000 AXNT20 KNHC 191651 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT TUE MAY 19 2015 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 1630 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE TROPICAL ATLANTIC NEAR 13N17W CONTINUING TO 05N23W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 05N36W TO THE NORTHERN COAST OF BRAZIL NEAR 00N50W. SCATTERED MODERATE CONVECTION IS WITHIN 120 NM S OF THE AXIS BETWEEN 18W AND 24W...WITHIN 60-90 NM EITHER SIDE OF THE AXIS BETWEEN 31W AND 36W...AND ALSO WITHIN 210 NM NW OF THE AXIS W OF 40W. ...DISCUSSION... GULF OF MEXICO... BROAD MIDDLE TO UPPER LEVEL TROUGHING IS ACROSS THE GULF E OF 90W WITH AN UPPER LEVEL RIDGING BUILDING IN ACROSS THE GULF W OF 90W. SURFACE OBSERVATIONS IN THE FAR NW GULF REPORTED PATCHY LIGHT FOG THIS MORNING EXTENDING INLAND OVER THE TEXAS HILL COUNTRY. A 1020 MB NEARLY STATIONARY SURFACE HIGH PRES CENTER IS LOCATED S OF MOBILE BAY NEAR 30N88W WITH A RIDGE AXIS EXTENDING TO THE W NEAR GALVESTON TEXAS AND TO THE SE TO NEAR TAMPA BAY FLORIDA. A WEAKENING SURFACE TROUGH IS IN THE SW GULF REACHING FROM 23N94W TO 18N95W AND SHOULD DISSIPATE LATER TODAY WHILE DRIFTING TO THE W. MAINLY FAIR WEATHER PREVAILS UNDER THE RIDGING WITH LIGHT TO MODERATE ANTICYCLONIC FLOW AND 2-4 FT SEAS...EXCEPT LIGHT AND VARIABLE AND 1-2 FT SEAS IN THE NE GULF NEAR THE HIGH CENTER. THERMAL TROUGHING WILL DEVELOP OVER THE YUCATAN PENINSULA AGAIN BY THIS EVENING...MOVING OFFSHORE INTO THE SW GULF INTO WED MORNING...AND YET AGAIN WED EVENING INTO THU MORNING. AS A RESULT WINDS WILL INCREASE TO FRESH OR EVEN LOCALLY STRONG NEAR THE NW YUCATAN PENINSULA WITH SEAS BUILDING TO UP TO 6 FT AS A RESULT. CARIBBEAN SEA... MIDDLE TO UPPER LEVEL SOUTHWESTERLY TO WESTERLY FLOW PREVAILS WHICH IS ADVECTING TROPICAL MOISTURE FROM THE NE PACIFIC OCEAN AND NORTHERN SOUTH AMERICA. A MIDDLE TO UPPER LEVEL TROUGH IS ACROSS THE NW CARIBBEAN WITH DRY AND STABLE AIR INDICATED BY WATER VAPOR SATELLITE IMAGERY. A LOCALIZED TIGHT PRES GRADIENT IS PRESENT IN THE S CENTRAL CARIBBEAN BETWEEN LOW PRES OVER NW COLOMBIA AND ATLC RIDGING N-NE OF THE AREA. THIS IS SUPPORTING FRESH TO STRONG TRADES NEAR THE NW COAST OF COLOMBIA AND SEAS OF 7-9 FT. THESE WINDS WILL CONTINUE TO PULSE NEAR THE COAST OF COLOMBIA THROUGH EARLY WED BEFORE DIMINISHING AS THE PRES GRADIENT RELAXES SLIGHTLY. OTHERWISE MODERATE TO LOCALLY FRESH TRADES AND 4-6 FT SEAS PREVAIL S OF 17N...WITH GENTLE TO MODERATE TRADES AND 2-4 FT SEAS N OF 17N. EXPECT SIMILAR WEATHER CONDITIONS THROUGH THE NEXT 48 HOURS. ...HISPANIOLA... LINGERING MOISTURE ASSOCIATED WITH A WEAKENING STATIONARY FRONT CURRENTLY REACHING ALONG THE NORTHERN COAST OF THE ISLAND WILL HELP TO SUPPORT ISOLATED CONVECTION THROUGH THE AFTERNOON AND EARLY MORNING HOURS. CONVECTIVE ACTIVITY THROUGH THE NEXT 48 HOURS WILL ALSO BE SUPPORT EACH AFTERNOON AND EVENING DUE TO OROGRAPHIC LIFTING AND DAYTIME HEATING. ATLANTIC OCEAN... A STATIONARY FRONT EXTENDS FROM 31N45W TO 21N65W THEN IS DISSIPATING AS IT CONTINUES TOWARD THE N COAST OF HISPANIOLA. SCATTERED TSTMS ARE OCCURRING N OF 26N WITHIN 60-90 NM EITHER SIDE OF THE BOUNDARY. THE SW PORTION OF THIS BOUNDARY WILL COMPLETELY DISSIPATE BY THIS EVENING. A COLD FRONT IS DROPPING S INTO THE AREA EXTENDING FROM 1008 MB LOW PRES NEAR 34N58W INTO THE AREA NEAR 32N59W TO 29N63W TO 32N71W. SCATTERED SHOWERS ARE ACCOMPANYING THE FRONT W OF 60W WITH SCATTERED SHOWERS AND TSTMS E OF 60W. THIS FRONT WILL GRADUALLY WEAKEN THROUGH THE NEXT 24-48 HOURS AS IT CONTINUES TO MOVE TO THE S-SE... EVENTUALLY STALLING ALONG 25N W OF 60W BY THU. A WEAK SURFACE TROUGH IS OVER THE WESTERN BAHAMAS WITH ISOLATED SHOWERS AND TSTMS PRESENT WITH THIS FEATURE. THIS TROUGH WILL DISSIPATE THROUGH THE AFTERNOON AS IT CONTINUES TO DRIFT TO THE W. OTHERWISE 1020 MB SURFACE HIGH PRES IS LOCATED NEAR 28N74W WITH A RIDGE AXIS EXTENDING TO THE W-NW TO NEAR JACKSONVILLE FLORIDA AND TO THE SE TO NEAR 22N70W. LIGHT AND VARIABLE WINDS ARE NEAR THE RIDGE AXIS WITH MODERATE ANTICYCLONIC FLOW ELSEWHERE. THE HIGH AND RIDGING WILL SHIFT TO THE SE DURING THE NEXT 24-48 HOURS AS A WEAK COLD FRONT APPROACHES THE NW CORNER OF THE SW N ATLC MOVING OFF THE SE GEORGIA COAST BY EARLY THU. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ LEWITSKY