000 AXNT20 KNHC 180003 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT FRI JUL 17 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... A TROPICAL WAVE IS JUST W OF THE CAPE VERDE ISLANDS ALONG 26W S OF 25W MOVING W NEAR 10 KT. THIS POSITION IS IN PHASE WITH THE SSMI/AMSRE DERIVED TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED SHOWERS ARE FROM 9N-14N BETWEEN 24W-30W. A TROPICAL WAVE IS ALONG 36W S OF 17N MOVING W NEAR 10 KT. THIS WAVE COINCIDES WITH A LOW TO MIDDLE LEVEL CYCLONIC CIRCULATION ALONG THE WAVE AXIS NEAR 12N. SCATTERED SHOWERS ARE FROM 7N-14N BETWEEN 34W-39W. A TROPICAL WAVE IS E OF THE LESSER ANTILLES ALONG 55W S OF 19N MOVING W NEAR 18 KT. THIS WAVE COINCIDES WITH A MOISTURE MAXIMUM ON THE SSMI/AMSRE DERIVED TOTAL PRECIPITABLE WATER IMAGERY SATELLITE IMAGERY. AN INVERTED-V PATTERN OF LOW CLOUDS IS ALSO EVIDENT ON SATELLITE IMAGERY. SCATTERED MODERATE CONVECTION IS FROM 12N-17N BETWEEN 53W-56W. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 11N15W 12N26W 10N30W 12N36W 9N40W 13N55W 11N63W. BESIDES THE CONVECTION AND SHOWERS MENTIONED IN THE TROPICAL WAVE SECTION ABOVE...SCATTERED MODERATE CONVECTION IS ALONG THE COAST OF WEST AFRICA FROM 10N-12N BETWEEN 12W-16W. ...DISCUSSION... GULF OF MEXICO... A SURFACE TROUGH IS OVER THE NORTHERN GULF STATES...E OF TEXAS TO FLORIDA...PRODUCING ISOLATED MODERATE CONVECTION OVER THE N GULF OF MEXICO FROM 27N-32N BETWEEN 82W-95W. A 1019 MB HIGH IS CENTERED OVER THE E GULF OF MEXICO NEAR 25N83W. MOSTLY FAIR SKIES ARE OVER THE S GULF S OF 27N. 10-15 KT ANTICYCLONIC SURFACE WINDS ARE OVER THE GULF. IN THE UPPER LEVELS...THE WESTERN EXTENT OF A RIDGE IS PRODUCING UPPER LEVEL EASTERLY FLOW. CONSIDERABLE UPPER LEVEL MOISTURE IS N OF 27N WITH STRONG SUBSIDENCE OVER THE S GULF. EXPECT MORE CONVECTION OVER THE N GULF N OF 27N AND E OF 95W OVER THE NEXT 24 HOURS. CARIBBEAN SEA... FRESH TO STRONG TRADEWINDS ARE OVER THE CARIBBEAN SEA WITH THE STRONGEST FLOW NEAR THE COAST OF COLOMBIA. A TROPICAL WAVE IS APPROACHING THE LESSER ANTILLES WITH CONVECTION...AND ANOTHER TROPICAL WAVE HAS MOVED INTO THE EASTERN PACIFIC. A GOOD AMOUNT OF DRY AIR AND SAHARAN DUST REMAINS BEHIND THE LAST TROPICAL WAVE SUPPRESSING THUNDERSTORMS AND SHOWERS IN THE CARIBBEAN. SCATTERED MODERATE CONVECTION IS INLAND HOWEVER OVER NORTHERN VENEZUELA AND NORTHERN COLOMBIA. SIMILAR CONVECTION IS OVER PANAMA AND COSTA RICA FROM 8N-11N BETWEEN 81W-85W. IN THE UPPER LEVELS...A SMALL UPPER LEVEL LOW IS CENTERED NEAR THE CAYMAN ISLANDS AT 19N81W. THE WESTERN EXTENT OF AN UPPER LEVEL HIGH IS OVER THE CENTRAL AND WESTERN CARIBBEAN PRODUCING MAINLY SW UPPER LEVEL FLOW. UPPER LEVEL MOISTURE IS OVER THE S CARIBBEAN S OF 13N. STRONG SUBSIDENCE IS OVER THE REMAINDER OF THE CARIBBEAN. EXPECT...CONVECTION OVER THE E CARIBBEAN DUE TO A TROPICAL WAVE OVER THE NEXT 24 HOURS. ALSO EXPECT CONTINUED CONVECTION OVER THE SOUTHERN CARIBBEAN S OF 13N. ATLANTIC OCEAN... A 1036 MB HIGH IS CENTERED NEAR THE AZORES AT 40N24W. SURFACE RIDGING EXTENDS W FROM THE HIGH TO E OF THE BAHAMAS NEAR 27N73W. MOSTLY FAIR WEATHER IS OVER THE ATLANTIC N OF 20N BETWEEN 20W-75W. IN THE UPPER LEVELS...A RIDGE IS OVER THE W ATLANTIC W OF 60W. AN UPPER LEVEL LOW IS OVER THE CENTRAL ATLANTIC NEAR 28N51W. AN UPPER LEVEL LOW IS OVER THE E ATLANTIC NEAR 31N21W. OVER THE TROPICS AN UPPER LEVEL HIGH IS CENTERED NEAR 18N46W. EXPECT...SHOWERS AND ISOLATED THUNDERSTORMS WITH THE TWO TROPICAL WAVES OVER THE NEXT 24 HOURS. $$ FORMOSA