000 AXNT20 KNHC 062355 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT THU JUN 06 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...SPECIAL FEATURES... TROPICAL STORM ANDREA IS CENTERED NEAR 29.8N 83.0W AT 07/0000 UTC OR 15 NM NNE OF CROSS CITY FLORIDA AND 40 NM W OF GAINESVILLE FLORIDA MOVING NE AT 13 KT. ESTIMATED CENTRAL PRESSURE IS 992 MB. MAXIMUM SUSTAINED WIND SPEED IS 45 KT WITH GUSTS TO 55 KT. SCATTERED MODERATE CONVECTION IS WITHIN 120 NM EITHER SIDE OF A LINE FROM 22N84W TO 31N77W. ANDREA IS FORECAST TO TRACK NE ACROSS NORTH FLORIDA AND SOUTHEAST GEORGIA THROUGH THE OVERNIGHT HOURS...THEN CONTINUE NE ALONG THE EASTERN U.S. COAST FRIDAY AND INTO THE WEEKEND. 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 10N47W TO 18N46W MOVING W-NW AT 10-15 KT. A 1012 MB LOW IS CENTERED ALONG THE WAVE AXIS NEAR 14N47W LIES WITHIN AN AREA OF MAXIMUM DEEP LAYER MOISTURE EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY FROM 12N-20N BETWEEN 40W-50W. THIS AREA OF MAXIMUM MOISTURE CORRESPONDS WITH SCATTERED MODERATE CONVECTION OCCURRING FROM 12N-16N BETWEEN 42W-46W...AND FROM 16N-19N BETWEEN 46W-48W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 11N15W TO 06N21W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 06N21W TO 05N23W TO 06N27W TO 05N36W TO 03N40W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 03N-07N BETWEEN 04W-15W...AND FROM 01N-06N BETWEEN 15W-24W. ...DISCUSSION... GULF OF MEXICO... TROPICAL STORM ANDREA REMAINS THE PRIMARY FEATURE ACROSS THE EASTERN GULF THIS EVENING AS IT CONTINUES TO PRODUCE NUMEROUS SHOWERS AND SCATTERED TSTMS STRETCHING FROM WESTERN CUBA N-NE ACROSS THE FLORIDA STRAITS AND KEYS...TO ACROSS MUCH OF THE FLORIDA PENINSULA AND INTO THE SW NORTH ATLC. WHILE ANDREA MOVES ACROSS THE FLORIDA PENINSULA THIS EVENING...IT REMAINS LOCATED EAST OF AN UPPER LEVEL TROUGH AXIS NOTED ON WATER VAPOR IMAGERY ALONG 87W WITH UPPER LEVEL DIFFLUENCE MAXIMIZED EAST OF THE TROUGH AXIS. THIS TROUGHING SUPPORTS A TRAILING SURFACE TROUGH ANALYZED FROM 26N85W TO THE YUCATAN PENINSULA NEAR 22N88W TO 18N91W. CONVECTION OCCURRING IN ASSOCIATION WITH ANDREA IS FOCUSED MAINLY EAST OF THIS SURFACE TROUGH WHERE LOW-LEVEL MOISTURE CONVERGENCE AND MIDDLE TO UPPER LEVEL DIFFLUENCE IS MAXIMIZED. EAST OF THE UPPER LEVEL TROUGH...MOSTLY DRY AIR AND STRONG SUBSIDENCE IS PROVIDING FOR OVERALL FAIR CONDITIONS AND CLEAR SKIES THIS EVENING. THE ONLY EXCEPTION IS AN AREA OF SCATTERED SHOWERS AND TSTMS OCCURRING OVER LOUISIANA AND MISSISSIPPI AS A MID-LEVEL SHORTWAVE TROUGH MOVES OVER THE LOWER MISSISSIPPI RIVER VALLEY THIS EVENING. OTHERWISE...AS ANDREA MOVES NE OF THE BASIN...BY LATE SATURDAY CONDITIONS ARE EXPECTED TO IMPROVE AS RIDGING ANCHORED OVER THE SW NORTH ATLC BUILDS IN ACROSS THE GULF PROVIDING FOR LIGHT E-SE WINDS THROUGH MONDAY. CARIBBEAN SEA... UPPER LEVEL RIDGING EXTENDS FROM OVER PORTIONS OF CENTRAL AMERICA NEAR 15N89W TO AN ANTICYCLONIC CIRCULATION CENTERED JUST NORTH OF CENTRAL CUBA NEAR 22N77W AND INTO THE SW NORTH ATLC. OVER THE NW CARIBBEAN...WATER VAPOR IMAGERY INDICATES MIDDLE TO UPPER LEVEL MOISTURE CONTINUES TO ADVECT NORTH-NORTHEASTWARD OVER WESTERN CUBA AND THE FLORIDA PENINSULA. AS TROPICAL STORM ANDREA CONTINUES TO TRACK NORTHEAST...REMNANT SURFACE TROUGHING EXTENDS FROM THE SE GULF OF MEXICO TO THE CENTRAL YUCATAN PENINSULA PROVIDING FOCUS FOR WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS N OF 18N W OF 83W. THIS CONVECTIVE ACTIVITY INCREASES IN COVERAGE ACROSS WESTERN CUBA AND INTO THE FLORIDA STRAITS THIS EVENING AS LOCALIZED FLOODING REMAINS A THREAT OVER CUBA W OF 82W. FARTHER EAST...NORTH-NORTHEASTERLY FLOW ALOFT DOMINATES BETWEEN 70W-81W AND IS PROVIDING FOR AN OVERALL TRANQUIL EVENING FOR THE SOUTHWEST AND CENTRAL CARIBBEAN. OTHERWISE...WATER VAPOR IMAGERY ALSO INDICATES AN UPPER LEVEL TROUGH AXIS EXTENDS FROM 20N60W TO A BASE NEAR 13N70W. MOIST SOUTHWESTERLY FLOW ALOFT IS NOTED EAST OF THE TROUGH AXIS WITH UPPER LEVEL CLOUDINESS STREAMING NE AWAY FROM THE SOUTH AMERICAN CONTINENT...HOWEVER MUCH OF THE EASTERN CARIBBEAN REMAINS PRECIPITATION-FREE AND VOID OF ANY SIGNIFICANT DEEP CONVECTION. HISPANIOLA... CURRENTLY AN AREA OF ISOLATED SHOWERS AND TSTMS ARE OCCURRING OVER NORTHWESTERN PORTIONS OF THE ISLAND. THIS CONVECTION IS EXPECTED TO DIMINISH OVER THE NEXT FEW HOURS WITH THE LOSS OF PEAK DAYTIME HEATING AND INSTABILITY. THEREAFTER...THE EVENING AND OVERNIGHT SHOULD REMAIN FAIRLY QUIET AS NORTH-NORTHEASTERLY FLOW ALOFT DOMINATES AND WILL PROVIDE FOR AN OVERALL STABLE ENVIRONMENT. LOOKING AHEAD...E-SE WINDS ARE EXPECTED TO PERSIST THROUGH THE UPCOMING WEEKEND WITH LOW-LEVEL MOISTURE CONVERGENCE EXPECTED ACROSS THE ISLAND INITIATING ISOLATED AFTERNOON AND EVENING SHOWERS AND TSTMS THE NEXT COUPLE OF DAYS. ATLANTIC OCEAN... WATER VAPOR IMAGERY INDICATES THE MIDDLE TO UPPER LEVEL CIRCULATION ASSOCIATED WITH TROPICAL STORM ANDREA IS EMBEDDED WITHIN A SHORTWAVE TROUGH PROGRESSING NORTHEAST OVER THE SE CONUS. THIS SHORTWAVE IS PART OF BROADER TROUGHING ACROSS THE EASTERN U.S. AND IS CREATING A LARGE AREA OF UPPER LEVEL DIFFLUENCE TO THE NORTH AND EAST OF THE TROPICAL CYCLONE. THIS DIFFLUENT ENVIRONMENT CONTINUES TO SUPPORT SCATTERED SHOWERS AND TSTMS OVER THE SW NORTH ATLC W OF 74W...INCLUDING INLAND PORTIONS OF THE FLORIDA PENINSULA...FLORIDA KEYS...AND FLORIDA STRAITS THIS EVENING. AS ANDREA TRACKS TO THE NE OVER THE NEXT 24 TO 36 HOURS...CONVECTION IS EXPECTED TO PERSIST DUE TO THE AREA OF MAXIMUM DIFFLUENCE AND CONTINUED S-SE SURFACE FLOW. OTHERWISE...THE REMAINDER OF THE SW NORTH ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1030 MB HIGH CENTERED OVER THE CENTRAL ATLC NEAR 36N42W. THE RIDGE AXIS EXTENDS FROM THE HIGH SW TO EASTERN CUBA NEAR 21N78W. THIS RIDGE REMAINS FAIRLY EXPANSIVE OVER THE CENTRAL AND EASTERN ATLC WITH THE ONLY AREA OF SIGNIFICANT WEATHER OCCURRING IN ASSOCIATION WITH THE TROPICAL WAVE ALONG 47W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN