000 AXNT20 KNHC 191143 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT MON SEP 19 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 1015 UTC. ...SPECIAL FEATURES... A 1008 MB LOW IS EMBEDDED ALONG THE MONSOON TROUGH AXIS NEAR 12N37W. TOTAL PRECIPITABLE WATER IMAGERY INDICATES THAT LOW-LEVEL MOISTURE IS MAXIMIZED FROM 06N-14N BETWEEN 34W-42W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM 07N-15N BETWEEN 36W-40W. ENVIRONMENTAL CONDITIONS REMAIN FAVORABLE FOR THE DEVELOPMENT OF A TROPICAL DEPRESSION DURING THE NEXT COUPLE OF DAYS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 18N16W TO 10N25W TO THE SPECIAL FEATURES 1008 MB LOW NEAR 12N37W TO 09N48W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM 11N-14N BETWEEN 23W-32W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 03N-08N BETWEEN 19W-30W...AND FROM 05N-12N BETWEEN 30W-34W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED OVER THE WESTERN GULF NEAR 24N92W AND CONTINUES TO SUPPORT A SURFACE RIDGE AXIS EXTENDING FROM THE SE CONUS OVER GEORGIA THROUGH 29N90W IN THE NORTH-CENTRAL GULF TO THE EAST-CENTRAL MEXICO COAST NEAR 21N97W. PRIMARILY E TO SE SURFACE WINDS IN THE RANGE OF 10-15 KT WERE NOTED ON AN EARLIER ASCAT PASS AROUND 19/0336 UTC AND THESE WINDS ARE EXPECTED TO PERSIST THROUGH MIDDAY MONDAY. WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL SHORTWAVE TROUGH PROGRESSING ACROSS THE SOUTHERN U.S. PLAINS WHICH SUPPORTS A FRONTAL BOUNDARY EXTENDING FROM EASTERN OKLAHOMA INTO NORTH AND CENTRAL PORTIONS OF TEXAS. THIS FRONT IS FORECAST TO ENTER NW PORTIONS OF THE GULF EARLY TUESDAY AND BEGIN TO STALL...WHILE A REINFORCING FRONT WILL IMPACT THE NORTHERN GULF BY THURSDAY. SOME WINDS OVER THE COASTAL WATERS OF THE TEXAS COAST ARE AS OF 19/0900 UTC S TO SW WITH SCATTERED SHOWERS AND TSTMS OCCURRING W OF A LINE FROM NEW ORLEANS LOUISIANA TO BROWNSVILLE TEXAS. LOW-LEVEL MOISTURE AND POSSIBLE ISOLATED LOW-TOPPED SHOWERS ARE PREVALENT ON SATELLITE IMAGERY THIS MORNING ACROSS MUCH OF THE EASTERN GULF E OF 90W. A SURFACE TROUGH IS ALSO ANALYZED IN THE BAY OF CAMPECHE FROM 21N92W TO 18N93W WITH ISOLATED SHOWERS OCCURRING S OF 20N BETWEEN 92W-95W. CARIBBEAN SEA... AN UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED OVER THE WESTERN CARIBBEAN NEAR 10N81W AND IS PROVIDING AN UPPER LEVEL DIFFLUENT ENVIRONMENT W OF 74W WITH SCATTERED SHOWERS AND TSTMS FOCUSED ON MAXIMIZED LOW-LEVEL SPEED CONVERGENCE ALONG THE COAST OF CENTRAL AMERICA. ISOLATED SHOWERS ARE OCCURRING S OF 19N W OF 81W. E OF 74W...AN UPPER LEVEL TROUGH EXTENDS FROM THE SW NORTH ATLC SOUTHWARD TO A BASE OVER THE SE CARIBBEAN. MIDDLE TO UPPER LEVEL MOISTURE CONTINUES TO BE ADVECTED ACROSS THE MUCH OF THE NE CARIBBEAN WITH ISOLATED SHOWERS AND TSTMS OCCURRING OVER THE EASTERN CARIBBEAN E OF 65W. THE UPPER LEVEL TROUGHING WILL BROADEN OUT THROUGH LATE TUESDAY OVER THE SW NORTH ATLC PROVIDING THE EASTERN AND CENTRAL CARIBBEAN WITH CONTINUED WEST- SOUTHWESTERLY FLOW AND HIGHER POSSIBILITY FOR WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS THROUGH WEDNESDAY. ATLANTIC OCEAN... AN UPPER LEVEL SHORTWAVE TROUGH IS PROGRESSING OVER THE WESTERN NORTH ATLC WITH AXIS ALONG 69W THAT SUPPORTS A COLD FRONT EXTENDING INTO THE DISCUSSION AREA NEAR 32N71W TO 31N73W WHERE THE FRONT BECOMES MORE DIFFUSE AS A DISSIPATING STATIONARY FRONT TO THE FLORIDA PENINSULA NEAR DAYTONA BEACH. SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING WITHIN 120 NM EITHER SIDE OF THE FRONT W OF 70W. FARTHER TO THE SE...WATER VAPOR IMAGERY INDICATES A MIDDLE TO UPPER LEVEL LOW IS CENTERED NEAR 24N67W. MIDDLE TO UPPER LEVEL MOISTURE CONTINUES TO STREAM NORTHWARD ON THE EASTERN PERIPHERY OF THE LOW WITH WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS OCCURRING OVER THE AREA FROM 18N-29N BETWEEN 61W-71W. ISOLATED SHOWERS ARE ALSO OCCURRING EAST OF THE LESSER ANTILLES FROM 13N-18N BETWEEN 58W-61W. THE REMAINDER OF THE CENTRAL AND EASTERN ATLC IS UNDER THE INFLUENCE OF A BROAD UPPER LEVEL TROUGH DIPPING SOUTHWARD TO 15N BETWEEN 30W-45W. THIS TROUGH SUPPORTS A SURFACE TROUGH EXTENDING INTO THE DISCUSSION AREA NEAR 32N41W TO 30N42W WITH ISOLATED SHOWERS AND TSTMS OCCURRING WITHIN 120 NM EITHER SIDE OF A LINE FROM 35N30W TO 27N42W. FARTHER SOUTH...A WEAK 1010 MB LOW IS CENTERED NEAR 17N47W THAT EXHIBITS A SMALL AREA OF SCATTERED MODERATE CONVECTION WITHIN 90 NM OF THE CENTER OF THE LOW. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN