000 AXNT20 KNHC 100018 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT TUE OCT 09 2007 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND THE 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 2345 UTC. ...TROPICAL WAVES... AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 48W/49W SOUTH OF 14N MOVING WEST 15 KT. A BIT OF CYCLONIC MOTION IN THE LOW CLOUDS ON THE 09/1800 VISIBLE IMAGERY. SMALL CELLS OF SHOWERS AND THUNDERSTORMS FROM 7N TO 8N BETWEEN 49W AND 50W. OTHER ITCZ SHOWERS AND THUNDERSTORMS NEAR THE WAVE WEAKENED WITH WARMING CLOUD TOP TEMPERATURES DURING THE LAST 4 TO 5 HOURS. AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 60W/61W SOUTH OF 20N MOVING WEST 10 KT. A SMALL LOW TO MIDDLE LEVEL CYCLONIC SWIRL OF CLOUDS IS NEAR 19N ALONG THE WAVE IN THE NORTHEASTERN CORNER OF THE AREA. THIS SWIRL IS THE REMNANT OF A SURFACE LOW PRESSURE CENTER FROM A FEW DAYS AGO AS THE WAVE MADE ITS WAY WESTWARD FROM 50W. NO DEEP CONVECTIVE PRECIPITATION IS NEAR THIS FEATURE. AN UPPER LEVEL TROUGH IS ALONG 11N60W 17N56W 20N54W SURROUNDED BY MIDDLE TO UPPER LEVEL DRY AIR/SUBSIDENCE. ...THE ITCZ... 10N14W 8N30W 10N49W 10N52W 10N61W. ISOLATED MODERATE SHOWERS AND BROKEN MULTILAYERED CLOUDS WITHIN 180 NM ON EITHER SIDE OF 10N14W 6N30W 7N40W. SCATTERED MODERATE TO STRONG SHOWERS/ THUNDERSTORMS ARE FROM 6N TO 9N BETWEEN 41W AND 44W. STRONG SHOWERS/THUNDERSTORMS IN THE ATLANTIC OCEAN FROM 12N TO 15N BETWEEN 53W AND 58W ARE IN AN AREA OF UPPER LEVEL DIFFLUENT FLOW. UPPER LEVEL FLOW ANTICYCLONIC FLOW AROUND A RIDGE COVERS THE AREA FROM 10N TO 21N BETWEEN 38W AND 60W. DISCUSSION... THE GULF OF MEXICO... A COLD FRONT APPROACHES THE NORTHERN GULF COAST...THROUGH GEORGIA AND ALABAMA INTO SOUTHEASTERN LOUISIANA. THE FRONT BECOMES STATIONARY FROM LOUISIANA INTO EAST TEXAS TO SOUTH CENTRAL TEXAS. A MIDDLE TO UPPER LEVEL TROUGH PASSES THROUGH EXTREME SOUTHEASTERN LOUISIANA TO THE WEST CENTRAL GULF WATERS TO THE MEXICO COAST NEAR 23N98W. A SECOND MIDDLE TO UPPER LEVEL TROUGH ENTERS THE EAST-CENTRAL TO SOUTHEASTERN GULF WATERS FROM THE ATLANTIC OCEAN ACROSS THE BAHAMAS. DRY AIR/SUBSIDENCE IS WEST OF THE WESTERN GULF TROUGH AND EAST OF 87W. AN UPPER LEVEL RIDGE IS NORTH OF 23N BETWEEN THE TWO AREAS OF CYCLONIC FLOW. CELLS OF STRONG SHOWERS/THUNDERSTORMS ARE IN THE SOUTHWESTERN CORNER OF THE AREA...SOUTH OF 22N WEST OF 94W. THIS PRECIPITATION IS TAKING PLACE CLOSE TO THE BASE OF THE WESTERN GULF OF MEXICO TROUGH AND SOMEWHAT IN AN AREA OF SOME UPPER LEVEL DIFFLUENT FLOW. THE CARIBBEAN SEA... A 1004 MB NORTHWESTERN CARIBBEAN SEA LOW PRESSURE CENTER WAS NEAR 18.5N 87.5W...IN THE NORTHWESTERN PART OF THE BANCO CHINCHORRO ABOUT 15 NM EAST OF THE SOUTHEASTERN YUCATAN PENINSULA AT 09/1800 UTC. THE LOW CENTER SINCE THEN HAS MOVED INLAND ALONG THE EAST COAST OF THE YUCATAN PENINSULA...ABOUT 60 MILES NORTH-NORTHEAST OF CHETUMAL MEXICO. THIS LOW CENTER IS DRIFTING WEST-NORTHWESTWARD AND IS EXPECTED TO REMAIN NEAR OR OVER THE YUCATAN PENINSULA DURING THE NEXT COUPLE OF DAYS. THIS LOW PRESSURE CENTER MAY PRODUCE LOCALLY HEAVY RAINFALL IN SECTIONS OF THE YUCATAN PENINSULA AND BELIZE EVEN THOUGH DEVELOPMENT OF THIS LOW INTO A TROPICAL CYCLONE IS NOT EXPECTED. NUMEROUS STRONG SHOWERS AND THUNDERSTORMS ARE IN NORTHERN BELIZE...AND IN SOUTHERN AND SOUTHWESTERN SECTIONS OF THE YUCATAN PENINSULA WIDELY SCATTERED TO SCATTERED MODERATE SHOWERS/ISOLATED STRONG THUNDERSTORMS ARE ELSEWHERE FROM 17N TO 22N BETWEEN 83W AND 91W IN THE NORTHWESTERN CARIBBEAN SEA WATERS AND INLAND ACROSS THE YUCATAN PENINSULA. AN UPPER LEVEL TROUGH AND CYCLONIC CIRCULATION CENTER ARE APPROACHING THE NORTHEASTERN CORNER FROM THE ATLANTIC OCEAN. THE TROUGH REACHES THE NORTHEASTERN CORNER OF VENEZUELA. DRY AIR/SUBSIDENCE IS ON THE WESTERN SIDE OF THIS SYSTEM HELPING TO BRING NO DEEP CONVECTIVE PRECIPITATION TO THE AREA. MIDDLE LEVEL ANTICYCLONIC FLOW IS BETWEEN THE EASTERNMOST TROUGH AND 70W. MIDDLE LEVEL CYCLONIC FLOW IS UNDERNEATH AN UPPER LEVEL RIDGE BETWEEN 70W AND CENTRAL AMERICA AND THE YUCATAN PENINSULA. A MIDDLE LEVEL CYCLONIC CIRCULATION CENTER IS ON TOP OF THE YUCATAN PENINSULA WITH AN UPPER LEVEL RIDGE ON TOP OF THAT CYCLONIC CENTER. CELLS OF STRONG SHOWERS/THUNDERSTORMS ARE IN NORTHERN COASTAL SECTIONS OF THE DOMINICAN REPUBLIC AND SOUTH OF CUBA FROM 18N TO 20N BETWEEN 78W AND 80W...IN SOME AMOUNT OF UPPER LEVEL DIFFLUENT FLOW. OTHER AREAS OF SIMILAR STRONG PRECIPITATION ARE FROM 15N TO 17N BETWEEN 71W AND 72W...AND FROM 16N TO 17N BETWEEN 76W AND 77W SOUTHEAST OF JAMAICA. THE ATLANTIC OCEAN... A MIDDLE TO UPPER LEVEL TROUGH EXTENDS FROM 31N62W TO A CYCLONIC CIRCULATION CENTER NEAR 27N68W...ACROSS THE NORTHERN BAHAMAS INTO AND BEYOND THE STRAITS OF FLORIDA. DRY AIR/SUBSIDENCE IS NORTH AND WEST OF 31N62W 25N70W 25N80W. A SURFACE TROUGH RUNS FROM 28N62W TO A 1010 MB LOW PRESSURE CENTER NEAR 26N65W TO 24N70W. MODERATE TO SCATTERED STRONG SHOWERS/THUNDERSTORMS WITHIN 15 TO 20 NM ON EITHER SIDE OF 25N64W 27N61W...AND WITHIN A 30 NM RADIUS OF 27N58.5W. ISOLATED MODERATE SHOWERS FROM 23N TO 25N BETWEEN 63W AND 68W. A MIDDLE TO UPPER LEVEL TROUGH PASSES THROUGH 32N43W TO 27N47W. A DISSIPATING COLD FRONT PASSES THROUGH 32N39W TO 30N41W. A TROUGH CONTINUES FROM 30N41W TO 23N53W. BROKEN TO OVERCAST MULTILAYERED CLOUDS WITH POSSIBLE SHOWERS WITHIN 120 TO 180 NM ON EITHER SIDE OF LINE THROUGH 31N75W 28N40W 26N44W...AND WITHIN 75 NM ON EITHER SIDE OF 26N44W 25N49W 22N54W. A MIDDLE TO UPPER LEVEL EASTERN ATLANTIC OCEAN TROUGH RUNS FROM A CYCLONIC CIRCULATION CENTER NEAR 33N14W...ACROSS THE CANARY ISLANDS TO 24N20W...TO A SECOND CYCLONIC CENTER NEAR 20N22W TO 14N30W TO 11N36W. $$ MT