000 AXPZ20 KNHC 190330 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC MON NOV 19 2012 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0300 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... MONSOON TROUGH FROM 09N84W TO 06N92W WHERE IT TRANSITIONS TO ITCZ...CONTINUING TO 08N115W TO 07N130W TO BEYOND 08N140W. SCATTERED MODERATE CONVECTION IS NOTED WITHIN 60 NM N OF AXIS BETWEEN 105W AND 111W...AND WITHIN 60 NM S OF AXIS BETWEEN 111W AND 113W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION CAN BE FOUND FROM 5.5N TO 10N W OF 130W. ...DISCUSSION... ALOFT...AN UPPER LEVEL TROUGH ENTERS THE FORECAST REGION NEAR 30N122W THEN CONTINUES SW TO NEAR 21N132W. STRONG W TO SW FLOW OF 90-100 KT...ASSOCIATED WITH A SUBTROPICAL JETSTREAM...ROUNDS THE BASE OF THE TROUGH THEN CONTINUES NE ACROSS CENTRAL BAJA CALIFORNIA AND NW MEXICO INTO THE SW CONUS. THIS JET CONTINUES TO TRANSPORT ABUNDANT MID/UPPER LEVEL MOISTURE ACROSS THE FORECAST REGION FROM THE HAWAIIAN ISLANDS TO BAJA CALIFORNIA AND NW MEXICO. SATELLITE IMAGERY SHOWS A WIDE BAND OF TRANSVERSE HIGH CLOUDS IN ASSOCIATION WITH THESE STRONG WINDS. SE OF THE TROUGH AXIS...A RIDGE COVERS MUCH OF THE REGION S OF 19N W OF 110W...AND IS CENTERED ON A WEAKENING UPPER ANTICYCLONE NEAR 12N102W THAT EXTENDS NE ACROSS SOUTH-CENTRAL MEXICO AND TEXAS AND INTO THE CENTRAL UNITED STATES. A BROAD UPPER TROUGH EXTENDS FROM A CUT-OFF LOW JUST OFF THE SE U.S. ACROSS FLORIDA AND THE NW CARIBBEAN TO CENTRAL AMERICA NEAR 15N92W. A LINGERING TUTT STRETCHES FROM 10N90W TO A CYCLONIC CIRCULATION NEAR 06N110W. SW FLOW IS NOTED E OF 90W FROM THE EQUATOR ACROSS COSTA RICA AND PANAMA INTO THE CARIBBEAN SEA. MODERATE TO STRONG SUBSIDENCE CONTINUES TO DOMINATE THE AREA E OF 100W...LIMITING CONVECTION ALONG THE MONSOON TROUGH AND THE ITCZ AXIS. AT THE SURFACE...A RIDGE CONTINUES TO BUILD ACROSS THE REGIONAL WATERS BRINGING AN INCREASE IN THE TRADE WIND FLOW...MAINLY FROM 10N TO 20N W OF 125W. EXPECT THE RIDGE TO STRENGTHEN SLIGHTLY DURING THE NEXT 24 HOURS...AND A NEW HIGH CENTER TO REFORM NEAR 29N124W BY MONDAY AFTERNOON...WHICH WILL PRODUCE A BROADER ZONE OF NE TO E WINDS 20-25 KT FROM 09N TO 20N W OF 118W AND BUILDING SEAS OF 8 TO 10 FT ACROSS THIS AREA....WITH MINOR CHANGE THROUGH TUESDAY. LONG PERIOD NW SWELL CONTINUES TO INVADE THE REGIONAL WATERS MAINLY W OF 110W AND NOW ARE RAISING SEAS TO 12 FT N OF 28N. THESE SWELLS WILL COMBINE WITH NE WIND WAVES DEVELOPING WITHIN THE TRADE WIND ZONE TO PRODUCE COMBINED SEAS OF 8 TO 10 FT. THE NEXT PULSE OF INCREASING NW SWELL IS EXPECTED TO REACH THE N WATERS EARLY WED. AS PREVIOUSLY MENTIONED...AN AREA OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS SEEN ON VISIBLE SATELLITE IMAGERY FROM 5.5N TO 10N W OF 130W ASSOCIATED WITH A WESTWARD MOVING TROUGH CURRENTLY ALONG 138W. UPPER DIFFLUENCE IS HELPING TO SUPPORT THIS CONVECTIVE ACTIVITY. GAP WINDS... PERSISTENT NORTHERLY WINDS OF 20-30 KT ARE BLOWING ACROSS THE GULF OF TEHUANTEPEC...AS A RIDGE CONTINUES TO DOMINATE THE WESTERN PART OF THE GULF OF MEXICO AND THE EASTERN SLOPES OF THE SIERRA MADRE MOUNTAINS. WINDS EXITING THE CHIVELAS PASS CONTINUE TO BE ENHANCED BY NOCTURNAL DRAINAGE FLOW ACROSS THE GULF OF TEHUANTEPEC...AND HAVE BEEN REACHING MINIMAL GALE FORCE ROUGHLY BETWEEN 0600 AND 1200 UTC EACH OF THE PAST FEW DAYS. AT 18/1800 UTC...SHIP CALL SIGN V7CG9 LOCATED NEAR 14N95W REPORTED 34 KT SUSTAINED WINDS WITH 12 FT SEAS. IN ADDITION...AN EARLIER WINDSAT PASS SHOWED SEVERAL WIND BARBS OF 30 KT. A GALE WARNING WAS ISSUED AT THIS TIME AND WILL CONTINUE IN EFFECT DURING THE FORECAST PERIOD. MARINE GUIDANCE SUGGESTS THAT THE NOCTURNAL PEAK IN WINDS WILL INCREASE TO 35-40 KT EARLY MONDAY MORNING... WITH SEAS BUILDING TO AROUND 13-14 FT DOWNSTREAM OF TEHUANTEPEC. SEE LATEST NHC HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS HSFEP2/FZPN03 KNHC FOR DETAILS ON THIS FLUCTUATING GAP WIND EVENT. PULSING OF NOCTURNAL WINDS ARE ALSO EXPECTED TO CONTINUE ACROSS THE GULF OF PAPAGAYO...WITH NOCTURNAL WINDS FORECAST TO REACH AROUND 20 KT FROM 0600 TO 1200 UTC...WITH SEAS OF 6-7 FT THROUGH AND DOWNWIND OF THE GULF. $$ GR