000 AXNT20 KNHC 062353 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT TUE OCT 06 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...SPECIAL FEATURES... HURRICANE JOAQUIN IS CENTERED NEAR 39.0N 56.9W AT 06/2100 UTC OR ABOUT 490 NM...9100 KM SSW OF CAPE RACE NEWFOUNDLAND MOVING ENE AT 20 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 974 MB. MAXIMUM SUSTAINED WIND SPEED IS 70 KT WITH GUSTS TO 85 KT. SCATTERED MODERATE CONVECTION WAS NOTED WITHIN 90 NM IN THE N AND 60 NM IN THE S SEMICIRCLES OF THE CENTER. CONVECTION APPEARS TO BE DECREASING IN OVERALL COVERAGE AS THE STORM CONTINUES ITS TREK OVER COOLER WATERS. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 03N40W TO 11N44W MOVING W AT 10 KT. THE WAVE COINCIDES WITH SHORTWAVE 700 MB TROUGHING BETWEEN 40W- 45W WITH A MAXIMUM IN 850 MB RELATIVE VORTICITY SURROUNDING THE WAVE AXIS. NO SIGNIFICANT DEEP CONVECTION IS NOTED WITH THE WAVE AT THIS TIME. TROPICAL WAVE EXTENDS FROM 11N51W TO 20N50W MOVING W AT 15 KT. THE WAVE COINCIDES WITH A 700 MB TROUGH BETWEEN 46W-53W AND REMAINS EMBEDDED WITHIN AN AREA OF MODERATE TO HIGH MOISTURE AND DIFFLUENT FLOW ALOFT. SCATTERED MODERATE CONVECTION WAS NOTED WITHIN 180 NM W OF AND 90 NM E OF THE WAVE AXIS FROM 15N-20N. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM THE AFRICAN COAST NEAR 17N16W TO 07N31W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 07N31W TO THE EQUATOR NEAR 46W. ASIDE FROM CONVECTION OCCURRING IN ASSOCIATION WITH THE TROPICAL WAVE ALONG 50W...WIDELY SCATTERED MODERATE CONVECTION IS FROM 05N-10N BETWEEN 22W-28W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED OVER THE CENTRAL GULF NEAR 24N90W WITH WATER VAPOR IMAGERY INDICATING VERY DRY AIR AND OVERALL STABILITY ALOFT ENCOMPASSING THE ENTIRE BASIN. AT THE SURFACE...CYCLONIC NORTHERLY FLOW PREVAILS WITH A 1011 MB LOW ABOUT 90 NM SW OF TAMPA BAY. THIS LOW WAS SITUATED ALONG A SURFACE TROUGH WHICH EXTENDED FROM THE SW N ATLC ACROSS CENTRAL FLORIDA TO 26N92W. ANOTHER SURFACE TROUGH EXTENDED FROM NEAR THE LOW PRESSURE SW TO THE NORTHERN YUCATAN PENINSULA. THESE FEATURES ARE PROVIDING FOCUS FOR POSSIBLE ISOLATED LOW TOPPED SHOWERS OCCURRING ACROSS PATCHES OF THE GULF EAST OF 88W THIS EVENING. OTHERWISE...HIGH PRESSURE ANCHORED BY A 1023 MB HIGH CENTERED OVER OKLAHOMA EXTENDS ACROSS COASTAL TEXAS...LOUISIANA...AND MEXICO AS WELL AS PORTIONS OF THE FAR WESTERN GULF. GENTLE TO MODERATE N-NE WINDS PREVAIL AND ARE EXPECTED TO GRADUALLY SHIFT E-NE BY THURSDAY AS THE SURFACE RIDGING SHIFTS EASTWARD ACROSS THE SE CONUS. THE BROKEN TO OVERCAST LOW CLOUDS ARE EXPECTED TO CLEAR OVER THE E GULF AS HIGH PRESSURE BUILDS EAST ON WED. CARIBBEAN SEA... MOSTLY FAIR WEATHER AND CLEAR SKIES PREVAIL ACROSS MUCH OF THE BASIN THIS EVENING AS RELATIVELY DRY AND STABLE AIR ALOFT PREVAILS. TWO EXCEPTIONS ARE NOTED AS SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING ACROSS THE FAR SE CARIBBEAN S OF 13N E OF 65W WITHIN FAVORABLE MIDDLE TO UPPER LEVEL DIFFLUENT FLOW ACROSS VENEZUELA AND THE SOUTHERN WINDWARD ISLANDS. THIS ACTIVITY IS WELL AHEAD OF A TROPICAL WAVE CURRENTLY ALONG 50W/51W THAT IS EXPECTED TO IMPACT THE LESSER ANTILLES BY THURSDAY. THE OTHER EXCEPTION IS SCATTERED SHOWERS AND STRONG TSTMS OCCURRING ACROSS THE FAR SW CARIBBEAN AND PORTIONS OF PANAMA AND COSTA RICA DUE LARGELY TO THE PROXIMITY OF THE MONSOON TROUGH AXIS IN THE EAST PACIFIC AND FAVORABLE MIDDLE TO UPPER LEVEL DIFFLUENCE. OTHERWISE...MODERATE TO FRESH TRADES CONTINUE E OF 80W WITH THE LOCALLY STRONG WINDS NOTED ALONG THE COAST OF COLOMBIA. THIS WAS NOTED IN A 1440 UTC ASCAT PASS. DURING THE NEXT 24 HOURS...THE PRESSURE GRADIENT E OF 80W IS EXPECTED TO STRENGTHEN SOMEWHAT INCREASING WINDS INTO THE FRESH TO STRONG RANGE GENERALLY BETWEEN 68W-78W. ...HISPANIOLA... CURRENTLY...BROKEN TO OVERCAST CLOUDS WITH ISOLATED SHOWERS ARE OCCURRING OVER INTERIOR AND NORTHEASTERN PORTIONS OF THE DOMINICAN REPUBLIC. THIS ACTIVITY SHOULD DECREASE ALTOGETHER OVER THE NEXT SEVERAL HOURS. A MID TO-UPPER LEVEL TROUGH AXIS EXTENDING FROM AN EXITING UPPER LOW OFF THE CAROLINAS INTO THE SE BAHAMAS WILL APPROACH THE AREA ON WED PROVIDING SOME DRYING IN THE MID LEVELS....HOWEVER WITH AFTERNOON HEATING AND OROGRAPHIC LIFT EXPECT AFTERNOON CONVECTION WITH THE ADDED INSTABILITY ALOFT. ATLANTIC OCEAN... A MIDDLE TO UPPER LEVEL LOW CENTERED OVER THE SW NORTH ATLC NEAR 34N71W IS RAPIDLY LIFTING OUT TO THE ENE AT 20 KT. THIS SYSTEM SUPPORTS A 1008 MB LOW CENTERED OFF THE COAST OF THE CAROLINAS NEAR 33N73W WITH A DETACHED SURFACE TROUGH EXTENDING FROM 30N77W TO THE FLORID EAST COAST NEAR FORT PIERCE. STRONG UPPER LEVEL DYNAMICS AND THE PRESENCE OF A SURFACE BOUNDARY CONTINUE TO SUPPORT SCATTERED SHOWERS AND POSSIBLE ISOLATED TSTMS WITHIN 45-60 NM OF A LINE FROM 32N69W TO THE SE BAHAMAS NEAR 23N74W. THE REMAINDER OF THE SW NORTH ATLC IS UNDER THE INFLUENCE OF A RATHER WEAK SURFACE RIDGE ANCHORED BY A 1019 MB HIGH CENTERED NEAR 25N56W...HOWEVER UPPER LEVEL RIDGING CENTERED NEAR 20N65W AND MID-LEVEL ENERGY TO THE NE IN THE VICINITY OF 25N57W IS GENERATING SCATTERED SHOWERS AND TSTMS FROM 22N-26N BETWEEN 55W- 60W. ACROSS THE CENTRAL ATLC...A 1014 MB SURFACE LOW IS CENTERED NEAR 31N46W WITH A STATIONARY FRONT EXTENDING ENE TO 32N38W. ISOLATED SHOWERS AND TSTMS ARE OCCURRING FROM 29N-32N BETWEEN 30W-46W. OTHERWISE... THE REMAINDER OF THE EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1023 MB HIGH CENTERED NEAR 30N30W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ COBB