000 AXNT20 KNHC 151045 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT WED APR 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...THE ITCZ... FROM 5N8W AT THE SOUTHERN COAST OF LIBERIA...CROSSING THE EQUATOR ALONG 18W TO 3S30W.....AND GOING INTO NORTHEASTERN BRAZIL NEAR 2S45W. A SURFACE TROUGH WAS ANALYZED ALONG 13W AT 15/0000 UTC. I STUDIED ALL THE AVAILABLE METEOSAT-9 VISIBLE SATELLITE FROM 14/0930 UTC UNTIL 14/1645 UTC AND I SAW ONLY A SMALL AMOUNT OF CYCLONIC TURNING AT AN UNKNOWN LEVEL IN THE ATMOSPHERE NEAR 2N17W AT THE END OF THAT CYCLE OF IMAGES. I SAW A SOLID FIELD OF LOW CLOUDS IN THAT CYCLE OF VISIBLE IMAGES MOVING FROM THE AREA TO THE SOUTH OF THE EQUATOR TOWARD THE ITCZ...WITHOUT CYCLONIC TURNING. I AM INCLINED NOT TO BELIEVE THAT A SURFACE TROUGH EXISTED AT THE TIME THAT IT WAS ADDED TO THE MAP AND WHERE IT WAS PUT ON THE MAP ANALYSIS YESTERDAY. THAT IS NOT TO SAY THAT A SURFACE TROUGH MAY NOT FORM AT SOME TIME IN THE FUTURE IN THE ITCZ. I HAVE STUDIED THE LATEST METEOSAT-9 VISIBLE IMAGERY THIS MORNING AND I AM CONVINCED THAT NO SURFACE TROUGH IS IN THE ITCZ AT THIS TIME. STRONG SHOWERS AND THUNDERSTORMS ARE AWAY FROM THE ITCZ AT THIS TIME...FROM THE EQUATOR TO 3N BETWEEN THE PRIME MERIDIAN AND 4W. ISOLATED AND DISORGANIZED MODERATE SHOWERS AND POSSIBLE THUNDERSTORMS ARE TO THE SOUTH OF 6N BETWEEN 10W AND 45W. ...DISCUSSION... THE GULF OF MEXICO... AN UPPER LEVEL RIDGE IS ALONG 97W AT THE COASTS OF TEXAS AND MEXICO. THE FLOW ON THE EASTERN SIDE OF THE RIDGE MOVES ACROSS THE OPEN WATERS OF THE GULF OF MEXICO RIGHT INTO THE DEEP LAYER TROUGH THAT IS SUPPORTING THE CURRENT EASTERN GULF OF MEXICO COLD FRONT. THE FRONT EXTENDS FROM THE ATLANTIC OCEAN THROUGH 30N79W TO THE FLORIDA COAST NEAR 28N TO THE WESTERN FLORIDA COAST DUE WEST OF LAKE OKEECHOBEE...INTO THE SOUTH CENTRAL GULF OF MEXICO JUST TO THE NORTH OF THE YUCATAN PENINSULA. A BLOB OF PRECIPITATION HAS MOVED ON TOP OF ANDROS ISLAND IN THE LAST INFRARED IMAGE. OTHER AREAS OF POSSIBLE PRECIPITATION IN THE ATLANTIC OCEAN APPEAR TO HAVE DISSIPATED. A SEPARATE AREA OF UPPER LEVEL ANTICYCLONIC FLOW MOVES FROM THE EASTERN PACIFIC OCEAN ACROSS SOUTHERN MEXICO AND THE SOUTHWESTERN CORNER OF THE GULF OF MEXICO TO THE YUCATAN PENINSULA...AND BEGINNING TO ENTER THE NORTHWESTERN CARIBBEAN SEA. THE CARIBBEAN SEA... A NORTH-TO-SOUTH SURFACE TROUGH IS IN THE YUCATAN PENINSULA ALONG 90W. THE PRECIPITATION FROM SIX HOURS AGO HAS DISSIPATED. UPPER LEVEL WESTERLY WIND FLOW PROBABLY SHEARED A LOT OF THE CLOUDS THAT WERE ASSOCIATED WITH THAT SITUATION. A LOT OF MIDDLE LEVEL TO UPPER LEVEL WESTERLY WIND FLOW IS MOVING ACROSS THE AREA. UPPER LEVEL SOUTHWESTERLY WIND FLOW MOVES ACROSS COSTA RICA AND PANAMA INTO THE SOUTHWESTERN CORNER OF THE CARIBBEAN SEA TOWARD THE CENTRAL WATERS OF THE AREA. A SHORTWAVE MIDDLE LEVEL TO UPPER LEVEL TROUGH ALONG 55W/56W IN THE ATLANTIC OCEAN IS IMPARTING CYCLONIC FLOW INTO THE AREA FROM PUERTO RICO EASTWARD. THE ATLANTIC OCEAN... LARGE-SCALE UPPER LEVEL ANTICYCLONIC FLOW COVERS THE AREA TO THE NORTH OF 20N BETWEEN 35W AND 80W. A SHORTWAVE MIDDLE LEVEL TO UPPER LEVEL TROUGH ALONG 55W/56W FROM 10N TO 20N IS IMPARTING CYCLONIC FLOW INTO THE CARIBBEAN SEA FROM PUERTO RICO EASTWARD. THIS CYCLONIC FLOW REACHES AT LEAST 15N40W BEFORE IT BECOMES LESS APPARENT. BROAD LARGE-SCALE UPPER LEVEL ANTICYCLONIC FLOW IS TO THE SOUTH OF 11N60W 17N40W 25N30W BEYOND 28N20W. THE SOUTHERN BOUNDARY OF AN EASTERN ATLANTIC OCEAN DEEP LAYER TROUGH REACHES MOROCCO ALONG 30N TO THE EAST OF 20W. THE COLD FRONT FROM 24 HOURS AGO HAS DISSIPATED. $$ MT