000 AXNT20 KNHC 102343 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT MON OCT 10 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ANALYZED FROM 10N62W TO 19N57W MOVING W AT 5-10 KT. TOTAL PRECIPITABLE WATER IMAGERY SHOWS A POLEWARD EXTENSION OF LOW-LEVEL MOISTURE IN THE VICINITY OF THE WAVE AXIS BETWEEN 58W-62W. NO SIGNIFICANT DEEP CONVECTION IS NOTED WITH THE WAVE AT THIS TIME. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 13N17W TO 09N20W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 09N20W TO 08N29W TO 06N43W. SCATTERED MODERATE CONVECTION IS FROM 07N-12N BETWEEN 11W-19W. ISOLATED MODERATE CONVECTION IS FROM 04N-10N BETWEEN 30W-44W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL LOW IS CENTERED OVER THE WESTERN FLORIDA PENINSULA NEAR 30N87W WHICH EXTENDS A NEGATIVELY TILTED TROUGH AXIS SOUTHEASTWARD OVER THE EASTERN GULF WATERS AND THE FLORIDA STRAITS INTO THE NW CARIBBEAN SEA SOUTH OF CUBA NEAR 20N77W. WHILE MOST OF THE ACTIVE WEATHER AND CONVECTION IS EAST OF THIS UPPER LEVEL TROUGH AXIS...THE UPPER LEVEL FEATURE SUPPORTS A 1005 MB LOW CENTERED OVER NORTHERN FLORIDA NEAR 30N84W AND A SURFACE TROUGH WHICH EXTENDS FROM THE LOW ACROSS THE EASTERN GULF ALONG 27N84W TO 24N90W. LOW-LEVEL CONVERGENCE AND OVERALL MIDDLE TO UPPER LEVEL LIFTING DYNAMICS ARE PROVIDING FOR ISOLATED SHOWERS AND TSTMS N OF 25N E OF THE SURFACE TROUGH AND ACROSS PORTIONS OF THE FLORIDA PENINSULA THIS EVENING. A WESTWARD EXTENSION OF THE SURFACE TROUGHING IS ANALYZED FROM 25N90W TO 27N95W WITH ISOLATED SHOWERS AND TSTMS OCCURRING WITHIN 120 NM NORTH OF THE SURFACE TROUGH BOUNDARY. AN EARLIER MORNING ASCAT PASS DEPICTED STRONGER NE WINDS IN THE RANGE OF 15 TO 20 KT BEHIND THIS FEATURE. FINALLY...CONDITIONS REMAIN QUIET ACROSS THE SW GULF THIS EVENING AS PRIMARILY LIGHT NORTHERLY WINDS DOMINATE UNDER FAIR SKIES. CARIBBEAN SEA... THE UPPER LEVEL LOW AND ASSOCIATED TROUGH AXIS OVER THE EASTERN GULF OF MEXICO EXTENDS TO A BASE OVER THE CENTRAL CARIBBEAN NEAR 16N76W. THIS UPPER LEVEL TROUGH IS SUPPORTING A WEAK SURFACE TROUGH EXTENDING FROM 15N76W TO 20N80W. VISIBLE SATELLITE IMAGERY APPEARS TO INDICATE POSSIBLE WEAK CYCLOGENESIS WITH GLOBAL MODEL DATA AND STREAMLINE ANALYSIS ALOFT INDICATING AT A MINIMUM THAT A LOW TO MID-LEVEL CIRCULATION IS APPARENT. GIVEN THE LOW-LEVEL MOISTURE CONVERGENCE NORTHEAST OF THIS BOUNDARY... SCATTERED SHOWERS AND TSTMS ARE OCCURRING N 15N BETWEEN 71W-77W...INCLUDING THE WINDWARD PASSAGE REGION. SW OF THIS AREA...THE MONSOON TROUGH CIRCULATION CROSSES NICARAGUA ALONG 13N INTO THE SW CARIBBEAN TO NEAR 13N80W. ISOLATED SHOWERS AND TSTMS ARE OCCURRING S OF 15N W OF 76W...INCLUDING INLAND PORTIONS OF PANAMA...COSTA RICA...AND COASTAL NICARAGUA. ACROSS THE FAR EASTERN CARIBBEAN...A TROPICAL WAVE IS SLOWLY MOVING WESTWARD ACROSS THE LESSER ANTILLES WITH INCREASED LOW-LEVEL MOISTURE IN PLACE E OF 62W. ISOLATED SHOWERS WILL CONTINUE TO BE POSSIBLE THROUGH THE OVERNIGHT HOURS OVER THE LESSER ANTILLES AS THE WAVE PROGRESSES WESTWARD. IN ADDITION...DRY NORTHERLY UPPER LEVEL FLOW IS PROVIDING FOR A RELATIVELY DRY AIRMASS ALOFT AND THEREFORE NO DEEP CONVECTION IS EXPECTED WITH THE TROPICAL WAVE. ATLANTIC OCEAN... AN UPPER LEVEL LOW AND ASSOCIATED TROUGH OVER THE EASTERN GULF OF MEXICO IS PROVIDING FOR A LARGE AREA OF DIFFLUENT FLOW ALOFT ACROSS THE SW NORTH ATLC THIS EVENING. THIS IS HELPING SUPPORT A 1005 MB LOW CENTERED OVER NORTHERN FLORIDA NEAR 30N84W WHICH CONTINUES TO DRAW LOW TO MIDDLE LEVEL MOISTURE NORTHWARD W OF 66W. SCATTERED SHOWERS AND TSTMS ARE OCCURRING FROM THE NORTH- CENTRAL CARIBBEAN SEA WATERS ACROSS THE WINDWARD PASSAGE REGION STRETCHING TO THE OUTER BANKS OF NORTH CAROLINA REMAINING MOSTLY W OF 70W. SOME OF THE MORE INTENSE ACTIVITY IS LOCATED OVER THE SE BAHAMAS AND ADJACENT COASTAL WATERS THIS EVENING FROM 20N-25N BETWEEN 73W-76W. FARTHER EAST...AN UPPER LEVEL TROUGH CONTINUES TO SWEEP SOUTHEASTWARD ACROSS THE CENTRAL ATLC IN SUPPORT OF A STATIONARY FRONT ANALYZED INTO THE DISCUSSION AREA NEAR 32N35W. THE FRONT CONTINUES SW ALONG 27N40W TO 23N50W TO 22N62W. A WIDE AREA OF SCATTERED SHOWERS AND ISOLATED TSTMS ARE WITHIN 180 NM OF A LINE FROM 32N35W TO 25N45W TO 20N57W. THE REMAINDER OF THE EASTERN ATLC IS UNDER THE INFLUENCE OF A WEAK SURFACE RIDGE EXTENDING FROM THE MADEIRA ISLANDS NEAR 33N17W TO 25N34W...AND WEAK SURFACE TROUGHING LOCATED BETWEEN THE CANARY ISLANDS AND CAPE VERDE ISLANDS. NO SIGNIFICANT WEATHER IS APPARENT AT THIS TIME WITH THE SURFACE TROUGHING DUE TO GENERALLY WESTERLY WINDS ALOFT AND A FAIR AMOUNT OF DUST PRESENT OVER THE EASTERN ATLC. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN