000 AXNT20 KNHC 040557 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT SUN OCT 04 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 34W S OF 15N MOVING W NEAR 15 KT. EMBEDDED WITHIN THE ITCZ...A BROAD SWATH OF DEEP LAYER MOISTURE SURROUNDS THE WAVE FROM 5N-14N BETWEEN 32W-41W AS OBSERVED IN THE TOTAL PRECIPITABLE WATER IMAGERY. LOW-LEVEL CYCLONIC TURNING IS NOTED PRIMARILY W OF THE WAVE AXIS ON SATELLITE IMAGERY AND IS ENHANCING SCATTERED STRONG CONVECTION FROM 9N-15N BETWEEN 33W-40W. TROPICAL WAVE IS ALONG 51W S OF 15N MOVING W NEAR 15 KT. RATHER WELL DEFINED ON SATELLITE IMAGERY...THIS WAVE EXHIBITS A MAXIMUM IN 850 MB RELATIVE VORTICITY IN THE CIMSS WAVETRAK MODEL GUIDANCE IN THE VICINITY OF THE WAVE AXIS NEAR 10N. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 10N-16N BETWEEN 46W-54W. TROPICAL WAVE IS ALONG 75W S OF 19N MOVING W NEAR 10 KT. WEAK CYCLONIC CURVATURE IS NOTED IN THE LOW-LEVEL CLOUD FIELD OVER THE CENTRAL CARIBBEAN. THE WAVE ALSO LIES BENEATH UPPER LEVEL TROUGHING BETWEEN 72W-78W. SCATTERED MODERATE CONVECTION IS FROM 12N-16N BETWEEN 70W-80W AND IS LIKELY ENHANCED BY THE UPPER LEVEL TROUGH. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 8N13W 11N33W 10N36W 9N50W 9N52W 8N61W. ASIDE FROM THE CONVECTION ASSOCIATED WITH THE TROPICAL WAVES...SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 4N-10N BETWEEN 38W-49W. ...DISCUSSION... GULF OF MEXICO... A STATIONARY FRONT EXTENDS ACROSS ALONG THE NRN GULF COAST FROM TALLAHASSEE TO NEW ORLEANS AND INTO SRN TEXAS NEAR GALVESTON. MOSTLY SELY WINDS OF UP TO 15 KT ARE OBSERVED OVER MUCH OF THE CENTRAL AND WRN GULF THIS EVENING. THIS MOIST LOW-LEVEL SLY FLOW ALONG WITH LOW-LEVEL CONVERGENCE NEAR THE FRONTAL BOUNDARY IS GENERATING SCATTERED SHOWERS AND ISOLATED TSTMS N OF 27N W OF 90W. THIS ACTIVITY IS BEING ENHANCED BY ANTICYCLONIC FLOW AND UPPER LEVEL DIFFLUENCE FOUND ACROSS MUCH OF THE GULF AS AN UPPER LEVEL HIGH IS CENTERED NEAR 21N98W. ELSEWHERE...THE GULF REMAINS RATHER TRANQUIL AS THE NLY FLOW REGIME ALOFT KEEPS STABLE ATMOSPHERIC CONDITIONS OVER THE GULF S OF 27N. CARIBBEAN SEA... AN UPPER LEVEL TROUGH COVERS THE CENTRAL CARIBBEAN FOCUSED ON AN UPPER LOW CENTERED NEAR 16N75W. COMBINED WITH THE UPPER LEVEL RIDGE LOCATED OVER THE GULF OF MEXICO...NLY WINDS ALOFT ARE PROVIDING DRY STABLE AIR N OF 16N W OF 78W. THE UPPER LEVEL TROUGHING COUPLED WITH THE TROPICAL WAVE ALONG 75W ARE GENERATING CLUSTERS OF SCATTERED SHOWERS AND ISOLATED TSTMS S OF 16N BETWEEN 72W-82W. E OF THE UPPER LEVEL TROUGH...A LARGE AREA OF MOIST SWLY FLOW AND UPPER LEVEL DIFFLUENCE ARE NOTED ON WATER VAPOR IMAGERY WHICH IS GENERATING ISOLATED SHOWERS E OF 74W COVERING MUCH OF THE ERN CARIBBEAN AND LESSER ANTILLES. ATLANTIC OCEAN... AN UPPER LEVEL TROUGH EXTENDS OVER THE W ATLC WATERS WITH AXIS ALONG 74W. THIS TROUGHING EXTENDS SWD INTO THE CENTRAL CARIBBEAN TROUGH ACROSS ERN CUBA...THE WINDWARD PASSAGE AND HISPANIOLA. E OF THE UPPER LEVEL TROUGH AXIS...A LARGE AREA OF UPPER DIFFLUENCE IS NOTED ON WATER VAPOR IMAGERY N OF 22N BETWEEN 64W-74W. ISOLATED SHOWERS ARE FOUND OVER THIS AREA...WITH SCATTERED SHOWERS FOUND MAINLY N OF 27N BETWEEN 65W-74W WHERE THE UPPER LEVEL FORCING IS STRONGEST. FARTHER TO THE E...A WEAKNESS IN THE CENTRAL ATLC SUBTROPICAL RIDGE IS NOTED BY A SURFACE TROUGH THAT EXTENDS FROM 30N50W TO 25N54W. SUPPORTED ALOFT BY A SHORTWAVE UPPER LEVEL TROUGH...MOST OF THE SCATTERED SHOWERS AND TSTMS BEING GENERATING ARE E OF THE SURFACE TROUGH FROM 24N-29N BETWEEN 42W-49W. THE UPPER LEVEL TROUGH EXTENDS SW FROM 24N50W TO E OF THE LESSER ANTILLES AND SUPPORTS ANOTHER SURFACE TROUGH EXTENDING FROM 21N57W TO 14N59W. SCATTERED SHOWERS ARE FOUND WITHIN 120 NM EITHER SIDE OF THE SURFACE TROUGH. ELSEWHERE OVER THE REMAINDER OF THE ERN ATLC...UPPER LEVEL ZONAL FLOW IS NOTED ON WATER VAPOR IMAGERY N OF 24N E OF 45W. EMBEDDED WITH THIS FLOW ALOFT IS A SURFACE TROUGH ANALYZED FROM 31N22W TO 28N35W. CLUSTERS OF SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING WITHIN 90 NM EITHER SIDE OF THE SURFACE TROUGH. THE TYPICAL E/W UPPER RIDGE DOMINATES MUCH OF THE TROPICS WITH THE AXIS EXTENDING ALONG 15N TO 50W ENHANCING THE CONVECTION ASSOCIATED WITH THE TROPICAL WAVES AND THE ITCZ. $$ HUFFMAN