000 AXNT20 KNHC 232354 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT TUE SEP 23 2008 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. ...SPECIAL FEATURES... A 1008 MB LOW PRESSURE CENTER IS OVER THE DOMINICAN REPUBLIC NEAR 19N70W. THE CIRCULATION AROUND THIS LOW REMAINS BROAD...WITH NUMEROUS SHOWERS AND THUNDERSTORMS IMPACTING AREAS AROUND PUERTO RICO... THE DOMINICAN REPUBLIC...AND ADJACENT WATERS. SCATTERED MODERATE CONVECTION IS S OF THE LOW CENTER FROM 16N-20N BETWEEN 68W-73W. A LARGE BAND OF SCATTERED MODERATE TO STRONG CONVECTION EXTENDS S OF PUERTO RICO TO N VENEZUELA FROM 9N-18N BETWEEN 65W-72W. A PORTION OF THAT CONVECTION S OF 16N COULD BE DUE TO A TROPICAL WAVE ALONG 71W. HEAVY RAINFALL WITH POTENTIALLY LIFE-THREATENING FLASH FLOODING AND MUDSLIDES IS EXPECTED TO CONTINUE IMPACTING THE AREA FROM PUERTO RICO THROUGH HISPANIOLA THROUGH EARLY WEDNESDAY. SURFACE PRESSURES ARE FALLING IN THE VICINITY OF THE SURFACE LOW...AND UPPER-LEVEL WINDS ARE EXPECTED TO BECOME A LITTLE MORE CONDUCIVE FOR DEVELOPMENT INTO THE NEXT COUPLE DAYS. THIS SYSTEM HAS THE POTENTIAL TO BECOME A TROPICAL DEPRESSION AT ANY TIME DURING THE NEXT DAY OR TWO AS IT MOVES N/NW AWAY FROM HISPANIOLA. ...TROPICAL WAVES... AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 36W S OF 18N MOVING W 10-15 KT. THIS WAVE REMAINS EMBEDDED WITHIN A BROAD AREA OF DEEP LAYER MOISTURE AS INDICATED BY MIMIC TOTAL PRECIPITABLE WATER ANIMATION. THIS AREA IS BECOMING BETTER DEFINED WITH TIME...AND MODEL GUIDANCE IS HINTING AT SOME VERY WEAK CIRCULATION ALONG THE WAVE AXIS N OF 14N. SCATTERED MODERATE CONVECTION IS FROM 11N-14N BETWEEN 33W-39W. AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 59W S OF 19N MOVING W 10-15 KT. WEAK COUNTERCLOCKWISE CURVATURE IS NOTED ON SURFACE OBSERVATIONS AND QUIKSCAT OBSERVATIONS E OF THE WINDWARD ISLANDS. ISOLATED MODERATE CONVECTION IS FROM 14N-17N BETWEEN 57W-59W. A CARIBBEAN SEA TROPICAL WAVE IS ALONG 71W S OF 16N MOVING W NEAR 15 KT. THIS WAVE IS ENHANCING CONVECTION OVER THE SE CARIBBEAN...EXTENDING S INTO NW VENEZUELA. A WESTERN CARIBBEAN SEA TROPICAL WAVE IS ALONG 85W/86W S OF 18N MOVING W NEAR 15 KT. AN INVERTED-V CURVATURE SIGNATURE IS NOTED THE LOW CLOUDS ON SATELLITE IMAGERY. WIDELY SCATTERED MODERATE CONVECTION IS OVER CENTRAL AMERICA FROM 7N-16N BETWEEN 80W-88W...WITH CONVECTION EXTENDING INTO THE E PACIFIC. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 9N13W 9N20W 12N35W 9N45W 10N62W. BESIDES THE CONVECTION MENTIONED ON THE TROPICAL WAVE SECTION...ISOLATED MODERATE CONVECTION IS FROM 3N-6N BETWEEN 18W-32W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 9N-12N BETWEEN 19W-25W. ...DISCUSSION... GULF OF MEXICO... A SURFACE TROUGH IS OVER THE W GULF OF MEXICO ALONG 25N97W 20N96W. SCATTERED MODERATE CONVECTION IS FROM 19N-25N BETWEEN 94W-98W. SCATTERED MODERATE TO STRONG CONVECTION IS FURTHER SE OVER THE E BAY OF CAMPECHE AND INLAND YUCATAN PENINSULA FROM 17N-21N BETWEEN 87W-92W. ELSEWHERE...SCATTERED MODERATE CONVECTION IS OVER S FLORIDA FROM 24N-26N BETWEEN 80W-82W. IN THE UPPER LEVELS...AN UPPER LEVEL HIGH IS OVER NE MEXICO NEAR 23N98W. ANTICYCLONIC FLOW EXTENDS E OVER THE ENTIRE GULF OF MEXICO. EXPECT...CONTINUED CONVECTION OVER THE SW GULF OF MEXICO TO INCLUDE THE BAY OF CAMPECHE AND THE YUCATAN PENINSULA FOR THE NEXT 24 HOURS. CARIBBEAN SEA... THE MAIN CONCERN FOR THE NEXT FEW DAYS IS THE AREA OF LOW PRESSURE DESCRIBED IN THE SPECIAL FEATURES SECTION. THREE TROPICAL WAVES ARE ALSO OVER THE CARIBBEAN AND CENTRAL AMERICA. SEE ABOVE. IN ADDITION...SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS S OF JAMAICA FROM 15N-17N BETWEEN 75W-78W. ISOLATED MODERATE CONVECTION IS OVER W CUBA AND THE YUCATAN CHANNEL FROM 21N-23N BETWEEN 81W-86W. IN THE UPPER LEVELS... THE UPPER LEVEL HIGH CENTERED OVER NE MEXICO IS PRODUCING NE FLOW OVER THE W CARIBBEAN AND CENTRAL AMERICA W OF 80W. A TROUGH IS OVER W CUBA AND JAMAICA PRODUCING SHEAR OVER THE SPECIAL FEATURE SURFACE LOW MENTIONED ABOVE. AN UPPER HIGH IS OVER THE E CARIBBEAN CENTERED NEAR 16N63W. EXPECT CONVECTION OVER MUCH OF THE CARIBBEAN SEA AND CENTRAL AMERICA DURING THE NEXT 24 HOURS. ATLANTIC OCEAN... A 1015 MB LOW IS OVER THE W ATLANTIC NEAR 32N74W. A FORMING COLD FRONT EXTENDS SW FROM THE LOW TOWARDS CENTRAL FLORIDA AT 28N80W. A PREFRONTAL TROUGH IS ALONG 31N73W 27N76W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 29N-32N BETWEEN 72W-76W. A 1020 MB SUBTROPICAL HIGH IS NEAR 32N53W PRODUCING FAIR WEATHER. A 1009 MB LOW IS OVER THE E ATLANTIC NEAR 33N22W. A SURFACE TROUGH EXTENDS SW FROM THE LOW TO 24N34W. SCATTERED SHOWERS ARE WITHIN 30 NM OF THE TROUGH. IN THE UPPER LEVELS...A RIDGE IS OVER THE W ATLANTIC N OF 20N AND W OF 70W. AN UPPER LEVEL LOW IS CENTERED NEAR 30N63W. ANOTHER UPPER LEVEL LOW IS CENTERED NEAR 25N49W. A THIRD UPPER LEVEL LOW IS OVER THE E ATLANTIC NEAR 30N27W. AN UPPER LEVEL HIGH IS OVER THE TROPICAL E ATLANTIC NEAR THE CAPE VERDE ISLANDS AT 15N25W. EXPECT...THE FRONT OVER THE W ATLANTIC TO MOVE E OVER THE NEST 24 HOURS WITH LIGHT CONVECTION. ALSO EXPECT THE SPECIAL FEATURE LOW ABOVE TO MOVE N OF HISPANIOLA TO THE TURKS AND CAICOS ISLANDS OVER THE NEXT 24 HOURS WITH CONVECTION. $$ FORMOSA