000 AXNT20 KNHC 161010 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT FRI OCT 16 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0900 UTC. ...SPECIAL FEATURES... STRONG HIGH PRESSURE BUILDING ACROSS THE SE UNITED STATES WILL STRENGTHEN NE WINDS ACROSS MOST OF THE GULF THIS WEEKEND. STRONG TO GALE FORCE NW TO N WINDS ARE EXPECTED SAT THROUGH TUE IN THE FAR SW GULF OF MEXICO OFFSHORE OF VERACRUZ MEXICO MAINLY S OF 21N W OF 95W. FOR MORE MORE INFORMATION...PLEASE REFER TO THE HIGH SEAS FORECAST UNDER AWIPS/WMO HEADER HSFAT2/FZNT02. A DEEP 1000 MB LOW PRES AREA IS CENTERED OVER THE EASTERN ATLC NEAR 30N21W...APPROXIMATELY 300 NM SW OF THE AZORES ISLANDS. EARLIER SHIP OBSERVATIONS AND SCATTEROMETER DATA INDICATED STRONG TO MINIMAL GALE FORCE WINDS HAVE BEEN ONGOING WITHIN 420 NM NW SEMICIRCLE OF THE LOW PRES. THIS MAY BE STARTING TO DIMINISH GRADUALLY THROUGH TODAY AS THE LOW SLOWLY WEAKENS AND SHIFTS TO THE ENE. ...TROPICAL WAVES... A TROPICAL WAVE IS OVER THE E ATLC WITH AN AXIS EXTENDING FROM 16N28W TO 10N30W...MOVING W AT AROUND 5 TO 10 KT. SSMI TPW INDICATES THE WAVE IS EMBEDDED IN DEEP MOISTURE S OF 13N. THE WAVE AXIS IS IN PHASE WITH A DEEP LAYER TROUGH IN THE MID LATITUDES...EXTENDING ACROSS THE NE ATLC. NO SIGNIFICANT CONVECTION IS NOTED NEAR THE TROPICAL WAVE AT THIS TIME. A TROPICAL WAVE IS OVER THE CENTRAL ATLC WITH AN AXIS EXTENDING FROM 18N46W TO 10N47W...MOVING W AT AROUND 5 TO 10 KT OVER THE PAST 24 HOURS AND IS EMBEDDED IN AN ENVIRONMENT OF MODERATE MOISTURE. THE WAVE IS LOCATED IN AN AREA OF DIFFLUENT SW FLOW ALOFT...BETWEEN AN UPPER LEVEL ANTICYCLONE AND AN UPPER TROUGH FARTHER TO THE NW. THIS IS SUPPORTING SCATTERED MODERATE CONVECTION FROM 17N TO 20N BETWEEN 45W AND 50W. A TROPICAL WAVE IS OVER THE W CARIBBEAN WITH AN AXIS EXTENDING FROM 19N84W TO EASTERN HONDURAS AND NICARAGUA. SUBTLE 700 MB TROUGHING IS CO-LOCATED WITH THE WAVE AXIS WITH HIGH MOISTURE IN THE ENVIRONMENT OF THE WAVE. CONVERGENCE OF MODERATE TO FRESH TRADE WIND FLOW ACROSS THE CENTRAL CARIBBEAN ALONG WITH DIVERGENCE ALOFT RELATED TO AN UPPER LEVEL ANTICYCLONE ARE ENHANCING SCATTERED MODERATE CONVECTION WITHIN WITHIN 90 NM EITHER SIDE OF A LINE FROM 12N78W IN THE SW CARIBBEAN TO 17N86W OFF THE COAST OF HONDURAS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM 15N17W TO 07N35W...WHERE THE ITCZ BEGINS AND EXTENDS TO 10N46W. SCATTERED MODERATE CONVECTION IS NOTED WITHIN 90 NM EITHER SIDE OF MONSOON TROUGH AXIS BETWEEN 28W AND 35W. ...DISCUSSION... GULF OF MEXICO... AN UPPER TROUGH REACHES ACROSS THE FAR WESTERN GULF...WEST OF A BROAD UPPER RIDGE OVER THE EASTERN GULF EXTENDING FROM AN UPPER ANTICYCLONE CENTERED OVER THE NW CARIBBEAN. COPIOUS DEEP LAYER MOISTURE CONTINUES TO STREAM ACROSS THE SOUTHERN GULF SOUTH OF A STATIONARY FRONTAL BOUNDARY REACHING FROM SW FLORIDA NEAR PORT CHARLOTTE TO THE CENTRAL GULF NEAR 24N93W. A FEW SHOWERS AND THUNDERSTORMS ARE NOTED FROM OFF THE NE YUCATAN PENINSULA THROUGH THE STRAITS OF FLORIDA...AS WELL AS OVER THE BAY OF CAMPECHE. THE UPPER TROUGH OVER THE WESTERN GULF IS ENHANCING A DIURNAL SURFACE TROUGH EXTENDING ACROSS THE WESTERN YUCATAN PENINSULA. WEAK RIDGING EXTENDS ACROSS THE NORTHERN GULF WATERS TO THE NORTH OF THE STATIONARY FRONT. A DISTINCT MOISTURE GRADIENT PERSISTS ALONG THE STATIONARY FRONT...SHOWING UP WELL ON TPW MICROWAVE IMAGERY. THIS BOUNDARY WILL BECOME MORE DIFFUSE THROUGH TODAY AS THE AIRMASSES MODIFY. REINFORCING HIGH PRES WILL BUILD INTO THE NORTHERN GULF THROUGH THE NEXT 24 TO 36 HOURS. WINDS WILL INCREASE ACROSS THE SW GULF ESPECIALLY ALONG THE HIGHER TERRAIN OF THE COAST OF VERACRUZ TO SUPPORT GALE FORCE WINDS BY EARLY SAT. CARIBBEAN SEA... A BROAD UPPER LEVEL ANTICYCLONE IS CENTERED OVER THE NW CARIBBEAN. THE UPPER LEVEL DIFFLUENCE FROM THIS UPPER LEVEL FEATURE COMBINED WITH A TROPICAL WAVE OVER THE WESTERN CARIBBEAN SUPPORTS CONVECTION OVER MUCH OF THE WESTERN CARIBBEAN. PLEASE REFER TO THE TROPICAL WAVES SECTION FOR MORE DETAILS. DRIER AND MORE STABLE CONDITIONS COVER THE CARIBBEAN W OF 75W...INHIBITING CONVECTION ACROSS THAT PORTION OF THE BASIN. MODERATE TO FRESH TRADE WINDS COVER THE MAJORITY OF THE CARIBBEAN AS INDICATED BY SCATTEROMETER DATA AND BUOY OBSERVATIONS. BUILDING HIGH PRES NORTH OF THE AREA WILL INCREASE TRADE WIND FLOW PRIMARILY OFF COLOMBIA. ...HISPANIOLA... HIGH PRES N OF THE AREA WILL MAINTAIN MODERATE TO OCCASIONALLY FRESH EASTERLY FLOW ACROSS HISPANIOLA. DEEP LAYER MOISTURE REMAINS AVERAGE...AND NW FLOW ALOFT RELATED TO AN UPPER RIDGE WEST OF THE AREA WILL INHIBIT LARGE SCALE CONVECTION. THIS PATTERN WILL SUPPORT FAST MOVING LOW TOPPED SHOWERS AND THUNDERSTORMS MOSTLY IN THE AFTERNOON INTO EARLY EVENING THROUGH THE WEEKEND. ATLANTIC OCEAN... A SHORTWAVE TROUGH PASSING 67W IS LIFTING NE OF THE AREA THIS MORNING. THIS HAD BEEN SUPPORTING A COLD FRONT ACROSS THE WATERS NORTH OF THE NW BAHAMAS...BUT THIS FRONT HAS APPEARED TO HAVE STALL FROM NEAR BERMUDA TO WEST PALM BEACH FLORIDA. A STARK MOISTURE GRADIENT IS NOTED ON TPW MICROWAVE IMAGERY. UPPER DIVERGENCE ON THE NORTHERN PERIPHERY OF AN UPPER RIDGE OVER THE NW CARIBBEAN IS SUPPORTING SCATTERED MODERATE SHOWERS AND THUNDERSTORMS ACROSS THE STRAITS OF FLORIDA THROUGH THE NW BAHAMAS. FARTHER EAST...AN UPPER LOW REMAINS CENTERED NEAR 20N55W WITH A SHARP UPPER TROUGH REACHING TO NE VENEZUELA. AN ASSOCIATED SURFACE TROUGH EXTENDS FROM 16N59W TO BARBADOS THEN FARTHER SOUTH TO TOBAGO. SUBSIDENCE ON THE WEST SIDE OF THIS TROUGH IS LIMITING CONVECTIVE GROWTH OVER THE LEEWARD ISLANDS THIS MORNING. CONVERSELY SCATTERED MODERATE SHOWERS AND THUNDERSTORMS ARE ONGOING NEAR THE CENTER OF THE UPPER LOW AND OVER THE WATERS EAST OF THE WINDWARD ISLANDS...AS WELL ENHANCING SHOWERS AND THUNDERSTORMS NORTH OF THE TROPICAL WAVE ALONG 46W/47W. OVER THE EASTERN ATLC...AN EARLY SEASON FRONTAL BOUNDARY IS MOVING ACROSS THE SUBTROPICS OVER THE WATERS N OF 20N E OF 25W ASSOCIATED WITH THE GALE CENTER NEAR 30N21W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ CHRISTENSEN