000 AXNT20 KNHC 292355 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SUN MAY 29 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. ...TROPICAL WAVES... TROPICAL WAVE IS FROM 06N TO 13N ALONG 62W MOVING W AT 10-15 KT. THE WAVE IS MOVING UNDERNEATH STRONG WESTERLY SHEARING FLOW ALOFT WHICH IS LIMITING CONVECTION AND ASSOCIATED CLOUDINESS. WHILE A CLASSIC SIGNATURE IS HARD TO DETECT USING VISIBLE SATELLITE IMAGERY...TOTAL PRECIPITABLE WATER IMAGERY INDICATES A POLEWARD EXTENSION OF LOW-LEVEL MOISTURE TO 14N IN THE VICINITY OF THE WAVE AXIS WHICH TAKES ON A MORE CLASSIC INVERTED-V SIGNATURE. ISOLATED SHOWERS ARE POSSIBLE FROM 12N-15N BETWEEN 60W-63W...INCLUDING THE WINDWARD ISLANDS. TROPICAL WAVE IS FROM 08N TO 13N ALONG 72W MOVING W AT 10-15 KT. WHILE MOST OF THE WAVE AXIS REMAINS OVER NORTHWESTERN VENEZUELA AND NORTHERN COLOMBIA...THE WAVE AND ITS ENERGY ARE QUICKLY BECOMING ABSORBED INTO BROAD CYCLONIC FLOW TYPICALLY EVIDENT ACROSS THE SW CARIBBEAN SEA. WEST-SOUTHWESTERLY UPPER LEVEL FLOW ACROSS THE SW CARIBBEAN SEA WATERS IN THE VICINITY OF THE WAVE IS ACTING TO SHEAR ANY SUSTAINED CONVECTION N OF 11N...HOWEVER BROAD SCALE UPPER LEVEL DIFFLUENCE ACROSS THE SW CARIBBEAN IS AIDING WIDELY SCATTERED MODERATE CONVECTION OCCURRING FROM 12N-16N BETWEEN 70W-75W. ...ITCZ... ITCZ AXIS IS ALONG 10N14W 02N36W 03N51W. WIDELY SCATTERED MODERATE CONVECTION IS WITHIN 120 NM EITHER SIDE OF THE AXIS BETWEEN 18W-31W. A SURFACE TROUGH IS ANALYZED ON THE WESTERN EXTENT OF THE AXIS FROM 03N53W TO 09N50W. SCATTERED MODERATE CONVECTION IS FROM THE EQUATOR TO 09N BETWEEN 49W-56W... INCLUDING INTERIOR PORTIONS OF FAR NORTHEASTERN BRAZIL...FRENCH GUIANA...AND SURINAME. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED OVER CENTRAL ALABAMA AND SPREADS ITS INFLUENCE ACROSS MUCH OF THE SE CONUS. WATER VAPOR IMAGERY INDICATES VERY DRY AIR AND A VERY STABLE ATMOSPHERE HOLDS ACROSS THE GULF BASIN THIS EVENING. AT THE SURFACE...A RIDGE EXTENDS FROM THE W ATLC ACROSS NORTHERN FLORIDA TO THE WESTERN GULF ANCHORED BY A 1023 MB HIGH CENTERED OFF THE COAST OF THE CAROLINAS NEAR 33N76W. WHILE MOSTLY FAIR CONDITIONS CONTINUE...SEABREEZE INTERACTION HAS GENERATED A FEW ISOLATED SHOWERS AND TSTMS OFF THE SOUTHWESTERN FLORIDA COAST FROM 24N-27N E OF 83W TO THE FLORIDA COAST. THIS ACTIVITY IS EXPECTED TO DIMINISH OVER THE NEXT FEW HOURS WITH THE LOSS OF PEAK DAYTIME HEATING. OTHERWISE...VISIBLE IMAGERY CONTINUES TO INDICATE A HAZY ATMOSPHERE IN THE SW GULF W OF 92W DUE TO THE ADVECTION OF SMOKE FROM SOUTHERN MEXICO WILDFIRES. A SELECT FEW OFFSHORE OIL RIGS IN THE NW GULF...AND LAND-BASED AIRFIELD METARS ACROSS SE COASTAL TEXAS AND EASTERN MEXICO ARE REPORTING VISIBILITIES BELOW 10 STATUTE MILES...OR 8.7 NM THIS EVENING. CARIBBEAN SEA... WEST-SOUTHWESTERLY FLOW ALOFT IS NOTED ACROSS MUCH OF THE CARIBBEAN SEA THIS EVENING AS MOSTLY DRY AIR IS EVIDENT ON WATER VAPOR IMAGERY NW OF A LINE FROM SOUTHERN BELIZE NEAR 16N89W TO WESTERN CUBA NEAR 22N81W. FAIR CONDITIONS AND RELATIVELY CLEAR SKIES PREVAIL OVER THIS PORTION OF THE NW CARIBBEAN WHILE ISOLATED SHOWERS AND TSTMS IN ASSOCIATION WITH PEAK DAYTIME HEATING AND INSTABILITY CONTINUE ACROSS INTERIOR PORTIONS OF CUBA. ELSEWHERE...CONVERGENT TRADEWIND FLOW IS FOCUSED ALONG A SURFACE TROUGH ANALYZED FROM 09N80W TO 16N82W IN THE SW CARIBBEAN. THIS SURFACE FEATURE ALONG WITH UPPER LEVEL DIFFLUENCE EAST OF AN UPPER LEVEL TROUGH AXIS ACROSS THE SW NORTH ATLC AND WESTERN CUBA IS GENERATING SCATTERED SHOWERS AND ISOLATED TSTMS OVER MUCH OF THE WESTERN AND CENTRAL CARIBBEAN BETWEEN 70W AND 86W. AS THE TROPICAL WAVE ALONG 72W CONTINUES TO MOVE WESTWARD...GLOBAL MODELS CONTINUE TO INDICATE ENERGY ASSOCIATED WITH THE WAVE WILL COMBINE WITH ALREADY EXISTING BROAD CYCLONIC FLOW ACROSS THE REGION. CYCLOGENESIS IN THE FORM OF A WEAK LOW PRESSURE CENTER IS FORECAST TO OCCUR IN THE 36 TO 72 HOUR WINDOW ACROSS THE SW CARIBBEAN SEA WATERS. ATLANTIC OCEAN... A SURFACE RIDGE COVERS THE WESTERN ATLC N OF 23N W OF 63W KEEPING CONDITIONS MOSTLY FAIR THIS EVENING. HOWEVER S OF 23N... ABUNDANT MIDDLE TO UPPER LEVEL MOISTURE CONTINUES TO ADVECT E-NE SOUTH OF AN UPPER LEVEL LOW CENTERED NEAR 28N72W AND THE ASSOCIATED TROUGHING THAT EXTENDS TO THE NE. SCATTERED SHOWERS ARE OCCURRING S OF 23N BETWEEN 56W-80W...INCLUDING OVER INTERIOR PORTIONS OF CUBA AND HISPANIOLA THIS EVENING. FARTHER EAST...AN ELONGATED UPPER LEVEL LOW CONTINUES TO SPIN NEAR 31N57W SUPPORTING A COMPLEX AREA OF LOW PRESSURE CENTERED BY A 1015 MB LOW NEAR 27N50W. TWO OTHER 1015 MB LOWS CIRCULATE TO THE NORTHWEST...ONE CENTERED NEAR 30N54W AND THE OTHER CENTERED NEAR 28N60W. A SURFACE TROUGH EXTENDS FROM THE EASTERNMOST LOW ALONG 26N48W 22N50W TO 19N57W SUPPORTING ISOLATED SHOWERS WITHIN 120 NM EITHER SIDE OF THE SURFACE TROUGH AXIS. ISOLATED SHOWERS COVER A WIDER AREA TO THE EAST OF THE SURFACE TROUGH FROM 18N-34N BETWEEN 40W-53W DUE TO LOW-LEVEL CONVERGENCE AND UPPER LEVEL DIFFLUENCE IN ASSOCIATION WITH THE TROUGH AXIS ALOFT. THE REMAINDER OF THE EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE EXTENDING SOUTHWARD INTO THE DISCUSSION AREA ALONG 34W. THE RIDGE IS ANCHORED BY A 1031 MB HIGH CENTERED W-NW OF THE AZORES NEAR 40N41W. 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