000 AXNT20 KNHC 181745 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...THE ITCZ... THE ITCZ AXIS IS CENTERED ALONG 5N9W 1N20W 1N30W CROSSING THE EQUATOR NEAR 37W THEN INTO NE BRAZIL NEAR 3S46W. ISOLATED MODERATE CONVECTION IS WITHIN 90 NM N OF AXIS AND EAST OF 20W TO THE COAST OF AFRICA. SIMILAR CONVECTION IS FROM THE EQUATOR TO 3N BETWEEN 32W-43W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS JUST OFFSHORE THE COAST OF BRAZIL BETWEEN 42W-51W. ...DISCUSSION... GULF OF MEXICO... A 1023 MB SFC HIGH IN THE W ATLC EXTENDS A RIDGE ACROSS FLORIDA AND INTO THE GULF OF MEXICO PRODUCING MOSTLY FAIR WEATHER ACROSS THE REGION. SCATTERED MULTI-LAYERED CLOUDS ARE OBSERVED OVER THE NORTHERN GULF WATERS WHILE SOUTHERLY RETURN FLOW OF UP TO 20 KT IS ESTABLISHED AHEAD OF A DEVELOPING LOW PRESSURE SYSTEM OVER THE CENTRAL CONUS. THIS SYSTEM WILL PUSH A COLD FRONT INTO THE GULF REGION THIS EVENING AS THE HIGH PRESSURE SHIFTS FURTHER EAST INTO THE CENTRAL ATLC. STRONG NLY WINDS AND BUILDING SEAS WILL FOLLOW THE FRONTAL PASSAGE. EXPECT SCATTERED SHOWERS AND TSTMS TO MOVE INTO THE NW GULF WITH THE FRONT. 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 ALOFT AND THE ASSOCIATED DRY AIR MASS. CARIBBEAN SEA... THE TAIL END OF A COLD FRONT EXTENDING FROM THE CENTRAL ATLC IS OVER THE NORTHERN LEEWARD ISLANDS WITH BROKEN LOW/MID CLOUDS AND ISOLATED SHOWERS. THE FRONT IS EXPECTED TO LINGER ACROSS THE NE CARIBBEAN AND THE LEEWARD ISLANDS THE REST OF TODAY BEFORE DISSIPATING THU. A SFC TROUGH...WITH AXIS ALONG 75W/76W S OF 15N...CONTINUES TO MOVE WESTWARD ACROSS THE CENTRAL CARIBBEAN GENERATING A LARGE AREA OF LOW/MID CLOUDS WITH ISOLATED SHOWERS MAINLY S OF 15N BETWEEN 68W-76W. CURACAO REPORTED 1.30 INCHES OF RAIN FOR THE PAST 24 HOURS ENDING THIS MORNING AT 7 AM DUE TO THE PASSAGE OF THIS TROUGH ACROSS THE ABC ISLANDS. PATCHY CLOUDS AND FAIR WEATHER COVER THE CARIBBEAN W OF 75W AND CENTRAL AMERICA UNDER A STABLE AIRMASS ALOFT. HIGH PRESSURE BEHIND THE FRONT WILL MAINTAIN STRONG TRADE WIND FLOW ACROSS THE CARIBBEAN. WIND SPEEDS ARE IN THE 20-30 KT RANGE WITH THE STRONGEST WINDS JUST OFFSHORE THE COLOMBIAN COAST AND SW OF THE MONA PASSAGE. THE NEXT COLD FRONT IS FORECAST BY THE COMPUTER MODELS TO REACH WESTERN CUBA AND THE NW CARIBBEAN ON FRIDAY AND DISSIPATE LATER IN THE DAY OVER THE CENTRAL BAHAMAS AND CENTRAL CUBA. ATLANTIC OCEAN... A STRONG EXTRATROPICAL LOW PRESSURE SYSTEM WITH HURRICANE FORCE WINDS IS SPINNING OVER THE N CENTRAL ATLC NEAR 42N52W. THE ASSOCIATED COLD FRONT ENTERS THE DISCUSSION AREA NEAR 32N47W AND CONTINUES SW TO THE NORTHERN LEEWARD ISLANDS. A BAND OF MULTI-LEVEL CLOUDS AND SCATTERED SHOWERS IS NOTED WITHIN 90 NM OF THE FRONT. A SECOND BAND OF LOW CLOUDS AND EMBEDDED SHOWERS SURROUNDS A PRE-FRONTAL TROUGH ANALYZED FROM 28N47W TO 15N58W. GALE FORCE WINDS EXTEND UP TO 180 NM E OF THE FRONT N OF 29N AND W OF THE FRONT TO 60W N OF 29N. COLD AIR STRATOCUMULUS CLOUDS AROUND A 1023 MB SFC HIGH NEAR 29N76W COVER THE W ATLC AND THE BAHAMAS BEHIND THE FRONTAL ZONE. EAST OF THE FRONT...A SFC RIDGE EXTENDS FROM A 1029 MB HIGH NEAR 33N25W PROVIDING FAIR WEATHER ACROSS THE E ATLC. THIS SYSTEM IS ALSO PRODUCING A WIDESPREAD SWATH 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. A RIDGE EXTENDS OVER THE CENTRAL ATLC TO BEYOND THE AZORES. E OF THE RIDGE...ANOTHER DEEP LAYERED TROUGH AXIS STRETCHES FROM THE MADEIRA ISLANDS TO THE CAPE VERDE ISLANDS. $$ GR