000 AXNT20 KNHC 091805 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SUN SEP 08 2013 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... AS OF 1500 UTC TROPICAL STORM HUMBERTO IS LOCATED NEAR 13.6N 24.1W OR ABOUT 73 NM SSE OF FOGO CAPE VERDE ISLANDS. ITS ESTIMATED MINIMUM CENTRAL PRESSURE IS 1005 MB. MAXIMUM SUSTAINED WIND SPEED IS 40 KT WITH GUSTS TO 50 KT. NUMEROUS STRONG CONVECTION IS FROM 12N-14N BETWEEN 24W-26W. NUMEROUS MODERATE CONVECTION IS FROM 09N-16N BETWEEN 23W-30W. SCATTERED MODERATE CONVECTION IS ELSEWHERE FROM 08N-16N BETWEEN 20W-34W. SEE LATEST NHC INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT4/WTNT34 KNHC AND THE FULL FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... A TROPICAL WAVE IS IN THE CENTRAL ATLC BEING ANALYZED FROM 24N42W THROUGH A 1013 MB LOW NEAR 18N40W TO 16N39W...MOVING W-NW NEAR 10 KT. NORTH OF THE LOW PRESSURE CENTER THE WAVE IS EMBEDDED WITHIN A HIGH MOIST ENVIRONMENT WHEREAS A VERY DRY ENVIRONMENT IS W AND SW OF THE LOW. A SMALL CLUSTER OF MODERATE CONVECTION WITH ISOLATED TSTMS IS NW OF THE LOW FROM 18N-20N BETWEEN 42W-44W. TROPICAL WAVE IS IN THE BAY OF CAMPECHE WITH AXIS EXTENDING FROM 21N90W TO 15N91W AND HAS BEEN MOVING NEAR 5 KT. AN ELONGATED LOW- LEVEL CYCLONIC CIRCULATION OVER THE YUCATAN PENINSULA HAS BEEN ADVECTING MOISTURE FROM THE E PACIFIC DURING THE LAST COUPLE OF HOURS THUS ENHANCING SCATTERED MODERATE CONVECTION WITHIN 150 NM EITHER SIDE OF THE AXIS FROM 18N-23N. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA TO OVER BURKINA FASO. THE MONSOON TROUGH AND ITCZ HAVE BEEN DISRUPTED BY THE DEVELOPMENT OF TROPICAL STORM HUMBERTO. BESIDES THE CONVECTION ASSOCIATED WITH HUMBERTO AND THE TRPCL WAVE...A CLUSTER OF MODERATE CONVECTION WITH EMBEDDED TSTMS IS FROM 16N-20N E OF 21W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LOW IS OVER W TEXAS EXTENDING A SHORTWAVE UPPER TROUGH ALONG THE WESTERN GULF WHICH IS SUPPORTING A SURFACE TROUGH ALONG 27N97W TO 23N97W 19N95W. MIDDLE-LEVEL DIFFLUENCE OVER THE WESTERN GULF W OF 90W IS SUPPORTING SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS S OF 29N W OF 89W. A WEAK SURFACE RIDGING IS OVER THE NE GULF WHERE TOTAL PRECIPITABLE WATER AND WATER VAPOR IMAGERY SHOW A VERY DRY ENVIRONMENT. SUBSIDENCE OF DRY AIR IN THIS PART OF THE GULF SUPPORTS FAIR WEATHER N OF 22N E OF 89W. THE TROPICAL WAVE WILL CONTINUE A WESTWARD TRACK OVER THE BAY OF CAMPECHE AND WILL MOVE INLAND LATE ON TUESDAY. THE SURFACE TROUGH IS EXPECTED TO DISSIPATE LATER TODAY. HOWEVER...A NEW SURFACE TROUGH OR AREA OF LOW PRESSURE IS EXPECTED TO DEVELOP OVER THE SW GULF WATERS BY WED. RAINSHOWERS ARE EXPECTED TO CONTINUE OVER THE WESTERN GULF THROUGH WED WHILE FAIR WEATHER IS EXPECTED TO CONTINUE IN THE N-NE GULF. CARIBBEAN SEA... TOTAL PRECIPITABLE WATER IMAGERY SHOW A MODERATE TO HIGH MOIST ENVIRONMENT IN THE BASIN W OF 70W. MIDDLE-LEVEL DIFFLUENCE OVER THE WESTERN CARIBBEAN IS ENHANCING SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS N OF 15N W OF 78W. IN THE UPPER-LEVEL...A WEAK RIDGE COVERS THE BASIN W OF 75W WHILE AN ELONGATED LOW IS OVER THE REMAINDER BASIN. THIS IS GENERATING UPPER LEVEL DIFFLUENCE THUS SUPPORTING SCATTERED MODERATE CONVECTION IN THE CENTRAL BASIN FROM THE NORTHERN COAST OF COLOMBIA TO THE TRENCH BETWEEN CUBA AND JAMAICA BETWEEN 72W-77W. THIS DIFFLUENCE IS ALSO ENHANCING ISOLATED SHOWERS AND TSTMS OVER HISPANIOLA. TRAILING MOISTURE FROM THE REMNANTS OF GABRIELLE OVER THE SW N ATLC IS ENHANCING ISOLATED SHOWERS ACROSS PUERTO RICO. IN THE SOUTHERN BASIN...THE MONSOON TROUGH IS GENERATING SHOWERS AND TSTMS S OF 11N E OF 80W. DRY AIR IN THE LOWER AND MIDDLE SUPPORTS FAIR WEATHER IN THE REMAINDER EASTERN BASIN. TRADE WINDS ARE BECOMING ESTABLISHED ACROSS THE CENTRAL AND E CARIBBEAN THROUGH EARLY WED THEN DIMINISH INTO FRI. HISPANIOLA... UPPER-LEVEL DIFFLUENCE FROM A WEAK RIDGE THAT COVERS THE CARIBBEAN BASIN W OF 75W AND AN ELONGATED LOW OVER THE REMAINDER BASIN IS SUPPORTING ISOLATED SHOWERS AND TSTMS OVER HISPANIOLA. THESE SHOWERS ARE BEING REINFORCED BY TRAILING MOISTURE FROM THE REMNANTS OF GABRIELLE OVER THE SW N ATLC. TUE THROUGH FRI EXPECT THE DAILY SCATTERED AFTERNOON SHOWERS/THUNDERSTORMS TO DEVELOP. ATLANTIC OCEAN... A MIDDLE TO UPPER LEVEL TROUGH ALONG THE W ATLC IS SUPPORTING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 22N-32N BETWEEN 71W-79W. A SURFACE TROUGH EXTENDS FROM 31N64W TO A 1008 MB LOW...REMNANTS OF GABRIELLE...NEAR 25N67W TO 21N69W. AN UPPER RIDGE E OF THE TROUGH IS GENERATING DIFFLUENCE ALOFT THUS ENHANCING A WIDE LINE OF MODERATE CONVECTION N OF 21N BETWEEN 62W-66W. SIMILAR CONVECTION IS N OF 27N BETWEEN 57W-62W. THE REMAINDER OF THE ATLC IS DOMINATED BY A SURFACE RIDGE ANCHORED BY A 1035 MB HIGH NEAR THE AZORES. THE REMNANT LOW OF GABRIELLE AND SURFACE TROUGH ARE FORECAST TO LIFT NE OF THE AREA TUE. A WEAK PRESSURE PATTERN WILL PREVAIL ELSEWHERE ACROSS THE AREA. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR