000 AXNT20 KNHC 020005 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT THU SEP 01 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...SPECIAL FEATURES... THE CENTER OF TROPICAL STORM KATIA AT 01/2100 UTC IS NEAR 16.1N 49.2W. THIS POSITION ALSO IS ABOUT 810 NM TO THE EAST OF THE NORTHEASTERN CARIBBEAN SEA ISLANDS. KATIA IS MOVING WESTWARD 16 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 990 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 CONVECTIVE PRECIPITATION COVERS THE ATLANTIC OCEAN FROM 15N TO 18N BETWEEN 47W AND 50W. ISOLATED MODERATE PRECIPITATION IS POSSIBLE IN THE REST OF THE ATLANTIC OCEAN FROM 11N TO 20N BETWEEN 45W AND 52W. TROPICAL DEPRESSION THIRTEEN HAS DEVELOPED IN THE NORTH CENTRAL GULF OF MEXICO AT 02/0000 UTC. THE CENTER OF TROPICAL DEPRESSION THIRTEEN AT 02/0000 UTC IS NEAR 26.6N 91.4W. THE DEPRESSION ALSO IS ABOUT 180 NM TO THE SOUTH-SOUTHWEST OF SOUTH CENTRAL COASTAL LOUISIANA. THE DEPRESSION IS MOVING NORTHWESTWARD 5 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1007 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. NUMEROUS STRONG CONVECTIVE PRECIPITATION COVERS THE GULF OF MEXICO FROM THE YUCATAN PENINSULA TO 28N BETWEEN 87W AND 91W...AND FROM NORTHERN GUATEMALA NEAR 17N TO THE NORTHERN COAST OF THE YUCATAN PENINSULA BETWEEN 88W AND 91W. BROKEN TO OVERCAST MULTILAYERED CLOUDS AND POSSIBLE CONVECTIVE PRECIPITATION ARE ELSEWHERE IN THE GULF OF MEXICO. WIDELY SCATTERED MODERATE CONVECTIVE PRECIPITATION IS IN WESTERN AND SOUTHERN FLORIDA TO THE SOUTH OF 27N. AN ATLANTIC OCEAN 1006 MB LOW PRESSURE CENTER IS NEAR 37N64W. THIS LOW CENTER IS ABOUT 300 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 10 TO 15 MPH TONIGHT. ...TROPICAL WAVES... AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 18N23W...TO A 1012 MB LOW PRESSURE CENTER THAT IS NEAR 12N26W...TO 6N29W. SCATTERED TO NUMEROUS STRONG CONVECTIVE PRECIPITATION IS FROM 6N TO 7N BETWEEN 29W AND 31W. ISOLATED MODERATE PRECIPITATION COVERS THE REST OF THE ATLANTIC OCEAN FROM 15N TO 16N BETWEEN 21W AND 26W...AND FROM 9N TO 13N BETWEEN 27W AND 30W. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH ONLY EXISTS ACROSS AFRICA. THE MONSOON TROUGH HAS BEEN DISRUPTED IN THE ATLANTIC OCEAN AND THUS IT HAS NOT BEEN INCLUDED IN THE ANALYSIS. NUMEROUS STRONG CONVECTIVE PRECIPITATION IS IN AFRICA FROM 12N TO 16N BETWEEN 12W AND 16W. ISOLATED MODERATE PRECIPITATION IS FROM 6N TO 10N BETWEEN AFRICA AND 25W. ...DISCUSSION... THE GULF OF MEXICO... THE MAIN FOCUS OF INTEREST RIGHT NOW IS THE NEWLY-DEVELOPED TROPICAL DEPRESSION THIRTEEN. PLEASE REFER TO THE SPECIAL FEATURES SECTION FOR ALL THE INFORMATION ABOUT THIS SYSTEM. MOST IF NOT ALL THE PRECIPITATION THAT IS OCCURRING IN THE GULF OF MEXICO NOW IS RELATED TO THE TROPICAL DEPRESSION... AND THE REMNANT SURFACE TROUGH THAT WAS ASSOCIATED WITH THE SYSTEM FROM AT LEAST SIX HOURS AGO. THE CARIBBEAN SEA... THE SOUTHERN END OF AN UPPER LEVEL TROUGH PASSES THROUGH 25N55W IN THE ATLANTIC OCEAN...TO 15N58W AND POSSIBLY 13N60W BETWEEN BARBADOS AND SAINT VINCENT. ISOLATED MODERATE CONVECTIVE PRECIPITATION IS POSSIBLE FROM 13N TO 20N BETWEEN 56W AND 61W. UPPER LEVEL NORTHERLY FLOW IS CURVING AWAY FROM THE SOUTHEASTERN GULF OF MEXICO AND THE WIND FLOW REGIME THAT IS ASSOCIATED WITH TROPICAL DEPRESSION THIRTEEN. THE NORTHERLY WIND FLOW REACHES 17N75W. THE FLOW CURVES TOWARD AN UPPER LEVEL INVERTED TROUGH... WHOSE NORTHERNMOST POINT IS NEAR 17N83W. THE CYCLONIC FLOW OF THIS TROUGH COVERS THE AREA OF NICARAGUA AND HONDURAS AND NEARBY WATERS THAT ARE TO THE SOUTH OF 18N TO THE WEST OF 80W. SOME OF THE CYCLONIC FLOW MAY BE REACHING EL SALVADOR ALSO. UPPER LEVEL WESTERLY-TO-NORTHWESTERLY WIND FLOW COVERS THE REST OF THE AREA. BROAD SURFACE LOW PRESSURE IS WITHIN 150 TO 250 NM ON EITHER SIDE OF THE LINE THAT EXTENDS FROM NORTHERN BELIZE TO 13N81W TO COLOMBIA NEAR 9N75W. ISOLATED MODERATE CONVECTIVE PRECIPITATION IS TO THE NORTH OF 18N BETWEEN THE MONA PASSAGE AND WESTERN JAMAICA. THE MONSOON TROUGH PASSES THROUGH NORTHERN COLOMBIA NEAR 11N74W TO 10N80W...AND BEYOND COSTA RICA NEAR 10N85W. INDIVIDUAL CLUSTERS OF SCATTERED TO NUMEROUS STRONG CONVECTIVE PRECIPITATION ARE IN THE WATERS AND COASTAL AND INLAND AREAS THAT ARE TO THE SOUTH OF 12N TO THE WEST OF 73W. THE ATLANTIC OCEAN... TROPICAL STORM KATIA IS MOVING THROUGH THE CENTRAL TROPICAL ATLANTIC OCEAN. AN UPPER LEVEL TROUGH EXTENDS FROM A 32N69W CYCLONIC CIRCULATION CENTER TO 25N74W. A SURFACE TROUGH IS ALONG 32N68W TO 28N72W. ISOLATED MODERATE CONVECTIVE PRECIPITATION IS TO THE NORTH OF 22N BETWEEN 63W AND 71W. AN UPPER LEVEL TROUGH EXTENDS FROM ONE CYCLONIC CIRCULATION CENTER THAT IS NEAR 32N51W TO 28N54W TO 25N55W...AND THEN TO 19N57W...AND POSSIBLY EVEN TO 15N58W...AND POSSIBLY TO 13N60W BETWEEN BARBADOS AND SAINT VINCENT. PRECIPITATION IS POSSIBLE FROM 13N TO 20N BETWEEN 56W AND 61W. ISOLATED MODERATE PRECIPITATION IS TO THE NORTH OF 20N BETWEEN 45W AND 62W. AN UPPER LEVEL TROUGH PASSES THROUGH 32N11W TO THE CANARY ISLANDS NEAR 28N15W. THE TROUGH SUPPORTS A DISSIPATING COLD FRONT THAT PASSES THROUGH 31N10W TO THE CENTRAL CANARY ISLANDS TO 27N22W. CLOUDS AND POSSIBLE PRECIPITATION ARE TO THE NORTH OF THE LINE THAT PASSES THROUGH 32N37W 28N32W 28N25W 29N20W BEYOND 32N13W. A SEPARATE UPPER LEVEL CYCLONIC CIRCULATION CENTER IS NEAR 25N27W. BROAD CYCLONIC FLOW COVERS THE AREA TO THE NORTH OF 20N TO THE EAST OF 40W. SURFACE ANTICYCLONIC WIND FLOW COVERS THE ATLANTIC OCEAN TO THE NORTH OF 24N BETWEEN 26W AND 55W...MOVING AROUND A 1026 MB HIGH PRESSURE CENTER THAT IS NEAR 33N41W. ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ MT