000 AXNT20 KNHC 202345 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT WED JUL 20 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... TROPICAL STORM BRET IS CENTERED NEAR 31.9N 73.0W AT 20/2100 UTC OR 235 NM SSE OF CAPE HATTERAS NORTH CAROLINA AND ABOUT 415 NM W OF BERMUDA MOVING NE AT 7 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1005 MB. MAXIMUM SUSTAINED WIND SPEED IS 40 KT WITH GUSTS TO 50 KT. SCATTERED MODERATE CONVECTION IS OCCURRING MOSTLY IN THE SOUTHERN SEMICIRCLE FROM 27N-31N BETWEEN 71W-74W. BRET IS FORECAST TO TRACK NE OVER THE NEXT 2 DAYS AND CONTINUE WEAKENING GRADUALLY AS NORTH AND NORTHWESTERLY MIDDLE TO UPPER LEVEL SHEAR TAKES ITS TOLL THROUGH LATE FRIDAY. SEE LATEST NHC FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/WTNT22 KNHC FOR MORE DETAILS. TROPICAL STORM CINDY IS CENTERED NEAR 35.2N 53.8W AT 20/2100 UTC OR 575 NM ENE OF BERMUDA AND ABOUT 1300 NM W OF THE AZORES MOVING NE AT 21KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1009 MB. MAXIMUM SUSTAINED WIND SPEED IS 35 KT WITH GUSTS TO 45 KT. SCATTERED MODERATE CONVECTION IS LOCATED MAINLY WITHIN 180 NM FROM CENTER IN THE NE QUADRANT. CINDY IS FORECAST TO TRACK NE OVER THE NEXT 2 TO 3 DAYS AND HAS A 48 HOUR WINDOW FOR MODEST STRENGTHENING BEFORE COOLER SEA SURFACE TEMPERATURES AND WESTERLY UPPER LEVEL SHEAR DISSIPATE THE SYSTEM ALTOGETHER BY LATE SATURDAY. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT3/WTNT23 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... TROPICAL WAVE IS ANALYZED FROM 07N46W TO 16N40W MOVING W AT 20 KT. THE WAVE IS LOCATED ON THE LEADING EDGE OF A RATHER LARGE AND BROAD AREA OF LOW-LEVEL MOISTURE TO THE EAST OF THE WAVE AXIS AS NOTED ON TOTAL PRECIPITABLE WATER IMAGERY. THIS ALONG WITH OVERALL BROAD CYCLONIC FLOW S OF 15N BETWEEN 35W-48W ACCOMPANY THE WAVE WHICH CONTINUES TO PERTURB THE ITCZ AXIS. ISOLATED MODERATE CONVECTION IS WITHIN 90 NM WEST OF THE WAVE N OF 12N. TROPICAL WAVE IS ANALYZED FROM 13N77W TO 22N75W MOVING W AT 20 KT. THE WAVE APPEARS VERY BROAD ON SATELLITE IMAGERY AND CONTINUES TO INTERACT ALOFT WITH AN UPPER LEVEL LOW CENTERED NEAR 19N72W. BOTH THE LOW-LEVEL CONVERGENCE AND UPPER LEVEL DIFFLUENCE ARE GENERATING AN AREA OF ISOLATED MODERATE CONVECTION FROM 17N-21N BETWEEN 69W-76W. IT IS VERY POSSIBLE THIS CONVECTION IS ASSOCIATED MORE WITH THE UPPER LEVEL LOW THAN THE LOWER-LEVEL WAVE DYNAMICS. TROPICAL WAVE IS ANALYZED FROM 17N TO 22N ALONG 94W MOVING W AT 15 KT. THE WAVE EXHIBITS CYCLONIC TURNING OF THE LOW-LEVEL CLOUD FIELD IN THE VICINITY OF THE WAVE AXIS HOWEVER IS QUICKLY BECOMING EMBEDDED WITHIN ANTICYCLONIC FLOW ACROSS THE WESTERN GULF OF MEXICO. NO ACTIVE CONVECTION IS NOTED WITH THE WAVE AT THIS TIME. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 12N16W TO 07N23W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 07N23W TO 11N42W...THEN RESUMES NEAR 07N48W TO 06N54W. ISOLATED MODERATE CONVECTION IS FROM 04N-07N BETWEEN 23W-34W...AND FROM 02N-07N BETWEEN 38W-46W. ...DISCUSSION... GULF OF MEXICO... WATER VAPOR IMAGERY INDICATES A BROAD UPPER LEVEL LOW IS CENTERED OVER THE WESTERN GULF NEAR 24N94W WHICH IS PROVIDING FOR MARGINAL MIDDLE TO UPPER LEVEL LIFT ACROSS MUCH OF THE NORTH-CENTRAL GULF BASIN THIS EVENING. WHILE A RELATIVELY WEAK SURFACE RIDGE EXTENDS ACROSS THE EASTERN GULF ANCHORED BY A 1017 MB HIGH CENTERED NEAR 28N87W...SOUTHERLY LOW-LEVEL MOISTURE TRANSPORT AND INSTABILITY ACROSS PORTIONS OF THE WESTERN GULF ARE GENERATING ISOLATED SHOWERS FROM 26N-29N BETWEEN 88W-95W. THE SURFACE HIGH IS EXPECTED TO REMAIN NEARLY STATIONARY OVER THE EASTERN GULF THROUGH THE WEEKEND AS AN AREA OF LOW PRESSURE DEVELOPS ACROSS THE WESTERN HIGH PLAINS OF THE U.S. CARIBBEAN SEA... AS MENTIONED ABOVE...A TROPICAL WAVE IS ALONG 76W IN THE CENTRAL CARIBBEAN AND CONTINUES TO INTERACT WITH AN UPPER LEVEL LOW CENTERED NEAR 19N72W. WHILE MOST OF THE ISOLATED SHOWERS ARE LOCATED OVER INTERIOR PORTIONS OF HISPANIOLA...THIS ISOLATED SHOWER ACTIVITY EXTENDS TO THE EAST OF THE WAVE AXIS ALONG 18N OVER PUERTO RICO AND THE US/UK VIRGIN ISLANDS. THE REMAINDER OF THE EASTERN CARIBBEAN IS OVERALL TRANQUIL THIS EVENING WITH MOSTLY CLEAR SKIES AND FAIR CONDITIONS. TO THE WEST OF THE WAVE AXIS...AN UPPER LEVEL ANTICYCLONE IS CENTERED OVER THE NW CARIBBEAN NEAR 18N84W AND EXTENDS AN UPPER LEVEL RIDGE AXIS SOUTHWARD TO COSTA RICA NEAR 11N83W. MOSTLY FAIR CONDITIONS ARE NOTED OVER MUCH OF THE WESTERN CARIBBEAN THIS EVENING...HOWEVER WITH AMPLE UPPER LEVEL DIFFLUENCE IN PLACE AND PEAK DAYTIME HEATING ACROSS CUBA AND INTERIOR NICARAGUA AND HONDURAS... SCATTERED SHOWERS AND TSTMS ARE OCCURRING OVER INTERIOR CUBA BETWEEN 78W-84W...AND FROM 11N-16N BETWEEN 84W-87W ACROSS CENTRAL AMERICA. ATLANTIC OCEAN... TROPICAL STORM BRET CONTINUES TO RESIDE ON THE NORTHERN PERIPHERY OF THE SUBTROPICAL RIDGE ACROSS THE W ATLC THIS EVENING. AS BRET TRACKS NE OVER THE NEXT FEW DAYS THE SURFACE RIDGE AXIS IS EXPECTED TO RE-ESTABLISH ITSELF ALONG 26N THROUGH THE REMAINDER OF THE WEEK AND GRADUALLY SHIFT NORTHWARD TO 29N BY SATURDAY. FARTHER TO THE E-NE OF BRET THIS EVENING WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL TROUGH EAST OF BERMUDA ALONG 63W THAT IS EXPECTED TO MOVE TROPICAL STORM CINDY NE THROUGH SATURDAY. ELSEWHERE...A STRONG 1034 MB AZORES HIGH IS CENTERED NEAR 40N31W AND CARRIES INFLUENCE ACROSS THE REMAINDER OF THE CENTRAL AND EASTERN TROPICAL ATLC N OF 18N WITH MOSTLY FAIR CONDITIONS AND A LARGE AREA OF NE TO E WINDS OF 15 TO 20 KT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN