000 AXNT20 KNHC 082342 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT MON OCT 08 2012 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 EXTENDS FROM 09N39W TO 17N41W MOVING W AT 10-15 KT. A 1008 MB LOW IS CENTERED AT THE SOUTHERN EXTENT OF THE WAVE AXIS NEAR 08N39W AND REMAINS EMBEDDED WITHIN THE ITCZ. TOTAL PRECIPITABLE WATER IMAGERY INDICATES MAXIMUM DEEP LAYER MOISTURE SURROUNDING THE WAVE FROM 05N-15N BETWEEN 37W-44W. SCATTERED MODERATE CONVECTION IS FROM 05N-12N BETWEEN 38W-44W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 13N17W TO 11N24W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 11N24W TO 08N39W TO 06N57W. SCATTERED MODERATE CONVECTION IS FROM 02N-09N BETWEEN 29W-36W...AND FROM 05N-12N BETWEEN 38W-44W. ISOLATED MODERATE CONVECTION IS FROM 05N-09N BETWEEN 44W-57W. ...DISCUSSION... GULF OF MEXICO... BROAD UPPER LEVEL TROUGHING IS OVER MUCH OF THE EASTERN CONUS WITH A BASE THAT REACHES SOUTHWARD TO 25N OVER PORTIONS OF THE NW GULF WATERS. SOUTHWARD FROM 25N95W...A SHARPER UPPER LEVEL TROUGH AXIS EXTENDS OVER CENTRAL MEXICO TO 17N101W. THE LARGER SYNOPTIC-SCALE TROUGH OVER THE EASTERN CONUS SUPPORTS A STATIONARY FRONT ANALYZED FROM JACKSONVILLE FLORIDA SW ALONG 27N90W TO 24N95W TO THE MEXICO COASTLINE NEAR 21N97W. SCATTERED SHOWERS AND WIDELY SCATTERED TSTMS ARE OCCURRING WITHIN 90 NM EITHER SIDE OF THE FRONT. A PRE-FRONTAL SURFACE TROUGH IS ANALYZED ACROSS THE EASTERN GULF FROM 28N84W TO 22N88W. MOST SCATTERED SHOWERS AND ISOLATED TSTMS ASSOCIATED WITH THIS SURFACE TROUGH ARE OCCURRING E OF 85W...INCLUDING PORTIONS OF THE FLORIDA PENINSULA THIS EVENING. WHILE LOW-LEVEL MOISTURE CONVERGENCE IS MAXIMIZED ALONG THE BOUNDARIES...THE OVERALL DIFFLUENT FLOW OVER THE GULF IS EXPECTED TO REMAIN IN PLACE THROUGH WEDNESDAY UNTIL AN UPPER LEVEL RIDGE OVER MEXICO IS FORECAST TO AMPLIFY AND ESTABLISH ITSELF PROVIDING NW FLOW ALOFT AND A SUBSIDENT ENVIRONMENT. OTHERWISE...TO THE NORTH AND WEST OF THE STATIONARY FRONT...STRONGER NE WINDS IN THE RANGE OF 15 TO 20 KT ARE EXPECTED THROUGH THE OVERNIGHT HOURS AS THE FRONT CONTINUES TO SLOWLY DISSIPATE AND BECOME MORE DIFFUSE WHILE SURFACE RIDGING BUILDS IN ACROSS THE BASIN BY MID-WEEK. CARIBBEAN SEA... AN UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED OVER THE WESTERN CARIBBEAN NEAR 16N82W AND IS PROVIDING PLENTY OF MIDDLE TO UPPER LEVEL MOISTURE W OF 80W. UPPER LEVEL DIFFLUENCE IS MAXIMIZED ON THE WESTERN PERIPHERY OF THE UPPER LEVEL HIGH AND IN TANDEM WITH A 1010 MB SURFACE LOW CENTERED IN THE SW CARIBBEAN NEAR 11N82W IS GENERATING SCATTERED SHOWERS AND TSTMS FROM 08N-15N BETWEEN 80W-87W...INCLUDING PORTIONS OF PANAMA... COSTA RICA...NICARAGUA...AND EASTERN HONDURAS. THIS AREA IS ONLY PART OF A LARGER AND MORE GENERAL SURFACE TROUGHING LOCATED BETWEEN 65W-90W. WITH PEAK DAYTIME HEATING AND INSTABILITY... SCATTERED SHOWERS AND TSTMS ARE OCCURRING OVER CUBA AND HISPANIOLA AND THESE ARE LIKELY TO DIMINISH GRADUALLY INTO THE OVERNIGHT HOURS. ON WATER VAPOR IMAGERY...AN UPPER LEVEL LOW IS CENTERED OVER THE EASTERN CARIBBEAN NEAR 16N69W THAT IS PROVIDING AMPLE LIFT TO GENERATE SCATTERED SHOWERS AND ISOLATED TSTMS FROM 13N-19N BETWEEN 60W-70W. ATLANTIC OCEAN... SOUTHWESTERLY UPPER LEVEL FLOW DOMINATES ACROSS THE SW NORTH ATLC THIS EVENING BETWEEN BROAD UPPER LEVEL TROUGHING OVER THE EASTERN CONUS AND AN UPPER LEVEL ANTICYCLONE CENTERED NEAR 25N69W. THE UPPER LEVEL TROUGHING SUPPORTS A FRONTAL BOUNDARY THAT RUNS PARALLEL WITH THE COASTLINE FROM 32N80W TO A 1014 MB LOW NEAR 31N82W THEN SW INTO THE GULF OF MEXICO. UPPER LEVEL DIFFLUENCE IS MAXIMIZED BETWEEN THE TWO UPPER LEVEL FEATURES WHICH IS RESULTING IN SCATTERED SHOWERS AND WIDELY SCATTERED TSTMS N OF 27N W OF 75W. TO THE SE OF THE TROUGHING AND SURFACE FRONT...A SURFACE TROUGH IS ANALYZED FROM 27N72W TO 22N77W. THE UPPER LEVEL TROUGHING TO THE NW IS PROVIDING INCREASED WIND SHEAR AND THUS LIMITING OVERALL CONVECTIVE ORGANIZATION THIS EVENING ALONG THE SURFACE TROUGH...HOWEVER...SCATTERED SHOWERS AND TSTMS ARE OCCURRING OVER A LARGE AREA FROM 22N-31N BETWEEN 67W-76W. E OF 65W...THE REMAINDER OF THE CENTRAL AND EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE AXIS WHICH STRETCHES FROM THE MADEIRA ISLANDS NEAR 32N17W TO 25N35W...AND A RIDGE STRETCHING SOUTHWARD ALONG 47W ANCHORED BY A 1027 MB HIGH CENTERED NEAR 41N47W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN