000 AXNT20 KNHC 182341 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST WED FEB 18 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 5N9W 1N20W CROSSING THE EQUATOR NEAR 38W THEN INTO NE BRAZIL NEAR 2S45W. ISOLATED MODERATE CONVECTION IS FROM THE EQUATOR TO 3N BETWEEN 9W-13W. SIMILAR CONVECTION IS WITHIN 150 NM N OF THE AXIS BETWEEN 18W-25W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 120 NM OFFSHORE THE COAST OF BRAZIL BETWEEN 46W-50W. ...DISCUSSION... GULF OF MEXICO... A 1022 MB SURFACE HIGH IN THE W ATLC EXTENDS A RIDGE ACROSS THE FLORIDA PENINSULA AND SRN GULF OF MEXICO PRODUCING MOSTLY FAIR WEATHER S OF 27N. SCATTERED MULTI-LAYERED CLOUDS WITH EMBEDDED ISOLATED SHOWERS ARE OBSERVED OVER THE NRN GULF WATERS AS SOUTHERLY RETURN FLOW OF UP TO 20 KT IS ESTABLISHED AHEAD OF A COLD FRONT DRAPED ACROSS THE TEXAS GULF COAST. THIS FRONT IS FORECAST TO MOVE INTO THE NW GULF THIS EVENING ALLOWING STRONG N-NE WINDS TO FOLLOW THE FRONTAL PASSAGE THROUGH THE DAY THURS. IN THE UPPER LEVELS...STRONG WNW FLOW AROUND AN UPPER RIDGE WITH AXIS ALONG 100W IS TRANSPORTING UPPER LEVEL MOISTURE ACROSS THE NRN GULF WATERS WHILE THE SRN GULF...INCLUDING SE MEXICO AND THE YUCATAN PENINSULA REMAINS RELATIVELY CLEAR UNDER MODERATE TO STRONG SUBSIDENCE. CARIBBEAN SEA... THE TAIL END OF A COLD FRONT EXTENDING FROM THE CENTRAL ATLC IS OVER THE GUADELOUPE PASSAGE WITH BROKEN LOW/MID CLOUDS AND ISOLATED SHOWERS. THE FRONTAL REMNANTS ARE EXPECTED TO BECOME MORE DIFFUSE ACROSS THE NE CARIBBEAN AND LEEWARD ISLANDS THROUGH THU. LOW-LEVEL CONVERGENCE OF FRESH TO STRONG EASTERLY TRADES ACROSS THE CENTRAL AND WRN CARIBBEAN ARE GENERATING ISOLATED SHOWERS WITHIN 60 NM OF A LINE FROM 15N70W TO 12N81W. HOWEVER... THESE SHALLOW SHOWERS REMAIN UNDER STRONG SUBSIDENCE IN THE MID TO UPPER LEVELS ACROSS MUCH OF THE BASIN. THE HIGHER PRESSURE ACROSS THE W ATLC WILL MAINTAIN STRONG TRADE WIND FLOW ACROSS THE CARIBBEAN THROUGH THU WITH THE NEXT COLD FRONT FORECAST TO REACH WRN CUBA AND THE NW CARIBBEAN EARLY FRIDAY. ATLANTIC OCEAN... A DEEP LAYERED TROUGH IS ACROSS THE NW ATLC AND SUPPORTS A COLD FRONT THAT ENTERS THE DISCUSSION AREA NEAR 32N46W AND CONTINUES SW TO GUADELOUPE. A BAND OF MULTI-LEVEL CLOUDS AND SCATTERED SHOWERS IS NOTED WITHIN 200 NM E OF THE FRONT N OF 26N AND WITHIN 120 NM E OF THE FRONT ALONG THE REMAINDER OF THE BOUNDARY TO THE LEEWARD ISLANDS. A SECOND BAND OF LOW CLOUDS AND EMBEDDED SHOWERS SURROUNDS A PRE-FRONTAL TROUGH ANALYZED FROM 21N52W TO 15N53W. COLD AIR STRATOCUMULUS CLOUDS AROUND A 1022 MB SURFACE HIGH NEAR 29N70W COVER THE W ATLC AND THE BAHAMAS BEHIND THE FRONTAL ZONE. E OF THE FRONT...A SURFACE RIDGE EXTENDS FROM A 1030 MB HIGH NEAR 32N25W PROVIDING FAIR WEATHER ACROSS THE E ATLC. THE SRN PERIPHERY OF THIS RIDGE IS ALSO PRODUCING A LARGE AREA OF MODERATE TO FRESH TRADE WINDS ACROSS THE TROPICS MAINLY EAST OF 45W. ALOFT...A HIGHLY AMPLIFIED TROUGH/RIDGE/TROUGH PATTERN DOMINATES THE ATLC OCEAN BASIN. THE DEEP LAYERED TROUGH OVER THE W ATLC SUPPORTS THE AFOREMENTIONED COLD FRONT WHILE A SHARP RIDGE EXTENDS OVER THE CENTRAL ATLC ALONG 36W TO BEYOND THE AZORES. E OF THE RIDGE...ANOTHER DEEP LAYERED TROUGH WITH UPPER LOW NEAR 30N13W STRETCHES FROM THE CANARY ISLANDS TO THE CAPE VERDE ISLANDS. $$ HUFFMAN