000 AXNT20 KNHC 241755 CCA TWDAT TROPICAL WEATHER DISCUSSION...COR NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT THU SEP 24 2009 CLARIFYING THE WEATHER FEATURES AND RELATED PRECIPITATION THAT JUST PERTAIN TO THE UPPER LEVEL ELONGATED TROUGH THAT EXTENDS FROM THE NORTHERN BAHAMAS INTO THE SOUTHWESTERN GULF OF MEXICO SECTION... 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... AN EASTERN ATLANTIC OCEAN TROPICAL WAVE IS MOVING ACROSS THE CAPE VERDE ISLANDS ALONG 24W/25W TO THE SOUTH OF 18N...MOVING WEST ABOUT 15 KT. A 1010 MB LOW PRESSURE CENTER IS ALONG THE WAVE NEAR 14N. THIS FEATURE SHOWS UP WELL IN THE VISIBLE SATELLITE IMAGERY. SCATTERED STRONG SHOWERS AND THUNDERSTORMS COVER THE AREA FROM 12N TO 16N BETWEEN 27W AND 30W. OTHER SHOWERS AND THUNDERSTORMS COVER THE REST OF THE AREA FROM 12N TO 17N BETWEEN 23W AND 30W. AN ATLANTIC OCEAN TROPICAL WAVE HAS BEEN MOVED TO 54W/55W TO THE SOUTH OF 19N...MOVING WEST 15 KT. ITS CURRENT POSITION AGREES WITH SURFACE OBSERVATIONS AND MODEL INFORMATION. THE WAVE HAS BEEN MOVED AT LEAST A FEW DEGREES OF LONGITUDE MORE TO THE WEST THAN MAY BE EXPECTED BASED ON ITS 24/0600 UTC POSITION. IT IS POSSIBLE THAT STRONG ITCZ PRECIPITATION FROM 9N TO 12N BETWEEN 52W AND 55W IS BEING ENHANCED BY THE WAVE. ...THE ITCZ... FROM NORTHERN SENEGAL TOWARD THE 1010 MB LOW CENTER THAT IS ALONG THE 24W/25W TROPICAL WAVE...TO 9N26W TO 7N35W TO 11N53W... INTO NORTHEASTERN VENEZUELA NEAR 10N62W. SCATTERED MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS ARE WITHIN 120 NM ON EITHER SIDE OF 9N22W 6N31W 6N36W 9N45W TO 10N60W AND 9N62W. ...DISCUSSION... FROM THE ATLANTIC OCEAN NEAR THE NORTHERN BAHAMAS..TO THE STRAITS OF FLORIDA...TO THE WATERS JUST TO THE NORTH OF THE YUCATAN PENINSULA...INTO THE SOUTHWESTERN CORNER OF THE GULF OF MEXICO AND THE ISTHMUS OF TEHUANTEPEC... AN ELONGATED UPPER LEVEL TROUGH COVERS THE AREA FROM THE NORTHERN BAHAMAS...THROUGH THE STRAITS OF FLORIDA...TO THE WATERS JUST TO THE NORTH OF THE YUCATAN PENINSULA...INTO THE SOUTHWESTERN CORNER OF THE GULF OF MEXICO AND THE ISTHMUS OF TEHUANTEPEC. ISOLATED MODERATE SHOWERS ARE ALONG THE NORTHERN EDGE OF THE CYCLONIC FLOW OF THE ELONGATED TROUGH...FROM THE BAHAMAS TO THE ISTHMUS OF TEHUANTEPEC. THE REST OF THE GULF OF MEXICO... A STATIONARY FRONT PASSES THROUGH SOUTHERN LOUISIANA INTO THE WESTERN GULF OF MEXICO...THE COASTAL WATERS OF TEXAS AND MEXICO TO THE MEXICO COAST NEAR 18N94W...IN THE NORTHERN ISTHMUS OF TEHUANTEPEC. ISOLATED MODERATE SHOWERS AND POSSIBLE THUNDERSTORMS ARE IN A 60 NM WIDE LINE THAT IS ON THE WESTERN SIDE OF THE STATIONARY FRONT. A SURFACE TROUGH IS ALONG 85W/86W FROM 23N TO 31N. ISOLATED MODERATE SHOWERS FROM 24N TO 26N BETWEEN 84W AND 88W. THE REST OF THE CARIBBEAN SEA... UPPER LEVEL CYCLONIC FLOW...FROM THE NORTHEAST-TO-SOUTHWEST ORIENTED UPPER LEVEL TROUGH THAT STRETCHES FROM THE NORTHERN BAHAMAS TO THE YUCATAN PENINSULA TO THE SOUTHWESTERN GULF OF MEXICO...COVERS THE CARIBBEAN SEA TO THE WEST OF 82W/83W TO THE NORTH OF NICARAGUA. STRONG SHOWERS AND THUNDERSTORMS ARE FROM 13N TO 15N BETWEEN 81W AND 82W...AND FROM 11N TO 13N BETWEEN 82W AND 84W...IN UPPER LEVEL DIFFLUENT WIND FLOW. OTHER SHOWERS AND THUNDERSTORMS ARE FROM 16N TO 18N BETWEEN 82W AND 86W IN THE SAME DIFFLUENT FLOW. A SURFACE TROUGH EXTENDS FROM JUST TO THE NORTH OF THE YUCATAN PENINSULA TO THE NORTHWESTERN CORNER OF THE PENINSULA TO NORTHWESTERN GUATEMALA. SCATTERED MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS EXTEND FROM THE GULF OF HONDURAS TO THE NORTHEASTERN YUCATAN PENINSULA. WARMING CLOUD TOP TEMPERATURES AND WEAKENING CONVECTIVE PRECIPITATION COVERS THE NORTHWESTERN CORNER OF THE AREA TO THE NORTH OF 18N BETWEEN JAMAICA AND THE WESTERN TIP OF CUBA. BROAD UPPER LEVEL CYCLONIC FLOW COVERS THE AREA TO THE EAST OF 71W. THIS CYCLONIC FLOW IS AT THE BASE OF A TROUGH THAT ORIGINATES FROM A 28N66W CYCLONIC CIRCULATION CENTER. THE REST OF THE ATLANTIC OCEAN... A WELL-ESTABLISHED UPPER LEVEL CYCLONIC CIRCULATION CENTER AND TROUGH EXTEND FROM 28N66W TO 20N67W TO 12N65W IN THE SOUTHEASTERN CARIBBEAN SEA. WIDELY SCATTERED MODERATE SHOWERS ARE TO THE NORTH OF 27N BETWEEN 60W AND 70W. SCATTERED MODERATE TO STRONG SHOWERS AND POSSIBLE THUNDERSTORMS COVER THE AREA FROM 24N TO 27N BETWEEN 52W AND 55W...AND FROM 30N TO 32N BETWEEN 57W AND 61W...IN AN AREA OF UPPER LEVEL DIFFLUENT FLOW THAT IS TO THE EAST OF THE 28N66W 20N67W TROUGH. A SURFACE TROUGH IS ALONG 24N52W 20N54W. EARLIER SHOWERS NEAR THE TROUGH HAVE DISSIPATED AND/OR HAVE BEEN DISSIPATING DURING THE LAST SIX HOURS. AN UPPER LEVEL CYCLONIC CIRCULATION CENTER IS NEAR 34N17W. CYCLONIC FLOW COVERS THE AREA TO THE NORTH OF 27N TO THE EAST OF 24W. $$ MT