000 AXNT20 KNHC 191102 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT MON OCT 19 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 24W S OF 17N MOVING W NEAR 15 KT. THE WAVE COINCIDES WITH A DEEP LAYER MOISTURE MAXIMUM ACROSS THE EASTERN TROPICAL ATLC AS OBSERVED IN TOTAL PRECIPITABLE WATER IMAGERY. GLOBAL MODEL GUIDANCE FIELDS OF 850 MB RELATIVE VORTICITY AND 700 MB STREAMLINES ALSO DEPICT CYCLONIC TURNING IN THE VICINITY OF THE WAVE AXIS BETWEEN 22W-28W. SCATTERED SHOWERS AND ISOLATED MODERATE CONVECTION ARE FROM 6N-17N BETWEEN 19W-27W. TROPICAL WAVE IS ALONG 37W S OF 15N MOVING W NEAR 12 KT. THE WAVE COINCIDES WITH THE LEADING EDGE OF A DEEP LAYER MOISTURE MAXIMUM OBSERVED ACROSS THE EASTERN TROPICAL ATLC E OF 40W IN TOTAL PRECIPITABLE WATER IMAGERY. CIMSS WAVETRAK MODEL GUIDANCE ALSO DEPICTS A MAXIMUM IN 850 MB RELATIVE VORTICITY FOCUSED ON THE NORTHERN EXTENT OF THE WAVE N OF 8N. ISOLATED SHOWERS ARE FROM 9N-16N BETWEEN 35W-39W. TROPICAL WAVE IS ALONG 60W S OF 12N MOVING W NEAR 15 KT. AN AREA OF DEEP LAYER MOISTURE IS PROPAGATING WWD ACROSS EASTERN VENEZUELA AND PORTIONS OF THE TROPICAL NORTH ATLC S OF 11N W OF 59W. SCATTERED SHOWERS AND ISOLATED MODERATE CONVECTION ARE FROM 8N-11N BETWEEN 57W-63W. TROPICAL WAVE IS ALONG 84W S OF 16N MOVING W NEAR 15 KT. THE WAVE LIES WITHIN A BROAD AREA OF DEEP MOISTURE OVER THE WESTERN CARIBBEAN AS OBSERVED IN TOTAL PRECIPITABLE WATER IMAGERY. A STATIONARY 1010 MB LOW IS IMMEDIATELY E OF THE WAVE AXIS CENTERED NEAR 12N82W. UPPER LEVEL DIFFLUENCE LIES ALOFT IN THE VICINITY OF THE WAVE AXIS AND IS ENHANCING NUMEROUS MODERATE AND SCATTERED STRONG CONVECTION FROM 11N-17N BETWEEN 78W-84W. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 11N15W 12N22W 12N25W 9N35W 8N39W 6N58W. BESIDES THE CONVECTION MENTIONED IN THE TROPICAL WAVE SECTION...SCATTERED SHOWERS AND ISOLATED MODERATE CONVECTION ARE FROM 8N-16N BETWEEN 24W-35W. SIMILAR CONVECTION IS ALONG THE W AFRICA COAST FROM 8N-14N BETWEEN 12W-17W. ...DISCUSSION... GULF OF MEXICO... A 1027 MB SURFACE HIGH CENTERED OVER EASTERN TENNESSEE NEAR 36N84W EXTENDS A SURFACE RIDGE OVER FLORIDA...THE ENTIRE GULF OF MEXICO AND EASTERN MEXICO. N-NE WINDS UP TO 20 KT DOMINATE OVER THE EASTERN GULF AND GRADUALLY DIMINISH TO 10-15 KT E-SE OVER THE NW GULF. THIS SURFACE HIGH IS SUPPORTED ALOFT BY A STABLE DRY AND COOLER AIRMASS ON THE BACKSIDE OF AN UPPER LEVEL TROUGH WITH AXIS ALONG THE EASTERN U.S. SEABOARD AND A PORTION OF THE WESTERN ATLC. NWLY WINDS ALOFT AND VERY STRONG SUBSIDENCE ARE OVER THE GULF AND FLORIDA PENINSULA. THE SURFACE RIDGE IS FORECAST TO SHIFT GRADUALLY EASTWARD REMAINING MOSTLY OVER MUCH OF THE GULF THROUGH MID-WEEK WITH SLY RETURN FLOW EXPECTED ACROSS THE WRN GULF BY WEDNESDAY AHEAD OF THE NEXT COLD FRONT TO ENTER THE NW GULF WATERS ON THURSDAY. CARIBBEAN SEA... AN UPPER LEVEL TROUGH IS OVER THE WESTERN ATLC AND GULF OF MEXICO DIPPING SOUTH INTO THE NW CARIBBEAN. THIS UPPER LEVEL TROUGHING SUPPORTS A STATIONARY FRONT THAT EXTENDS INTO THE CARIBBEAN SEA THROUGH THE WINDWARD PASSAGE AND CONTINUES ALONG 19N80W TO THE NORTH CENTRAL HONDURAS COAST NEAR 16N85W. LOW-LEVEL CONVERGENCE IN THE VICINITY OF THE FRONTAL BOUNDARY COUPLED WITH UPPER LEVEL DIFFLUENCE E OF THE UPPER LEVEL TROUGH ARE GENERATING SCATTERED SHOWERS AND ISOLATED TSTMS WITHIN 120 NM EITHER SIDE OF THE FRONTAL BOUNDARY. TO THE SOUTH OVER THE SW CARIBBEAN...THE TROPICAL WAVE ALONG 84W AND A 1010 MB LOW CENTERED NEAR 12N82W ARE PRODUCING NUMEROUS SHOWERS AND SCATTERED STRONG TSTMS FROM THE ITCZ AXIS ACROSS PANAMA ALONG 9N TO 17N BETWEEN 76W-84W. UPPER LEVEL RIDGING POSITIONED ACROSS THE SW CARIBBEAN W OF 72W IS ALSO ENHANCING THIS CONVECTION. E OF 72W...UPPER LEVEL TROUGHING AND GENERALLY DRY NWLY FLOW ALOFT ARE ACROSS THE EASTERN CARIBBEAN WITH ELY TRADE WINDS UP TO 20 KT. A FEW ISOLATED LOW-LEVEL SHOWERS ARE HOWEVER OCCURRING N OF 15N E OF 72W. ATLANTIC OCEAN... A COLD FRONT ENTERS THE DISCUSSION AREA NEAR 32N68W AND EXTENDS S-SW TO THE WINDWARD PASSAGE NEAR 20N74W. SCATTERED SHOWERS AND TSTMS ARE OCCURRING WITHIN 120 NM EITHER SIDE OF THE FRONT. THIS FRONT IS SUPPORTED ALOFT BY A SHARP UPPER LEVEL TROUGH W OF 68W WITH AXIS ALONG THE EASTERN U.S. SEABOARD TO THE NW BAHAMAS AND CENTRAL CUBA. A 1023 MB SURFACE HIGH IS OVER THE CENTRAL ATLC NEAR 34N51W. A WEAKNESS IN THE SUB-TROPICAL RIDGE IS ANALYZED AS A SURFACE TROUGH THAT EXTENDS FROM 16N49W TO 27N44W AND BEYOND 32N45W. LOW-LEVEL CONVERGENCE NEAR THE SURFACE TROUGH IS GENERATING SCATTERED SHOWERS WITHIN 90 NM EITHER SIDE OF THE BOUNDARY. ANOTHER SURFACE TROUGH IS OVER THE EASTERN ATLC ALONG 26N31W TO 31N27W. THESE TWO SURFACE FEATURES ARE SUPPORTED ALOFT BY AN ELONGATED UPPER LEVEL LOW CENTERED NEAR 23N42W. THE UPPER LOW STRETCHES NE TO 28N31W AND SW TOWARDS THE LESSER ANTILLES AND EXTREME EASTERN CARIBBEAN SEA NEAR 13N64W. $$ HUFFMAN