000 AXNT20 KNHC 271100 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT TUE MAY 27 2014 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 1045 UTC. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 07N32W TO 01N33W MOVING W AT 15-20 KT. THE WAVE REMAINS LARGELY LOW-AMPLITUDE AND EMBEDDED WITHIN THE ITCZ AXIS. WEAK 700 MB TROUGHING ALOFT AND TRACES OF LOW- LEVEL VORTICITY AT 850 MB ARE NOTED ON GLOBAL MODEL FIELDS IN THE VICINITY OF THE WAVE AXIS. SCATTERED MODERATE CONVECTION WITH WARMING CLOUD TOP TEMPERATURES IS LESS SCATTERED THAN OBSERVED 3 TO 6 HOURS...AND IS PRESENT WITHIN 60-75 NM OF THE WAVE AXIS. THIS WAVE IS LIKELY TO BECOME FURTHER SUPPRESSED THROUGH THE NEXT 24 HOURS AS IT CONTINUES WESTWARD UNDER THE SOUTHERN PERIPHERY OF ATLC HIGH PRESSURE TO ITS N. TROPICAL WAVE EXTENDS FROM 10N55W SSW TO INLAND THE COAST OF GUYANA AT 06N56W. THE WAVE IS ALSO MOVING W AT 15-20 KT. FIRST MORNING VISIBLE IMAGERY SHOWS A SUBTLE CYCLONIC TURNING OF THE LOW-LEVEL CLOUD FIELD BETWEEN 53W-59W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 240 NM W OF THE WAVE FROM 07N TO 09N. ISOLATED SHOWERS AND TSTMS ARE S OF 07N E OF THE WAVE TO 52W. TROPICAL WAVE EXTENDS FROM 13N71W S TO INLAND VENEZUELA MOVING W AT ABOUT 16 KT. SSMI TOTAL PRECIPITABLE WATER IMAGERY SHOWS A PATCH OF DEEP MOISTURE TRAILING THE WAVE TO NEAR 66W. 700 MB STREAMLINE ANALYSIS SUGGESTS CONVERGENCE WITHIN THE AREA OF DEEP MOISTURE. ISOLATED SHOWERS AND TSTMS WITHIN 240 NM E OF THE WAVE. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM THE AFRICAN COAST NEAR 12N16W TO 09N21W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 09N21W TO 04N30W WHERE IT ENDS BRIEFLY. IT RESUMES AT 02N34W TO EQUATOR AT 40W...AND TO THE COAST OF SOUTH AMERICA NEAR 01S49W. ISOLATED MODERATE CONVECTION IS SEEN FROM 02N-07N BETWEEN 25W-29W. SCATTERED MODERATE CONVECTION IS NOTED FROM JUST N OF THE EQUATOR TO 04N ELSEWHERE W OF 34W. ...DISCUSSION... GULF OF MEXICO... A SURFACE RIDGE EXTENDING FROM THE WESTERN ATLC HIGH ACROSS THE FAR NORTHERN AND CENTRAL GULF PORTIONS IS THE MAIN SYNOPTIC FEATURE OVER THE AREA. THE RIDGE IS SUPPORTED BY RIDGING ALSO IN THE UPPER LEVELS WITH AN AXIS ROUGHLY ALONG 93W/94W. AT THE SURFACE...ANTICYCLONIC FLOW IS RESULTING IN GENERALLY AND E-SE FLOW OF 10-15 KT OVER MUCH OF THE AREA...WITH THE EXCEPTION OF THE FAR WESTERN GULF WHERE A TIGHTER PRES GRADIENT BETWEEN THE RIDGE AND LOW PRESSURE OVER WESTERN TEXAS IS INDUCING SE 15-20 KT WINDS THERE. A JET STREAM BRANCH CROSSING THE NW GULF IS AIDING IN THE ADVECTION OF UPPER LEVEL MOISTURE ACROSS MUCH OF THE NW AND N CENTRAL GULF SECTIONS. ISOLATED STRONG TSTM CLUSTERS EARLIER NOTED ALONG THE SOUTHERN TEXAS COAST AND OVER NE MEXICO HAVE JUST ABOUT DISSIPATED. ISOLATED SHOWERS AND ISOLATED TSTMS ARE OVER THE FAR NW WATERS MOVING E. THIS ACTIVITY IS EXPECTED TO GRADUALLY SPREAD EASTWARD OVER THE NEXT 24 HOURS OR SO...WHILE SCATTERED SHOWERS AND TSTMS MOVE INTO THE WESTERN GULF AHEAD OF A TROUGH THAT APPROACHES THE TEXAS COAST AS THE RIDGE WEAKENS. ELSEWHERE...CONDITIONS ARE FAIR WITH JUST SMALL POCKETS OF LOW LEVEL MOISTURE IN THE FORM OF LOW CLOUDS WITH ISOLATED SHOWERS MOVING TO THE NW UNDER THE SOUTHERN PERIPHERY OF THE RIDGE. CARIBBEAN SEA... A LOW AMPLITUDE TROPICAL WAVE IS OVER THE SOUTH CENTRAL CARIBBEAN AND VENEZUELA AS DESCRIBED ABOVE UNDER TROPICAL WAVES. IN THE UPPER LEVELS...BROAD UPPER LEVEL RIDGING COVERS THE SEA W OF 78W. NW TO N STRONG UPPER LEVEL WINDS ARE OVER THIS PORTION OF THE SEA. ASSOCIATED MODERATE SUBSIDENCE IS KEEPING SKIES GENERALLY CLOUD FREE THERE WITH ONLY SCATTERED LOW CLOUDS MOVING WESTWARD IN THE TRADES WITH POSSIBLE ISOLATED SHOWERS. TO THE E OF THE RIDGE...A MID/UPPER LEVEL TROUGH WITH A RATHER SHARP AXIS IS SEEN ON WATER VAPOR IMAGERY TO STRETCH FROM THE WINDWARD PASSAGE SW TO 14N75W AND TO ACROSS NW COLOMBIA. A NE TO SW JET STREAM BRANCH TO THE E OF THE TROUGH IS TRANSPORTING DEEP ATMOSPHERIC MOISTURE NEWD ACROSS MUCH OF THE EASTERN CARIBBEAN SEA. ISOLATED TO WIDELY SCATTERED SHOWERS AND TSTMS ARE POSSIBLE WITH THIS MOISTURE. THE TROUGH WILL SLOWLY MOVE EASTWARD THROUGH THE NEXT 24 HOURS. THIS SHOULD BRING AN INCREASE OF MOISTURE WITH SCATTERED SHOWERS AND TSTMS ACROSS MUCH OF THE EASTERN PART OF THE SEA...INCLUDING PUERTO RICO AND MOST OF THE LESSER ANTILLES AS ADDITIONAL MOISTURE FROM A TROPICAL WAVE PASSING ACROSS THE FAR SOUTHERN WATERS BECOMES ENTRAINED INTO THE SW FLOW ALOFT IN ADVANCE OF THE AFOREMENTIONED MID/UPPER TROUGH. TRADE WINDS OF 15-20 KT ARE OVER MUCH OF THE CENTRAL PART OF THE CARIBBEAN...WHILE TRADES OF 10-15 KT ARE PRESENT ELSEWHERE. ...HISPANIOLA... CURRENTLY...ONLY ISOLATED SHOWERS ARE POSSIBLE ACROSS HISPANIOLA DUE TO PERSISTENT E-SE WINDS ALONG WITH LOW-LEVEL MOISTURE ADVECTION...AND OROGRAPHIC LIFT. A SMALL POCKET OF SCATTERED SHOWERS AND TSTMS HAS RECENTLY FORMED JUST W OF HAITI...AND OVER THE WINDWARD PASSAGE AIDED BY MAINLY A MID/UPPER TROUGH IN THAT VICINITY. THIS ACTIVITY SHOULD CONTINUE THROUGH TONIGHT...THEN DIMINISH AS THE TROUGH SHIFTS FURTHER E. THE TROUGH SHOULD AID IN THE DEVELOPMENT OF SHOWER/TSTM ACTIVITY OVER SOME AREAS OF THE INTERIOR PORTION THROUGH WED...BUT SHOULD BE SHORT-LIVED AS DRY AIR ALOFT IN THE WAKE OF THE TROUGH BEGINS TO FILTER IN OVER THE ISLAND. ATLANTIC OCEAN... A 1024 MB HIGH IS AT 32N62W WITH A RIDGE WESTWARD TO A 1021 MB HIGH OVER SE GEORGIA. A COLD FRONT MOVING SLOWLY E AND WEAKENING EXTENDS FROM 32N51W SW TO 29N55W...WHERE IT BECOMES STATIONARY TO 26N62W TO 27N66W WHERE IT IS DISSIPATING TO 26N74W. A MID TO UPPER LEVEL TROUGH EXTENDS FROM 32N57W W TO NEAR 32N69W...THEN SW TO A WEAK CYCLONIC CIRCULATION AT 28N73W...AND SW TO THE WINDWARD PASSAGE. FROM THERE IT EXTENDS FURTHER SW WELL ACROSS THE CENTRAL CARIBBEAN SEA. THIS FEATURE IS SUPPORTING THE FRONT WHILE ALSO ENHANCING LIFT ALONG AND NEAR ITS WESTERN SEGMENT. AS A RESULT...SCATTERED SHOWERS AND TSTMS ARE QUITE ACTIVE ALONG AND WITHIN 120 NM N OF THE FRONT BETWEEN 67W AND 72W. THE FRONT WILL CONTINUE TO WEAKEN...AND EVENTUALLY DISSIPATE WITHIN THE NEXT 24 HOURS...OR SHORTLY AFTERWARDS. A 1030 MB HIGH IS OVER THE EASTERN ATLC NEAR 34N32W WITH A RIDGE SW TO NEAR 28N49W. IT IS BRINGING FAIR WEATHER OVER THAT PART OF THE ATLC. ONLY SCATTERED TO BROKEN STRATOCUMULUS CLOUDS MOVING WSW ARE NOTED OVER THAT PORTION OF THE ATLC. A TIGHT SURFACE PRESSURE GRADIENT IS PRODUCING GALE FORCE WINDS ALONG THE COAST OF MOROCCO NEAR 31N10W. AN UPPER LEVEL RIDGE IS OVER THE CENTRAL ATLANTIC BETWEEN 40W AND 60W WITH ITS MEAN CENTER AT 14N46W. AN UPPER LEVEL TROUGH IS OVER THE E ATLANTIC N OF 18N E OF 35W WITH DRY CONDITIONS ALOFT IN THAT AREA KEEPING A CAP ON MOISTURE AND PRECIPITATION OVER THAT AREA. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ AGUIRRE