000 AXPZ20 KNHC 082204 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC THU APR 08 2010 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2100 UTC. ...ITCZ... AXIS ALONG 06N76W TO 04N82W TO 07N101W TO 06N111W TO 09N117W TO 02N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION WAS OCCURRING WITHIN 90 NM EITHER SIDE OF AXIS BETWEEN 82W AND 97W. SCATTERED TO LOCALLY MODERATE TO STRONG CONVECTION WAS OCCURRING WITHIN 240 NM EITHER SIDE OF AXIS BETWEEN 101W AND 128W. SCATTERED MODERATE ISOLATED STRONG CONVECTION WAS OCCURRING WITHIN 150 NM EITHER SIDE OF AXIS W OF 131W. ...DISCUSSION... A MID/UPPER LEVEL S/W TROUGH EXTENDS FROM SRN CALIFORNIA SW TO TO 22N119W...THEN CONTINUES S-SE TO 16N114W THEN CUTS SW TO 09N122W. A BROAD MID/UPPER LEVEL RIDGE LIES TO THE W OF THIS TROUGH S OF 22N. A PROGRESSIVE PATTERN OF WESTERLIES ALOFT GENERALLY DOMINATES THE ENTIRE AREA N OF 14N...WITH A TROPICAL JET STREAM BRANCH ENTERING THE AREA NEAR 20N140W THEN DIVING SE THROUGH 181N121W. THE UPPER LEVEL FLOW THEN BECOMES BROADLY DIFFLUENT E OF 121W...AIDED BY PERSISTENT DEEP CONVECTION PULSING OVER THE PAST 24-48 HOURS S OF 15N AND BETWEEN 105W AND 125W. THE BROAD MID/UPPER LEVEL RIDGE IS BEING NUDGED EWD BY A BROAD LONG WAVE TROUGH WELL W OF THE REGION. ACROSS THE THE DEEP TROPICS...ACTIVE CONVECTION ALONG THE ITCZ W OF 100W CONTINUES TO HELP MAINTAIN UPPER LEVEL RIDGING ALIGNED ROUGHLY ALONG 5-9N WITH AN ASSOCIATED ANTICYCLONES NEAR 7N106W AND 07N133W. WITH UPPER LEVEL DIFFLUENCE IN PLACE AND SOME INSTABILITY PROVIDED BY MID/UPPER TROUGHS SWEEPING BY TO THE N...EXPECT CONVECTION NEAR THE ITCZ TO REMAIN FAIRLY ACTIVE W OF 95W THROUGH AT LEAST THE NEXT 48 HRS. OVER THE EASTERN PORTION OF THE AREA...A WEAK MID/UPPER LEVEL TROUGH EXTENDS FROM NEAR GUATEMALA SW TO NEAR 5N93W...AND IS PROVIDING VENTILATION TO ITCZ CONVECTION E OF 100W. A WEAK MID/UPPER LEVEL CYCLONIC CIRCULATION DRIFTING W IS JUST S OF THE EQUATOR AT 94W. AT THE SURFACE...A RIDGE STRETCHES INTO THE AREA FROM A 1039 MB HIGH NEAR 40N141W SE TO 17N112W...WITH A SMALL INDUCED ANTICYCLONE EVIDENT NEAR 14N106W. HIGH PRES COVERED THE AREA N OF 14N AND W OF 115W. THE PRES GRADIENT BETWEEN THE RIDGE AND LOWER PRES ASSOCIATED WITH THE ITCZ WAS MAINTAINING A LARGE AREA OF NE-E TRADES IN THE RANGE OF 20-25 KT N OF 5N AND W OF 125W. A TIGHT PRES GRADIENT BETWEEN THE AFOREMENTIONED RIDGE AND TROUGHING OVER THE SIERRA MADRE OCCIDENTALS HAS RESULTED IN DECREASING NW WINDS OF 20 KT THROUGH THE GULF OF CALIFORNIA FROM 24N TO 29N...WHERE SEAS HAVE JUST DROPPED BELOW 8 FT. THESE WINDS ARE FORECAST TO WEAKEN TO LESS THAN 20 KT BY THIS EVENING. THE PARENT HIGH CENTER WILL SLIDE ESE OVER THE NEXT 24 HRS IN RESPONSE TO A STRONG FRONTAL SYSTEM MAKING HEADWAY TO THE E. THE RESULTANT TIGHTENING PRES GRADIENT IS EXPECTED N OF THE AREA E OF 130W DUE TO THE HIGH INTERACTING WITH LOW PRES OVER THE WRN U.S. WILL USHER IN ANOTHER BATCH OF N-NE 20-25 KT WINDS INTO THE NE PORTION TONIGHT. THE WINDS WILL DIMINISH SOME BETWEEN 36-48 HRS AS THE GRADIENT WEAKENS. THE 1200 UTC SEA STATE ANALYSIS INDICATED AN AREA OF MAXIMUM SEA HEIGHT OF 12 FT N OF 24N BETWEEN 118W AND 125W. THIS IS IN PRETTY GOOD AGREEMENT WITH MAJORITY OF THE WAVEWATCH GUIDANCE AND LATEST NWW3 ENSEMBLE MAX SIGNIFICANT WAVE HEIGHTS. THE GUIDANCE DEPICTS THE ENTIRE AREA W OF ABOUT 110W N OF 15N...AND W OF 93W S OF 15N WITH SEAS IN THE RANGE OF 8-11 FT IN NW TO N SWELLS. AT THE SAME TIME...IT APPEARS THAT LONG PERIOD SRN HEMISPHERIC SW SWELLS ARE MERGING WITH THE NW SWELLS OVER THE SE TWO-THIRDS OF THE AREA...AND WILL CONTINUE TO DO SO THROUGH AT LEAST THE NEXT 48 HRS. PRESENT INDICATIONS ARE THAT SEAS THROUGHOUT THE AFFECTED SWELL AREAS WILL SLOWLY SUBSIDE GOING INTO THE UPCOMING WEEKEND ...WITH HIGHEST SEAS (POSSIBLY UP TO 13 FT IN A N SWELL) LINGERING IN THE FAR NE SECTION. GAP WINDS... FRESH TO STRONG TRADES OVER THE CARIBBEAN SEA CONTINUE TO FUNNEL W ACROSS THE GULF OF PAPAGAYO RESULTING IN NE 20 KT WINDS. THESE WINDS WILL PULSATE DURING THE NEXT 48 HRS WITH MAXIMUM WINDS OCCURRING MAINLY IN THE EARLY MORNING HOURS DUE TO ENHANCED NOCTURNAL DRAINAGE FLOW. A COLD FRONT CURRENTLY SWEEPING THROUGH THE NORTHWESTERN GULF OF MEXICO WILL USHER IN N TO NE 20 KT WINDS INTO THE GULF OF TEHUANTEPEC THIS EVENING. THESE WINDS ARE FORECAST TO EXPAND DOWNSTREAM IN A NARROW PLUME OVER THE NEXT 24-26 HOURS AND COULD REACH AT OR JUST BELOW GALE FORCE BRIEFLY FRI MORNING AROUND SUNRISE...WITH SEAS BUILDING UP TO 11 FT. WIND AND SEAS THERE WILL THEN GRADUALLY DIMINISH THROUGH SAT EVENING...AND THEN PULSE UP AND DOWN ACROSS A SMALL AREA N OF 14N THROUGH MON NIGHT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ STRIPLING