000 AXNT20 KNHC 051716 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SAT SEP 05 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 1645 UTC. ...TROPICAL WAVES... AN EASTERN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 30W FROM 10N TO 21N MOVING WEST 15 TO 20 KT. A 1011 MB LOW PRESSURE IS ALONG THE WAVE NEAR 16N. SCATTERED MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS FROM 12N TO 21N BETWEEN 28W AND 32W. THE CHANCE OF THIS FEATURE BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS IS LOW. AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 40W/41W FROM 12N TO 19N MOVING WEST 15 KT. A 1011 MB LOW PRESSURE CENTER IS ALONG THE WAVE NEAR 15.5N. ISOLATED MODERATE SHOWERS AND POSSIBLE THUNDERSTORMS ARE FROM 15N TO 18N BETWEEN 39W AND 41W. THE CHANCE OF THIS FEATURE BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS IS LOW. AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 57W/58W TO THE SOUTH OF 17N MOVING WESTWARD 15 KT. THE SHOWER ACTIVITY THAT EARLIER WAS MAINTAINING ITSELF FROM 10N TO 14N BETWEEN 58W AND 61W HAS WEAKENED IN INTENSITY. CONVECTIVE DEBRIS CLOUDS AND POSSIBLY LINGERING PRECIPITATION ARE IN THAT AREA. ...THE ITCZ... 18N16W 16N28W 11N34W 9N45W 7N56W. DISORGANIZED SHOWERS AND POSSIBLE THUNDERSTORMS ARE WITHIN 60 NM TO 90 NM ON EITHER SIDE OF 10N31W 9N42W 7N48W 10N58W. ...DISCUSSION... THE GULF OF MEXICO... MIDDLE LEVEL TO UPPER LEVEL CYCLONIC FLOW FROM A TROUGH COVERS THE THE AREA TO THE EAST OF 90W. ONE CLUSTER OF SHOWERS AND THUNDERSTORMS IS ON TOP OF SOUTH FLORIDA. A SECOND CLUSTER IS IN THE ATLANTIC OCEAN FROM 28N TO 32N BETWEEN 76W AND 81W. DISORGANIZED ISOLATED MODERATE SHOWERS TO POSSIBLE THUNDERSTORMS COVER THE REST OF THE AREA THAT IS IN CYCLONIC FLOW. A MIDDLE LEVEL TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS MOVING ONSHORE...ON TOP OF MAZATLAN MEXICO...CONTINUING EASTWARD. LOW LEVEL TO MIDDLE LEVEL CYCLONIC FLOW IS UNDERNEATH UPPER LEVEL ANTICYCLONIC FLOW FROM 102W IN MEXICO EASTWARD TO 90W. THE UPPER LEVEL ANTICYCLONIC FLOW EVENTUALLY BLENDS WITH THE CYCLONIC FLOW ALONG 89W/90W. ONE CLUSTER OF SHOWERS AND THUNDERSTORMS IS FROM 23N TO 24N BETWEEN 90W AND 91W. A SECOND CLUSTER IS FROM 21N TO 23N BETWEEN 96W AND 98W. ISOLATED MODERATE SHOWERS ARE ELSEWHERE TO THE WEST OF 90W. A SURFACE TROUGH WINDS ITS WAY FROM THE NORTHWESTERN GULF OF MEXICO TO SOUTHEASTERN LOUISIANA INTO THE NORTHEASTERN CORNER...THROUGH CENTRAL FLORIDA...AND BEYOND 30N77W IN THE ATLANTIC OCEAN. THE CARIBBEAN SEA... LARGE SCALE UPPER LEVEL ANTICYCLONIC FLOW COVERS PRETTY MUCH MOST OF THE AREA...EXCEPT FOR THE SOUTHEASTERN CORNER OF THE AREA AND THE NORTHWESTERN CORNER. MIDDLE LEVEL TO UPPER LEVEL CYCLONIC FLOW WITH A TROUGH PASSES THROUGH THE GULF OF MEXICO AND THE YUCATAN CHANNEL INTO THE NORTHWESTERN CORNER...AND THEN SHOOTS NORTHWARD ACROSS CUBA. THE SURFACE TROUGH THAT IS THE REMNANT OF ERIKA IS ALONG 21N69W...THROUGH THE MONA PASSAGE... TO 15N69W. THE UPPER LEVEL CYCLONIC FLOW AROUND THE 26N65W ATLANTIC CYCLONIC CIRCULATION CENTER GRAZES THE NORTHEASTERN CORNER OF THE CARIBBEAN SEA. ISOLATED MODERATE SHOWERS TO LOCALLY STRONG THUNDERSTORMS ARE FROM 16N TO 18N BETWEEN 66W AND 72W...AND FROM THE NORTHERN COAST OF PUERTO RICO TO 20N BETWEEN 64W AND 68W. SOME OF THE CLOUD TOP TEMPERATURES IN THESE AREAS HAVE BEEN DISSIPATING WITH TIME DURING THE LAST SIX HOURS. SCATTERED MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS ARE FROM 13N TO 14N BETWEEN 81W AND 83W AT THE NICARAGUA COAST. ISOLATED MODERATE SHOWERS ARE FROM 11N TO 12N BETWEEN 79W AND 81W. THIS PRECIPITATION IS TO THE EAST OF A LOW LEVEL TO MIDDLE LEVEL TROUGH THAT IS ALONG 83W FROM COSTA RICA TO 15N NEAR THE HONDURAS/NICARAGUA BORDER. THE ATLANTIC OCEAN... LARGE SCALE UPPER LEVEL CYCLONIC FLOW COVERS THE AREA FROM 20N TO 33N BETWEEN 60W AND 75W...AROUND THE 26N65W CYCLONIC CENTER. ISOLATED MODERATE SHOWERS ARE FROM 22N TO 24N BETWEEN 59W AND 60W. POSSIBLE SHOWERS FROM 23N TO 30N BETWEEN 60W AND 70W. AN UPPER LEVEL TROUGH EXTENDS FROM ONE CYCLONIC CIRCULATION CENTER NEAR 33N33W TO 28N38W TO 23N43W TO 15N46W $$ MT