000 AXNT20 KNHC 110555 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT THU AUG 11 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...SPECIAL FEATURES... A 1010 MB LOW CENTERED NEAR 13N31W IS WELL EMBEDDED WITHIN THE MONSOON TROUGH ACROSS THE TROPICAL ATLC MOVING W AT 10 KT. ENERGY ASSOCIATED WITH THE LOW-LEVEL CYCLONIC MONSOON GYRE CONTINUES TO CONSOLIDATE AND COVERS A SMALL AREA FROM 09N-18N BETWEEN 27W-40W. THE LOW CONTINUES TO POSITION ITSELF ON THE SOUTHWESTERN PERIPHERY OF AN UPPER LEVEL ANTICYCLONE CENTERED NEAR 20N28W. LOW-LEVEL CONVERGENCE ALONG WITH A FAVORABLE MIDDLE TO UPPER LEVEL DIFFLUENT ENVIRONMENT IS SUSTAINING SCATTERED MODERATE CONVECTION OVER TWO AREAS...ONE FROM 07N-12N BETWEEN 29W-33W SE OF THE LOW CENTER...AND THE OTHER FROM 13N-17N BETWEEN 31W-35W NW OF THE LOW CENTER. ...TROPICAL WAVES... TROPICAL WAVE IS ANALYZED FROM 14N66W TO 20N63W MOVING W AT 15 KT. THE WAVE REMAINS WITHIN AN AREA OF HIGHER TOTAL PRECIPITABLE WATER VALUES ADVECTING ACROSS THE EASTERN CARIBBEAN SEA FROM 13N-20N BETWEEN 62W-69W. WHILE AN UNFAVORABLE UPPER LEVEL ENVIRONMENT IS IN THE VICINITY OF THE WAVE...THUS INHIBITING ANY SIGNIFICANT DEEP CONVECTION...LOW-LEVEL MOISTURE CONVERGENCE IS GENERATING A FEW ISOLATED SHOWERS MOSTLY WEST OF THE WAVE AXIS FROM 13N-18N BETWEEN 65W-70W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 17N16W ALONG 15N26W TO 13N31W TO 07N45W. A 1012 MB LOW IS CENTERED OFF THE W AFRICA COAST NEAR 10N17W AND CONTINUES TO SHOW SIGNS OF CONVECTIVE ORGANIZATION AS IT HAS EMERGED OFF THE COAST THE PAST 12 HOURS. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM 06N-14N BETWEEN 17W-23W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL ANTICYCLONE IS CENTERED OVER THE CENTRAL GULF NEAR 26N89W AND CONTINUES TO SUPPORT A SURFACE RIDGE AXIS ACROSS THE GULF ALONG 24N. THE RIDGE AXIS REMAINS ANCHORED BY A 1014 MB HIGH CENTERED NEAR 24N87W. WHILE A MAJORITY OF CENTRAL AND WESTERN GULF ARE UNDER CLEAR SKIES AND FAIR CONDITIONS THIS EVENING...E OF 86W A FEW ISOLATED SHOWERS LINGER DUE TO WEAK SURFACE TROUGHING ACROSS THE W ATLC WATERS AND FLORIDA PENINSULA. A PAIR OF SURFACE TROUGHS ARE ANALYZED OVER FLORIDA WHICH ARE PROVIDING THE FOCUS FOR LOW-LEVEL CONVERGENCE. THE SURFACE RIDGE IS FORECAST TO REMAIN ACROSS THE GULF ALONG 24N THROUGH FRIDAY AND GRADUALLY SHIFT NORTHWARD TO 26N/27N BY SATURDAY INTO SUNDAY. CARIBBEAN SEA... WATER VAPOR IMAGERY SHOWS A WEAK UPPER LEVEL TROUGH AXIS EXTENDING FROM SW NORTH ATLC ACROSS EASTERN CUBA NEAR 20N77W TO THE YUCATAN PENINSULA NEAR 18N89W. AT THE SURFACE...MOSTLY FRESH TO MODERATE EASTERLY TRADES CONTINUE WITH ONLY A FEW ISOLATED SHOWERS DUE TO LOW-LEVEL MOISTURE CONVERGENCE BETWEEN JAMAICA AND THE GULF OF HONDURAS FROM 14N-19N BETWEEN 78W-85W. THE MONSOON TROUGH EXTENDS SOUTH OF PANAMA ALONG 07N WITH ISOLATED SHOWERS AND TSTMS OCCURRING S OF 11N W OF 79W. FARTHER EAST...A TROPICAL WAVE CONTINUES TO MOVE WESTWARD ACROSS THE EASTERN CARIBBEAN WITH ISOLATED SHOWERS OCCURRING MAINLY WEST OF THE WAVE AXIS FROM 13N-18N BETWEEN 65W-74W. THE EASTERLY TRADES ACROSS CENTRAL PORTIONS OF THE CARIBBEAN ARE EXPECTED TO REMAIN STRONG THROUGH SUNDAY DUE TO A HIGH PRESSURE RIDGE ALONG 24N IN THE W ATLC. ATLANTIC OCEAN... MIDDLE TO UPPER LEVEL TROUGHING IS NOTED ON WATER VAPOR IMAGERY WELL EAST OF THE EASTERN U.S. SEABOARD WITH AXIS EXTENDING FROM 42N67W TO 31N78W. WHILE A COLD FRONT IS SUPPORTED BY THIS UPPER LEVEL TROUGH NORTH OF THE DISCUSSION AREA...A PAIR OF SURFACE TROUGHS ARE OVER THE W ATLC WATERS AND FLORIDA PENINSULA THIS EVENING. ONE SURFACE TROUGH IS ANALYZED FROM 32N77W TO 26N81W AND THE OTHER IS ANALYZED FROM COASTAL GEORGIA NEAR 32N81W ACROSS THE NORTHERN FLORIDA PENINSULA TO THE TAMPA BAY REGION. LOW-LEVEL MOISTURE AND CONVERGENCE ARE GENERATING ISOLATED SHOWERS AND TSTMS OVER THE W ATLC WATERS W OF A LINE FROM 32N71W TO 22N78W. FARTHER EAST...AN UPPER LEVEL LOW IS CENTERED NEAR 38N47W WITH THE ASSOCIATED UPPER LEVEL TROUGH AXIS DIPPING SOUTHWARD TO 30N54W. THIS UPPER LEVEL FEATURE SUPPORTS A SURFACE TROUGH ANALYZED FROM 32N50W TO 25N57W. ISOLATED SHOWERS COVER THE AREA FROM 22N-29N BETWEEN 43W-58W...WITH A FEW ISOLATED TSTMS WITHIN THIS AREA FROM 25N-28N BETWEEN 49W AND THE SURFACE TROUGH. THE REMAINDER OF THE EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED ON A 1028 MB HIGH CENTERED OVER THE AZORES NEAR 38N25W. THE RIDGE AXIS EXTENDS FROM THE HIGH ALONG 32N33W TO 18N56W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN