000 AXPZ20 KNHC 112159 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC WED NOV 11 2015 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2100 UTC. ...SPECIAL FEATURE... GULF OF TEHUANTEPEC...N-NE WINDS IN THE RANGE OF 20-25 KT ACROSS THE GULF WILL DIMINISH TO 15-20 KT THIS EVENING AS THE PRESSURE GRADIENT OVER SOUTHEASTERN MEXICO SLACKENS. THE RESPITE WILL BE SHORT-LIVED AS HIGH PRESSURE BUILDING SE BEHIND A COLD FRONT THAT SWEEPS ACROSS THE GULF OF MEXICO THU BEGINS TO SURGE SOUTHWARD ACROSS THE EASTERN SLOPES OF THE SIERRA MADRE ORIENTAL MOUNTAINS AND TOWARDS SOUTHEASTERN MEXICO SENDING STRONG NORTHERLY WINDS THROUGH THE CHIVELA PASS ON THU. THESE WINDS WILL QUICKLY INTENSIFY TO GALE FORCE THROUGH THE GULF OF TEHUANTEPEC THU NIGHT AS THE COOLER AND DENSER AIR MIXES DOWNWARD OVER VERY WARM SEA SURFACE TEMPERATURES IN THE GULF. BUILDING SEAS OF 11-12 FT ARE EXPECTED IN ASSOCIATION WITH THESE WINDS. A GALE WARNING IS ALREADY IN EFFECT FOR THE GULF THROUGH FRI. ...TROPICAL WAVES... A TROPICAL WAVE IS ALONG 103W FROM 07N TO 15N MOVING W AT 15-20 KT. SCATTERED MODERATE TO ISOLATED TSTMS CONVECTION IS NOTED ON SATELLITE IMAGERY IN ASSOCIATION WITH THIS WAVE...MAINLY FROM 07N TO 13N BETWEEN 101W AND 106W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... MONSOON TROUGH AXIS EXTENDS FROM 08N82W TO 09N103W TO 07N117W. ITCZ CONTINUES FROM 07N117W TO 09N127W TO 08N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS FROM 07N TO 13N BETWEEN 101W AND 106W...AND FROM 06N TO 08N BETWEEN 106W AND 110W. A CLUSTER OF MODERATE TO STRONG CONVECTION IS FROM 07N TO 11N BETWEEN 124W AND 127W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS FROM 04N TO 11N BETWEEN 127W AND 136W. ...DISCUSSION... THE ANTICYCLONIC CIRCULATION ASSOCIATED WITH AN ANTICYCLONE CENTERED OVER E CENTRAL MEXICO COVERS THE EASTERN PORTION OF THE AREA N OF 10N E OF 111W. BROAD UPPER TROUGHING IS W OF THE ANTICYCLONE OVER THE REMAINDER OF THE N WATERS TO 140W. MODERATE TO STRONG SW WINDS ALOFT BETWEEN THE ANTICYCLONIC FLOW AND TROUGH ARE ADVECTING AMPLE MOISTURE NE TOWARDS MUCH OF BAJA CALIFORNIA...AND TO OVER NW MEXICO TO ACROSS CENTRAL TEXAS. MODERATE SUBSIDENCE AND RESULTANT DRY AIR BEHIND THE TROUGH TO NEAR 138W IS MAINTAINING RATHER STABLE CONDITIONS ACROSS THAT PORTION OF THE AREA. A COLD FRONT...SUPPORTED BY THE UPPER TROUGH...IS CROSSING THE GULF OF CALIFORNIA AND EXTENDS FROM NEAR LOS MOCHIS MEXICO TO ACROSS SOUTHERN BAJA CALIFORNIA TO NEAR 21N115W. VERY STRONG HIGH PRESSURE OF 1038 MB IS NW OF THE AREA NEAR 37N145W WITH ITS ASSOCIATED RIDGING STRETCHING SE TO 32N129W TO 27N121W TO JUST W OF THE FRONT NEAR 21N115W. THE HIGH PRESSURE SYSTEM IS FORECAST TO MOVE SE AND WEAKEN SLIGHTLY AS IT REACHES NEAR 33N142W IN ABOUT 24 HOURS. THE PRESSURE GRADIENT BETWEEN THE HIGH PRESSURE AND LOWER PRESSURE IN THE VICINITY OF THE ITCZ CONTINUES TO SUSTAIN AN AREA OF FRESH TO STRONG WINDS N OF 12N W OF 130W... AND FROM 13N TO 26N BETWEEN 120W AND 130W. MODERATE TO FRESH WINDS PREVAIL ELSEWHERE N OF 10N AND W OF 115W. SEAS ARE IN THE 8-12 FT RANGE OVER THIS AREA BASED ON A PAIR OF ALTIMETER PASSES...A COMBINATION OF NW SWELL WITH NE WIND WAVES. THE COLD FRONT WILL DISSIPATE W OF BAJA CALIFORNIA BY THIS EVENING. THE STRONG HIGH PRESSURE RIDGING WILL SLOWLY WEAKEN THROUGH FRI. GAP WINDS... GULF OF CALIFORNIA...STRONG HIGH PRESSURE OF 1030 MB HAS SET UP OVER EASTERN CALIFORNIA WITH BROAD TIGHT RIDGING ENTRENCHED ACROSS THE GREAT BASIN REGION OF THE U.S. THIS SYNOPTIC PATTERN IS VERY FAVORABLE FOR PRODUCING A FETCH OF NW FLOW DOWNSTREAM OF CALIFORNIA. THIS IS PRESENTLY OBSERVED AS STRONG NW WINDS FUNNELING THROUGH THE GULF OF CALIFORNIA WHERE SEAS ARE BUILDING AS WELL. THE TIGHT GRADIENT WILL CONTINUE TO MAINTAIN THESE WINDS THROUGH EARLY ON THU WITH SEAS TO 9 FT...THEN BEGIN TO DIMINISH IN AREAL COVERAGE THU AFTERNOON WITH THE WINDS MORE CONFINED FROM 24N-28N WITH SEAS TO 8 FT THERE. BY LATE THU NIGHT...WINDS ARE FORECAST TO DIMINISH TO 15-20 KT WITH SEAS SUBSIDING TO AROUND THE 4-6 FT RANGE. SOME OF THE STRONG NW WIND FLOW MAY EXTEND A LITTLE FURTHER S OF THE BAJA CALIFORNIA PENINSULA TONIGHT AND THU. GULF OF PAPAGAYO...PULSING NE-E WINDS IN THE 15-20 KT RANGE ARE EXPECTED ACROSS THE GULF AGAIN TONIGHT...MAINLY BETWEEN 06-12 UTC WITH THE ASSISTANCE OF THE NOCTURNAL DRAINAGE FLOW. THESE WINDS MAY START UP AGAIN FRI NIGHT. $$ GR