000 AXNT20 KNHC 282337 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT WED OCT 28 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 29W S OF 18N MOVING W NEAR 10 KT. SATELLITE IMAGERY SHOWS A 1011 MB LOW ALONG THE WAVE AXIS NEAR 29N WITH LOW-LEVEL CYCLONIC FLOW IN THE VICINITY OF THE WAVE AXIS BETWEEN 25W-31W. STRONG WESTERLY UPPER LEVEL SHEAR IS INHIBITING MOST CONVECTION WEST OF THE WAVE AXIS...HOWEVER... SCATTERED SHOWERS AND SCATTERED MODERATE CONVECTION IS E OF THE AXIS FROM 12N-18N BETWEEN 19W-28W. TROPICAL WAVE IS ALONG 53W S OF 16N MOVING W NEAR 15 KT. BROAD LOW-LEVEL CYCLONIC FLOW IS EVIDENT IN VISIBLE SATELLITE IMAGERY NEAR THE WAVE AXIS WITH A BULK OF THE PRECIPITABLE WATER MAXIMUM REMAINING S OF 12N. DEEP CONVECTION IS CONFINED TO THE ITCZ AS NUMEROUS MODERATE/SCATTERED STRONG CONVECTION IS FROM 7N-12N BETWEEN 49W-56W. TROPICAL WAVE IS ALONG 66W S OF 17N MOVING W NEAR 10 KT. THE WAVE LIES WITHIN A BROAD AREA OF ENHANCED TOTAL PRECIPITABLE WATER VALUES ACROSS THE EASTERN CARIBBEAN WITH ISOLATED SHOWERS NOTED ON SATELLITE IMAGERY FROM 14N-18N BETWEEN 62W-69W MOSTLY ACROSS THE NE CARIBBEAN. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 7N11W 6N17W 10N27W 10N31W 10N51W 11N55W 9N61W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS ALONG THE W AFRICA COAST FROM 8N-13N BETWEEN 8W-15W. SCATTERED MODERATE CONVECTION IS FROM 3N-7N BETWEEN 13W-17W. NUMEROUS MODERATE CONVECTION IS WITHIN 120 NM EITHER SIDE OF THE AXIS BETWEEN 38W-51W AND BETWEEN 55W-62W. ...DISCUSSION... GULF OF MEXICO... AS OF 2100 UTC...A STATIONARY FRONT EXTENDS ACROSS THE FLORIDA PANHANDLE AND ENTERS THE NE GULF NEAR 30N85W. THE FRONT CONTINUES WSW TO 29N90W. MOST OF THE UPPER LEVEL SUPPORT FOR THIS FRONT HAS MOVED NE OF THE AREA AND THE LINGERING FRONT IS GENERATING A FEW WIDELY SCATTERED SHOWERS N OF THE BOUNDARY BETWEEN 85W-90W. MOIST SWLY UPPER LEVEL FLOW IS PRESENT ACROSS MUCH OF THE GULF BETWEEN BROAD TROUGHING ACROSS A MAJORITY OF THE WESTERN CONUS AND AN UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED OVER THE SE GULF NEAR 24N84W. SOUTHERLY SURFACE WINDS UP TO 25 KT ARE FORECAST ACROSS MUCH OF THE GULF AS DEVELOPING LOW PRESSURE AND THE ASSOCIATED COLD FRONT APPROACH THE NW GULF WATERS BY LATE THURSDAY/EARLY FRIDAY. UNTIL THEN...ISOLATED SHOWERS WILL CONTINUE TO DEVELOP N OF 25N W OF 87W AND MOVE INLAND OVER THE GULF COAST STATES. CARIBBEAN SEA... MOST OF THE CARIBBEAN IS EXPERIENCING GENERALLY FAIR WEATHER THIS EVENING WHILE UNDER THE INFLUENCE OF A BROAD UPPER LEVEL LOW CENTERED NEAR 16N74W. NWLY WINDS ALOFT AND STRONG SUBSIDENCE REINFORCE CLEAR SKIES N OF 14N W OF 73W THIS EVENING. E-SE UPPER LEVEL FLOW IS OBSERVED ON WATER VAPOR IMAGERY S OF 14N ACROSS THE SOUTHERN PORTION OF THE CARIBBEAN WITH POSSIBLE ISOLATED LOW-LEVEL SHOWERS BEING USHERED IN ACROSS THE BASIN ON MODERATE ELY TRADEWINDS. INTERACTION BETWEEN THE UPPER LEVEL LOW AND A TROPICAL WAVE ALONG 66W IS ENHANCING ISOLATED SHOWERS FROM 14N-18N BETWEEN 62W-69W. TROPICAL MOISTURE ASSOCIATED WITH THE ITCZ AXIS ALONG 8N ACROSS PANAMA IS GENERATING SCATTERED SHOWERS AND TSTMS S OF 11N...INCLUDING PANAMA AND COSTA RICA. ATLANTIC OCEAN... THE W ATLC IS INFLUENCED BY A SURFACE RIDGE ANCHORED BY A 1018 MB SURFACE HIGH CENTERED NEAR 29N67W. THIS SURFACE HIGH IS SUPPORTED ALOFT BY AN UPPER LEVEL RIDGE AXIS THAT EXTENDS FROM THE SE GULF OF MEXICO NE TO AN UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED NEAR 29N67W. THE UPPER LEVEL RIDGING IS PROVIDING A MAJORITY OF THE SW NORTH ATLC WITH NELY UPPER LEVEL FLOW RESULTING IN A DRY AND STABLE ATMOSPHERE UNDER MOSTLY CLEAR SKIES THIS EVENING. FARTHER E...A COLD FRONT EXTENDS INTO THE AREA NEAR 32N31W ALONG 28N44W 29N52W. ISOLATED SHOWERS ARE WITHIN 90 NM EITHER SIDE OF THE FRONT. UPPER LEVEL TROUGHING N OF 27N OVER THE EASTERN ATLC IS SUPPORTING THE FRONT. A WEAK SURFACE RIDGE ANCHORED BY A 1018 MB HIGH NEAR 30N12W COVERS THE REMAINDER OF THE BASIN. $$ HUFFMAN