[Tropical] Tropical Weather Discussion

[EMWIN Server]

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






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