000 AXNT20 KNHC 071803 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST MON NOV 07 2011 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...SPECIAL FEATURES... A 1005 MB OCCLUDED LOW PRESSURE AREA CENTERED NEAR 28N69W CONTINUES TO DEVELOP CHARACTERISTICS OF A SUBTROPICAL SYSTEM OVER THE SW NORTH ATLC. AT THE CURRENT TIME...THE FRONTAL BOUNDARIES ASSOCIATED WITH THIS LOW CONTINUE TO DISSIPATE. SCATTERED MODERATE CONVECTION REMAINS MOSTLY NORTH OF THE DISSIPATING OCCLUDED FRONT ALONG 29N CONFINED TO THE AREA FROM 27N-32N BETWEEN 63W-72W. WHILE THIS CONVECTION REMAINS WITHIN THE NORTHERN QUADRANT...NORTHEASTERLY GALE FORCE WINDS ACCOMPANY THE LOW N OF 27N BETWEEN 67W AND 73W IN THE 30 TO 40 KT RANGE. SEAS CONTINUE TO REMAIN IMPRESSIVE AS WELL TO 22 FT IN NE SWELL. THE LOW MAY ACQUIRE SUBTROPICAL CHARACTERISTICS DURING THE NEXT 48 HOURS AS IT DRIFTS SLOWLY WESTWARD TODAY AND NORTHWESTWARD ON TUESDAY. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 13N17W TO 12N19W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 12N19W TO 05N35W TO 05N50W. SCATTERED MODERATE CONVECTION IS FROM 03N-07N BETWEEN 32W-44W...AND WITHIN 120 NM EITHER SIDE OF A LINE FROM 06N44W TO 13N55W. ...DISCUSSION... GULF OF MEXICO... A BROAD UPPER LEVEL RIDGE AXIS EXTENDS OVER THE MIDDLE GULF WATERS ALONG 90W THAT SUPPORTS A SURFACE RIDGE ACROSS THE ENTIRE BASIN THIS AFTERNOON. WITH A 1033 MB HIGH CENTERED OVER WEST VIRGINIA...THE RIDGE AXIS EXTENDS SOUTHWESTWARD ACROSS THE SE CONUS AND ALONG 30N89W TO THE WESTERN BAY OF CAMPECHE NEAR 20N97W. THE SURFACE RIDGE IS EXPECTED TO REMAIN NEARLY STATIONARY THROUGH LATE TUESDAY WHEN THE NEXT COLD FRONT IS FORECAST TO EMERGE OFF THE TEXAS GULF COAST EARLY WEDNESDAY AND USHER IN ANOTHER ROUND OF STRONG NORTHERLY WINDS WEST OF THE FRONT ACROSS THE WESTERN GULF WATERS. CARIBBEAN SEA... AN UPPER LEVEL TROUGH IS NOTED ON WATER VAPOR IMAGERY OVER MUCH OF THE W ATLC IN SUPPORT OF THE SPECIAL FEATURES LOW MENTIONED ABOVE. THE TROUGH AXIS DIPS SOUTHWARD ALONG 70W TO 12N AND SUPPORTS A DISSIPATING COLD FRONT ANALYZED FROM 20N67W ACROSS EASTERN HISPANIOLA TO NEAR 18N70W. A SURFACE TROUGH IS NOTED SOUTHWEST OF THE COLD FRONT ALONG 15N72W TO 10N77W. THE COLD FRONT ALONG WITH THE SURFACE TROUGH ARE PROVIDING FOCUS FOR ISOLATED SHOWERS WITHIN 90 NM EITHER SIDE OF THE BOUNDARIES. WATER VAPOR IMAGERY ALSO INDICATES THAT WEST OF THIS BOUNDARY...VERY DRY AIR IS IN PLACE OVER THE WESTERN CARIBBEAN AND CENTRAL AMERICA N OF 10N PROVIDING OVERALL FAIR CONDITIONS THIS AFTERNOON. THE REMAINDER OF THE EASTERN CARIBBEAN IS EXPERIENCING E TO SE WINDS AND MOSTLY FAIR CONDITIONS WITH A FEW ISOLATED SHOWERS NOTED OVER PORTIONS OF THE LEEWARD ISLANDS AND US/UK VIRGIN ISLANDS. FINALLY...ISOLATED SHOWERS AND TSTMS ARE OCCURRING S OF 10N BETWEEN 76W-83W DUE TO CLOSE PROXIMITY TO THE MONSOON TROUGH AXIS SOUTH OF PANAMA ALONG 07N. ATLANTIC OCEAN... AN UPPER LEVEL LOW IS CENTERED OVER THE W ATLC WATERS NEAR 34N72W WITH AXIS FROM THE LOW TO 20N69W. BENEATH THIS MIDDLE TO UPPER LEVEL TROUGH...THE SPECIAL FEATURES OCCLUDED 1005 MB LOW IS CENTERED NEAR 28N69W. THE DISSIPATING COLD FRONT EXTENDS FROM 29N64W TO THE MONA PASSAGE NEAR 19N68W. ASIDE FROM GALE FORCE WINDS WITHIN THE NORTHERN SEMICIRCLE OF THE LOW AND THE OVERALL STRONGER WIND FIELD SURROUNDING THE LOW...MOST OF THE SCATTERED SHOWERS AND ISOLATED TSTMS ARE LOCATED NORTH FROM 27N-32N BETWEEN 63W-72W. ISOLATED SHOWERS AND TSTMS ARE ALSO OCCURRING WITHIN 120 NM EITHER SIDE OF A LINE FROM 23N64W TO 32N57W OVER AN AREA OF MAXIMUM MIDDLE TO UPPER LEVEL DIFFLUENCE. FARTHER EAST...A WEAK 1013 LOW IS CENTERED NEAR 24N56W WITH A SURFACE TROUGH EXTENDING SW FROM THE LOW TO 21N60W. SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING FROM 20N-24N BETWEEN 53W-57W. ANOTHER UPPER LEVEL TROUGH...LOCATED WELL NORTH OF THE DISCUSSION AREA ACROSS THE EASTERN NORTH ATLC...SUPPORTS A COLD FRONT ANALYZED FROM 32N30W TO 27N42W WHERE IT BECOMES STATIONARY TO 27N51W. WIDELY SCATTERED SHOWERS ARE WITHIN 120 NM EITHER SIDE OF THE FRONT. A PRE-FRONTAL SURFACE TROUGH EXTENDS FROM THE COLD FRONT NEAR 27N41W TO 20N49W. THE REMAINDER OF THE EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1021 MB HIGH CENTERED NEAR THE MADEIRA ISLANDS NEAR 32N15W. THE SURFACE RIDGE AXIS EXTENDS SW FROM THE HIGH ALONG 25N32W TO NEAR 22N43W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN