED SHOWERS. FARTHER TO THE 
EAST...A 1030 MB SURFACE HIGH CENTERED W OF THE AZORES NEAR 
36N37W EXTENDS A RIDGE OVER MUCH OF THE CENTRAL AND E ATLC. 
AROUND THE SOUTHERN PERIPHERY OF THIS RIDGE...MODERATE TO FRESH 
TRADE WINDS ARE ADVECTING FRAGMENTS OF LOW LEVEL MOISTURE ACROSS 
THE TROPICAL ATLANTIC INTO THE CARIBBEAN SEA. A SFC TROUGH IS 
ALSO ANALYZED OVER THE E ATLC AND RUNS FROM 31N31W TO 23N24W. 
ISOLATED SHOWERS ARE OBSERVED EITHER SIDE OF THE TROUGH AXIS. 
IN THE UPPER LEVELS...BROAD UPPER LEVEL RIDGE DOMINATES MOST OF 
THE W AND CENTRAL ATLC WHILE A LARGE UPPER LEVEL LOW IS OVER 
EASTERN ATLC AT 30N23W. AN UPPER-LEVEL TROUGH STRETCHES FROM THE 
LOW SW TO NEAR 10N50W. STRONG SWLY FLOW WITH CORE WINDS OF 
110-130 KT IS NOTED AHEAD OF THIS TROUGH BETWEEN THE CANARY AND 
THE CAPE VERDE ISLANDS. 

$$
GR