000 AXNT20 KNHC 201805 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT MON SEP 19 2011 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...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...SPECIAL FEATURES... A 1008 MB LOW PRESSURE CENTER IS NEAR 12N38W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTIVE PRECIPITATION IS FROM 8N TO 15N BETWEEN 33W AND 42W. ISOLATED MODERATE RAINFALL TO POSSIBLE THUNDERSTORMS ARE FROM 10N TO 14N BETWEEN 40W AND 46W...AND FROM 6N TO 8N BETWEEN 42W AND 53W. THE SYSTEM DOES NOT HAVE A WELL-DEFINED CENTER OF CIRCULATION AT THIS TIME. CONDITIONS ARE EXPECTED TO REMAIN CONDUCIVE FOR A TROPICAL DEPRESSION TO FORM IN THIS AREA LATER TODAY OR ON WEDNESDAY. THE LOW CENTER IS FORECAST TO MOVE WESTWARD 5 TO 10 MPH. ...TROPICAL WAVES... A TROPICAL WAVE IS ALONG 17W/18W. ISOLATED MODERATE RAINSHOWERS TO POSSIBLE THUNDERSTORMS ARE FROM 10N TO 16N BETWEEN AFRICA AND 20W. ...THE MONSOON TROUGH/THE ITCZ... THE MONSOON TROUGH REACHES THE AFRICAN COAST NEAR 18N16W. IT IS BROKEN UP BY THE 17W/18W TROPICAL WAVE. THE MONSOON TROUGH CONTINUES FROM 14N19W TO 9N27W...TO THE 1008 MB LOW PRESSURE CENTER THAT IS NEAR 12N38W...CURVING TO 9N48W. RAINSHOWERS ARE POSSIBLE ELSEWHERE FROM 5N TO 12N TO THE EAST OF 30W. ...DISCUSSION... THE GULF OF MEXICO... AN UPPER LEVEL TROUGH CUTS THROUGH THE ALABAMA...TO THE DEEP SOUTH OF TEXAS...INTO CENTRAL MEXICO. A COLD FRONT PASSES THROUGH EASTERN TEXAS INTO SOUTH CENTRAL TEXAS. UPPER LEVEL CLOUDS MOVE FROM CENTRAL MEXICO...ACROSS THE NORTHWESTERN CORNER OF THE AREA...BEYOND THE FLORIDA BIG BEND. A SURFACE TROUGH IS ALONG 89W FROM 27N NORTHWARD INTO MISSISSIPPI. ISOLATED MODERATE RAINSHOWERS TO LOCALLY STRONG THUNDERSTORMS HAVE DEVELOPED TO THE EAST OF 90W...IN SURFACE SOUTHEASTERLY WINDS AND AFTERNOON HEATING. WEAK UPPER LEVEL CYCLONIC WIND FLOW...FROM A WEAK CYCLONIC CIRCULATION CENTER...REMAINS IN SOUTH CENTRAL MEXICO... JUST TO THE WEST OF THE ISTHMUS OF TEHUANTEPEC. RAINSHOWERS ARE POSSIBLE TO THE SOUTH OF 20N IN THE SOUTHWESTERN CORNER OF THE AREA. THE CARIBBEAN SEA... AN UPPER LEVEL WESTERN ATLANTIC OCEAN TROUGH PASSES THROUGH 32N68W...ACROSS THE SOUTHERN HALF OF THE BAHAMAS TO 22N74W... ...ACROSS SOUTHEASTERN CUBA...TO 18N79W AND 17N83W IN THE NORTHWESTERN CORNER OF THE AREA. DEBRIS CLOUDS FROM ALREADY- WEAKENED CONVECTIVE PRECIPITATION...COVERS THE AREA FROM 16N TO 20N BETWEEN 79W AND 84W. SCATTERED MODERATE RAINSHOWERS TO ISOLATED STRONG THUNDERSTORMS ARE FROM 16N TO THE SOUTHERN COASTS OF HAITI AND JAMAICA BETWEEN 72W AND SOUTH CENTRAL COASTAL JAMAICA. A SURFACE TROUGH IS ALONG 80W FROM 14N TO 22N. THE MONSOON TROUGH PASSES THROUGH COLOMBIA NEAR 10N75W...TO WESTERN PANAMA...AND BEYOND THE PANAMA BORDER WITH COSTA RICA. THE BASE OF AN UPPER LEVEL TROUGH IS IN THE SOUTHWESTERN CORNER OF THE AREA. SCATTERED MODERATE RAINSHOWERS TO ISOLATED STRONG THUNDERSTORMS ARE TO THE SOUTH OF 12N BETWEEN 74W AND COASTAL NICARAGUA AND COSTA RICA. AN UPPER LEVEL TROUGH IS ALONG 66W. THE TROUGH WAS IN THE EASTERN CARIBBEAN SEA 24 HOURS AGO. THE 24-HOUR RAINFALL TOTAL FOR THE PERIOD ENDING AT 20/1200 UTC FOR GUADELOUPE WAS 1.59 INCHES...FOR ST. THOMAS IN THE VIRGIN ISLANDS IT WAS 0.54 INCHES...AND IN BARBADOS TOTAL RAINFALL FOR THE SAME TIME PERIOD WAS 0.38 INCHES. SCATTERED STRONG RAINSHOWERS ARE FROM 16N TO 17N BETWEEN 64W AND 65W...ABOUT 85 NM TO THE SOUTHEAST OF PUERTO RICO. SCATTERED MODERATE RAINSHOWERS TO ISOLATED STRONG THUNDERSTORMS ARE WITHIN 65 NM TO THE SOUTH OF THE DOMINICAN REPUBLIC. ISOLATED MODERATE RAINSHOWERS ARE WITHIN 250 NM TO THE NORTH OF VENEZUELA AND COLOMBIA BETWEEN 67W AND 73W. THE ATLANTIC OCEAN... A 1013 MB LOW PRESSURE CENTER IS NEAR 17N55W. UPPER LEVEL WESTERLY WINDS ARE SHEARING THIS SYSTEM. BROKEN TO OVERCAST CONVECTIVE DEBRIS CLOUDS AND POSSIBLE RAINSHOWERS REMAIN FROM 15N TO 20N BETWEEN 50W AND 56W. AN UPPER LEVEL WESTERN ATLANTIC OCEAN TROUGH PASSES THROUGH 32N68W...ACROSS THE SOUTHERN HALF OF THE BAHAMAS TO 22N74W......ACROSS SOUTHEASTERN CUBA...TO 18N79W AND 17N83W IN THE NORTHWESTERN CORNER OF THE CARIBBEAN SEA. SCATTERED MODERATE TO ISOLATED STRONG CONVECTIVE PRECIPITATION IS FROM 20N TO 24N BETWEEN 65W AND 73W. RAINSHOWERS ARE POSSIBLE ELSEWHERE TO THE NORTH OF 20N BETWEEN 65W AND 74W. AN UPPER LEVEL CYCLONIC CIRCULATION CENTER IS NEAR 27N61W. THIS CENTER WAS ASSOCIATED WITH THE UPPER LEVEL TROUGH OF 24 HOURS AGO THAT EXTENDED INTO THE EASTERN CARIBBEAN SEA. RAINSHOWERS ARE POSSIBLE TO THE NORTH OF 25N BETWEEN 56W AND 64W. AN UPPER LEVEL TROUGH PASSES THROUGH 31N39W TO 22N46W AND 11N55W. WINDS FROM THIS TROUGH ARE SHEARING THE 17N55W LOW PRESSURE CENTER. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ MT