000 AXNT20 KNHC 150516 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT THU OCT 15 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 0345 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 64W S OF 14N MOVING W NEAR 15 KT. WAVE IS AT THE LEADING EDGE OF AN AREA OF DEEP MOISTURE AS INDICATED IN THE TOTAL PRECIPITABLE WATER IMAGERY AND REMAINS AT A LOW AMPLITUDE. ISOLATED SHOWERS ARE S OF 14N TO INLAND OVER VENEZUELA BETWEEN THE WINDWARD ISLANDS AND 67W. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 11N14W 7N27W 8N46W 10N52W 8N57W 10N62W. A SURFACE TROUGH IS EMBEDDED WITHIN THE ITCZ ALONG 33W/34W FROM 4N-10N AND A SECOND SURFACE TROUGH ALSO EMBEDDED WITHIN THE ITCZ ALONG 52W FROM 8N-14N. SCATTERED MODERATE/STRONG CONVECTION IS WITHIN 75 NM OF THE COAST OF W AFRICA BETWEEN FREETOWN SIERRA LEONE AND BISSAU IN GUINEA-BISSAU. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 6N-13N BETWEEN 17W-29W AND FROM 7N-11N BETWEEN 52W-59W. ...DISCUSSION... GULF OF MEXICO... BROAD UPPER RIDGE CONTINUES TO DOMINATE THE GULF ANCHORED OVER N/CENTRAL MEXICO WITH AN AXIS EXTENDING E ACROSS EXTREME S FLORIDA INTO THE W ATLC. MOSTLY DRY STABLE AIR DOMINATES THE AREA WITH SOME LINGERING ISOLATED SHOWERS OVER THE NE GULF N OF 27N E OF 86W AS A RESULT OF AN UPPER LEVEL SHORTWAVE TROUGH MOVING ACROSS NE FLORIDA INTO THE W ATLC. AFTERNOON THUNDERSTORMS THAT DEVELOPED INLAND OVER THE YUCATAN PENINSULA ARE MOVING INTO THE E BAY OF CAMPECHE WITHIN 60 NM S OF 21N E OF 92W. SIMILAR ACTIVITY DEVELOPED OVER W CUBA MOVING INTO THE SE GULF AND THE YUCATAN CHANNEL WITHIN 45 NM OF LINE FROM 23N83W TO 22N87W. THE REMAINDER OF THE GULF IS EXPERIENCING FAIR WEATHER WITH REMARKABLY CLEAR SKIES AGAIN TONIGHT. THE NEXT FRONT TO ENTER THE GULF WATERS WILL BE ON FRI. CARIBBEAN SEA... THE BROAD UPPER RIDGE THAT COVERS MOST OF THE ATLC AND GULF OF MEXICO IS GIVING THE CARIBBEAN UPPER EASTERLY WINDS N OF A SHEAR AXIS THAT ENTERS THE CARIBBEAN OVER THE LESSER ANTILLES BETWEEN MARTINIQUE AND DOMINICA ALONG 14N73W TO PANAMA NEAR 9N79W PRODUCING PATCHES OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS OVER HAITI FROM 17N-19N BETWEEN 71W-75W AND WITHIN 90 NM ALONG THE S COAST OF CUBA FROM 77W-80W AND IN THE SW CARIBBEAN S OF 12N E OF 82W TO INLAND OVER COLOMBIA AND PANAMA. ISOLATED SHOWERS ARE OVER THE NE CARIBBEAN N OF 17N E OF 71W FROM THE LEEWARD ISLANDS TO THE DOMINICAN REPUBLIC. THE REMAINDER OF THE CARIBBEAN IS UNDER A VERY DRY AND STABLE AIRMASS GIVING THAT AREA CLEAR SKIES AGAIN TONIGHT. ATLANTIC OCEAN... AN UPPER LEVEL SHORTWAVE TROUGH IS MOVING ACROSS NE FLORIDA INTO THE W ATLC N OF 29N W OF 78W. A MID/UPPER LEVEL TROUGH IS FURTHER TO THE E AND N OF 30N FROM 50W-55W SUPPORTING A COLD FRONT THAT ENTERS THE REGION NEAR 32N54W EXTENDING ALONG 27N67W 27N72W THEN NW TO A 1009 MB LOW OFF THE COAST OF SOUTH CAROLINA NEAR 32N79W. A DISSIPATING FRONTAL BOUNDARY IS JUST TO THE N EXTENDING THROUGH 32N57W 28N67W TO 29N74W. SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS ARE WITHIN 60/75 NM OF LINE FROM 27N61W TO BEYOND 32N50W WITH CLUSTERS OF SIMILAR ACTIVITY N OF 28N W OF 70W. A WEAK 1015 MB HIGH IS OVER THE BAHAMA ISLANDS NEAR 26N76W. A BROAD UPPER RIDGE CONTINUES TO DOMINATE THE ATLC W OF 35W EXTENDING AN AXIS FROM ACROSS THE GULF OVER EXTREME S FLORIDA ALONG 25N68W TO NEAR 22N35W AND IS PROVIDING DIFFLUENCE ALOFT TO ENHANCING THE ACTIVITY ASSOCIATED WITH THE FRONT ABOVE. A SHARP UPPER TROUGH DIGS S INTO THE E ATLC NEAR 32N27W S TO 16N30W THEN EXTENDS W AS A SHEAR AXIS ALONG 20N47W OVER THE LESSER ANTILLES BETWEEN MARTINIQUE AND DOMINICA INTO THE S CARIBBEAN. THIS UPPER TROUGH IS SUPPORTING A WEAKENING SURFACE TROUGH EXTENDING ALONG 30N31W 25N31W THEN W TO 24N40W. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE FROM 25N-29N BETWEEN 21W AND THE ABOVE SURFACE TROUGH. $$ WALLACE