000 AXNT20 KNHC 130625 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT MON OCT 13 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0545 UTC. ...SPECIAL FEATURES... THE CENTER OF TROPICAL STORM NANA AT 13/0300 UTC IS NEAR 16.6N 38.8W...MOVING WEST-NORTHWEST OR 285 DEGREES 7 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1006 MB. THE MAXIMUM SUSTAINED WIND SPEEDS ARE 35 KT WITH GUSTS TO 45 KT. PLEASE READ THE LATEST NHC PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT4/WTNT34 KNHC AND THE FULL FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC FOR MORE DETAILS. TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 85 NM FROM THE CENTER IN THE EASTERN SEMICIRCLE. NUMEROUS STRONG SHOWERS AND THUNDERSTORMS ARE FROM 15N TO 17N BETWEEN 35W AND 37W. NANA IS EXPECTED TO WEAKEN DURING THE NEXT DAY OR SO... AND FORECAST TO BECOME A TROPICAL DEPRESSION LATER TODAY. A 1008 MB CARIBBEAN SEA LOW PRESSURE CENTER IS NEAR 16N69W. IT IS POSSIBLE THAT THIS LOW CENTER MAY BECOME A TROPICAL CYCLONE DURING THE NEXT 24 HOURS OR SO. NUMEROUS STRONG SHOWERS AND THUNDERSTORMS ARE FROM 14N TO 16N BETWEEN 63W AND 68W. THIS SYSTEM IS EXPECTED TO RESULT IN HEAVY RAINS IN PUERTO RICO AND PARTS OF THE LEEWARD ISLANDS DURING THE NEXT FEW DAYS. THESE RAINS MAY CAUSE FLASH FLOODS IN SOME AREAS. ...TROPICAL WAVES... AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 20N46W 10N44W MOVING WEST 10 TO 15 KT. IT IS NOT READILY APPARENT THAT ANY CONVECTIVE PRECIPITATION IS ACCOMPANYING THIS WAVE. AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 56W/57W SOUTH OF 20N MOVING WEST 10 KT. ISOLATED TO WIDELY SCATTERED MODERATE SHOWERS ARE FROM 18N TO 22N BETWEEN 55W AND 60W. A MIDDLE TO UPPER LEVEL IS NEAR 21N62W. A CARIBBEAN SEA TROPICAL WAVE IS ALONG 70W/71W SOUTH OF 20N MOVING WEST 10 KT. THE WAVE EXTENDS FROM THE WESTERN DOMINICAN REPUBLIC TO NORTHWESTERN VENEZUELA. UPPER LEVEL SOUTHWESTERLY WIND FLOW IS MOVING ON TOP OF THE AREA OF THIS WAVE. MODERATE SHOWERS AT THE NORTHERN COAST OF COLOMBIA BETWEEN 73W AND 74W... AND STRONG THUNDERSTORMS WITHIN A 15 NM RADIUS OF 8N72.5W NEAR THE COLOMBIA/VENEZUELA BORDER MAY HAVE BEEN ASSOCIATED WITH THIS WAVE. THOSE AREAS OF CONVECTIVE PRECIPITATION HAVE DISSIPATED DURING THE LAST 2 TO 3 HOURS. ...THE ITCZ... 12N16W 5N31W 9N43W 10N47W 10N60W. SCATTERED MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS ARE SOUTH OF 7N BETWEEN 29W AND 37W. ISOLATED MODERATE SHOWERS TO POSSIBLE THUNDERSTORMS ELSEWHERE FROM 3N TO 10N BETWEEN 10W AND 29W. ISOLATED MODERATE SHOWERS TO LOCALLY STRONG THUNDERSTORMS ELSEWHERE FROM 6N TO 15N BETWEEN 38W AND 60W. A 1010 MB LOW PRESSURE CENTER IS NEAR 12N42W. SCATTERED STRONG THUNDERSTORMS IN SOME CELLS ARE FROM 12N TO 13N BETWEEN 41W AND 42W. ...DISCUSSION... THE GULF OF MEXICO... MIDDLE TO UPPER LEVEL NORTHERLY FLOW AND DRY AIR IN SUBSIDENCE ON THE WESTERN SIDE OF A TROUGH. THE TROUGH RUNS FROM NORTHEASTERN FLORIDA TO A CYCLONIC CIRCULATION CENTER ALONG THE NORTHWESTERN CORNER OF THE YUCATAN PENINSULA...TO THE NORTHEASTERN COAST OF THE ISTHMUS OF TEHUANTEPEC. ISOLATED MODERATE SHOWERS AND POSSIBLE THUNDERSTORMS ARE ON THE EASTERN SIDE OF THE TROUGH. THE CARIBBEAN SEA... A SPECIAL FEATURE 1008 MB LOW PRESSURE CENTER IS NEAR 16N69W. MIDDLE TO UPPER LEVEL SOUTHWESTERLY WIND FLOW COVERS THE AREA WEST OF A LINE FROM SOUTHEASTERN CUBA TO THE HONDURAS COAST. THIS FLOW IS DUE TO THE CYCLONIC FLOW WITH THE NORTHEASTERN FLORIDA-TO-NORTHWESTERN YUCATAN PENINSULA MIDDLE TO UPPER LEVEL TROUGH. SCATTERED MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS ARE WEST OF THE LINE FROM CUBA TO HONDURAS. BROAD UPPER LEVEL ANTICYCLONIC WIND FLOW COVERS THE AREA TO THE EAST OF THE CUBA-TO-HONDURAS LINE. THE ATLANTIC OCEAN... AN UPPER LEVEL TROUGH PASSES THROUGH 33N14W TO 30N20W 32N24W. UPPER LEVEL ANTICYCLONIC FLOW...THAT IS NORTH OF 22N17W 22N30W BEYOND 32N38W...IS MOVING ON TOP OF THIS TROUGH. A MIDDLE TO UPPER LEVEL TROUGH PASSES THROUGH 33N40W TO 24N42W. A STATIONARY FRONT PASSES THROUGH 32N43W TO 27N50W. ISOLATED MODERATE SHOWERS TO POSSIBLE THUNDERSTORMS ARE NORTH OF 26N BETWEEN 40W AND 50W. ONE MIDDLE TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS NEAR 24N57W. A SECOND MIDDLE TO UPPER LEVEL CYCLONIC CENTER IS NEAR 24N64W. UPPER LEVEL ANTICYCLONIC FLOW IS MOVING ON TOP OF THE AREA OF THESE TWO CYCLONIC CENTERS. ISOLATED MODERATE SHOWERS TO POSSIBLE THUNDERSTORMS ARE FROM 24N TO 26N BETWEEN 57W AND 61W...SOME PRECIPITATION HAS BEEN DISSIPATING DURING THE LAST TWO TO THREE HOURS. SCATTERED MODERATE SHOWERS AND THUNDERSTORMS ARE WITHIN A 15 TO 30 NM RADIUS OF 27N76W...ASSOCIATED WITH A COMPARATIVELY FAST-MOVING LOW TO MIDDLE LEVEL CYCLONIC CIRCULATION CENTER. THIS PRECIPITATION MAY PASS OVER THE NORTHERN BAHAMAS DURING THE NEXT FEW HOURS AND IT MAY REACH THE FLORIDA COAST EVEN...IF IT REMAINS INTACT. $$ MT