[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 192349
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST THU FEB 19 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...THE ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 5N8W 2N20W CROSSING THE EQUATOR
NEAR 33W AND INTO NE BRAZIL NEAR 2S45W. SCATTERED MODERATE/
ISOLATED STRONG CONVECTION IS FROM 2N-5N BETWEEN 6W-17W.

...DISCUSSION...

GULF OF MEXICO...
STRONG WESTERLY FLOW ALOFT COVERS THE GULF IN THE BASE OF A DEEP
TROUGH OVER THE ERN CONUS. THE COLD FRONT ASSOCIATED WITH THIS
TROUGH EXTENDS ACROSS CENTRAL FLORIDA ALONG 26N90W 25N95W SWD TO
19N95W AND INLAND NEAR VERACRUZ MEXICO. FUNNELING OF THE COOLER
AIRMASS ACROSS THE WRN GULF THROUGHOUT THE DAY HAS RESULTED IN
A WEAK 1014 MB SURFACE LOW NEAR 21N95W. LOW LEVEL CONVERGENCE IS
SUPPORTING SCATTERED SHOWERS WITH EMBEDDED ISOLATED TSTMS WITHIN
60 NM EITHER SIDE OF THE FRONT E OF 84W. S OF THE FRONT ACROSS
THE SE GULF AND YUCATAN PENINSULA...FAIR WEATHER CONDITIONS ARE
OBSERVED...WHERE ATMOSPHERIC STABILITY IS IN PLACE. IN THE WAKE
OF THE FRONT...STRONG N TO NE WINDS OF 20 TO 25 KT ARE ACROSS
THE WRN GULF AND THESE CONDITIONS CONTINUE TO USHER IN A COOLER
AND DRIER AIRMASS OVER THE REGION THIS EVENING.

CARIBBEAN SEA...
FRESH TRADE WINDS CONTINUE ACROSS A LARGE PART OF THE CENTRAL
AND E CARIBBEAN WITH A RIDGE PRESENT IN THE CENTRAL ATLC. THE
STRONGEST WINDS...UP TO 30 KT...ARE FOUND ALONG THE COAST OF
COLOMBIA. GENERALLY FAIR WEATHER CONDITIONS ARE PRESENT ACROSS
THE CARIBBEAN REGION WITH AN UPPER RIDGE DOMINATING THE BASIN...
THOUGH PATCHES OF LOW-LEVEL MOISTURE IN THE FORM OF ISOLATED
SHOWERS CONTINUE TO BE ADVECTED WWD ACROSS THE CARIBBEAN ON
EASTERLY TRADE WINDS...MOST NOTABLY N OF 16N E OF 68W...
INCLUDING PUERTO RICO AND THE LEEWARD ISLANDS.

ATLANTIC OCEAN...
A DEEP TROUGH OVER THE ERN CONUS CONTINUES TO PROGRESS EWD WITH
THE ASSOCIATED COLD FRONT ACROSS THE W ATLC ENTERING THE
DISCUSSION AREA NEAR 32N76W AND EXTENDING SW TO MELBOURNE
FLORIDA AND INTO THE GULF OF MEXICO. THE STRONG PRESSURE
GRADIENT ASSOCIATED WITH THIS FRONT IS SUPPORTING SOUTHWESTERLY
GALE FORCE WINDS AHEAD OF THE FRONT BASED ON RECENT SHIP
OBSERVATIONS. SCATTERED SHOWERS AND TSTMS ARE OCCURRING WITHIN
90 NM EITHER SIDE OF THE FRONT. FARTHER TO THE E...A 1025 MB
SURFACE HIGH IS CENTERED NEAR 28N53W. SUBSIDENCE ASSOCIATED WITH
THIS FEATURE IS RESULTING IN FAIR WEATHER CONDITIONS ACROSS A
LARGE PART OF THE CENTRAL ATLC. FARTHER TO THE E...A SURFACE
COLD FRONT ENTERS THE DISCUSSION AREA NEAR 32N37W AND EXTENDS TO
24N47W BECOMING A WEAKENING STATIONARY BOUNDARY TO NEAR BARBUDA.
SURFACE CONFLUENCE NEAR THESE BOUNDARIES IS SUPPORTING INCREASED
CLOUDINESS AND ISOLATED SHOWERS WITHIN 60 NM EITHER SIDE OF
THESE FRONTS. ACROSS THE E ATLC...SUBSIDENCE ASSOCIATED WITH A
SURFACE RIDGE AND A 1026 MB SURFACE HIGH NEAR 33N29W IS
RESULTING IN GENERALLY FAIR WEATHER CONDITIONS. ACROSS THE
TROPICAL ATLC...DEEP LAYER DRY AIR EMBEDDED WITHIN AN UPPER
TROUGH THAT EXTENDS SWD FROM THE CENTRAL ATLC IS SUPPRESSING
CONVECTION OVER THE WRN HALF OF THE ITCZ. UPPER LEVEL DIVERGENCE
E OF THIS TROUGH IS ENHANCING THE CONVECTION OVER THE ERN HALF
OF THE ITCZ.

$$
HUFFMAN




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