000 AXNT20 KNHC 171756 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SAT OCT 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 77W S OF 18N MOVING W NEAR 10 KT. WAVE COINCIDES WITH A SURGE OF DEEP LAYER MOISTURE OBSERVED IN TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE TO STRONG CONVECTION IS W OF THE WAVE AXIS FROM 9N-13N BETWEEN 78W-82W. ...THE ITCZ... THE ITCZ AXIS IS CENTERED ALONG 12N16W 9N20W 7N40W 9N48W 7N60W. THE ITCZ REMAINS ACTIVE WITH CLUSTERS OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION FROM 5N-12N BETWEEN 12W-30W. ISOLATED MODERATE CONVECTION IS FROM 6N-10N BETWEEN 30W-34W...AND FROM 8N-11N BETWEEN 45W-54W. SCATTERED MODERATE CONVECTION IS FROM 7N-8N BETWEEN 50W-53W. ...DISCUSSION... THE GULF OF MEXICO... AS OF 1500 UTC...A COLD FRONT EXTENDS FROM SOUTH FLORIDA TO THE BAY OF CAMPECHE ALONG 26N80W 21N93W 18N94W. WIDELY SCATTERED MODERATE CONVECTION IS OVER S FLORIDA FROM 25N-27N BETWEEN 80W-82W. SCATTERED MODERATE CONVECTION IS FROM 22N-23N BETWEEN 89W-91W. WIDELY SCATTERED MODERATE CONVECTION IS ALSO OVER THE SW GULF OF MEXICO FROM 18N-23N BETWEEN 93W-98W. 20-25 KT NORTHERLY WINDS ARE N OF THE FRONT. 10 KT NORTHERLY WINDS ARE S OF THE FRONT W 0F 85W. 10 KT WESTERLY WINDS ARE S OF THE FRONT E OF 85W. MOSTLY FAIR SKIES ARE OVER THE NW GULF. THERE IS A 30 DEGREE FAHRENHEIT DROP IN TEMPERATURE BETWEEN SOUTH FLORIDA AND THE FLORIDA PANHANDLE. IN THE UPPER LEVELS...AN UPPER LEVEL TROUGH IS OVER THE GULF OF MEXICO N OF 23N SUPPORTING THE SURFACE COLD FRONT. AN UPPER LEVEL HIGH OVER S MEXICO NEAR 17N99W PRODUCING RIDGING OVER THE SW GULF S OF 23N. EXPECT THE FRONT TO CONTINUE MOVING SE ACROSS THE GULF REACHING NW CUBA BY TONIGHT. HIGH PRESSURE WILL BUILD IN THE WAKE OF THE FRONT. THE CARIBBEAN SEA... A TROPICAL WAVE IS ALONG 77W PRODUCING CONVECTION OVER THE SW CARIBBEAN. SEE ABOVE. FRESH BREEZE TRADEWINDS ARE OVER THE E CARIBBEAN E OF 77W WHILE GENTLE BREEZE TRADEWINDS ARE W OF 77W. SCATTERED SHOWERS ARE OVER THE LEEWARD ISLANDS S OF PUERTO RICO. SIMILAR SHOWERS ARE OVER THE CENTRAL CARIBBEAN BETWEEN 68W-80W. SCATTERED MODERATE CONVECTION IS W OF THE CAYMAN ISLANDS FROM 18N-20N BETWEEN 83W-85W. IN THE UPPER LEVELS...AN UPPER LEVEL HIGH IS CENTERED OVER N COLOMBIA NEAR 12N71W. SIGNIFICANT UPPER LEVEL MOISTURE IS OVER THE CARIBBEAN EXCEPT FOR THE NW CARIBBEAN AND CENTRAL AMERICA N OF HONDURAS WHERE STRONG SUBSIDENCE IS NOTED. EXPECT...THE COLD FRONT TO EXTEND FROM W CUBA TO THE YUCATAN PENINSULA AT 19N IN 24 HOURS WITH CONVECTION. ALSO EXPECT THE TROPICAL WAVE TO MOVE W AND PRODUCE MORE CONVECTION OVER THE SW CARIBBEAN. THE ATLANTIC OCEAN... AS OF 1500 UTC...A COLD FRONT ENTERS THE DISCUSSION AREA NEAR 32N72W AND EXTENDS SW TO SOUTH FLORIDA NEAR 26N80W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 27N-30N BETWEEN 74W-77W... AND OVER THE N BAHAMAS FROM 25N-27N BETWEEN 76W-79W. A 1024 MB HIGH IS OVER THE CENTRAL ATLANTIC NEAR 27N55W. THE TAIL END OF A COLD FRONT IS FURTHER E FROM 32N37W TO 23N42W. SCATTERED SHOWERS ARE WITHIN 45 NM OF THE FRONT. A SURFACE TROUGH IS OVER THE E ATLANTIC ALONG 30N26W 26N30W 20N34W. SCATTERED MODERATE CONVECTION IS E OF THE TROUGH AXIS FROM 28N-30N BETWEEN 23W-25W. IN THE UPPER LEVELS...AN UPPER LEVEL TROUGH IS OVER THE W ATLANTIC N OF 24N AND W OF 75W. AN UPPER LEVEL HIGH IS CENTERED NEAR 26N61W. AN UPPER LEVEL LOW IS OVER THE E ATLANTIC NEAR 29N33W. ANOTHER UPPER LEVEL LOW IS CENTERED N OF THE CAPE VERDE ISLANDS NEAR 24N23W. EXPECT...MORE CONVECTION ALONG THE ITCZ ESPECIALLY E OF 40W OVER THE NEXT 24 HOURS. $$ FORMOSA