000 AXNT20 KNHC 081058 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT SAT JUN 08 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 1115 UTC. ...SPECIAL FEATURES... POST-TROPICAL CYCLONE ANDREA IS CENTERED NEAR 40.1N 73.8W AT 08/0600 UTC ABOUT 113 NM WSW OF NANTUCKET MASSACHUSETTS OR 30 NM WSW OF THE EASTERN TIP OF LONG ISLAND MOVING NE AT 30 KT. ESTIMATED CENTRAL PRESSURE IS 998 MB. MAXIMUM SUSTAINED WIND SPEED IS 39 KT WITH 50 KT GUSTS. RADAR IMAGERY SHOW SCATTERED SHOWERS WITH ISOLATED THUNDERSTORMS FROM CONNECTICUT TO MAINE. THE CENTER OF ANDREA WILL CONTINUE TO MOVE NORTHEASTWARD NEAR THE U.S. EAST COAST TODAY...AND THEN ACROSS ATLANTIC CANADA LATE TODAY THROUGH SUNDAY. LITTLE CHANGE IN STRENGTH IS FORECAST DURING THE NEXT 48 HOURS. SEE LATEST NHC INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT1/WTNT31 KNHC AND THE FULL FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 08N45W TO 1N49W MOVING W AT 15 KT. THE WAVE IS EMBEDDED WITHIN THE ITCZ AXIS AND AN AREA OF MAXIMUM MOISTURE EXTENDING FROM 1N-8N BETWEEN 41W-49W AS INDICATED BY TOTAL PRECIPITABLE WATER IMAGERY. THE CONVECTION OF THE WAVE LOOKS MORE ORGANIZED THIS MORNING. A CLUSTER OF MODERATE/ISOLATED STRONG CONVECTION IS FROM 5N-8N BETWEEN 44W- 48W. SCATTERED MODERATE CONVECTION IS FROM 2N-5N WITHIN 170 NM WEST OF THE AXIS. TROPICAL WAVE EXTENDS FROM 20N58W TO 11N59W MOVING W-NW AT 20 KT AROUND THE SW PERIPHERY OF A BROAD SURFACE RIDGE. TOTAL PRECIPITABLE WATER IMAGERY INDICATE THAT MOISTURE CONTINUES TO DECREASE WITHIN THE WAVE ENVIRONMENT. A TONGUE OF LIGHT MOISTURE EXTENDS JUST NORTH OF THE WAVE FROM 19N-22N BETWEEN 48W-62W. THE METEOSAT-9 SAL TRACKING PRODUCT CONTINUES TO SHOW SOME DRY IN THE IMMEDIATE ENVIRONMENT OF THE WAVE...PARTICULARLY N OF 17N AND NW OF THE WAVE. THIS DRY AIR IS LIMITING THE CONVECTION OF THE WAVE WHICH IS DEPICTED IN SATELLITE IMAGERY AS A LINE OF SCATTERED MODERATE FROM 19N-21N BETWEEN 52W-60W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 16N16W TO 10N18W 06N22W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 06N22W TO 04N34W 04N43W. SCATTERED MODERATE CONVECTION IS WITHIN 100 NM EITHER SIDE OF THE MONSOON TROUGH AXIS BETWEEN 16W- 21W AND WITHIN 120 NM NORTH OF THE ITCZ AXIS. ...DISCUSSION... GULF OF MEXICO... WATER VAPOR IMAGERY INDICATE THAT A BROAD MIDDLE TO UPPER LEVEL TROUGH CONTINUES ACROSS THE GULF THIS MORNING. OVER THE NW GULF...THIS TROUGH IS SUPPORTING A WEAK COLD FRONT EXTENDING FROM A 1009 MB LOW NEAR 36N80W WHICH TRANSITIONS TO A STATIONARY FRONT FROM LOUISIANA TO CENTRAL TEXAS. ITS ALSO SUPPORTS A PRE- FRONTAL TROUGH EXTENDING FROM 29N94W TO 28N96W 26N97W WHICH ALONG WITH MOISTURE BEING ADVECTED FROM NWLY FLOW ALOFT IS ENHANCING ISOLATED SHOWERS AND THUNDERSTORMS N OF 26N W OF 93W. MIDDLE TO UPPER LEVEL MOISTURE CONTINUES TO ADVECT NORTHEASTWARD OVER THE SE GULF AND FLORIDA PENINSULA. THIS MOISTURE AS WELL AS UPPER LEVEL DIFFLUENCE IS ENHANCING SCATTERED MODERATE CONVECTION NE OF A SURFACE TROUGH EXTENDING FROM 26N90W TO 21N92W 17N92W. OTHERWISE...WINDS IN THE RANGE OF 10-15 KT DOMINATE THE BASIN. THE FRONT IS EXPECTED TO DISSIPATE WITHIN THE NEXT 24 HOURS AND THE SURFACE TROUGH IS EXPECTED TO PREVAIL. A PATTERN OF UPPER LEVEL DIFFLUENCE ALONG WITH ABUNDANT LOW LEVEL MOISTURE COULD BE SUPPORTING MORE SHOWERS IN THE SE GULF WITHIN THIS PERIOD. CARIBBEAN SEA... UPPER LEVEL RIDGING DOMINATES THE WESTERN AND EASTERN CARIBBEAN WHILE A NARROW INVERTED TROUGH EXTENDS SW IN THE CENTRAL CARIBBEAN FROM LA HISPANIOLA ALL THE WAY TO PANAMA. WATER VAPOR IMAGERY AS WELL AS TOTAL PRECIPITABLE WATER IMAGERY INDICATE THAT DRY STABLE AIR DOMINATES ACROSS MOST OF THE BASIN PROVIDING FOR FAIR WEATHER CONDITIONS. MIDDLE TO UPPER LEVEL MOISTURE ADVECTING NORTHEASTWARD TO THE SE GULF EXTENDS OVER THE WEST CARIBBEAN. THIS MOISTURE AS WELL AS UPPER LEVEL DIFFLUENCE IN THIS REGION IS ENHANCING SCATTERED MODERATE TO ISOLATED STRONG CONVECTION OVER BELIZE ALSO EXTENDING 100 NM OFF ITS COAST. IN THE SOUTHERN CARIBBEAN CLUSTERS OF MODERATE TO ISOLATED STRONG CONVECTION ARE S OF 11N AND ARE ASSOCIATED TO THE MONSOON TROUGH WHICH AXIS EXTENDS OVER COSTA RICA AND PANAMA. A TROPICAL EASTERLY WAVE IS FAST APPROACHING THE NE CARIBBEAN BRINGING SOME CONVECTION WITH IT. OTHERWISE...EASTERLY TRADEWINDS IN THE RANGE OF 15-20 KT SPREAD ACROSS THE BASIN. THE TROPICAL WAVE IS EXPECTED TO ENTER THE NE CARIBBEAN DURING THE DAY TODAY AND EXTENDS OVER EASTERN PUERTO RICO WITHIN 24 HOURS. CHANCES OF PRECIPITATION FOR THIS REGION MAY BE MARGINAL AS SAL DRY AIR IS LIMITING THE CONVECTION IN ITS ENVIRONMENT. HISPANIOLA... A SURFACE RIDGE OVER THE ATLC EXTENDS TO THE ISLAND. IN THE UPPER LEVELS A NARROW INVERTED TROUGH EXTENDS SW FROM LA HISPANIOLA ALL THE WAY TO PANAMA. WATER VAPOR IMAGERY AS WELL AS TOTAL PRECIPITABLE WATER IMAGERY CONTINUE TO INDICATE THE PRESENCE OF VERY DRY AIR ACROSS THE ISLAND WHICH IS FAVORING CLEAR SKIES AND FAIR WEATHER THIS MORNING. ISOLATED AFTERNOON AND EVENING SHOWERS WITH POSSIBLE TSTMS CAN BE EXPECTED DURING SATURDAY AND SUNDAY. OTHERWISE... EASTERLY WINDS OF 10-15 KT PREVAIL ACROSS THE ISLAND. WITHIN 48 HOURS THE TROPICAL WAVE CURRENTLY EAST OF THE LESSER ANTILLES WILL BE NORTH OF THE ISLAND POSSIBLY BRINGING SOME RAINSHOWERS WITH IT. ATLANTIC OCEAN... MOIST SOUTHWESTERLY FLOW ALOFT IS NOTED BETWEEN MIDDLE TO UPPER LEVEL TROUGHING OVER THE EASTERN CONUS AND AN UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED OVER THE SW NORTH ATLC NEAR 23N78W. THIS MOISTURE ALONG WITH AN OVERALL DIFFLUENT ENVIRONMENT ALOFT IS SUPPORTING ISOLATED SHOWERS W OF 77W N OF 23N. A WEAK SURFACE TROUGH IS ANALYZED FROM 32N31W TO 28N30W WITH NO CONVECTION ASSOCIATED TO IT. OTHERWISE THE REMAINDER OF THE SW NORTH ATLC...ALONG WITH THE CENTRAL AND EASTERN ATLC ARE UNDER THE INFLUENCE OF A BROAD SURFACE RIDGE ANCHORED BY A 1033 MB HIGH CENTERED NEAR 35N46W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ RAMOS