000 AXNT20 KNHC 211151 TWDAT TROPICAL WEATHER DISCUSSION... NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT THU AUG 21 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...SPECIAL FEATURES... TROPICAL STORM FAY IS CENTERED NEAR 29.2N 80.7W OR ABOUT 17 NM EAST OF DAYTONA BEACH FLORIDA AT 21/1200 UTC. FAY HAS BEEN NEAR STATIONARY OVER THE PAST SEVERAL HOURS AND IS EXPECTED TO SLOWLY MOVE WEST-NORTHWEST LATER TODAY. MINIMUM CENTRAL PRESSURE AS MEASURED BY AN AIR FORCE RESERVE UNIT HURRICANE HUNTER AIRCRAFT IS 994 MB. MAXIMUM SUSTAINED WIND SPEED IS 50 KT WITH GUSTS TO 60 KT. PLEASE SEE THE LATEST NHC THE FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC AND PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT1/WTNT31 KNHC FOR MORE DETAILS. THE UPPER HIGH ASSOCIATED WITH FAY REMAINS ELONGATED E/W PROVIDING OUTFLOW OVER THE W ATLC TO 74W AND THE GULF OF MEXICO TO 86W. SCATTERED/HEAVY SHOWERS WITH EMBEDDED THUNDERSTORMS ARE WITHIN 120 NM OF THE STORM CENTER. SCATTERED/HEAVY SHOWERS WITH THUNDERSTORMS ARE WITHIN 60/75 NM OF LINE FROM 23N79W ACROSS THE N BAHAMA ISLANDS ALONG 27N77W TO 31N79W. OUTER RAIN BANDS OF SHOWERS WITH EMBEDDED ISOLATED THUNDERSTORMS ARE S OF THE STORM TO THE FLORIDA STRAITS BETWEEN 77W-79W AND N OF THE STORM TO 34N W OF 76W TO JUST INLAND OVER SOUTH CAROLINA...GEORGIA...AND FAR NE FLORIDA. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 31W S OF 19N WITH A 1008 MB LOW ALONG THE WAVE NEAR 12N MOVING W NEAR 10 KT. WAVE REMAINS EMBEDDED WITHIN SOME RATHER DRY AIR BUT ISOLATED SHOWERS ARE FROM 13N-16N BETWEEN 29W-31W. A SMALL 1007 MB LOW IS ANALYZED IN THE CENTRAL ATLC NEAR 12N46W MOVING W NEAR 15 KT. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS TO THE W OF THE LOW WITHIN 75 NM OF LINE FROM 12N47W TO 14N52W. TROPICAL WAVE IN THE W TROPICAL ATLC IS ALONG 54W S OF 18N MOVING W NEAR 10 KT. NO ASSOCIATED SHOWER ACTIVITY/CONVECTION. TROPICAL WAVE IN THE CENTRAL CARIBBEAN IS ALONG 74W/75W S OF 20N MOVING W NEAR 15 KT. NO ASSOCIATED SHOWERS/CONVECTION. ...THE ITCZ... THE ITCZ IS CENTERED ALONG 13N16W 14N24W 9N37W 8N50W 10N62W. LARGE CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE FROM 5N-11N W OF 33W TO INLAND OVER SOUTH AMERICA. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 11N-15N E OF 19W TO INLAND OVER W AFRICA. ...DISCUSSION... GULF OF MEXICO... SHOWER ACTIVITY ASSOCIATED WITH T.S. FAY ARE IN THE E GULF... SEE SPECIAL FEATURES ABOVE. AN UPPER LOW IS MOVING N OVER ARKANSAS EXTENDING AN UPPER TROUGH OVER TEXAS INTO THE NW GULF COAST GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 28N BETWEEN VERMILION BAY LOUISIANA AND HOUSTON TEXAS. THE UPPER LEVEL RIDGE ANCHORED OFF THE W COAST OF MEXICO EXTENDS INTO THE SW GULF ALONG 22N TO 92W WITH A SECOND UPPER RIDGE ANCHORED OVER W CUBA COVERING THE REMAINDER OF THE S GULF. A WEAK SURFACE TROUGH IS ALONG THE W COAST OF THE YUCATAN PENINSULA WITH SCATTERED SHOWERS/THUNDERSTORMS INLAND AND WITHIN 90 NM ALONG THE COAST OF MEXICO W OF THE TROUGH TO THE TEXAS BORDER. THE REMAINDER OF THE GULF REMAINS RATHER CLEAR THIS MORNING WITH A WEAK 1014 MB HIGH OFF THE SE COAST OF LOUISIANA NEAR 28N91W. CARIBBEAN SEA... AN INDUCED INVERTED UPPER TROUGH EXTENDS FROM CENTRAL NICARAGUA TO THE MONA PASSAGE SEPARATING AN UPPER RIDGE ANCHORED OVER W CUBA AND A SECOND UPPER RIDGE ANCHORED OVER THE LEEWARD ISLANDS. THE ITCZ AXIS EXTENDS FROM COLOMBIA N OF PANAMA INTO THE E PACIFIC NEAR THE COSTA RICA BORDER GENERATING SCATTERED SHOWERS/ THUNDERSTORMS S OF 12N BETWEEN 75W-81W. CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 30 NM OF LINE FROM 18N83W TO E CUBA NEAR 20N77W. MODERATE EASTERLY TRADE WINDS CONTINUE OVER THE AREA AND COUPLED WITH ADVECTED TROPICAL MOISTURE FROM THE UPPER RIDGE OVER THE E CARIBBEAN ARE USHERING IN SCATTERED SHOWERS/THUNDERSTORMS S OF 16N E OF 72W. THE REMAINDER OF THE CARIBBEAN IS DOMINATED BY MODERATE SUBSIDENCE AND DRY STABLE AIR...THUS CLEAR SKIES ELSEWHERE THIS MORNING. ATLANTIC OCEAN... THE MAIN CONCERN FOR THE FAR W ATLC AGAIN THIS MORNING IS THE ACTIVITY ASSOCIATED WITH T.S. FAY...SEE SPECIAL FEATURES ABOVE. AN UPPER LOW IS IN THE W ATLC CENTERED NEAR 22N67W COVERING THE AREA FROM 27N TO THE GREATER ANTILLES BETWEEN 61W-72W. A DEEP LAYERED TROUGH IS OVER THE NW ATLC TO 30N E OF T.S. FAY WITH THE ASSOCIATED FRONTAL BOUNDARY N OF THE REGION. HOWEVER...IT IS INDUCING AN UPPER RIDGE TO THE E OF BERMUDA AND GENERATING SCATTERED SHOWERS/THUNDERSTORMS N OF 29N FROM 59W-67W. A SECOND LARGER BENIGN UPPER LOW COVERS MOST OF THE CENTRAL ATLC CENTERED NEAR 23N53W WITH AN UPPER HIGH ANCHORED OVER THE LEEWARD ISLANDS NEAR GUADELOUPE. AN E/W UPPER RIDGE COVERS THE E ATLC WITH A WEAK UPPER TROUGH BEGINNING TO PUSH S OVER THE NE ATLC TO JUST W OF THE CANARY ISLANDS. MODERATE SUBSIDENCE AND SOMEWHAT DRY STABLE AIR COVERS THE ATLC E OF 60W GIVING THE REMAINDER OF THE AREA FAIR WEATHER CONDITIONS AGAIN THIS MORNING. A SURFACE RIDGE REMAINS OVER MOST OF THE ATLC N OF 23N E OF 72W ANCHORED BY A SERIES OF HIGHS N OF THE REGION AND A WEAK 1021 MB HIGH S OF BERMUDA NEAR 29N65W. $$ WALLACE