000 AXNT20 KNHC 180551 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT SUN OCT 18 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 0530 UTC. ...SPECIAL FEATURES... THE COMBINATION OF STRONG HIGH PRESSURE ACROSS EASTERN MEXICO... LOWER PRESSURE ACROSS CENTRAL AMERICA AND SOUTHERN MEXICO...AND A SURFACE TROUGH ANALYZED ACROSS THE SW GULF OF MEXICO WATERS IS SUPPORTING NEAR GALE TO GALE FORCE NW WINDS ALONG THE COAST OF VERACRUZ...MAINLY S OF 21N W OF 95W. SEE LATEST NWS HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 FOR MORE DETAILS. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 16N54W TO 10N48W MOVING W AT 5-10 KT. AN ASCAT PASS FROM 00 UTC CAPTURED CYCLONIC TURNING THE WIND PATTERN ON THE NORTHERN END OF THE WAVE AXIS. THE WAVE COINCIDES WITH A LOW-AMPLITUDE 700 MB TROUGH BETWEEN 47W-55W. IN ADDITION...A NEARBY UPPER LEVEL LOW CENTERED NEAR 22N57W IS INTERACTING WITH THE WAVE AND SHEARING THE CONVECTION TO THE EAST OF THE WAVE AXIS. ISOLATED MODERATE CONVECTION IS FROM 09N TO 17N BETWEEN 45W AND 53W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM THE AFRICAN COAST NEAR 11N15W TO LOW PRES 1013 MB NEAR 07N19W TO 08N28W...THEN RESUMES IN THE VICINITY OF LOW PRES 1014 MB NEAR 1309N37W TO 07N45W WHERE IT TRANSITIONS TO AN ITCZ CONTINUES TO 04N52W. ISOLATED MODERATE CONVECTION IS NOTED FROM 04N TO 08N BETWEEN 25W AND 35W. SCATTERED MODERATE CONVECTION IS ALSO NOTED WITHIN 60 NM N OF ITCZ AXIS BETWEEN 45W AND 50W. ...DISCUSSION... GULF OF MEXICO... THE MAIN ENERGY ASSOCIATED WITH A BROAD LONG WAVE TROUGH OVER THE EASTERN UNITED STATES IS MOVING OFF THE MID ATLANTIC COAST THIS MORNING...SUPPORTING THE MOVEMENT OF A COLD FRONT IN THE NORTHEAST AND NORTH CENTRAL GULF OF MEXICO. UPPER FLOW IS TURNING MORE ZONAL ACROSS THE WESTERN GULF...AND SURFACE ARE VEERING EASTERLY ALLOWING THE FRONT TO SLOW AND STALL ALONG THE S TEXAS COAST. FARTHER SOUTH...A STATIONARY FRONT PERSISTS OVER THE SE AND S CENTRAL GULF BETWEEN MORE MOIST TROPICAL AIRMASS TO THE SOUTH...AND SLIGHTLY DRIER AIRMASS FROM SOUTH FLORIDA TO THE CENTRAL GULF. THE COLD FRONT WILL EVENTUALLY MERGE WITH THE STATIONARY FRONT LATE TODAY...WITH NORTHERLY FLOW FUNNELING ALONG THE MEXICAN COAST AND OVER THE FAR WESTERN GULF AS WELL. THE STRONG HIGH PRES NORTH OF THE FRONT WILL SUPPORT CONTINUED GALE CONDITIONS OFF THE COAST OF VERACRUZ THROUGH THE PERIOD...WITH FRESH TO STRONG NE TO E WINDS ELSEWHERE ACROSS THE GULF THROUGH MID WEEK. CARIBBEAN SEA... A BROAD UPPER LEVEL ANTICYCLONIC CIRCULATION INFLUENCES MUCH OF THE WESTERN CARIBBEAN AND CENTRAL AMERICA TONIGHT PROVIDING AN OVERALL DIFFLUENT ENVIRONMENT ALOFT. AN AREA OF LOW PRESSURE ACROSS CENTRAL AMERICA FOCUSES ON A 1008 MB LOW CENTERED NEAR 18N89W. THE LOW IS ASSOCIATED WITH A LARGE AND BROAD MONSOONAL GYRE THAT COVERS A LARGE PORTION OF CENTRAL AMERICA AND A PORTION OF THE EASTERN PACIFIC WATERS N OF 10N BETWEEN 90W-100W. THE OVERALL CIRCULATION SUPPORTS SCATTERED SHOWERS AND TSTMS OVER THE NW CARIBBEAN WEST OF 85W...INCLUDING INLAND PORTIONS OF CENTRAL AMERICA...CUBA...AND THE YUCATAN PENINSULA. AS THE AREA OF LOW PRESSURE PERSISTS THROUGH THE REMAINDER OF THE WEEKEND... CONTINUED PRECIPITATION IS EXPECTED ACROSS THE WESTERN CARIBBEAN AND MORE IMPORTANTLY CENTRAL AMERICA RESULTING IN POSSIBLE FLASH FLOODING POTENTIAL AND MUD SLIDES. ELSEWHERE ACROSS THE EASTERN CARIBBEAN...DRIER AIR AND SUBSIDENCE ALOFT SUPPORTS GENERALLY FAIR WEATHER CONDITIONS E OF 78W WITH ONLY A FEW ISOLATED SHOWERS AND TSTMS OCCURRING ACROSS HISPANIOLA. MODERATE TO OCCASIONAL FRESH TRADE WINDS PREVAIL ACROSS THE BASIN WITH LITTLE CHANGE EXPECTED THROUGH MID WEEK. ...HISPANIOLA... NW TO N WINDS ALOFT PERSIST ACROSS HISPANIOLA BETWEEN AN UPPER ANTICYCLONE TO THE WEST AND A AN UPPER TROUGH TO THE EAST. WITH RELATIVELY HIGH DEEP LAYER MOISTURE IN PLACE...THIS PATTERN FAVORS LOW TOPPED AND FAST MOVING SHOWERS AND THUNDERSTORMS FAVORING THE HIGHLAND PORTIONS OF WESTERN DOMINICAN REPUBLIC AND EASTERN HAITI DURING THE AFTERNOON AND EVENING HOURS OVER THE NEXT COUPLE OF DAYS. ATLANTIC OCEAN... A COLD FRONT IS MOVING SE ACROSS THE GULF STREAM WATERS OFF NE FLORIDA THIS MORNING AS THE SUPPORTING MAIN MID/UPPER ENERGY PUSHES OFF THE MID ATLANTIC COAST TO THE NORTH. FARTHER SOUTH...A STATIONARY FRONT PERSISTS FROM BERMUDA TO THE NW BAHAMAS. A FEW MODERATE SHOWERS AND THUNDERSTORMS PERSIST SOUTH OF THE STATIONARY FRONT...MAINLY ACROSS THE CENTRAL BAHAMAS. THE COVERAGE AND INTENSITY OF THESE SHOWERS AND THUNDERSTORMS AS DIMINISHED OVER THE PAST COUPLE OF DAYS AS TRADE WIND CONVERGENCE HAS TAPERED OFF. THE COLD FRONT WILL EVENTUALLY MERGE WITH THE STATIONARY BOUNDARY AND REACH FROM NEAR BERMUDA TO THE NW BAHAMAS AND SOUTH FLORIDA BY LATE TODAY. STRONG HIGH PRES BUILDING OFF THE CAROLINAS WILL ALLOW FRESH TO STRONG NE WINDS RESULTING IN VERY ROUGH AND BUILDING SEAS W OF 65W. FARTHER EAST...AN UPPER LOW REMAINS IN PLACE OVER 22N57W WITH AN ADJOINING UPPER TROUGH EXTENDING ACROSS THE EASTERN CARIBBEAN TO N CENTRAL VENEZUELA. SW FLOW ALOFT ASSOCIATED WITH THIS UPPER TROUGH IS SHEARING CONVECTION ALONG THE TROPICAL WAVE AXIS AS WELL AS INHIBITING THE WESTERN PROGRESSION OF THE TROPICAL WAVE. SCATTERED MODERATE CONVECTION IS ONGOING NEAR THE CENTER OF THE UPPER LOW AS WELL...FROM 22N TO 25N BETWEEN 52W AND 57W. A DRIER AIRMASS PREVAILS ACROSS THE SUBTROPICAL ATLC WATERS EAST OF 45W...BEHIND AN EARLY SEASON COLD FRONT OVER THE EASTERN ATLC THAT PENETRATED AS FAR SOUTH AS 16N BEFORE EVENTUALLY DISSIPATING LATE YESTERDAY. A COLLECTION OF VERY WEAK LOW PRES AREAS ARE PULSING ALONG A DISORGANIZED MONSOON TROUGH OVER THE DEEP TROPICS OF THE EASTERN ATLC. A QUASI-STATIONARY 1014 MB LOW PRES WAS ANALYZED NEAR 09N37W. THIS HAD BEEN CONSIDERED A TROPICAL WAVE ON EARLY CHARTS...BUT HAS WEAKENED AND MOSTLY STALLED IN PLACE OVER THE PAST COUPLE OF DAYS AS DRIER AIR MOVED INTO THE TROPICAL AREA OF THE CENTRAL ATLC ASSOCIATED WITH THE EARLIER COLD FRONT. TRADE WINDS ARE EXPECTED TO INCREASE SLIGHTLY OVER THE CENTRAL AND EASTERN ATLC THROUGH MID WEEK AS HIGH PRES BUILDS N OF THE AREA. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ CHRISTENSEN