000 AXNT20 KNHC 161146 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT THU MAY 16 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. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 8N43W TO 2N44W MOVING W AT 10-15 KT. THE WAVE REMAINS LOW-AMPLITUDE AND EMBEDDED WITHIN THE ITCZ AXIS. TOTAL PRECIPITABLE WATER IMAGERY INDICATES THE WAVE LIES WITHIN A LARGE AREA OF MAXIMUM MOISTURE. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 4N-7N BETWEEN 40W- 43W. A FEW CLUSTERS OF STRONG CONVECTION ARE WEST OF THE AXIS FROM 5N-7N BETWEEN 44W-48W. THE WAVE IS EXPECTED TO CONTINUE MOVING WESTWARD. MOISTURE ASSOCIATED WITH THIS FEATURE SHOULD REACH THE WINDWARD ISLANDS DURING THE UPCOMING WEEKEND. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE COAST OF GUINEA BISSAU NEAR 11N16W TO 6N22W. THE ITCZ BEGINS AT 6N22W AND CONTINUES ALONG 4N31W 6N41W 1N53W. SCATTERED MODERATE/STRONG CONVECTION IS FROM 6N-9N BETWEEN 12W-17W. SIMILAR ACTIVITY IS FROM 3N-5N BETWEEN 30W-33W...FROM 4N-7N BETWEEN 33W-40W...AND FROM EQ-3N BETWEEN 46W-52W. ...DISCUSSION... GULF OF MEXICO... SURFACE RIDGING DOMINATES THE GULF OF MEXICO AROUND A 1019 MB HIGH SOUTH OF THE FLORIDA PANHANDLE NEAR 29N84W. AN UPPER LEVEL RIDGE ALONG 85W SUPPORTS THE SURFACE RIDGE. CLEAR SKIES ARE NOTED OVER THE MAJORITY OF THE BASIN EXCEPT FOR SOME MODERATE MOISTURE EXTENDING FROM ALABAMA AND THE WESTERN FLORIDA PANHANDLE TO THE CENTRAL GULF NEAR 25N92W. ISOLATED SHOWERS ARE PRESENT ACROSS THIS AREA. LIGHT ANTI-CYCLONIC WINDS ARE IN THE NE GULF DIRECTLY NEAR THE HIGH CENTER AND QUICKLY INCREASE TO 15 KT AWAY FROM THE CENTER. A FEW 20 KT WINDS ARE ALSO OBSERVED NEAR THE TEXAS COAST. 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 THE WESTERN CARIBBEAN ALONG 85W. A LARGE CLUSTER OF STRONG CONVECTION IS OVER EASTERN PANAMA CONTINUING INLAND INTO COLOMBIA. AN UPPER LEVEL TROUGH IS DIGGING SOUTH INTO THE EASTERN CARIBBEAN WITH AXIS NEAR 65W. WHILE MOSTLY DRY AIR STILL REMAINS ACROSS THE AREA PROVIDING FAIR CLEAR SKIES THROUGHOUT...A THIN SWATH OF MOISTURE EXTENDS FROM NEAR HISPANIOLA EASTWARD ACROSS THE NE CARIBBEAN ISLANDS. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE IN THIS AREA FROM 16N-18N BETWEEN 65W-76W. 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. MODEL GUIDANCE INDICATES THAT THE UPPER TROUGH OVER THE EASTERN CARIBBEAN SHOULD SHIFT EAST OVER THE NEXT COUPLE OF DAYS. HOWEVER...THE MOISTURE IN THIS AREA APPEARS TO DRIFT WEST AND WILL LIKELY CONTINUE TO PRODUCE SHOWERS AND THUNDERSTORMS ACROSS THE NORTHERN CARIBBEAN. HISPANIOLA... A THIN SWATH OF MOISTURE LIES ACROSS HISPANIOLA AROUND AN UPPER LEVEL TROUGH ACROSS THE EASTERN CARIBBEAN. CURRENTLY ONLY A SMALL AREA OF SHOWERS IS ACROSS THE SE CORNER OF THE ISLAND IN HAITI WITH SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS SOUTH OF THE ISLAND AND TO THE EAST. MODEL GUIDANCE INDICATES THAT ENHANCED MOISTURE WILL REMAIN OVER THE ISLAND FOR AT LEAST THE NEXT 24-48 HOURS...WHICH MEANS SHOWERS WILL BE LIKELY...ESPECIALLY DURING THE AFTERNOON HOURS. LOCALIZED FLOODING IS POSSIBLE NEAR AREAS OF HEAVY RAIN. ATLANTIC OCEAN... SURFACE HIGH PRESSURE CONTINUES TO PROVIDE FAIR CONDITIONS ACROSS THE WESTERN ATLC AROUND A 1022 MB HIGH NEAR 32N67W. AN UPPER LEVEL TROUGH TO THE EAST ALONG 32N54W TO 19N65W SUPPORTS A COLD FRONT THAT ENTERS THE DISCUSSION AREA NEAR 32N56W AND CONTINUES TO 23N64W WHERE IT TRANSITIONS TO A SHEAR AXIS TO EASTERN CUBA AT 21N75W. SCATTERED SHOWERS AND THUNDERSTORMS ARE WITHIN 60 NM OF THE AXIS NORTH OF 30N. ISOLATED SHOWERS ARE WITHIN 60 NM OF THE AXIS ELSEWHERE. AN UPPER LEVEL RIDGE IS ALONG 43W SUPPORTING A BROAD SURFACE RIDGE ACROSS MUCH OF THE CENTRAL AND EASTERN ATLC ANCHORED BY A 1034 MB HIGH NEAR 46N36W. HOWEVER...A WEAK 1018 MB SURFACE LOW NEAR 28N43W DISTURBS THE RIDGE ALONG WITH A SURFACE TROUGH THAT EXTENDS THROUGH THE LOW CENTER ALONG 30N44W 27N42W. POSSIBLE ISOLATED SHOWERS WITHIN 150 NM OF THE LOW CENTER. A SECOND SURFACE TROUGH EXTENDS FROM NORTHERN AFRICA ALONG 30N TO 24W. NO SHOWERS ARE ASSOCIATED WITH THE TROUGH. BROAD UPPER LEVEL RIDGING DOMINATES THE REMAINDER OF THE TROPICAL ATLC PROVIDING FAIR CONDITIONS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON