000 AXNT20 KNHC 090558 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT SAT MAY 09 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...SPECIAL FEATURE... SUBTROPICAL STORM ANA IS CENTERED NEAR 32.2N 77.5W AT 09/0600 UTC OR ABOUT 115 NM SE OF MYRTLE BEACH SOUTH CAROLINA MOVING N AT 2 KT. ESTIMATED MINIMUM SURFACE PRESSURE IS 998 MB. MAXIMUM WIND SPEED IS 50 KT WITH GUSTS TO 60 KT. SCATTERED MODERATE CONVECTION IS FROM 32N-34N BETWEEN 74W-78W. A BAND OF NUMEROUS SHOWERS IS MOVING INLAND OVER PORTIONS OF NORTH CAROLINA COAST. PLEASE SEE LATEST NHC INTERMEDIATE PUBLIC ADVISORY UNDER WMO/AWIPS HEADERS MIATCMPAT1/ WTNT31 KNHC AND THE FULL FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE TROPICAL ATLC NEAR 11N15W TO 7N21W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 4N26W 2N37W THEN S OF THE EQUATOR INTO SOUTH AMERICA NEAR 42W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 2N-6N BETWEEN 29W-33W AND FROM 3N-5N BETWEEN 33W-37W. ...DISCUSSION... GULF OF MEXICO... AN UPPER RIDGE ANCHORED IN THE E PACIFIC REGION EXTENDS A RIDGE AXIS ACROSS THE W GULF OF MEXICO TO OVER THE LOWER MISSISSIPPI VALLEY WHILE AN UPPER TROUGH THAT ENCOMPASSES SUBTROPICAL ANA EXTENDS OVER THE E GULF OF MEXICO WITH THE AXIS IN THE W ATLC. A SURFACE RIDGE COVERS THE GULF ANCHORED BY A 1018 MB HIGH NEAR 27N85W. A SURFACE TROUGH HAS MOVED OFF THE COAST OF THE YUCATAN AT 09/0300 UTC EXTENDING FROM 22N91W TO 18N92W WITH ISOLATED SHOWERS WITHIN 45 NM EITHER SIDE OF THE TROUGH AXIS. THE UPPER RIDGE IS ADVECTING MOISTURE ACROSS THE FAR W GULF WHICH IS GENERATING ISOLATED SHOWERS INLAND AND WITHIN 90 NM ALONG THE COAST BETWEEN TAMPICO MEXICO AND GALVESTON TEXAS. THIS IS LEAVING THE REMAINDER OF THE GULF UNDER REMARKABLE CLEAR SKIES TONIGHT. HIGH PRESSURE WILL PREVAIL OVER THE AREA THROUGH THE WEEKEND INTO NEXT WEEK. A SURFACE TROUGH WILL MOVE WESTWARD OFF THE YUCATAN PENINSULA AND ACROSS THE E BAY OF CAMPECHE EACH EVENING. CARIBBEAN SEA... THE UPPER TROUGH OVER THE E GULF OF MEXICO AND W ATLC EXTENDS INTO THE CARIBBEAN ACROSS CENTRAL CUBA TO CENTRAL PANAMA. THE WESTERLY FLOW ALOFT ALONG 80W COMBINING WITH THE EASTERLY SURFACE FLOW ARE GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 18N TO OVER CUBA BETWEEN 78W-82W. THE EASTERLY TRADE WINDS ARE BANKING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS INLAND AND WITHIN 60 NM ALONG THE COAST OF PANAMA AND COSTA RICA W OF 80W. THE REMAINDER OF THE CARIBBEAN IS UNDER FAIR SKIES THIS EVENING. FRESH TO STRONG TRADE WINDS PREVAILING OVER MUCH OF THE CARIBBEAN WILL EXPAND WESTWARD TO GULF OF HONDURAS THROUGH THE FIRST OF NEXT WEEK. ...HISPANIOLA... SKIES ARE CLEARING ACROSS THE ISLAND TONIGHT. SOUTHWESTERLY FLOW ALOFT ASSOCIATED WITH THE UPPER TROUGH OVER THE W CARIBBEAN WILL PERSIST THROUGH THE WEEKEND. LOW LEVEL MOISTURE WILL INCREASE AGAIN SAT NIGHT WHICH COULD BRING MORE SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS FOR SAT NIGHT THROUGH MON. ATLANTIC OCEAN... THE UPPER TROUGH THAT ENCOMPASSES SUBTROPICAL STORM ANA EXTENDS ALONG 77W INTO THE CARIBBEAN AND IS GENERATING SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS FROM 26N-32N BETWEEN 73W- 78W. A SURFACE RIDGE COVERS THE REMAINDER OF THE ATLC WITH THE RIDGE AXIS EXTENDING FROM A 1026 MB HIGH NEAR 34N20W ALONG 28N31W TO A 1025 MB HIGH NEAR 27N46W TO 30N60W. ANA IS EXPECTED TO CONTINUE SLOWLY N-NW WITH A NORTHERLY TURN AS IT APPROACHES THE COAST OF THE CAROLINAS. OTHERWISE THE SURFACE RIDGE WILL BUILD IN FROM THE E IN THE WAKE OF ANA. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW