000 AXNT20 KNHC 160541 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 8N42W TO 2N43W MOVING W AT 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 7N-10N BETWEEN 39W-45W...AND FROM 2N- 5N BETWEEN 44W-47W. 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 12N16W TO 8N20W. THE ITCZ BEGINS AT 8N20W AND CONTINUES ALONG 5N30W 6N42W 3N51W. SCATTERED MODERATE/STRONG CONVECTION IS FROM 4N-7N BETWEEN 11W-15W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 2N-6N BETWEEN 24W-28W...FROM 4N-7N BETWEEN 32W-39W...AND FROM EQ-5N BETWEEN 47W-53W. ...DISCUSSION... GULF OF MEXICO... SURFACE RIDGING DOMINATES THE GULF OF MEXICO AROUND A 1021 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 OVER THE WESTERN GULF ALONG THE MEXICO AND TEXAS COASTS. A FEW ISOLATED SHOWERS MAY ALSO BE OVER ALABAMA AND THE WESTERN FLORIDA PANHANDLE CONNECTED TO AN UPPER LEVEL LOW OVER OKLAHOMA. LIGHT ANTI-CYCLONIC WINDS ARE IN THE NE GULF AROUND THE HIGH CENTER INCREASING TO 15 KT ON THE OUTER PERIMETER OF THE BASIN INCLUDING MUCH OF THE WESTERN HALF WEST OF 90W. 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. ONLY A FEW WIDELY ISOLATED SHOWERS ARE POSSIBLE ACROSS CUBA AND TO THE SOUTH ASSOCIATED WITH A DISSIPATING COLD FRONT IN THE ATLC THAT EXTENDS TO EASTERN CUBA. AN UPPER LEVEL TROUGH IS DIGGING SOUTH INTO THE EASTERN CARIBBEAN. WHILE MOSTLY DRY AIR STILL REMAINS ACROSS THE AREA PROVIDING FAIR CLEAR SKIES ACROSS MUCH OF THE AREA...A THIN SWATH OF MOISTURE EXTENDS FROM NEAR HISPANIOLA EASTWARD ACROSS THE NE CARIBBEAN ISLANDS. SCATTERED SHOWERS ARE IN THIS AREA FROM 16N-19N BETWEEN 65W-74W. 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 SCATTERED SHOWERS WITH ISOLATED THUNDERSTORMS APPEAR TO BE CONCENTRATED OVER THE SW PORTION OF THE ISLAND WITH ACTIVITY ALSO SOUTH OF THE ENTIRE ISLAND. 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 BUILD ACROSS THE WESTERN ATLC AROUND A 1023 MB HIGH NEAR 32N71W. AN UPPER LEVEL TROUGH TO THE EAST ALONG 31N57W TO 19N65W SUPPORTS A COLD FRONT THAT ENTERS THE DISCUSSION AREA NEAR 32N56W AND CONTINUES TO 23N67W WHERE IT DISSIPATES TO EASTERN CUBA AT 21N77W. ISOLATED SHOWERS ARE WITHIN 100 NM OF THE AXIS WITH A CLUSTER OF SCATTERED ACTIVITY AND ISOLATED THUNDERSTORMS NEAR 25N60W. AN UPPER LEVEL RIDGE IS ALONG 45W SUPPORTING A BROAD SURFACE RIDGE ACROSS THE REMAINDER OF THE CENTRAL AND EASTERN ATLC ANCHORED BY A 1037 MB HIGH NEAR 46N37W. HOWEVER...A WEAK 1018 MB SURFACE LOW NEAR 29N41W DISTURBS THE RIDGE ALONG WITH A SURFACE TROUGH THAT EXTENDS THROUGH THE LOW CENTER ALONG 31N41W 26N42W. POSSIBLE ISOLATED SHOWERS ARE NORTH OF 25N BETWEEN 33W-37W...AND NORTH OF 28N BETWEEN 37W-45W. BROAD UPPER LEVEL RIDGING DOMINATES THE REMAINDER OF THE TROPICAL ATLC. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON