000 AXNT20 KNHC 150527 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT WED MAY 15 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0445 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE COAST OF SIERRA LEONE NEAR 8N13W TO 6N17W. THE ITCZ BEGINS FROM 6N17W AND CONTINUES ALONG 4N30W 2N40W 4N51W. A LARGE CLUSTER OF STRONG CONVECTION IS JUST MOVING OFF THE COAST OF AFRICA FROM 5N-10N EAST OF 14W. SCATTERED MODERATE/STRONG CONVECTION IS FROM 3N-6N BETWEEN 22W- 37W. SIMILAR ACTIVITY IS FROM 4N-7N BETWEEN 49W-55W. ...DISCUSSION... GULF OF MEXICO... SURFACE RIDGING DOMINATES THE GULF OF MEXICO AROUND A 1024 MB HIGH SOUTH OF THE FLORIDA PANHANDLE NEAR 30N87W. AN UPPER LEVEL RIDGE ALONG 90W SUPPORTS THE SURFACE RIDGE. CLEAR SKIES ARE NOTED OVER THE MAJORITY OF THE BASIN EXCEPT FOR THE FAR WESTERN PORTION ALONG THE MEXICO COAST. WEST OF 95W ISOLATED SHOWERS ARE POSSIBLE SOUTH OF 27N. LIGHT ANTI-CYCLONIC WINDS ARE IN THE NE GULF AROUND THE HIGH CENTER INCREASING TO 15 KT ON THE OUTER PERIMETER...AND REACHING 20 KT ACROSS THE TEXAS COAST. A WEAK SURFACE TROUGH IS ALSO ANALYZED IN THE SW GULF ALONG 22N93W TO 18N94W. ISOLATED SHOWERS ARE EAST OF THE TROUGH OVER THE YUCATAN PENINSULA. SURFACE RIDGING WILL CONTINUE TO DOMINATE THE BASIN FOR AT LEAST THE NEXT SEVERAL DAYS. CARIBBEAN SEA... MOSTLY FAIR CONDITIONS SPREAD ACROSS THE CARIBBEAN DUE TO DRY AIR ALOFT AROUND AN UPPER LEVEL RIDGE COVERING MUCH OF THE GULF OF MEXICO CARIBBEAN...AND AN UPPER LEVEL TROUGH WITH AXIS JUST EAST OF THE LESSER ANTILLES. A FEW ISOLATED SHOWERS ARE NOTED SOUTH OF WESTERN CUBA...AND ACROSS THE NE CARIBBEAN MOVING WESTWARD WITH THE TRADEWINDS. ISOLATED SHOWERS ARE ALSO OVER HISPANIOLA NEAR A WEAK SURFACE TROUGH ALONG 22N68W TO 18N71W. 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. ISOLATED TO SCATTERED SHOWERS MAY REMAIN OVER THE NE CARIBBEAN AS MODEL GUIDANCE INDICATES ENHANCED MOISTURE WILL STAY OVER THIS AREA. ATLANTIC OCEAN... AN UPPER LEVEL TROUGH ALONG 66W SUPPORTS A COLD FRONT THAT ENTERS THE DISCUSSION AREA NEAR 32N62W AND CONTINUES TO THE BAHAMAS NEAR 24N76W...AND DISSIPATES TO 23N79W. A PRE-FRONTAL SURFACE TROUGH IS EAST OF THE FRONT ALONG 31N62W 23N69W. WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS ARE UP TO 250 NM EAST OF THE TROUGH AXIS NORTH OF 28N. ISOLATED SHOWERS ARE WITHIN 60 NM OF THE FRONTAL BOUNDARY. A SECOND SURFACE TROUGH IS THE SOUTH ALONG 22N68W TO 18N71W SUPPORTING ISOLATED SHOWERS WITHIN 60 NM AS WELL. A RIDGE TROUGH RIDGE PATTERN COVERS THE REMAINDER OF THE UPPER LEVELS ACROSS THE BASIN. THE FIRST RIDGE IS NARROW AND ALONG 53W. THE UPPER TROUGH IS ALONG 43W SUPPORTING A SURFACE TROUGH ALONG 32N41W TO 24N41W. SCATTERED SHOWERS ARE EAST OF THE TROUGH FROM 28N-31N BETWEEN 34W-41W. THE SECOND UPPER RIDGE IS BROAD AND COVERS THE MAJORITY OF THE TROPICAL ATLC. AT THE SURFACE...A BROAD SURFACE RIDGE DOMINATES THE CENTRAL AND EASTERN ATLC...EXCEPT FOR THE SURFACE TROUGH...ANCHORED BY A 1040 MB HIGH NEAR 45N41W. FAIR CONDITIONS SPREAD ACROSS THIS AREA EXCEPT FOR AN AREA OF SHOWERS NEAR THE SURFACE TROUGH. 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