000 AXNT20 KNHC 191738 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST THU NOV 19 2009 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 1700 UTC. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 10N13W 6N20W 9N30W 6N44W 11N57W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS ALONG THE AXIS BETWEEN 25W-29W. AN EMBEDDED SURFACE TROUGH IS ANALYZED FROM 11N32W TO 4N30W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS SHEARED E OF THE TROUGH AXIS FROM 9N-11N BETWEEN 25W-31W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 8N-14N BETWEEN 50W-55W. ...DISCUSSION... GULF OF MEXICO... AS OF 1500 UTC...A DYING STATIONARY FRONT EXTENDS ACROSS CENTRAL FLORIDA N OF LAKE OKEECHOBEE ENTERING THE GULF OF MEXICO S OF FORT MYERS NEAR 26N82W CONTINUING ALONG 24N86W 22N91W. THE FRONT IS SUPPORTED BY A DEEP-LAYER TROUGH OVER THE ERN CONUS EXTENDING TO THE NRN GULF OF MEXICO. THE FRONT PROTRUDES INTO A SURFACE RIDGE COVERING THE MAJORITY OF THE BASIN CENTERED N OF THE AREA NEAR A 1024 MB HIGH OVER THE MISSISSIPPI/ALABAMA BORDER. ANTI-CYCLONIC SURFACE WINDS OF 10-15 KTS ARE AROUND THE SURFACE RIDGE. IN THE UPPER LEVELS... MAINLY ZONAL WLY FLOW ALOFT IS DRAWING SLIGHTLY MOIST AIR ACROSS THE BASIN. EXPECT THE FRONT TO BECOME DIFFUSE LATER TODAY AS HIGH PRESSURE BUILDS FROM THE N AHEAD OF LOW PRESSURE EXPECTED TO MOVE OFF THE TEXAS COAST FRI. CARIBBEAN SEA... MUCH OF THE CARIBBEAN IS EXPERIENCING GENERALLY FAIR WEATHER UNDER THE INFLUENCE OF DRY AIR AND STRONG SUBSIDENCE ASSOCIATED WITH A BROAD UPPER LEVEL RIDGE EXTENDING FROM HONDURAS ACROSS ERN CUBA AND INTO THE WRN ATLC. ISOLATED SHOWERS ARE NOTED ACROSS THE NW CARIBBEAN AFFECTING JAMAICA...CAYMAN ISLANDS...AND HONDURAS. SCATTERED SHOWERS/THUNDERSTORMS ARE IN THE SW CARIBBEAN AFFECTING PORTIONS OF COSTA RICA/PANAMA S OF 10N BETWEEN 76W-80W DUE TO SURFACE CONVERGENCE NEAR THE E PACIFIC ITCZ ALONG WITH DIFFLUENT FLOW ALOFT. THE TAIL END OF A SURFACE TROUGH EXTENDING FROM THE CENTRAL ATLC CROSSES INTO THE NE CARIBBEAN TO 17N65W. ISOLATED SHOWERS ARE POSSIBLE NEAR THE TROUGH AXIS. SHOWERS/POSSIBLE THUNDERSTORMS ARE ALSO BEGINNING TO AFFECT THE LESSER ANTILLES WITH THE APPROACH OF A SURFACE TROUGH JUST E OF THE ISLANDS. MODERATE TO FRESH TRADE WINDS ARE ACROSS MUCH OF THE BASIN WITH HIGHER WINDS NEAR THE COAST OF COLOMBIA AND S AMERICA. EXPECT SHOWERS TO CONTINUE OVER THE LESSER ANTILLES. ATLANTIC OCEAN... BROAD LOW PRESSURE CONTINUES OVER THE W/CENTRAL ATLC. AS OF 1500 UTC...A STATIONARY FRONT EXTENDS FROM A 1017 MB LOW OFF THE S CAROLINA COAST NEAR 33N78W TO THE CENTRAL FLORIDA COAST NEAR 28N80W CONTINUING AS A DYING STATIONARY FRONT ACROSS THE SE GULF OF MEXICO. ISOLATED SHOWERS/THUNDERSTORMS ARE POSSIBLE ALONG THE FRONT AXIS.THE FRONT IS SUPPORTED BY A DEEP LAYER TROUGH OVER THE ERN CONUS. UPPER DIFFLUENT FLOW ALOFT BETWEEN THIS UPPER TROUGH AND A BROAD UPPER LEVEL RIDGE EXTENDING FROM THE WRN CARIBBEAN ACROSS THE WRN ATLC TO NEAR 39N69W...NW OF BERMUDA...IS ENHANCING SCATTERED SHOWERS/THUNDERSTORMS FROM 29N-33N BETWEEN 71W-75W. A SURFACE TROUGH EXTENDS ALONG 26N61W 21N62W INTO THE FAR NE CARIBBEAN NEAR 17N65W. THE TROUGH IS SUPPORTED BY AN UPPER LEVEL TROUGH EXTENDING FROM 31N58W TO E OF THE LESSER ANTILLES NEAR 10N51W. THIS UPPER LEVEL TROUGH ALSO SUPPORTS A SECOND SURFACE TROUGH E OF THE LESSER ANTILLES WITH AXIS FROM 16N59W TO 9N59W. ISOLATED SHOWERS/POSSIBLE THUNDERSTORMS ARE WITHIN 100 NM W OF THE TROUGH AXIS. SCATTERED SHOWERS/THUNDERSTORMS ARE WITHIN 250 NM E OF THE TROUGH AXIS. TO THE N...A 1016 MB LOW IS CENTERED NEAR 30N50W. A COLD FRONT E OF THE LOW CENTER ENTERS THE DISCUSSION AREA NEAR 32N34W BECOMING STATIONARY AT 30N41W CONTINUING THROUGH THE LOW CENTER ALONG 30N50W 30N62W. SCATTERED SHOWERS/THUNDERSTORMS ARE WITHIN 100 NM OF THE FRONT...AND N OF 23N BETWEEN 47W-58W. ACROSS THE ERN ATLC... A WEAK SURFACE RIDGE IS ANCHORED BY A 1023 MB HIGH NEAR 35N11W PROVIDING GENERALLY FAIR WEATHER ACROSS THE AREA. A PAIR OF SURFACE TROUGHS PROTRUDE INTO THE RIDGE. THE FIRST IS FROM 23N42W TO 18N46W. THE SECOND IS FROM 22N34W TO 16N36W. ISOLATED SHOWERS ARE POSSIBLE ALONG BOTH TROUGH AXES. THESE SMALL SURFACE TROUGHS ARE SUPPORTED BY AN UPPER LEVEL TROUGH EXTENDING ACROSS NW AFRICA TO W OF THE CAPE VERDE ISLANDS TO NEAR 12N40W. THIS UPPER LEVEL TROUGH AND ASSOCIATED UPPER JET TO THE E SIDE OF THE TROUGH IS SHEARING MOISTURE AND SHOWER ACTIVITY FROM THE ITCZ TO THE NE-E. $$ WALTON