000 AXNT20 KNHC 011737 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...SPECIAL FEATURE... HURRICANE KATIA IS CENTERED NEAR 15.3N 47.5W AS OF 01/1500 UTC OR ABOUT 915 NM KM E OF THE NORTHERN LEEWARD ISLANDS MOVING W AT 16 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 987 MB. MAXIMUM SUSTAINED WIND SPEED IS 65 KT WITH GUSTS TO 80 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. SCATTERED MODERATE/ISOLATED STRONG CONVECTION COVERS THE AREA FROM 14N-18N BETWEEN 45W-49W WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 11N-20N BETWEEN 41W-53W. TROPICAL WAVE OVER THE GULF OF MEXICO AT 01/1500 UTC EXTENDS FROM 28N90W TO INLAND OVER S MEXICO NEAR CIUDAD DEL CAMPECHE TO 17N92W. SCATTERED/HEAVY SHOWERS WITH EMBEDDED CLUSTERS OF THUNDERSTORMS COVERS THE E GULF E OF 90W. UPPER LEVEL WINDS ARE FORECAST TO BECOME MORE CONDUCIVE FOR DEVELOPMENT AND THIS SYSTEM COULD BECOME A TROPICAL DEPRESSION DURING THE NEXT DAY OR SO. THIS SYSTEM HAS A HIGH CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS AS IT MOVES SLOWLY NORTHWESTWARD. INTERESTS ALONG THE ENTIRE NORTHERN GULF OF MEXICO COAST SHOULD MONITOR THE PROGRESS OF THIS DISTURBANCE. THE LOW PRESSURE SYSTEM LOCATED ABOUT 315 NM N OF BERMUDA NEAR 37N64W APPEARS TO BE ACQUIRING SOME TROPICAL CHARACTERISTICS BUT HAS CHANGED LITTLE OVER THE PAST FEW HOURS. THIS SYSTEM IS PRODUCING WINDS OF TROPICAL STORM FORCE AND ONLY A SLIGHT INCREASE IN ORGANIZATION COULD RESULT IN THE FORMATION OF A TROPICAL STORM. THE LOW IS MOVING LITTLE AT THIS TIME BUT SHOULD BEGIN TO MOVE NORTHEASTWARD TONIGHT. THIS SYSTEM HAS A MEDIUM CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS. PLEASE SEE THE HIGH SEAS FORECAST UNDER AWIPS/WMO HEADER NFDHSFAT1/FZNT01 KWBC FOR MORE DETAILS. ...TROPICAL WAVES... TROPICAL WAVE WAS INTRODUCED IN THE E TROPICAL ATLC EXTENDING FROM THE CAPE VERDE ISLANDS NEAR 16N23W THROUGH A PREVIOUSLY ANALYZED SURFACE LOW NEAR 11N23W...NOW A 1012 MB LOW NEAR 10N25W...TO 7N26W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE WITHIN 120/150 NM OF LINE FROM 15N24W TO 8N29W. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH IS ANALYZED ACROSS AFRICA AND DOES NOT ENTER THE E TROPICAL ATLC REGION. CLUSTERS OF SCATTERED MODERATE TO SCATTERED STRONG CONVECTION DOT THE TROPICS WITHIN 150 NM OF LINE FROM THE COAST OF SW AFRICA NEAR 8N13W TO 5N31W. ...DISCUSSION... GULF OF MEXICO... A TROPICAL WAVE IS OF INTEREST IN THE GULF THIS AFTERNOON...SEE SPECIAL FEATURES SECTION ABOVE. AN ABUNDANCE OF DEEP LAYER MOISTURE COVERS THE GULF. A SHORTWAVE UPPER TROUGH EXTENDS FROM MOBILE ALABAMA THROUGH AN UPPER LOW NEAR 30N91W TO THE COAST OF TEXAS NEAR HOUSTON GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 28N E OF 90W. AN UPPER RIDGE DOMINATES MOST OF THE GULF ANCHORED INLAND OVER S/CENTRAL TEXAS EXTENDING AN AXIS ROUGHLY E ALONG 25N TO ACROSS S FLORIDA. CLUSTERS OF SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE OVER THE W GULF S OF 26N W OF 90W. THE TROPICAL WAVE WILL MOVE SLOWLY W THROUGH SAT. A LOW PRESSURE WILL LIKELY FORM ALONG THE N PORTION OF THE WAVE LATER THIS AFTERNOON THEN WILL SLOWLY MOVE NW TOWARDS THE NW GULF THROUGH FRI...POSSIBLY AS A TROPICAL CYCLONE. CARIBBEAN SEA... AN ABUNDANCE OF DEEP LAYER MOISTURE COVERS THE NW CARIBBEAN WHERE AN UPPER RIDGE EXTENDING ACROSS THE GULF OF MEXICO IS GIVING THE NW CARIBBEAN NE FLOW ALOFT. AN INVERTED UPPER TROUGH EXTENDS ACROSS THE CENTRAL CARIBBEAN FROM COSTA RICA TO E CUBA NEAR 20N76W ENHANCING THE NE FLOW OVER THE NW CARIBBEAN AND THE SCATTERED SHOWERS/THUNDERSTORMS N OF 19N W OF 84W. THE MONSOON TROUGH EXTENDS ACROSS THE SW CARIBBEAN FROM COLOMBIA NEAR 11N74W TO ACROSS NICARAGUA INTO THE E PACIFIC REGION NEAR 12N84W AND GENERATING SCATTERED/HEAVY SHOWERS WITH EMBEDDED THUNDERSTORMS S OF 14N W OF 80W TO INLAND OVER CENTRAL AMERICA. THE REMAINDER OF THE CARIBBEAN IS UNDER MOSTLY CLEAR SKIES THIS AFTERNOON. HIGH PRESSURE OVER THE CAROLINAS WILL WEAKEN AS HURRICANE KATIA MOVES THROUGH THE ATLC ALLOWING TRADE WINDS TO DIMINISH OVER THE CARIBBEAN THIS WEEKEND. ATLANTIC OCEAN... TROPICAL STORM KATIA REMAINS IN THE CENTRAL TROPICAL ATLC...SEE SPECIAL FEATURES SECTION ABOVE. AN UPPER TROUGH EXTENDS OVER THE W ATLC N OF 26N W OF 65W SUPPORTING SURFACE FEATURES N OF THE DISCUSSION AREA AND A SURFACE TROUGH THAT EXTENDS FROM 31N67W TO 25N72W GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 180 NM E OF THE SURFACE TROUGH AND ISOLATED SHOWERS/ THUNDERSTORMS WITHIN 90/120 NM OF 27N W OF 69W TO INLAND OVER THE FLORIDA PENINSULA. A BROAD UPPER TROUGH COVERS THE CENTRAL ATLC WITH THE AXIS EXTENDING FROM BEYOND 32N55W THROUGH AN UPPER LOW NEAR 27N55W TO THE TROPICS NEAR 18N59W GENERATING CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 90 NM OF LINE FROM 23N53W TO 30N49W AND N OF 30N BETWEEN 45W-55W. A SURFACE RIDGE COVERS THE CENTRAL INTO THE E ATLC ANCHORED BY A 1025 MB HIGH N OF THE DISCUSSION ABOUT 700 NM WSW OF THE AZORES. AN UPPER TROUGH IS OVER THE E ATLC EXTENDING FROM BEYOND 32N14W THROUGH AN UPPER LOW NEAR 25N26W TO NE OF HURRICANE KATIA NEAR 21N33W SUPPORTING A COLD FRONT THAT EXTENDS THROUGH 32N10W ACROSS THE CANARY ISLANDS TO NEAR 28N17W WHERE IT DISSIPATES TO 27N21W. ISOLATED SHOWERS ARE WITHIN 45 NM SE OF THE COLD FRONT. HURRICANE KATIA WILL GRADUALLY INTENSIFY AS IT MOVES INTO THE W TROPICAL ATLC THROUGH THE WEEKEND THEN TO THE NE OF THE LEEWARD ISLANDS. HIGH PRESSURE OVER THE CAROLINAS TO BERMUDA WILL WEAKEN AS KATIA MOVES THROUGH THE ATLC. ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW