000 AXNT20 KNHC 172347 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT WED MAR 17 2010 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC... ...ITCZ... ITCZ AXIS IS CENTERED ALONG 7N12W 3N20W 2N40W CROSSING THE EQUATOR NEAR 47W AND INTO NE BRAZIL NEAR 1S48W. ISOLATED MODERATE CONVECTION IS FROM 2N-5N BETWEEN 21W-29W. ...DISCUSSION... GULF OF MEXICO... AS OF 2100 UTC...A VIGOROUS UPPER LEVEL SHORTWAVE TROUGH IS EVIDENT ON WATER VAPOR IMAGERY LOCATED OVER THE SE CONUS AND IS INDUCING CYCLOGENESIS OFF THE COAST OF NE FLORIDA WITH A 1011 MB SURFACE LOW CENTERED NEAR 29N80W. A SURFACE TROUGH EXTENDS SW FROM THE LOW ACROSS THE SOUTHERN FLORIDA PENINSULA AND INTO THE SE GULF TO 24N84W. MOSAIC DOPPLER RADAR AND VISIBLE SATELLITE IMAGERY INDICATE ISOLATED SHOWERS OVER THE EASTERN GULF E OF 88W AND OVER INLAND PORTIONS OF THE FLORIDA PENINSULA...MOST NOTABLY NEAR TAMPA BAY AND N OF 29N. THE LOW IS FORECAST TO MOVE NE INTO THE WESTERN ATLC OFFSHORE ZONES WITH N-NW WINDS UP TO 20 KT FOLLOWING BEHIND THE SURFACE TROUGH BOUNDARY OVER THE EASTERN GULF. THE REMAINDER OF THE GULF W OF 88W IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1029 MB HIGH CENTERED OVER NORTHERN MEXICO. THE RIDGE IS ENHANCED ALOFT BY VERY DRY AND SUBSIDENT NW FLOW STREAMING OVER THE WESTERN GULF FROM THE SOUTHERN U.S. PLAINS. IT WILL CONTINUE TO DRIFT EASTWARD LOCATING OVER THE FLORIDA PENINSULA BY LATE SATURDAY. MEANWHILE...THE NEXT COLD FRONT IS FORECAST TO EMERGE OFF THE TEXAS GULF COAST BY LATE SATURDAY AS WELL BRINGING STRONG NORTHERLY WINDS ONCE AGAIN TO THE NW GULF WATERS. CARIBBEAN SEA... WITH THE UPPER LEVEL SHORTWAVE TROUGH LOCATED OVER NORTHERN FLORIDA...THE UPPER LEVEL TROUGH AXIS EXTENDS ACROSS THE SE GULF OF MEXICO AND REMAINS DRAPED ACROSS THE YUCATAN CHANNEL THIS EVENING. MOIST SOUTHWESTERLY UPPER LEVEL FLOW EAST OF THE TROUGH AXIS IS ADVECTING EAST PACIFIC TROPICAL MOISTURE AND CLOUDINESS NORTHEASTWARD ACROSS PORTIONS OF NORTHERN CENTRAL AMERICA WITH ISOLATED SHOWERS OVER THE NW CARIBBEAN NW OF A LINE FROM EASTERN CUBA NEAR 20N76W TO EASTERN HONDURAS NEAR 15N84W. ELSEWHERE OVER THE NE CARIBBEAN...A SURFACE TROUGH EXTENDS FROM THE CENTRAL ATLC ALONG 18N63W TO 15N70W. ISOLATED SHOWERS ARE WITHIN 90 NM NW OF THE BOUNDARY. THESE SHOWERS ARE CONTINUING TO BE LARGELY SUPPRESSED BY STRONG MIDDLE TO UPPER LEVEL SUBSIDENCE ASSOCIATED WITH A BROAD ANTICYCLONIC CIRCULATION CENTERED OVER EASTERN VENEZUELA THAT IS PROVIDING VERY DRY AIR ALOFT OVER MUCH OF THE CARIBBEAN E OF 75W. THE UPPER LEVEL RIDGE IS ALSO ENHANCING SCATTERED SHOWERS AND TSTMS OVER COASTAL NORTHERN COLOMBIA AND NW VENEZUELA THIS EVENING FROM 10N-13N BETWEEN 68W-76W. ATLANTIC OCEAN... A VIGOROUS UPPER LEVEL SHORTWAVE TROUGH IS LOCATED OVER THE SE CONUS WITH CYCLOGENESIS OCCURRING OVER THE W ATLC THIS EVENING. AS OF 2100 UTC...A 1011 MB SURFACE LOW IS CENTERED NEAR 29N80W WITH A SURFACE TROUGH EXTENDING SW ACROSS THE SOUTHERN FLORIDA PENINSULA AND INTO THE SE GULF OF MEXICO. MOSAIC DOPPLER RADAR AND SATELLITE IMAGERY INDICATE SCATTERED SHOWERS AND ISOLATED TSTMS FROM 23N TO BEYOND 32N W OF 68W...INCLUDING PORTIONS OF THE FLORIDA PENINSULA AND MUCH OF THE FLORIDA STRAITS. FARTHER EAST...ANOTHER UPPER LEVEL SHORTWAVE TROUGH AND LOW IS CENTERED NEAR 35N46W AND SUPPORTS A BROAD FRONTAL TROUGH DRAPED ACROSS MUCH OF THE CENTRAL ATLC. WITHIN THIS FRONTAL TROUGH TWO COLD FRONTS EXTEND INTO THE DISCUSSION AREA. THE EASTERNMOST COLD FRONT IS ANALYZED FROM 32N29W TO 24N50W BECOMING A DISSIPATING COLD FRONT TO EASTERN HISPANIOLA NEAR 19N68W. A PRE-FRONTAL TROUGH IS ALSO LOCATED SE OF THIS COLD FRONT FROM 23N50W TO THE NE CARIBBEAN NEAR 18N63W. THE WESTERNMOST COLD FRONT EXTENDS INTO THE DISCUSSION AREA NEAR 32N41W AND CONTINUES SW ALONG 26N50W TO 23N63W. SCATTERED SHOWERS ARE WITHIN 300 NM EITHER SIDE OF A LINE FROM 32N31W TO 24N50W AND WITHIN 120 NM EITHER SIDE OF THE PRE-FRONTAL SURFACE TROUGH. ELSEWHERE ACROSS THE REMAINDER OF THE EASTERN ATLC...A SURFACE RIDGE ANCHORED BY A 1020 MB HIGH CENTERED NEAR 27N20W EXTENDS FROM THE CANARY ISLANDS SW TO 15N50W. THE COLD FRONTS ASSOCIATED WITH THE BROAD FRONTAL TROUGH ARE FORECAST TO MERGE AND CONTINUE MOVING EASTWARD OVER THE NEXT 24 HOURS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN