000 AXNT20 KNHC 231750 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST MON FEB 23 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 4N7W TO 2N10W CROSSING THE EQUATOR NEAR 15W EXTENDING SW TO 3S26W TO 3S36W INTO NE BRAZIL NEAR 3S40W. THE AXIS WAS CONVECTION FREE FROM THE COAST OF AFRICA TO THE EQUATOR. ISOLATED MODERATE TO STRONG CONVECTION WAS FROM 1-3S BETWEEN 04E AND 04W. NUMEROUS MODERATE/ISOLATED STRONG CONVECTION WAS S OF 2S BETWEEN 10W-43W AND THEN CONTINUED WWD ALONG THE COAST OF S AMERICA TO 3N51W. ...DISCUSSION... GULF OF MEXICO... A SHARP MID TO UPPER LEVEL TROUGH CONTINUES ACROSS THE GULF OF MEXICO THIS MORNING...EXTENDING FROM NE FLORIDA NEAR JACKSONVILLE SW TO NW PORTIONS OF THE BAY OF CAMPECHE...THEN CROSSES MEXICO AND EXTENDS INTO THE TROPICAL EPAC. AN UPPER LEVEL JET AXIS TO THE S OF THIS TROUGH EXTENDS FROM THE EXTREME SE GULF ENE ACROSS S FLORIDA AND THE N HALF OF THE BAHAMAS AND CONTINUES NE INTO THE NW ATLC. 60-70 KT WSW WINDS ACROSS THE SE GULF ACCELERATE TO 100 KT ACROSS THE NW ATLC N OF BERMUDA. AN ASSOCIATED SURFACE COLD FRONT WAS SOMEWHAT ILL DEFINED ACROSS THE AREA AND EXTENDED FROM EXTREME S FLORIDA SW TO THE N COAST OF THE YUCATAN PENINSULA NEAR MERIDA. GOOD LOW LEVEL CONVERGENCE N OF THE FRONT WAS SUPPORTING SCATTERED SHOWERS WITH GUSTY WINDS WITHIN 12 NM NW OF THE FRONT EXTENDING INTO THE BAY OF CAMPECHE. A WEAK CYCLONIC CURL WAS NOTED IN THE LOW CLOUDS ACROSS THE W GULF FROM 25N95W S FOR A FEW DEGREES...BUT A MORNING QUIKSCAT PASS SHOWED ONLY A VERY WEAK SURFACE REFLECTION. FARTHER TO THE N OF THIS FRONT...GENERALLY FAIR WEATHER IS PRESENT WHERE NORTHWESTERLY FLOW ALOFT WAS SUPPORTING SUBSIDENCE AND STABLE ATMOSPHERIC CONDITIONS. FRESH NORTHEASTERLY SURFACE WINDS IN THE WAKE OF THE COLD FRONT ARE USHERING IN A RELATIVELY COOLER AND DRIER AIRMASS ACROSS THE N AND W GULF. ADDITIONALLY...STRONG N TO NE SURFACE WINDS ARE BLOWING THROUGH THE ISTHMUS OF TEHUANTEPEC RESULTING IN STORM FORCE WINDS THROUGH THE GULF OF TEHUANTEPEC REGION. CARIBBEAN SEA... AN INCREASED SURFACE PRESSURE GRADIENT HAS RESULTING IN STRONG TRADE WINDS ACROSS THE ENTIRE CARIBBEAN SEA...WITH NE TO E SURFACE WINDS OF 20 TO 25 KT WITH HIGHER GUSTS BASIN WIDE... AND WINDS TO 30 KT WITH HIGHER GUSTS IN THE SW CARIBBEAN OFF OF THE COLOMBIAN COAST. AN UPPER LEVEL RIDGE ACROSS THE REGION AND SHALLOW LOW LEVEL MOISTURE ARE RESULTING IN GENERALLY FAIR WEATHER CONDITIONS...AND FAST MOVING SHOWERS ACCOMPANIED WITH GUSTY WINDS. FRESH NNE FLOW ACROSS THE NW CARIB WAS RESULTING IN NUMEROUS SHOWERS ACROSS A GOOD PORTION OF CENTRAL AMERICA...FROM THE INTERIOR AND HIGHER ELEVATIONS OF CHIAPAS MEXICO TO THE COASTS AND INTERIOR OF NICARAGUA. ATLANTIC OCEAN... A DEEP TROUGH OVER THE W ATLC IS ASSOCIATED WITH A SURFACE COLD FRONT THAT EXTENDS FROM NEAR 30N 69W TO EXTREME S FLORIDA... WHILE AN OLD FRONT LINGERING ACROSS THE SW N ATLC WAS JUST AHEAD OF THIS PREVIOUS FRONT FROM 30N 66W TO THE CENTRAL BAHAMAS... WHERE IT WAS NEARLY STATIONARY. THESE FRONT ARE EXPECTED TO MERGE BY 24 HOURS AS THE UPPER SUPPORT AND A LARGE SURFACE HIGH ACROSS THE ERN U.S. CONTINUE TO DRIVE THE NORTHERN MOST FRONT SEWD. LOW LEVEL CONVERGENCE ALONG AND BEHIND THIS MORE NRN FRONT IS SUPPORTING SCATTERED SHOWERS WITHIN 60 NM EITHER SIDE OF EACH OF THESE FRONTS...WHILE THE UPPER JET CONTINUES TO SPREAD HIGH CLOUDS NE ACROSS THE REGION. A BROAD ZONE OF UPPER DIVERGENCE ASSOCIATED WITH THE JET WAS ACTING TO ENHANCE SOME OF THE SHOWERS NEAR THESE FRONTAL BOUNDARIES...YIELDING ISOLATED TSTMS THAT WERE QUICKLY BEING SHEARED. E AND SE OF THESE FRONTS... SUBSIDENCE ASSOCIATED WITH A SURFACE RIDGE WAS SUPPORTING FAIR WEATHER CONDITIONS...AND FRESH TO STRONG NE TO E TRADE WINDS ACROSS THE ENTIRE BASIN S OF 24N. AN UPPER TROUGH WAS PRESENT FROM THE CANARY ISLANDS SW TO 18N32W THEN CONTINUED SW AND THEN WSW TO JUST E OF TRINIDAD AND TOBAGO. A SURFACE TROUGH WAS REFLECTED FROM THE CANARIES SWD ALONG THE W COAST OF AFRICA TO MAURITANIA. WITHIN THE W END OF THIS UPPER TROUGH..STRONG SUBSIDENCE WAS OCCURRING FROM 13N TO 9N BETWEEN 62W AND 40W. UPPER LEVEL RIDGING TO THE S OF THE UPPER TROUGH WAS ACTING TO VENTILATE CONVECTION ALONG MUCH OF THE NE COAST OF S AMERICA AND WITHIN 4 DEGREES S OF THE ITCZ TO 25W...WHERE ABUNDANT LOW LEVEL MOSITURE WAS PRESENT. CONVECTION WILL REMAIN VERY ACTIVE ACROSS THE W HALF OF THE DEEP TROPICAL ATLC THROUGHOUT THE NEXT 12 TO 18 HOURS. $$ STRIPLING