000 AXPZ20 KNHC 080935 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC THU APR 08 2010 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0915 UTC. ...ITCZ... AXIS IS CENTERED ALONG 6N78W 7N92W 6N104W 4N111W 3N125W 3N140W. SCATTERED MODERATE TO STRONG CONVECTION IS S OF THE AXIS BETWEEN 105W-110W. SCATTERED MODERATE CONVECTION IS WITHIN 120 NM N OF THE AXIS BETWEEN 131W-135W. ...DISCUSSION... A MID/UPPER LEVEL TROUGH EXTENDS FROM SRN CALIFORNIA SW TO TO A WEAK ELONGATED CYCLONIC CIRCULATION NEAR 26N125W MOVING E 15 KT...THEN CONTINUES S TO 18N125W AND SW TO 12N129W. TO THE W OF CYCLONIC CIRCULATION...A SHORTWAVE RIDGE IS MOVING EWD KICKING THE CIRCULATION EWD. WESTERLIES ALOFT DOMINATE MUCH OF THE AREA S OF THESE FEATURES...WITH A TROPICAL JET STREAM BRANCH DIVING SE INTO THE AREA FROM 21N140W TO 14N131W...THEN CONTINUING NEWD THROUGH 16N120W TO 20N112W TO ACROSS CENTRAL MEXICO AND WELL TO THE ACROSS THE CENTRAL U.S. AHEAD OF A DEEP LAYER TROUGH. BROAD MID/UPPER LEVEL RIDGING THAT THE JET STREAM MAKES ITS DIVE SEWD IS JUST ENTERING THE SW PORTION OF THE AREA IS BEING NUDGED EWD BY A LONG WAVE TROUGH WELL W OF THE REGION. ACROSS THE THE DEEP TROPICS...ACTIVE CONVECTION ALONG THE ITCZ IS MAINTAINING UPPER LEVEL RIDGING ALIGNED ROUGHLY ALONG 7N WITH AN ASSOCIATED ANTICYCLONE NEAR 7N104W. WITH THIS IN PLACE AND TROUGHS PASSING TO THE N...EXPECT CONVECTION NEAR THE ITCZ TO REMAIN PRETTY ACTIVE W OF ABOUT 97W THROUGH AT LEAST THE NEXT 48 HRS. IN ADDITION...DIFFLUENCE ALOFT OVER THE ITCZ SECTION W OF 137W WILL SUPPORT ENHANCED CONVECTION THERE. OVER THE EASTERN PORTION OF THE AREA...A WEAK MID/UPPER LEVEL TROUGH EXTENDS FROM NEAR GUATEMALA SW TO NEAR 8N93W. THE TROUGH IS SLIGHTLY ENHANCING ITCZ CONVECTION BETWEEN 88W-92W. CONVECTIVE ACTIVITY REMAINS RATHER SUPPRESSED OVER THIS PORTION OF THE AREA DUE TO AN ABUNDANCE OF MODERATE SUBSIDENCE AND ASSOCIATED DRY CONDITIONS EVIDENT ON EITHER SIDE OF THE TROUGH. A WEAK MID/UPPER LEVEL CYCLONIC CIRCULATION DRIFTING W IS NEAR THE EQUATOR AT 93W...BUT NOT PRODUCING ANY CONVECTION DUE TO DRY AIR WRAPPED INTO ITS CIRCULATION. AT THE SURFACE...A RIDGE STRETCHES INTO THE AREA FROM 30N135W SE TO 23N124W TO 18N115W WITH THE PARENT HIGH CENTER OF 1041 MB WELL N OF THE AREA NEAR 41N148W. 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 8N AND W OF 122W. A TIGHT PRES GRADIENT BETWEEN THE AFOREMENTIONED RIDGE AND TROUGHING OVER THE SIERRA MADRE OCCIDENTALS IS LEADING TO A SMALL AREA OF NW-N WINDS TO 20 KT ALONG THE W COAST OF THE BAJA PENINSULA FROM 24N-28N AS WAS EVIDENT IN A HIGH RESOLUTION ASCAT PASS FROM 0244 UTC LAST NIGHT. THIS GRADIENT IS ALSO RESPONSIBLE FOR NW WINDS OF 20-25 KT THROUGH THE GULF OF CALIFORNIA FROM 25N TO 28N...WHERE SEAS ARE REACHING CLOSE TO 8 FT. THESE WINDS ARE FORECAST TO WEAKEN TO LESS THAN 20 KT BY LATE TONIGHT. THE HIGH CENTER NEAR 41N148W 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. SEA STATE ANALYSIS FROM THE NIGHT REVEALED A 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 SRN SECTION 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 14 FT IN A N SWELL) LINGERING IN THE FAR NE SECTION. GAP WINDS... FRESH TO STRONG TRADES OVER THE CARIBBEAN WATERS 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 OCCURRENCES MAINLY IN THE EARLY MORNING HOURS DUE TO ENHANCED NOCTURNAL DRAINAGE FLOW. A COLD FRONT SWEEPING THROUGH THE WESTERN GULF OF MEXICO WILL BRING AND ONSET OF N-NE 20 KT WINDS INTO THE GULF OF TEHUANTEPEC BEGINNING LATE TONIGHT. THESE WINDS ARE FORECAST TO EXPAND IN AREAL COVERAGE S TO 12N AND BETWEEN 94W-97W BY LATE FRI NIGHT WITH SEAS POSSIBLY BUILDING UP TO 9 FT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ AGUIRRE