000 AXNT20 KNHC 292342 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT WED SEP 29 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS ALONG 07N36W 14N35W 20N38W MOVING W AT 15-20 KT. BROAD LOW-LEVEL CYCLONIC FLOW EXTENDS NORTHWARD IN THE VICINITY OF THE WAVE AXIS FROM THE ITCZ REGION ALONG 09N BETWEEN 32W-42W. TOTAL PRECIPITABLE WATER IMAGERY ALSO SHOWS A CLASSIC DEPICTION OF THE LOW-LEVEL MOISTURE ASSOCIATED WITH THE WAVE BREAKING OVER THE NORTHERN EXTENT OF THE AXIS. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM 10N-15N BETWEEN 32W-40W. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 08N14W 07N24W 10N33W 08N37W 09N48W. A SMALL COMPLEX OF SCATTERED MODERATE TO STRONG CONVECTION IS ALONG THE W AFRICA COAST FROM 08N-12N BETWEEN 12W-16W AND IS LIKELY ASSOCIATED WITH THE NEXT TROPICAL WAVE TO EMERGE OFF THE W AFRICA COAST OVER THE NEXT DAY OR TWO. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS WITHIN 210 NM S OF THE AXIS BETWEEN 17W-33W. FARTHER WEST...A PAIR OF SURFACE TROUGHS ARE NEARING THE LESSER ANTILLES. ONE IS ANALYZED FROM 10N50W TO 18N49W MOVING W AT 10-15 KT. LOCATED ON THE SW PERIPHERY OF AN UPPER LEVEL ANTICYCLONE...UPPER LEVEL DIFFLUENCE ALONG WITH THE LOW-LEVEL SURFACE CONVERGENCE NEAR THE TROUGH AXIS IS GENERATING A LARGE AREA OF NUMEROUS MODERATE AND SCATTERED STRONG CONVECTION FROM 08N-20N BETWEEN 44W-54W. THE OTHER SURFACE TROUGH EXTENDS FROM 10N57W TO 16N56W. AS THIS SURFACE TROUGH MOVES W AT 10-15 KT AND COMES UNDER INCREASED VERTICAL WIND SHEAR DUE TO UPPER LEVEL TROUGHING BETWEEN 56W-62W...ISOLATED MODERATE CONVECTION IS WITHIN 120 NM EITHER SIDE OF THE AXIS WHICH CONTINUES TO DISSIPATE THIS EVENING. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL LOW IS LOCATED OVER NORTHERN ALABAMA AND EXTENDS AN UPPER LEVEL TROUGH AXIS TO THE NE GULF NEAR 29N86W THEN SW TO THE EASTERN MEXICO COAST NEAR 22N98W. WATER VAPOR IMAGERY SHOWS A VERY DRY AND STABLE AIRMASS OVER MUCH OF THE GULF W OF 83W. THIS STABILITY IS FURTHER SUPPORTED BY NORTHERLY SURFACE WINDS WITH HIGH DEWPOINT DEPRESSIONS LOCATED WEST OF THE REMNANT CYCLONIC CIRCULATION CURRENTLY MOVING N-NE OVER THE FLORIDA STRAITS AND FAR W ATLC. EAST OF THE UPPER LEVEL TROUGH AXIS... COPIOUS AMOUNTS OF TROPICAL MOISTURE ARE ADVECTING NORTHWARD OVER THE FLORIDA STRAITS AND PORTIONS OF THE FLORIDA PENINSULA E OF 81W GENERATING NUMEROUS SHOWERS OVER THE FAR SE FLORIDA PENINSULA STRETCHING INTO THE W ATLC WATERS. AS THE BROAD AREA OF LOW PRESSURE OVER THE FLORIDA PENINSULA MOVES NORTH OF THE DISCUSSION AREA...NORTH-NORTHEAST WINDS ARE EXPECTED TO PERSIST OVER THE ENTIRE GULF THROUGH LATE SUNDAY. CARIBBEAN SEA... BETWEEN AN UPPER LEVEL TROUGH LOCATED OVER THE GULF OF MEXICO AND AN UPPER LEVEL ANTICYCLONE CENTERED NEAR 18N75W...DEEP LAYERED MOIST SOUTHWESTERLY FLOW IS ACROSS THE NW CARIBBEAN PROVIDING AN UPPER LEVEL DIFFLUENT ENVIRONMENT. THIS REGIME IS SUPPORTING NUMEROUS SHOWERS AND SCATTERED TSTMS N OF 15N BETWEEN 74W-86W THAT COINCIDES WITH A BROAD AND ELONGATED AREA OF LOW PRESSURE CENTERED OVER THE FLORIDA STRAITS THIS EVENING. WHILE THE REMNANT CYCLONIC CIRCULATION MOVES N-NE OVER THE W ATLC THIS EVENING...A MONSOONAL TROUGH AXIS EXTENDS ACROSS CENTRAL CUBA NEAR 21N80W TO SOUTHERN BELIZE NEAR 16N89W. ASIDE FROM THE CONVECTION PREVIOUSLY MENTIONED...SCATTERED SHOWERS AND ISOLATED TSTMS LINGER SW OVER THE GULF OF HONDURAS AND INLAND PORTIONS OF BELIZE AND GUATEMALA WITHIN 90 NM EITHER SIDE OF THE MONSOON TROUGH AXIS. AN UPPER LEVEL RIDGE AXIS EXTENDS SE FROM THE CENTER OF THE ANTICYCLONE ALOFT TO NEAR 13N64W. MIDDLE TO UPPER LEVEL DIFFLUENCE IS GENERATING NUMEROUS SHOWERS AND SCATTERED TSTMS FROM 14N-19N BETWEEN 66W-70W...WHICH IS CAPTURED NICELY BY THE SAN JUAN PUERTO RICO DOPPLER RADAR THIS EVENING. ATLANTIC OCEAN... DIVERGENT UPPER LEVEL FLOW IS LOCATED ACROSS THE W ATLC W OF 72W DUE TO AN UPPER LEVEL TROUGH ACROSS THE GULF OF MEXICO AND A BROAD AREA OF SURFACE LOW PRESSURE...ANALYZED AS A 995 MB LOW CENTERED NEAR 24N80W AT 29/2100 UTC. SURFACE TROUGHING EXTENDS NORTHWARD TO THE GEORGIA COAST NEAR 31N81W WHERE IT INTERSECTS A STATIONARY FRONTAL BOUNDARY DRAPED ALONG THE EASTERN CONUS COAST FROM JACKSONVILLE FLORIDA TO CAPE HATTERAS NORTH CAROLINA. NUMEROUS SHOWERS AND ISOLATED TSTMS ARE OCCURRING FROM 20N TO BEYOND 32N BETWEEN 74W-81W. THIS ENTIRE AREA OF LOW PRESSURE IS FORECAST TO MOVE N-NE AND ELONGATE FURTHER WITH A NEW SURFACE LOW DEVELOPING EARLY THURSDAY OVER THE CAROLINAS AND MOVING NORTHWARD TOWARDS THE MID-ATLC STATES. ELSEWHERE OVER THE REMAINDER OF THE CENTRAL AND EASTERN ATLC...SURFACE RIDGING DOMINATES N OF 20N E OF 70W...ANCHORED BY A 1026 MB HIGH CENTERED NEAR 39N52W. HOWEVER...A WEAKNESS WITHIN THE RIDGE EXISTS...ANALYZED AS A SURFACE TROUGH FROM 28N31W TO 30N37W WITH NO SIGNIFICANT PRECIPITATION OCCURRING WITH THIS FEATURE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN