000 AXNT20 KNHC 281750 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT FRI AUG 28 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 1715 UTC. ...SPECIAL FEATURES... TROPICAL STORM DANNY IS CENTERED NEAR 30.1N 75.7W AT 28/1800 UTC OR ABOUT 310 NM S OF CAPE HATTERAS NORTH CAROLINA AND ABOUT 720 NM SSW OF NANTUCKET MASSACHUSETTS MOVING NNW AT 9 KT. THE MINIMUM CENTRAL PRESSURE MEASURE BY AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT WAS 1007 MB. MAXIMUM SUSTAINED WIND SPEED IS 35 KT WITH GUSTS TO 45 KT. SEE LATEST NHC INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT5/WTNT35 KNHC AND THE FULL FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT5/WTNT25 KNHC FOR MORE DETAILS. THE LOW LEVEL CENTER IS COMPLETELY EXPOSED AS THE DEEP CONVECTION IS TO THE E. SCATTERED/MODERATE STRONG CONVECTION IS WITHIN 75 NM OF LINE FROM 27N70W TO 31N73W WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS DOT THE REMAINDER OF THE AREA FROM 26N-31N BETWEEN 69W-75W. TROPICAL WAVE WAS ADJUSTED TO ALONG 36W BASED ON THE 1011 MB SURFACE LOW POSITION. THE LOW IS CENTERED NEAR 10.5N36W. THE SYSTEM IS MOVING W NEAR 20 KT OVER THE PAST 24 HOURS. THIS WAVE/LOW COINCIDES WITH A BROAD AREA OF LOW LEVEL CYCLONIC CURVATURE FOCUSED AROUND THE SURFACE LOW AND IS EMBEDDED IN AN AREA OF DEEP LAYERED MOISTURE AS INDICATED BY PRECIPITABLE WATER IMAGERY. ENVIRONMENTAL CONDITIONS APPEAR CONDUCIVE FOR FURTHER DEVELOPMENT OF THIS SYSTEM OVER THE NEXT COUPLE OF DAYS. SCATTERED MODERATE/STRONG CONVECTION IS W OF TE WAVE FROM 8N-12N BETWEEN 39W-42W. SMALL CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 11N-15N BETWEEN 34W-39W. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 54W S OF 16N MOVING W 15-20 KT OVER THE PAST 24 HOURS. WAVE IS LOCATED AT AN INVERTED PEAK IN MAXIMUM MOISTURE AS INDICATED BY PRECIPITABLE WATER IMAGERY. HOWEVER... THE LOWER LEVELS ARE DRY SO THERE IS NO ASSOCIATED SHOWERS/CONVECTION. TROPICAL WAVE IS ALONG 83W/84W S OF 16N MOVING W 15-20 KT OVER THE PAST 24 HOURS. WAVE IS BEGINNING TO MOVE INLAND OVER CENTRAL AMERICA AND IS BENEATH AN UPPER TROUGH WITH DEEP LAYERED DRY STABLE AIR...SO NO ASSOCIATED SHOWERS/CONVECTION. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 14N15W 10N30W 7N41W 9N50W 11N60W THEN ACROSS THE N PORTION OF SOUTH AMERICA INTO THE E PACIFIC REGION OVER E PANAMA. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 10N-14N BETWEEN 15W-20W INCLUDING THE COAST OF W AFRICA. CLUSTERS OF SIMILAR CONVECTION ARE FROM 10N-16N BETWEEN 20W-28W. ...DISCUSSION... GULF OF MEXICO... A SURFACE TROUGH EXTENDS INTO THE GULF ACROSS THE FLORIDA PANHANDLE W OF TALLAHASSEE THROUGH APALACHEE BAY ALONG 26N86W TO 23N91W GENERATING SCATTERED SHOWERS/THUNDERSTORMS E OF THE TROUGH TO INLAND OVER THE W COAST OF FLORIDA PENINSULA N OF FORT MYERS. THIS SURFACE TROUGH IS SUPPORTED BY AN UPPER LEVEL TROUGH THAT COVERS THE GULF N OF 25N AND AN UPPER LOW OVER CENTRAL ALABAMA. AN UPPER LEVEL RIDGE COVERS THE REMAINDER OF THE GULF ANCHORED BY AN UPPER LEVEL HIGH S MEXICO. DIFFLUENCE ALOFT OVER THE SW GULF IS GENERATING SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS S OF 23N INTO THE BAY OF CAMPECHE BETWEEN 92W-96W. THE NEXT FRONTAL BOUNDARY THAT IS EXPECTED TO MOVE INTO THE NW GULF ON SUN IS CURRENTLY INLAND OVER TEXAS WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS AHEAD OF THE FRONT WITHIN 90 NM ALONG THE COAST OF W LOUISIANA W OF VERMILION BAY AND E TEXAS N OF MATAGORDA BAY. CARIBBEAN SEA... AN UPPER LEVEL LOW COVERS THE W CARIBBEAN TO THE YUCATAN PENINSULA CENTERED NEAR 16N80W. AN UPPER HIGH OVER THE W/CENTRAL ATLC COVERS THE E CARIBBEAN DRAWING UPPER LEVEL MOISTURE OVER THE CENTRAL CARIBBEAN BUT DUE TO THE DRY AIR OVER THE ARE IS ONLY ABLE TO PRODUCE SOME ISOLATED SHOWERS S OF 16N FROM 74W-78W. THE ITCZ CROSSES THE N PORTION OF SOUTH AMERICA AND PANAMA INTO THE E PACIFIC REGION WITH SCATTERED MODERATE/STRONG CONVECTION WITHIN 75 NM ALONG THE COAST OF PANAMA AND COSTA RICA. MODERATE/STRONG EASTERLY TRADE WINDS ARE ACROSS THE CARIBBEAN BASIN USHERING IN ISOLATED LOW LEVEL FAST MOVING SHOWERS MAINLY N OF 15N E OF 68W TO OVER THE LEEWARD ISLANDS TO PUERTO RICO. OTHERWISE THE REMAINDER OF THE CARIBBEAN REMAINS RATHER TRANQUIL TODAY. ATLANTIC OCEAN... ATTENTION REMAINS FOCUSED ON TROPICAL STORM DANNY IN THE W ATLC. THE REMAINDER OF THE W ATLC REMAINS FAIRLY TRANQUIL AS AN UPPER LEVEL RIDGE IS TO THE W OF DANNY. AN UPPER HIGH IS OVER THE CENTRAL ATLC AND INTO THE E CARIBBEAN CENTERED NEAR 25N67W. AN UPPER LOW TO THE NE NEAR 29N45W IS GENERATING ISOLATED SHOWERS FROM 28N-32N BETWEEN 42W-48W. THE REMAINDER OF THE CENTRAL AND E ATLC ARE DOMINATED BY BENIGN UPPER LEVEL FEATURES AND A SURFACE RIDGE ANCHORED BY A 1036 MB HIGH NE OF THE AZORES AND A WEAKER 1024 MB HIGH NE OF BERMUDA. $$ WALLACE