000 AXNT20 KNHC 021150 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT FRI SEP 02 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 1115 UTC. ...SPECIAL FEATURES... THE CENTER OF TROPICAL STORM KATIA AT 02/0900 UTC IS NEAR 17.0N 51.8W. THIS POSITION ALSO IS ABOUT 650 NM EAST OF THE NORTHERN LEEWARD ISLANDS. KATIA IS MOVING WNW AT 13 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 994 MB. THE MAXIMUM SUSTAINED WIND SPEEDS ARE 60 KT WITH GUSTS TO 75 KT. PLEASE READ 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. NUMEROUS STRONG CONVECTION COVERS THE ATLANTIC OCEAN FROM 16N-21N BETWEEN 49W-53W. ELSEWHERE SCATTERED MODERATE CONVECTION EXTENDS FROM 15N-23N BETWEEN 47W-55W. THE CENTER OF TROPICAL DEPRESSION THIRTEEN AT 02/1200 UTC IS NEAR 27.0N 91.6W. THIS POSITION IS ABOUT 180 NM SW OF THE MOUTH OF THE MISSISSIPPI RIVER. THE DEPRESSION IS NEARLY STATIONARY MOVING N AT 1 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1005 MB. THE MAXIMUM SUSTAINED WIND SPEEDS ARE 30 KT WITH GUSTS TO 40 KT. PLEASE READ THE LATEST INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADER MIATCPAT3/WTNT33 KNHC AND THE FULL FORECAST/ADVISORY UNDER AWIPS/WMO HEADER MIATCMAT3/WTNT23 KNHC FOR MORE DETAILS. SCATTERED MODERATE TO STRONG CONVECTION IS OVER THE CENTRAL GULF OF MEXICO FROM 22N-29N BETWEEN 85W-91W. AN ATLANTIC OCEAN 1005 MB LOW IS NEAR 38N63W. THIS LOW CENTER IS ABOUT 350 NM TO THE NORTH OF BERMUDA. THIS LOW CENTER IS PRODUCING WINDS OF TROPICAL STORM FORCE. IT IS POSSIBLE THAT THIS FEATURE MAY DEVELOP INTO A TROPICAL CYCLONE WITH ONLY A SLIGHT INCREASE IN ORGANIZATION. THIS LOW CENTER IS EXPECTED TO MOVE NORTHEASTWARD AT 10-15 KT. ...TROPICAL WAVES... AN ATLANTIC OCEAN TROPICAL WAVE EXTENDS FROM 18N27W...TO A 1011 MB LOW PRESSURE CENTER NEAR 11N29W...TO 6N29W. WIDELY SCATTERED MODERATE CONVECTION IS W OF THE CAPE VERDE ISLANDS FROM 9N-16N BETWEEN 28W-33W. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH OVER WEST AFRICA EXITS THE COAST NEAR 16N16W AND EXTENDS SW TO ONLY 15N20W. THE TROPICAL LOW/TROPICAL WAVE... AND T.S. KATIA HAVE DISRUPTED THE MONSOON TROUGH AND ITCZ AXIS OVER THE REMAINDER OF THE TROPICAL ATLANTIC. SCATTERED MODERATE CONVECTION IS ALONG THE COAST OF WEST AFRICA FROM 6N-17N BETWEEN 16W-20W. SCATTERED MODERATE CONVECTION IS FROM 5N-7N BETWEEN 31W-35W. ...DISCUSSION... THE GULF OF MEXICO... THE MAIN FOCUS OF INTEREST RIGHT NOW IS TROPICAL DEPRESSION THIRTEEN. PLEASE REFER TO THE SPECIAL FEATURES SECTION FOR ALL THE INFORMATION ABOUT THIS SYSTEM. MOST OF THE PRECIPITATION THAT IS OCCURRING IN THE CENTRAL GULF OF MEXICO IS RELATED TO THE TROPICAL DEPRESSION. NUMEROUS BUOYS AND SHIPS OVER THE CENTRAL GULF ARE REPORTING 25-30 KT WINDS. IN ADDITION...SCATTERED SHOWERS ARE OVER S FLORIDA...THE STRAITS OF FLORIDA...AND W CUBA FROM 22N-27N BETWEEN 80W-84W. SIMILAR SHOWERS ARE WITHIN 90 NM OF THE TEXAS COAST. ISOLATED MODERATE CONVECTION IS OVER THE BAY OF CAMPECHE S OF 21N. EXPECT... TROPICAL DEPRESSION THIRTEEN TO DRIFT N OVER THE NEXT 24 HOURS AND INTENSIFY TO A TROPICAL STORM PRODUCING LOCALIZED FLOODING AND A STORM SURGE OF 2-4 FT. THE CARIBBEAN SEA... SE TO S SURFACE FLOW IS OVER THE NW CARIBBEAN AND THE YUCATAN PENINSULA. SCATTERED SHOWERS ARE OVER THE YUCATAN PENINSULA N OF 17N...AND OVER THE NW CARIBBEAN N OF 20N. A GOOD AMOUNT OF TROPICAL MOISTURE WITH NUMEROUS STRONG CONVECTION IS ALSO OVER N COLOMBIA AND THE SW CARIBBEAN S OF 12N DUE TO THE MONSOON TROUGH THAT EXTENDS FROM LAKE MARACAIBO VENEZUELA TO N COSTA RICA. ELSEWHERE...SCATTERED SHOWERS ARE OVER E CUBA...HAITI...AND JAMAICA FROM 18N-21N BETWEEN 72W-77W. THE LEEWARD AND WINDWARD ISLANDS HAVE MOSTLY FAIR WEATHER WITH STRONG SUBSIDENCE ALOFT. 15-25 KT TRADEWINDS ARE OVER THE CARIBBEAN SEA WITH STRONGEST WINDS ALONG THE COAST OF N COLOMBIA. EXPECT LITTLE CHANGE OVER THE NEXT 24 HOURS. THE ATLANTIC OCEAN... THE MAIN FEATURE OF INTEREST IS TROPICAL STORM KATIA IN THE CENTRAL TROPICAL ATLANTIC. SEE ABOVE. ELSEWHERE A 1010 MB LOW IS OVER THE W ATLANTIC NEAR 32N69W. A SURFACE TROUGH EXTENDS S FROM THE LOW TO 30N67W 25N72W. ISOLATED MODERATE CONVECTION IS WITHIN 120 NM E OF THE TROUGH AXIS. A 1024 MB HIGH IS OVER THE CENTRAL ATLANTIC NEAR 33N41W. IN THE UPPER LEVELS...AN UPPER LEVEL LOW IS CENTERED OVER THE CENTRAL ATLANTIC NEAR 27N55W. THIS LOW IS PRODUCING UPPER LEVEL SHEAR OVER T.S. KATIA. EXPECT KATIA TO MOVE CLOSER TO THE LEEWARD ISLANDS OVER THE NEXT 24 HOURS. ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORMOSA