000 AXNT20 KNHC 201719 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST WED JAN 20 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1630 UTC. ...THE ITCZ... THE ITCZ AXIS IS CENTERED FROM THE S IVORY COAST OF AFRICA NEAR 5N2W ALONG 5N18W 3N32W TO THE NE BRAZIL COAST NEAR EQ50W. ISOLATED MODERATE CONVECTION IS FROM 2N-4N BETWEEN 26W-30W. ...DISCUSSION... GULF OF MEXICO... A SURFACE RIDGE ANCHORED BY A 1018 MB HIGH N OF TAMPA FLORIDA NEAR 29N82W DOMINATES THE ERN GULF OF MEXICO TODAY PROVIDING GENERALLY FAIR WEATHER ACROSS MUCH OF THE BASIN EXCEPT FOR SOME ISOLATED SHOWERS/THUNDERSTORMS MOVING ACROSS SE LOUISIANA AND S MISSISSIPPI INDICATED BY RADAR IMAGERY. ANTI-CYCLONIC SURFACE FLOW IS AROUND THE RIDGE REACHING 20 KT ACROSS THE W AND MIDDLE GULF. IN THE UPPER LEVELS...MAINLY ZONAL WLY FLOW ALOFT COVERS THE BASIN ALONG WITH MODERATELY DRY AIR IN THE MID AND UPPER LEVELS. EXPECT THE SURFACE RIDGE TO CONTINUE SHIFTING E AND WEAKENING ALLOWING SLY RETURN FLOW TO INCREASE TODAY ACROSS THE W AND MIDDLE GULF AHEAD OF THE NEXT COLD FRONT FORECAST TO MOVE OFF THE TEXAS COAST EARLY TOMORROW. THE CARIBBEAN SEA... MOST OF THE CARIBBEAN IS EXPERIENCING GENERALLY FAIR WEATHER TODAY UNDER THE INFLUENCE OF DRY AIR AND SUBSIDENCE ALOFT AROUND AN UPPER LEVEL RIDGE WITH AXIS ALONG 55W. A NARROW SWATH OF MODERATE MOISTURE EXTENDS ACROSS THE NW CARIBBEAN AROUND THE E SIDE OF A BROAD UPPER LEVEL TROUGH THAT SUPPORTS A FRONTAL BOUNDARY IN THE W ATLC CONTINUING TO N DOMINICAN REPUBLIC NEAR 20N70W. A FEW ISOLATED SHOWERS ARE NOTED ACROSS CENTRAL DOMINICAN REPUBLIC AND E OF JAMAICA DUE TO SURFACE CONVERGENCE NEAR THE FRONT. A SURFACE TROUGH IS AHEAD OF THE FRONT BISECTING PUERTO RICO FROM 20N63W TO 17N68W. ISOLATED SHOWERS ARE WITHIN 30 NM OF THE TROUGH AXIS. A SECOND SURFACE TROUGH EXTENDS ACROSS THE LEEWARD ISLANDS FROM 18N60W TO 15N63W. ISOLATED SHOWERS ARE WITHIN 90 NM OF THE AXIS N OF 17N. FRESH TO STRONG TRADEWINDS CONTINUE ACROSS MUCH OF THE BASIN WITH THE STRONGEST WINDS OFF THE COAST OF COLOMBIA WHERE THEY REACH GALE FORCE UP TO 35 KT FROM 11N-15N BETWEEN 72W-77W. THE GALE FORCE WINDS ARE FORECAST TO PERSIST FOR ANOTHER 24 HOURS. THE ATLANTIC OCEAN... A WEAK SURFACE RIDGE COVERS THE FAR SW N ATLC ANCHORED BY A 1018 MB HIGH N OF TAMPA FLORIDA...AND A 1019 MB HIGH S OF BERMUDA NEAR 30N65W PROVIDING GENERALLY FAIR WEATHER ACROSS THIS PORTION OF THE BASIN. IMMEDIATELY E...A DYING COLD FRONT ENTERS THE DISCUSSION AREA NEAR 32N49W CONTINUING ALONG 28N58W TO 27N68W. ISOLATED SHOWERS ARE ALONG THE FRONT AXIS. THE PRIMARY COLD FRONT IS FARTHER E EXTENDING FROM A 980 MB LOW ENTERING THE DISCUSSION AREA NEAR 32N41W CONTINUING SW ALONG 28N50W 25N59W BECOMING STATIONARY TO NRN DOMINICAN REPUBLIC NEAR 20N70W. SCATTERED SHOWERS ARE WITHIN 90 NM AHEAD OF THE FRONT AND 45 NM BEHIND OF THE FRONT N OF 24N WITH ISOLATED SHOWERS WITHIN 30 NM ELSEWHERE ALONG THE FRONT. A BROAD UPPER LEVEL SHORTWAVE TROUGH WITH AXIS ALONG 70W SUPPORTS THE FRONTAL SYSTEM ALONG WITH A NARROW SWATH OF MODERATE MID-UPPER LEVEL MOISTURE EXTENDING FROM ERN CUBA TO THE NE. A SURFACE TROUGH IS E OF THE FRONT FROM 20N63W TO 17N68W BISECTING PUERTO RICO. ISOLATED SHOWERS ARE WITHIN 30 NM OF THE TROUGH AXIS. A SHEAR LINE CONTINUES E OF THE NRN LESSER ANTILLES DEPICTING A LINE OF CONVERGING WIND SPEEDS ALONG 17N46W 15N52W 17N59W. SCATTERED SHOWERS ARE WITHIN 30 NM OF THE SHEAR AXIS BETWEEN 50W-59W. AN UPPER LEVEL RIDGE COVERS THE REMAINDER OF THE W AND CENTRAL ATLC WITH AXIS ALONG 55W SUPPORTING A SURFACE RIDGE ANCHORED BY A 1027 MB HIGH N OF THE CANARY ISLANDS NEAR 34N15W. THE SURFACE RIDGE IS PROVIDING GENERALLY AIR WEATHER ACROSS THE E ATLC. HOWEVER...A NARROW UPPER LEVEL TROUGH WITH AXIS ALONG 32W IS SUPPORTING SOME HIGH CLOUDS ACROSS THE AREA ALONG WITH ENHANCING SOME MODERATE CONVECTION ALONG THE ITCZ. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE. $$ WALTON