000 AXNT20 KNHC 181153 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST FRI FEB 18 2011 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... THE ITCZ IS ANALYZED FROM W AFRICA NEAR 6N8W 4N12W 3N19W THEN S OF THE EQUATOR NEAR 27W INTO SOUTH AMERICA. CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE FROM THE EQUATOR TO 4N BETWEEN 2W-15W. SCATTERED MODERATE CONVECTION IS WITHIN 90/120 NM OF THE ITCZ BETWEEN 20W-22W. ...DISCUSSION... GULF OF MEXICO... A SURFACE RIDGE REMAINS OVER THE SE CONUS/W ATLC AND INTO THE GULF ANCHORED BY A 1028 MB HIGH IN THE W ATLC WITH A WEAK 1024 MB HIGH OFF THE COAST OF FLORIDA NEAR 29N85W. A BROAD UPPER RIDGE AXIS EXTENDS FROM THE YUCATAN PENINSULA ACROSS NE FLORIDA GIVING THE GULF W TO SW FLOW ALOFT. STRONG SUBSIDENCE AND DRY STABLE AIR DOMINATES THE GULF BASIN LEAVING THE AREA WITH MOSTLY FAIR CONDITIONS AGAIN THIS MORNING. RETURN FLOW AROUND THE SURFACE RIDGE IS GIVING THE W GULF SOUTHERLY FLOW WHICH IS BANKING LOW LEVEL CLOUDS OVER THE NW GULF TO INLAND ALONG THE COAST OF MEXICO N OF VERACRUZ TO OVER TEXAS AND W LOUISIANA. SURFACE RIDGE WILL CHANGE LITTLE THROUGH MON. A COLD FRONT MAY APPROACH THE FAR NW WATERS TUE. CARIBBEAN SEA... REMNANT SURFACE MOISTURE REMAINS ACROSS THE NW CARIBBEAN AND CONTINUES TO GENERATE CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 60 NM OF LINE FROM PUERTO RICO/MONA PASSAGE ALONG 16N70W S OF JAMAICA TO NEAR 17N85W. AN UPPER TROUGH DIPS ACROSS CUBA AND HAITI FROM THE W ATLC LEAVING THE REMAINDER OF THE CARIBBEAN DOMINATED BY AN UPPER RIDGE ANCHORED IN THE W TROPICAL ATLC GIVING THE CARIBBEAN S OF 20N SW TO W FLOW ALOFT. MODERATE/STRONG SUBSIDENCE AND DRY STABLE AIR DOMINATES THE ENTIRE CARIBBEAN BASIN LEAVING THE REMAINDER OF THE CARIBBEAN WITH REMARKABLY CLEAR SKIES THIS MORNING. THE EXCEPTION IS SOME LOW LEVEL CLOUDS WITH ISOLATED SHOWERS BANKING ALONG THE MOUNTAINS OF W PANAMA TO SE NICARAGUA AND IN THE SW CARIBBEAN WITHIN 90 NM ALONG THE COAST S OF 13N W OF 81W. SURFACE RIDGE OVER THE W ATLC WILL DRIFT SLOWLY SE THROUGH SAT. TRADE WINDS WILL INCREASE SAT NIGHT THROUGH MON AS THIS SURFACE RIDGE STRENGTHENS. ATLANTIC OCEAN... A SURFACE RIDGE COVERS THE W ATLC W OF 45W INTO GULF OF MEXICO ANCHORED BY A 1028 MB HIGH NEAR BERMUDA. A BROAD UPPER TROUGH COVERS THE N/CENTRAL ATLC WITH A SHORTWAVE UPPER TROUGH AXIS EXTENDING INTO THE W ATLC THROUGH 30N60W SW ACROSS CUBA AND HAITI INTO THE CARIBBEAN TO NEAR 20N75W. THE BROAD UPPER TROUGH OVER THE N/CENTRAL ATLC SUPPORTS A LINGERING COLD FRONT THAT ENTERS THE E/CENTRAL ATLC NEAR 32N28W EXTENDING ALONG 27N35W TO 26N39W WHERE IT BECOMES A SHEAR AXIS ALONG 23N54W TO N OF HISPANIOLA NEAR 20N69W. ISOLATED SHOWERS ARE WITHIN 60 NM E OF THE FRONT N OF 30N. A BROAD UPPER RIDGE EXTENDS FROM THE W TROPICAL ATLC NEAR 8N41W NE TO BEYOND 32N16W. DIFFLUENCE ALOFT COUPLED WITH AN UPPER LEVEL JETSTREAM WITH WINDS OF 90 TO 110 KT COVERING THE AREA N OF LINE FROM 19N63W TO 25N25W ARE GENERATING SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS WITHIN 250/300 NM NW OF THE SHEAR AXIS BETWEEN 45W-65W. A WEAK SURFACE RIDGE COVERS THE E ATLC ANCHORED BY A 1020 MB HIGH NEAR 27N24W GIVING THE AREA E OF THE FRONT FAIR CONDITIONS AGAIN THIS MORNING. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW