000 AXNT20 KNHC 170001 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST SAT FEB 16 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 2345 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA AND EMERGES INTO THE E TROPICAL ATLC OVER SIERRA LEONE NEAR 8N13W THEN ALONG 6N15W TO 3N23W WHERE THE ITCZ CONTINUES ALONG 2N30W THEN S OF THE EQUATOR NEAR 36W/37W TO THE COAST OF SOUTH AMERICA. LARGE CLUSTERS OF SCATTERED TO LOCALLY NUMEROUS MODERATE/STRONG CONVECTION EXTEND FROM THE SOUTHERN COAST OF AFRICA TO 4S E OF THE PRIME MERIDIAN. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM THE EQUATOR TO 4N BETWEEN 8W-11W. SCATTERED MODERATE CONVECTION WAS NOTED FROM THE EQUATOR TO 5N W OF 45W TO THE COAST OF SOUTH AMERICA. ...DISCUSSION... GULF OF MEXICO... A SHARPENING UPPER TROUGH OVER THE E CONUS WITH MAIN AXIS ALONG 85W IS DIGGING INTO THE EASTERN GULF. THIS AMPLIFIED TROUGH IS SUPPORTING A STRONG RAPIDLY MOVING COLD FRONT THAT AS OF 2100 UTC EXTENDS FROM NAPLES FLORIDA TO THE BAY OF CAMPECHE NEAR 21N94W. THIS FRONT IS EXPECTED TO CLEAR THE GULF OF MEXICO WITHIN THE NEXT SEVERAL HOURS. THE FRONT WAS USHERING STRONG NW WINDS OF 20-30 KT OVER MOST OF THE GULF E OF 90W WITH SEVERAL NOAA BUOYS REPORTING SEAS OF 10 FT. THE STRONG NORTHERLY WINDS WERE ALSO BANKING LOW CLOUDS WITH AREAS OF EMBEDDED RAIN OVER THE FAR SW GULF S OF 23N...THE BAY OF CAMPECHE AND WESTWARD TO THE SLOPES OF THE SIERRA MADRE. SKIES HAVE CLEARED OVER THE NW THIRD OF THE GULF IN THE WAKE OF A BUILDING 1032 MB SURFACE HIGH CENTERED OVER LAREDO TEXAS. HIGH PRES BUILDS OVER THE GULF SUN WITH WINDS DECREASING OVER THE ENTIRE BASIN. AS THE HIGH MOVES E ON MON EXPECT SOUTHERLY WINDS TO INCREASE AHEAD OF A WEAKER COLD FRONT SLATED TO REACH THE NW GULF MON NIGHT OR TUE. CARIBBEAN SEA... A BROAD UPPER RIDGE CONTINUES TO DOMINATE MOST OF THE CARIBBEAN AND CURRENTLY EXTENDS FROM AN ANTICYCLONE NEAR 13N77W NE ACROSS HISPANIOLA INTO THE W-CENTRAL ATLC. WATER VAPOR SATELLITE IMAGERY CONTINUES TO SHOW VERY STRONG SUBSIDENCE AND DRY STABLE AIR ALOFT ACROSS THE BASIN WITH THE EXCEPTION OF UPPER LEVEL MOISTURE ACROSS THE YUCATAN CHANNEL. A WEAK COLD FRONT ENTERS THE CARIBBEAN FROM THE SW ATLC ACROSS CUBA JUST E OF THE ISLE OF YOUTH ALONG 20N84W TO THE GULF OF HONDURAS NEAR ROATAN. SCATTERED SHOWERS ARE WITHIN 60-90 NM W OF THE FRONT. A WEAK PRESSURE PATTERN PERSISTS ACROSS THE REMAINDER OF THE BASIN WHICH HAS ALLOWED THE FRESH TO STRONG TRADE WINDS OVER THE CENTRAL CARIBBEAN TO ABATE SOMEWHAT. A 1628 UTC OSCAT PASS INDICATED EASTERLY WINDS OF 20 KT E OF 75W...WITH 25 KT WINDS WITHIN 60 NM OF THE COAST OF COLOMBIA. A STRONGER REINFORCING COLD FRONT OVER THE SE GULF IS EXPECTED TO SWEEP THROUGH THE YUCATAN CHANNEL LATER TONIGHT AND OVERTAKE THE EXISTING WEAKER FRONT BY SUNRISE SUN. THE MERGED FRONT WILL EXTEND FROM THE WINDWARD PASSAGE TO THE E COAST OF NICARAGUA SUN MORNING THEN STALL AND BECOMING DIFFUSE IN THE SAME AREA MON. ATLANTIC OCEAN... SHARPENING UPPER LEVEL TROUGH OVER THE E CONUS IS BEGINNING TO EMERGE INTO THE FAR NW ATLC. 250 MB WINDS OF 150-175 KT INDICATED THE PRESENCE OF A POWERFUL POLAR JETSTREAM WHICH WAS CONTRIBUTING TO RAPID CYCLOGENESIS OFF THE NC COAST. A STRONG COLD FRONT EXTENDED FROM THE DEVELOPING SURFACE LOW AND ENTERS THE AREA NEAR 32N78W TO THE FLORIDA EAST COAST NEAR CAPE CANAVERAL. STRONG COLD AIR BEHIND THE FRONT WILL RESULT IN RAPIDLY INCREASING NW WINDS WHICH WILL REACH GALE FORCE OVER THE NEXT FEW HOURS OVER THE FAR NW OFFSHORE WATERS ZONES. WINDS HAVE INCREASED TO 25-27 KT OVER THE PAST HOUR AT BUOYS 41009...41010 AND 41012 WITH SEAS BUILDING UP TO 8 FT. FURTHER EAST A WEAKER SLOW MOVING COLD FRONT EXTENDS FROM NEAR 32N70W EXTENDING ACROSS THE CENTRAL BAHAMAS THEN INTO THE CARIBBEAN ACROSS THE N COAST OF CUBA NEAR 23N80W. SCATTERED SHOWERS ARE WITHIN 75 NM W OF THE FRONT. A WEAK SURFACE TROUGH FROM 32N66W TO 25N71W WITH LITTLE IN THE WAY OF SENSIBLE WEATHER ASSOCIATED WITH IT. THE STRONGER COLD FRONT IS EXPECTED TO OVERTAKE THE WEAKER FRONT OVERNIGHT TONIGHT AND EARLY SUN WITH GALE FORCE WINDS EXPANDING EASTWARD OVER THE OFFSHORE WATERS N OF 29N. THE UPPER RIDGE OVER THE CARIBBEAN EXTENDS ACROSS HISPANIOLA TO BEYOND 32N48W. A BROAD UPPER TROUGH NE OF DISCUSSION AREA SUPPORTS A COLD FRONT WHICH ENTERS THE E PORTION OF THE DISCUSSION AREA THROUGH 32N26W TO 28N40W. A NARROW UPPER TROUGH IS TO THE S ACROSS THE E ATLC EXTENDING FROM AN UPPER LOW OVER AFRICA NEAR 27N7W ALONG 23N25W INTO THE TROPICS TO NEAR 13N48W. A LARGE SURFACE RIDGE DOMINATES THE ATLC E OF THE FRONTS AND SURFACE TROUGH AND ANCHORED BY A 1024 MB HIGH NEAR 30N44W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ COBB