000 AXNT20 KNHC 181049 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0900 UTC. ...SPECIAL FEATURES... THE COMBINATION OF STRONG HIGH PRESSURE ACROSS EASTERN MEXICO... LOW 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. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM THE AFRICAN COAST NEAR 12N16W TO 11N20W TO LOW PRES 1011 MB NEAR 12N29W TO LOW PRES 1012 MB NEAR 10N37W TO 08N45W. THE ITCZ CONTINUES FROM 08N45W TO 05N53W. SCATTERED MODERATE CONVECTION IS NOTED WITHIN 120 NM N OF MONSOON TROUGH AXIS BETWEEN 26W AND 29W...AND WITHIN 120 NM N OF ITCZ BETWEEN 45W AND 48W. ...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 THROUGH THE NORTHERN GULF OF MEXICO. UPPER FLOW IS TURNING MORE ZONAL ACROSS THE WESTERN GULF...AND SURFACE ARE VEERING EASTERLY ALLOWING THE FRONT TO SLOW 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. 1009 MB LOW PRES IS ANALYZED ALONG THE COAST IN THE BAY OF CAMPECHE NEAR CIUDAD DEL CARMEN AND WILL DRIFT NW TODAY...SUPPORTING GALE FORCE WINDS ALONG THE COAST OF VERACRUZ. THE TIGHT GRADIENT WILL SUPPORT FRESH TO STRONG NE TO E WINDS ACROSS THE GULF THROUGH EARLY NEXT 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 19N93W. 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 PERIODIC SHOWERS AND THUNDERSTORMS MAINLY OVER THE NW CARIBBEAN. 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 ASSOCIATED WITH AN UPPER TROUGH OVER THE FAR EASTERN CARIBBEAN SUPPORTS GENERALLY FAIR WEATHER CONDITIONS E OF 80W. 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... ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 16N54W TO 10N48W MOVING W AT 5-10 KT. 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. 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 SOUTHERN BAHAMAS. 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 SURFACE TROUGH EAST OF THE WINDWARD ISLANDS. 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 1011 MB LOW PRES WAS ANALYZED LOW PRES NEAR 12N29W...AND A 1012 MB LOW NEAR 10N37W. 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