000 AXNT20 KNHC 212349 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST SAT FEB 21 2015 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...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...SPECIAL FEATURES... ...GALE WARNING FOR THE SW CARIBBEAN... A GALE WARNING WILL GO INTO EFFECT OFF THE NW COAST OF COLOMBIA LATER TONIGHT AND WILL PULSE AGAIN AT NIGHT THROUGH MON NIGHT. PLEASE SEE THE LATEST HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE TROPICAL ATLC NEAR 7N11W ALONG 2N16W TO 00N24W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 1N30W THEN S OF THE EQUATOR INTO SOUTH AMERICA NEAR 34W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 7N TO S OF THE EQUATOR BETWEEN 2W-14W. SCATTERED MODERATE CONVECTION IS FROM 3N TO S THE EQUATOR BETWEEN 30W-40W AND FROM 6N TO S THE EQUATOR BETWEEN 40W-51W. ...DISCUSSION... GULF OF MEXICO... NEAR ZONAL WESTERLY FLOW ALOFT DOMINATES THE GULF THIS EVENING. MODERATE TO STRONG SUBSIDENCE AND DRY AIR DOMINATE THE S GULF. A SURFACE RIDGE EXTENDS FROM THE NW ATLC ACROSS NE FLORIDA TO TAMPICO MEXICO DOMINATING THE GULF. STRONG SOUTHERLY SURFACE FLOW IS OVER THE N GULF WITH ISOLATED SHOWERS DOTTING THE NW GULF N OF 26N W OF 88W LEAVING THE REMAINDER OF THE GULF UNDER CLEAR SKIES THIS EVENING. A MID/UPPER LEVEL TROUGH WITH THE ASSOCIATED COLD FRONT IS MOVING THROUGH THE PLAIN STATES TOWARD THE MISSISSIPPI VALLEY. THIS IS THE NEXT FRONT EXPECTED TO ENTER THE N GULF SUN AFTERNOON. THE SURFACE RIDGE WILL SHIFT E AHEAD OF THIS FRONT ALLOWING WINDS AND SEAS TO DIMINISH QUICKLY TONIGHT INTO SUN. THE FRONT WILL SINK S ALONG 25N BY SUN NIGHT WHERE IT WILL BECOME STATIONARY. CARIBBEAN SEA... A STATIONARY FRONT EXTENDS FROM THE W/CENTRAL ATLC TO THE WINDWARD PASSAGE. ISOLATED SHOWERS ARE N OF THE FRONT. A SURFACE TROUGH IS MOVING THROUGH THE CENTRAL CARIBBEAN EXTENDING FROM THE E MONA PASSAGE ALONG 15N69W TO TO THE COAST OF VENEZUELA OVER PARAGUANA PENINSULA. ISOLATED SHOWERS ARE WITHIN 120 NM EITHER SIDE OF THE TROUGH AXIS. NEAR ZONAL NW FLOW ALOFT COVERS THE CARIBBEAN THIS EVENING. EASTERLY SURFACE FLOW IS GENERATING AFTERNOON SHOWERS INLAND OVER HISPANIOLA AND OVER THE NW CARIBBEAN W OF 84W. STRONG SURFACE RIDGE ACROSS THE W ATLC WILL ALLOW OVERNIGHT WINDS TO PULSE TO GALE FORCE OFF COLOMBIA OVERNIGHT TONIGHT AND EVERY NIGHT THROUGH MON NIGHT. ...HISPANIOLA... LINGERING MOISTURE COUPLED WITH THE STRONG EASTERLY WINDS CONTINUE TO GENERATE SCATTERED SHOWERS ACROSS THE ISLAND THIS EVENING. LINGERING MOISTURE AND THE APPROACHING SURFACE TROUGH WILL CONTINUE THESE SHOWERS THROUGH THE REMAINDER OF THE WEEKEND INTO MON. ATLANTIC OCEAN... THE UPPER TROUGH OVER THE W ATLC HAS RETREATED N COVERING THE AREA N OF 24N BETWEEN 55W-70W SUPPORTING A STATIONARY FRONT THAT EXTENDS THROUGH 32N54W ALONG 26N61W TO THE WINDWARD PASSAGE NEAR 20N74W. SCATTERED SHOWERS ARE WITHIN 150 NM EITHER SIDE OF THE FRONT N OF 25N WITH ISOLATED SHOWERS WITHIN 120 NM W OF THE REMAINDER OF THE FRONT. A SURFACE RIDGE COVERS THE AREA W OF THE FRONT ANCHORED BY A 1037 MB HIGH ABOUT 200 NM S OF NOVA SCOTIA. BROKEN TO OVERCAST COLD AIR STRATOCUMULUS CLOUDS COVER MOST OF THE REMAINDER OF THE W ATLC W OF THE FRONT. A SECOND LARGE SURFACE RIDGE DOMINATES THE REMAINDER OF THE ATLC E OF THE FRONT ANCHORED BY A 1038 MB HIGH ABOUT 300 NM W-SW OF THE AZORES. THE FRONT WILL CONTINUE TO DRIFT E AND DISSIPATE OVERNIGHT. THE W ATLC SURFACE RIDGE WILL MOVE FROM E ACROSS THE NW ATLC THROUGH SUN. ANOTHER COLD FRONT WILL MOVE INTO THE W ATLC LATE SUN REACHING FROM NEAR BERMUDA TO THE STRAITS OF FLORIDA BY LATE MON. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW