000 AXNT20 KNHC 172340 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST SUN FEB 17 2013 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. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA ENTERING THE E TROPICAL ATLC THROUGH SIERRA LEONE TO 04N20W WHERE THE ITCZ CONTINUES TO 1N30W THEN S OF THE EQUATOR NEAR 38W TO NE BRAZIL. SMALL CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 4N TO 7N BETWEEN 11W AND 18W. SIMILAR CONVECTION IS FOUND FROM THE EQUATOR TO 3N BETWEEN 28W-38W. ...DISCUSSION... GULF OF MEXICO... A 1029 MB HIGH PRES LOCATED NEAR 30N87W EXTENDS A RIDGE SW TO THE BAY OF CAMPECHE COVERING THE ENTIRE GULF WATERS AND THE STATE OF FLORIDA. COLD AIR STRATOCUMULUS CLOUDS...DUE TO THE ADVECTION OF COLD AIR OVER RELATIVELY WARM WATERS...COVER THE GULF MAINLY S OF 27N E OF 94W TO OFF THE FLORIDA PENINSULA WHERE A DRY AND COLD AIR MASS PREVAILS. EASTERLY SURFACE WINDS ARE BANKING LOW LEVEL CLOUDS WITH ISOLATED SHOWERS ALONG THE COAST OF MEXICO TO THE E SLOPES OF THE SIERRA MADRE MOUNTAINS. THE MOST RECENT SCATTEROMETER DATA SHOW NORTHERLY WINDS OF 20-25 KT OVER THE EASTERN GULF WHILE SOUTHERLY RETURN FLOW HAS ALREADY ESTABLISHED OVER THE NW PORTION OF THE REGION. EXPECT THE RETURN FLOW TO SPREAD EWD AND INCREASE TO 20-25 KT WITH HIGHER GUSTS ON MON AS THE HIGH PRES MOVES TOWARD THE WESTERN ATLC. THE NEXT COLD FRONT IS FORECAST TO MOVE INTO THE NW GULF TUE THEN STALL AND DISSIPATE OVER NORTHERN GULF WATERS WED. ALOFT...BROAD UPPER TROUGH OVER THE E CONUS DIGS S INTO FLORIDA AND WESTERN CUBA. A RIDGE DOMINATES MEXICO AND THE WESTERN GULF. CARIBBEAN SEA... A COLD FRONT HAS MOVED ACROSS CUBA AND THE CARIBBEAN SEA AND NOW EXTENDS FROM EASTERN CUBA TO NE NICARAGUA. SCATTEROMETER PASSES INDICATE NLY WINDS IN THE 20 TO 25 KT RANGE WITH HIGHER GUSTS W OF THE FRONT WHILE FRESH TO STRONG TRADE WINDS DOMINATE THE REMAINDER OF THE BASIN. THIS FRONT WILL REACH FROM THE WINDWARD PASSAGE TO THE COAST OF NICARAGUA TONIGHT WHERE IT WILL STALL AND DISSIPATE THROUGH MON. VISIBLE SATELLITE PICTURES REVEALS A TONGUE OF DRY AND COLD AIR COVERING THE STATE OF FLORIDA AND THE STRAITS OF FLORIDA AND ALMOST REACHING THE COAST OF WESTERN CUBA. IF THIS TREND CONTINUES TONIGHT AND THE COLD AIR INVADES WEST-CENTRAL CUBA...EXPECT TEMPERATURES BELOW 10 DEGREES CELSIUS ACROSS THE PROVINCES OF HAVANA AND MATANZAS OVERNIGHT. COLD AIR STRATOCUMULUS CLOUDS ARE ALSO NOTICED BEHIND THE COLD FRONT IMPLYING THAT A COLD AIR MASS HAS INVADED THE NW CARIBBEAN. THE NLY WINDS BEHIND THE COLD FRONT ARE TRANSPORTING PATCHES OF LOW LEVEL CLOUDS WITH EMBEDDED LIGHT TO MODERATE SHOWERS INTO PARTS OF HONDURAS AND NICARAGUA. IN THE UPPER LEVEL...THE TROUGH OVER THE EASTERN CONUS DIPS S OVER THE NW CARIBBEAN N OF 20N SUPPORTING THE AFOREMENTIONED COLD FRONT. NEAR ZONAL WESTERLY FLOW ALOFT DOMINATES THE REMAINDER OF THE CARIBBEAN SEA. WATER VAPOR SATELLITE IMAGERY CONTINUES TO SHOW VERY STRONG SUBSIDENCE AND DRY STABLE AIR ALOFT E OF 75 ACROSS THE REMAINDER OF THE BASIN. STRONG HIGH PRESSURE IN THE WAKE OF THE FRONT WILL MAINTAIN FRESH TO STRONG TRADE WINDS MAINLY ACROSS THE EAST AND CENTRAL CARIBBEAN THROUGH AT LEAST TUE WITH THE STRONGEST WINDS OF 25-30 KT...AS USUAL...NEAR THE COAST OF COLOMBIA. ATLANTIC OCEAN... THE PREVIOUSLY MENTIONED BROAD UPPER LEVEL TROUGH SUPPORTS A STRONG COLD FRONT THAT ENTERS THE DISCUSSION AREA AT 17/1800 UTC NEAR 31N63W EXTENDING SW THROUGH THE SE BAHAMAS AND EASTERN CUBA INTO THE CARIBBEAN SEA. GALE FORCE WINDS ARE STILL BLOWING W OF THE FRONT...PARTICULARLY N OF 29N TO 74W. THE 1718 UTC OSCAT PASS ALONG WITH SURFACE DATA CONFIRMED THE PRESENCE OF THESE STRONG WINDS. THIS GALE EVENT IS FORECAST TO END IN ABOUT 6 HOURS. A WIDE BAND OF MULTILAYERED CLOUDS WITH EMBEDDED SHOWERS IS ASSOCIATED WITH THE FRONT. THE NORTHERN PORTION OF THE FRONT WILL CONTINUE TO MOVE EWD WHILE THE SOUTHERN PART WILL STALL AND DISSIPATE BETWEEN THE SE BAHAMAS AND HISPANIOLA ON MON. STRONG HIGH PRES FOLLOWS THE FRONT AND WILL SHIFT EASTWARD JUST N OF 31N MON CROSSING NEAR BERMUDA TUE. E OF THE FRONT...A 1025 MB HIGH PRES IS CENTERED NEAR 30N40W AND IS EXPECTED TO REMAIN NEARLY STATIONARY OVER THE NEXT 24 HOURS. THIS SYSTEM EXTENDS A RIDGE OVER MOST OF THE E AND CENTRAL ATLC. FRESH TO STRONG TRADE WINDS ARE NOTED ON THE SOUTHERN PERIPHERY OF THE RIDGE. ALOFT...AN UPPER RIDGE COVERS THE CENTRAL ATLC. A BROAD UPPER TROUGH IS OVER THE E ATLC AND EXTENDS FROM 31N23W ALL THE WAY SW TO NEAR BARBADOS IN THE WINDWARD ISLANDS. THIS TROUGH SUPPORTS A DISSIPATING COLD FRONT CURRENTLY LOCATED BETWEEN THE MADEIRA AND THE CANARY ISLANDS. STRONG SWLY FLOW IS NOTED ON THE SOUTH SIDE OF THE TROUGH AXIS. THESE WINDS INCREASE TO 90-110 KT OVER WESTERN AFRICA. THE NEXT COLD FRONT WILL MOVE INTO THE NW PORTION OF THE FORECAST AREA EARLY WED. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GR