000 AXNT20 KNHC 141802 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SUN AUG 14 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...SPECIAL FEATURES... TROPICAL DEPRESSION SEVEN WAS UPGRADED TO TROPICAL STORM GERT AT 14/1800 UTC. T.S. GERT IS CENTERED NEAR 28.6N 63.1W OR ABOUT 240 NM SSE OF BERMUDA AT 14/1800 UTC MOVING NNW AT 6 KT. ESTIMATED CENTRAL PRESSURE IS 1009 MB. MAXIMUM SUSTAINED WIND SPEED IS 35 KT WITH GUSTS TO 45 KT. PLEASE SEE THE LATEST NHC INTERMEDIATE PUBLIC ADVISORY MIATCPAT1/WTNT32 KNHC AND THE FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/WTNT22 KNHC FOR MORE DETAILS. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 27N-29N BETWEEN 61W-64W. SCATTERED SHOWERS COVER THE REMAINDER OF THE AREA FROM 26N-32N BETWEEN 59W-63W. A 1012 MB LOW IS CENTERED NEAR 23N59W WITH CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION FROM 23N-25N BETWEEN 57W-60W. ENVIRONMENTAL CONDITIONS ARE EXPECTED TO REMAIN ONLY MARGINALLY CONDUCIVE FOR DEVELOPMENT OVER THE NEXT COUPLE OF DAYS DUE TO PROXIMITY TO T.S. GERT. THIS SYSTEM HAS A MEDIUM CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS AS IT MOVES TOWARD THE W-NW AT 13-17 KT. ...TROPICAL WAVES... TROPICAL WAVE IN THE TROPICAL ATLC EXTENDS FROM 16N45W TO 10N43W MOVING W NEAR 15-20 KT. WAVE IS EMBEDDED WITHIN AN AREA OF DEEP LAYER MOISTURE AS DEPICTED IN TOTAL PRECIPITABLE WATER IMAGERY. WAVE HAS BECOME TILTED NW/SE WITH SCATTERED MODERATE/ISOLATED STRONG CONVECTION WELL TO THE W OF THE WAVE FROM 12N-16N BETWEEN 50W-54W. TROPICAL WAVE EXTENDS FROM THE GULF OF MEXICO NEAR 22N90W TO ACROSS S MEXICO NEAR 18N91W THEN INTO THE E PACIFIC REGION MOVING W NEAR 15 KT. NO ASSOCIATED DEEP CONVECTION. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS OFF THE COAST OF W AFRICA NEAR 17N16W CONTINUING ALONG 13N20W 10N37W TO 8N41W. THE ITCZ AXIS CONTINUES FROM 8N41W TO INLAND OVER SOUTH AMERICA NEAR 7N54W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE WITHIN 180 NM S OF THE ITCZ BETWEEN 41W-50W. CLUSTERS OF ISOLATED MODERATE CONVECTION ARE FROM 4N-8N BETWEEN 19W-30W AND FROM 6N-11N E OF 19W TO INLAND OVER W AFRICA. ...DISCUSSION... GULF OF MEXICO... AN UPPER TROUGH OVER THE E CONUS EXTENDS S TO THE N GULF COAST WHERE AT 14/1500 UTC A SURFACE TROUGH EXTENDS FROM S GEORGIA NEAR VALDOSTA ACROSS THE FLORIDA PANHANDLE NEAR PANAMA CITY INTO THE GULF WATERS ALONG 30N88W THEN RETURNS INLAND OVER SE LOUISIANA ACROSS LAKE PONTCHARTRAIN TO CENTRAL LOUISIANA. SCATTERED TO HEAVY SHOWERS AND ISOLATED THUNDERSTORMS ARE WITHIN 90 NM S OF THE SURFACE TROUGH BETWEEN APALACHICOLA FLORIDA AND ATCHAFALAYA BAY LOUISIANA. EASTERLY FLOW ALOFT DOMINATES THE GULF WATERS. A SURFACE RIDGE EXTENDS FROM THE W ATLC THROUGH THE STRAITS OF FLORIDA THEN NW TO THE COAST OF W LOUISIANA/TEXAS WITH A 1015 MB HIGH LOCATED NEAR 27N90W. ISOLATED SHOWERS DOT THE REMAINDER OF THE GULF N OF 22N WITH ADDITIONAL ISOLATED THUNDERSTORMS WITHIN 75/90 NM OF 24N E OF 91W TO OVER S FLORIDA AND THE FLORIDA KEYS. THE SURFACE RIDGE WILL REMAIN THROUGH TUE. A WEAK COLD FRONT WILL MOVE INTO THE FAR NE GULF ON MON THEN STALL AND WEAKEN THROUGH WED. A SURFACE HIGH WILL THEN BECOME CENTERED OVER THE NW GULF WED AND THU. CARIBBEAN SEA... EASTERLY FLOW ALOFT DOMINATES THE N CARIBBEAN N OF 17N WITH LIGHT AND VARIABLE WINDS ALOFT COVERING THE REMAINDER OF THE CARIBBEAN. THE EASTERLY FLOW ALOFT ACROSS THE N CARIBBEAN IS USHERING IN SOME SCATTERED SHOWERS ACROSS HISPANIOLA...E CUBA AND JAMAICA. THE MONSOON TROUGH EXTENDS ACROSS THE SW CARIBBEAN FROM COLOMBIA NEAR 10N75W TO ACROSS COSTA RICA/NICARAGUA BORDER INTO THE E PACIFIC REGION GENERATING SCATTERED MODERATE/STRONG CONVECTION WITHIN 60 NM OF LINE FROM 9N77W TO 11N80W INCLUDING THE COAST OF PANAMA THEN STREAMS SCATTERED MODERATE/ISOLATED STRONG CONVECTION WITHIN 90 NM OF LINE FROM 11N80W TO INLAND OVER NICARAGUA NEAR 13N84W. THIS IS LEAVING THE REMAINDER OF THE CARIBBEAN UNDER CLEAR SKIES THIS AFTERNOON. ATLC SURFACE RIDGE WILL WEAKEN THROUGH MON ALLOWING FOR TRADE WINDS TO DIMINISH SOME OVER THE W CARIBBEAN. THE 1012 MB LOW IN THE SPECIAL FEATURES WILL PULL AWAY FROM THE CARIBBEAN THIS AFTERNOON AND TONIGHT. THE TROPICAL WAVE IN THE TROPICAL ATLC IS EXPECTED TO MOVE INTO THE E CARIBBEAN WED THEN REACH THE CENTRAL CARIBBEAN THU. ATLANTIC OCEAN... THE PRIMARY CONCERN FOR THE AFTERNOON IS T.S. GERT IN THE SPECIAL FEATURES...PRIMARILY FOR BERMUDA...SEE ABOVE. THE UPPER TROUGH INLAND OVER THE E CONUS IS GENERATING SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS N OF 29N BETWEEN 75W-80W. AN UPPER RIDGE COVERS THE REMAINDER OF THE W ATLC ANCHORED OVER THE N BAHAMA ISLANDS WITH A WEAK SURFACE RIDGE ANCHORED BY A 1016 MB HIGH NEAR 27N70W AND EXTENDING A RIDGE AXIS THROUGH THE STRAITS OF FLORIDA INTO THE GULF OF MEXICO. UPPER LOW IS JUST N OF THE VIRGIN ISLANDS NEAR 22N64W WITH AN UPPER TROUGH EXTENDING N TO NEAR T.S. GERT. TO THE W OF THE UPPER TROUGH IS A SURFACE TROUGH THAT EXTENDS FROM 23N65W TO THE E TIP OF THE DOMINICAN REPUBLIC. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE W OF THE TROUGH TO A LINE FROM 24N68W TO THE WINDWARD PASSAGE WITH THE SHOWERS EXTENDING INLAND OVER HISPANIOLA. TO THE E OF THE UPPER TROUGH IS THE 1012 MB LOW ALSO IN THE SPECIAL FEATURES ABOVE. THE REMAINDER OF THE ATLC IS DOMINATED BY BENIGN UPPER LEVEL FEATURES AND A SURFACE RIDGE THAT COVERS THE AREA N OF 20N BETWEEN 20W-55W AND ANCHORED BY A 1022 MB HIGH NEAR 32N48W. DRY SAHARAN AIR ALSO COVERS THE E ATLC N OF 15N E OF 55W AS SEEN ON VISIBLE SATELLITE IMAGES. THE SURFACE HIGH OVER THE W ATLC WILL DISSIPATE THROUGH TONIGHT AS T.S. GERT MOVES WNW. T.S. GERT IS FORECAST TO MOVE N OF THE DISCUSSION AREA MON MORNING BEFORE LIFTING FURTHER N. THE SURFACE TROUGH N OF THE GREATER ANTILLES WILL TRACK W REACHING THE FAR SE BAHAMAS TONIGHT THEN MOVE THROUGH THE REMAINDER ISLANDS THROUGH TUE BEFORE REACHING THE NW BAHAMAS AND FLORIDA WED INTO THU. THE 1012 MB LOW IN THE SPECIAL FEATURES SHOULD PASS THROUGH THE W/CENTRAL ATLC MON NIGHT... POSSIBLY AS A TROPICAL CYCLONE. A WEAK COLD FRONT WILL ENTER THE NW ATLC MON NIGHT AND DISSIPATE WED. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW