000 AXNT20 KNHC 141105 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT TUE MAY 14 2013 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. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE COAST OF GUINEA-BISSAU NEAR 12N16W TO 9N21W. THE ITCZ BEGINS FROM 9N21W AND CONTINUES ALONG 5N30W 2N47W EQ51W. SCATTERED MODERATE CONVECTION IS WITHIN 150 NM SOUTH OF THE AXIS BETWEEN 24W-33W...AND WITHIN 120 NM NORTH OF THE AXIS BETWEEN 33W-45W. SCATTERED MODERATE/STRONG CONVECTION IS FROM EQ-3N BETWEEN 45W-51W. ...DISCUSSION... GULF OF MEXICO... A COLD FRONT CONTINUES TO MOVE SLOWLY THROUGH THE GULF OF MEXICO CURRENTLY EXTENDING ACROSS THE FLORIDA KEYS FROM 25N81W TO 23N86W BECOMING STATIONARY ALONG 23N90W 24N95W 19N96W...AS OF 0900 UTC. A SURFACE TROUGH IS IN THE SW GULF EAST OF THE FRONT ALONG 23N94W 19N92W. ISOLATED SHOWERS AND POSSIBLE THUNDERSTORMS EXTEND WEST OF THE FRONT AND INTO EASTERN MEXICO SOUTH OF 96N. THE REMAINDER OF THE BASIN IS UNDER MOSTLY CLEAR SKIES. SURFACE RIDGING IS BUILDING ACROSS THE NORTHERN GULF AROUND A 1024 MB HIGH NEAR 30N93W. LIGHT ANTI-CYCLONIC FLOW IS AROUND THE HIGH CENTER INCREASING TO 15 KT NORTH OF THE FRONTAL BOUNDARY. WINDS TO THE SOUTH OF THE FRONT ARE ALSO REACHING 15 KT WITH SOME 20 KT WINDS IN THE FAR SW GULF. ALOFT...SOUTHWEST TO WEST FLOW COVERS THE BASIN AROUND A BROAD UPPER LEVEL RIDGE COVERING MUCH OF THE CARIBBEAN. AN UPPER LEVEL TROUGH SUPPORTING THE FRONT IS BEGINNING TO PUSH SOUTH INTO THE AREA OVER THE NE GULF...WHICH IS DRAWING DRY AIR ACROSS THIS PORTION OF THE BASIN. THE EASTERN PORTION OF THE FRONT WILL CONTINUE TO MOVE EAST WHILE THE WESTERN PORTION WILL LIKELY DISSIPATE. MOISTURE OVER THE SW GULF WILL ALSO LIFT NORTH AS RETURN FLOW BUILDS AROUND THE WESTERN SIDE OF THE SURFACE RIDGE. CARIBBEAN SEA... MOSTLY FAIR CONDITIONS SPREAD ACROSS THE CARIBBEAN DUE TO DRY AIR ALOFT AROUND AN UPPER LEVEL RIDGE COVERING MUCH OF THE CARIBBEAN...AND AN UPPER LEVEL TROUGH WITH AXIS JUST EAST OF THE LESSER ANTILLES. ONLY A SMALL AREA OF WIDELY ISOLATED SHOWERS ARE MOVING THROUGH THE FAR EASTERN PORTION OF THE BASIN. POSSIBLE ISOLATED SHOWERS ARE ALSO OVER HISPANIOLA. TRADEWIND FLOW OF 15-20 KT DOMINATES THE MAJORITY OF THE EASTERN AND CENTRAL CARIBBEAN WITH A FEW 25 KT WINDS NEAR THE COAST OF COLOMBIA. LITTLE CHANGE IS EXPECTED OVER THE NEXT 24 HOURS. THERE MAY BE AN INCREASE IN MOISTURE ACROSS THE NORTHERN CARIBBEAN ISLANDS AS THE FRONTAL BOUNDARY IN THE WEST ATLC AND GULF OF MEXICO MOVES EASTWARD JUST NORTH OF THE BASIN. ATLANTIC OCEAN... AN UPPER LEVEL TROUGH NORTH OF THE DISCUSSION AREA ALONG 71W IS PUSHING SOUTH AND SUPPORTS A COLD FRONT THAT ENTERS THE DISCUSSION AREA NEAR 32N68W AND CONTINUES TO THE BAHAMAS ALONG 25N75W 25N80W...AS OF 0900 UTC. A PRE-FRONTAL SURFACE TROUGH IS EAST OF THE FRONT ALONG 32N65W 23N70W. SCATTERED SHOWERS AND THUNDERSTORMS ARE UP TO 120 NM EAST OF THE TROUGH AXIS NORTH OF 28N. A RIDGE TROUGH RIDGE PATTERN COVERS THE REMAINDER OF THE UPPER LEVELS ACROSS THE BASIN. THE FIRST RIDGE IS NARROW AND ALONG 58W. THE UPPER TROUGH IS ALSO NARROW AND EXTENDS FROM 30N42W TO JUST EAST OF THE WINDWARD ISLANDS NEAR 10N60W. THE SECOND UPPER RIDGE IS BROAD AND COVERS THE MAJORITY OF THE TROPICAL ATLC CENTERED NEAR 12N23W. AT THE SURFACE...A BROAD SURFACE RIDGE DOMINATES THE CENTRAL AND EASTERN ATLC ANCHORED BY A 1038 MB HIGH NEAR 42N39W. FAIR CONDITIONS SPREAD ACROSS THIS AREA EXCEPT FOR AN AREA OF SHOWERS NEAR A SHEAR AXIS ANALYZED ALONG 28N29W TO 26N46W. SCATTERED SHOWERS ARE UP TO 75 NM NORTH OF THE AXIS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE AT THE REQUEST OF METEO-FRANCE AND THE METEOROLOGICAL SERVICES OF HAITI AND THE DOMINICAN REPUBLIC...THE TROPICAL ANALYSIS AND FORECAST BRANCH (TAFB) WILL BEGIN PROVIDING...ON A TEMPORARY BASIS...A SEPARATE DETAILED SECTION WITHIN THE ATLANTIC TROPICAL WEATHER DISCUSSION (TWDAT). IT WILL COVER BOTH HAITI AND THE DOMINICAN REPUBLIC DUE TO THE SHARED GEOGRAPHY OF BOTH COUNTRIES ON THE ISLAND OF HISPANIOLA. THE SECTION BEGINS ON MAY 15 2013 AT 1800 UTC...2 PM EDT. IT WILL PROVIDE GUIDANCE FOR SIGNIFICANT WEATHER EVENTS THAT ARE EXPECTED TO IMPACT THE REGION THROUGH 48 HOURS...WITH THE FOCUS ON ASSESSING THE POTENTIAL FOR HEAVY RAINFALL. $$ WALTON