000 AXNT20 KNHC 061148 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT TUE SEP 05 2011 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...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1045 UTC. ...SPECIAL FEATURES... HURRICANE KATIA IS CENTERED NEAR 26.5N 65.1W AT 06/0900 UTC OR ABOUT 350 NM S OF BERMUDA MOVING NW AT 9 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 950 MB. MAXIMUM SUSTAINED WIND SPEED IS 110 KT WITH GUSTS TO 135 KT. PLEASE SEE THE LATEST INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADER MIATCPAT2/WTNT32 KNHC AND THE FULL FORECAST/ADVISORY UNDER AWIPS/WMO HEADER MIATCMAT2/ WTNT22 KNHC FOR MORE DETAILS. SCATTRED/NUMEROUS STRONG CONVECTION IS WITHIN 75 NM OF THE CENTER OVER THE W SEMICIRCLE AND WITHIN 150 NM OVER THE SE SEMICIRCLE. SCATTERED MODERATE/ ISOLATED STRONG CONVECTION COVERS THE REMAINDER OF THE AREA FROM 23N-30N BETWEEN 61W-67W. LARGE SWELLS GENERATED BY HURRICANE KATIA ARE EXPECTED TO AFFECT MOST OF THE EAST COAST OF THE UNITED STATES...BERMUDA...THE GREATER ANTILLES...AND EAST FACING BEACHES OF THE BAHAMAS DURING THE NEXT FEW DAYS. THESE SWELLS ARE LIKELY TO CAUSE LIFE THREATENING SURF AND RIP CURRENT CONDITIONS. PLEASE CONSULT PRODUCTS ISSUED BY LOCAL NATIONAL WEATHER SERVICE OFFICES FOR MORE INFORMATION. A BROAD AREA OF LOW PRESSURE ASSOCIATED WITH 1009 MB LOW IS CENTERED SW OF THE CAPE VERDE ISLANDS NEAR 10N32W MOVING W 10-15 KT. THIS FEATURE IS EMBEDDED WITHIN AN BROAD AREA OF DEEP LAYER MOISTURE AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS MOSTLY NW OF THE CENTER FROM 10N-15N BETWEEN 31W-41W. SHOWER ACTIVITY ASSOCIATED WITH THIS FEATURE GRADUALLY IS BECOMING BETTER ORGANIZED. ENVIRONMENTAL CONDITIONS APPEAR FAVORABLE FOR A TROPICAL DEPRESSION TO FORM DURING THE NEXT DAY OR TWO. THIS SYSTEM HAS A HIGH CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS. ...TROPICAL WAVES... TROPICAL WAVE IN THE W TROPICAL ATLC EXTENDS FROM 19N50W ALONG 16N50W TO 12N48W MOVING W NEAR 15 KT. THE 1012 MB LOW IS NO LONGER A CLOSED CIRCULATION. THE WAVE N OF 13N IS EMBEDDED WITHIN AN AREA OF DEEP LAYER MOISTURE AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY WITH DRIER AIR UNDERCUTTING THE WAVE. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE W OF THE WAVE FROM 13N-18N BETWEEN 51W-55W. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH IS ANALYZED ACROSS AFRICA ENTERING THE E TROPICAL ATLC NEAR 17N16W ALONG 13N21W TO E OF THE 1009 MB LOW IN THE SPECIAL FEATURES NEAR 11N27W. CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE FROM 4N-10N BETWEEN 15W-23W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 4N-10N BETWEEN 30W-49W. ISOLATED SHOWER/THUNDERSTORMS ARE WITHIN 90/120 NM ALONG THE COAST OF W AFRICA S OF 9N W OF 10W. ...DISCUSSION... GULF OF MEXICO... BROAD UPPER TROUGH IS MOVING E OF THE MISSISSIPPI VALLEY AND CONTINUES TO LIFT THE REMNANTS OF LEE NE ACROSS NE ALABAMA AND NW GEORGIA. THIS UPPER TROUGH EXTENDS OVER THE GULF W OF A LINE FROM THE BIG BEND AREA OF FLORIDA TO VERACRUZ MEXICO SUPPORTING A COLD FRONT THAT AT 06/0900 UTC ENTERS THE GULF WATERS NEAR CEDAR KEY FLORIDA ALONG 26N86W WHERE IT PULLS UP STATIONARY ALONG 22N94W THEN S TO THE COAST OF MEXICO BETWEEN VERACRUZ AND THE ISTHMUS OF TEHUANTEPEC. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 45/60 NM EITHER SIDE OF THE COLD FRONT...WITHIN 90 NM W OF THE STATIONARY BOUNDARY...AND WITHIN 75 NM ALONG THE COAST OF MEXICO IN THE BAY OF CAMPECHE S OF 20N. DRY AIR ALOFT AND CLEARING SKIES DOMINATE THE NW AND SE GULF WATERS THIS MORNING. THE COLD FRONT WILL BECOME STATIONARY FROM FLORIDA BIG BEND AREA TO DEVELOPING LOW PRESSURE OVER THE E BAY OF CAMPECHE AND WEAKEN THROUGH WED. FRONT WILL THEN MOVE S AND DISSIPATE THU AND FRI WHILE THE LOW PRESSURE LINGERS IN THE SW GULF. CARIBBEAN SEA... AN ELONGATED UPPER LOW COVERS THE NW CARIBBEAN EXTENDING FROM CENTRAL HONDURAS TO W CUBA AND THE ISLE OF YOUTH ENHANCING SCATTERED SHOWERS/THUNDERSTORMS IN THE GULF OF HONDURAS S OF 19N W OF 86W. THE SW UPPER FLOW OVER THE SW CARIBBEAN IS CONVERGING WITH LOW LEVEL EASTERLY FLOW TO GENERATE A BAND OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 45/60 NM OF LINE FROM 14N83W TO 17N84W. THE MONSOON TROUGH EXTENDS CROSS THE SW CARIBBEAN FROM COLOMBIA NEAR 10N75W ALONG 12N80W TO OVER NICARAGUA NEAR 12N84W WITH SCATTERED SHOWERS/THUNDERSTORMS S OF THE MONSOON TROUGH TO THE COAST OF PANAMA BETWEEN 78W-82W. DRY STABLE AIR ALOFT DOMINATES THE CARIBBEAN E OF 80W. THIS IS LEAVING THE REMAINDER OF THE CARIBBEAN UNDER REMARKABLY CLEAR SKIES THIS MORNING. TROPICAL WAVE WILL MOVE NW THROUGH PUERTO RICO THU. THE BROAD LOW PRESSURE IN THE SPECIAL FEATURES WILL ENTER TROPICAL N ATLC LATE THU AND APPROACH LESSER ANTILLES ON SAT. ATLANTIC OCEAN... NW UPPER FLOW WITH MOSTLY DRY STABLE AIR DOMINATES THE W ATLC W OF HURRICANE KATIA. THE UPPER RIDGE ASSOCIATED WITH HURRICANE KATIA COVERS AN AREA FROM 19N-32N BETWEEN 58W-73W. AN UPPER LOW IS OVER THE CENTRAL ATLC CENTERED NEAR 28N52W AND IS EMBEDDED WITHIN A MUCH LARGER UPPER TROUGH THAT COVERS THE REMAINDER OF THE CENTRAL AND E ATLC INTO THE TROPICS WITH THE AXIS EXTENDING THROUGH 32N27W SW TO 16N45W GENERATING SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS N OF 30N BETWEEN 32W-37W. A SURFACE RIDGE DOMINATES THE ATLC N OF 20N W OF 60W AND ANCHORED BY A 1026 MB HIGH BETWEEN THE AZORES AND PORTUGAL AND A 1025 MB HIGH N OF THE DISCUSSION AREA ABOUT 700 NM E-NE OF BERMUDA. HURRICANE KATIA WILL CONTINUE TO MOVE THROUGH THE W ATLC THROUGH WED MOVING THEN N OF THE AREA OVERNIGHT WED NIGHT. WEAK COLD FRONT WILL ENTER FAR NW ATLC WATERS TONIGHT AND DISSIPATE BY THU. SURFACE RIDGE WILL THEN BUILD ACROSS THE W ATLC IN WAKE OF KATIA THU THROUGH SAT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW