000 AXPZ20 KNHC 120959 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC SAT APR 12 2008 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... ITCZ AXIS IS CENTERED ALONG 7N83W 4N90W 5N103W 2N115W 2N125W 3N140W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION EXISTS FROM 2N-6N BETWEEN 89W-92W...AND WITHIN 60 NM EITHER SIDE OF THE AXIS BETWEEN 109W-112W. ...DISCUSSION... W OF 110W... A NEARLY STATIONARY MID/UPPER LEVEL CYCLONE IS NEAR 22N126W WITH AN ASSOCIATED TROUGH EXTENDING SSW TO 13N129W. A MID/UPPER LEVEL TROUGH OVER THE SRN GREAT PLAINS EXTENDS SW INTO THE REGION ACROSS NRN BAJA AS A SHEAR AXIS TO 28N119W AND SW FROM THERE TO THE CYCLONE NEAR 22N126W. THE UPPER LEVEL FLOW IS CYCLONIC FROM 14N-28N BETWEEN 118W-135W...BUT BECOMES ANTICYCLONIC N OF 28N AND W OF 135W. A JET STREAM BRANCH ROUNDS THE BASE OF THE TROUGH FROM 14N130W ENE TO 15N120W TO 19N110W AND CONTINUES NEWD TO ACROSS CENTRAL MEXICO. SATELLITE-DERIVED WINDS INDICATE MAXIMUM WINDS OF 60-70 KT ASSOCIATED WITH THIS JET. AMPLE UPPER LEVEL MOISTURE IN THE FORM OF HIGH LEVEL CLOUDS IS BEING TAPPED FROM THE DEEP CENTRAL TROPICS BY THE JET AND CHANNELED NEWD TOWARDS NRN AND CENTRAL MEXICO...AND TO ALONG THE FAR WRN GULF OF MEXICO. WATER VAPOR IMAGERY IS DEPICTING MODERATE TO STRONG SUBSIDENCE IN THE AREA OF UPPER CYCLONIC FLOW DUE TO THE CYCLONIC CIRCULATION NEAR 22N126W...AND ALSO WITHIN 120 NM EITHER SIDE OF THE SHEAR AXIS. ANTICYCLONIC FLOW W OF 135W IS DUE TO BROAD MID/UPPER RIDGING NOTED JUST W OF THE REGION WITH EXTENSIVE MID/UPPER CLOUDINESS RIDING OVER THE RIDGE AND TOWARDS THE REGION ...BUT ERODING ALONG 140W AS IT ENCOUNTERS DRY AIR RESULTING FROM THE MODERATE TO STRONG SUBSIDENCE THAT IS PRESENT. MID/UPPER LEVEL SW FLOW IS SEEN IN THE VICINITY OF THE ITCZ W OF 120W. NWP MODELS CONTINUE TO SUGGEST THAT A COLD FRONT WILL PUSH INTO THE FAR NW PORTION OF THE AREA ON SUN FOLLOWED BY STRONG HIGH PRES AND A RESULTING TIGHTENING PRES GRADIENT. THE FRONT STARTS TO WEAKEN LATE SUN INTO MON AS THE HIGH BUILDS SEWD INTO THE AREA. THIS WILL ALLOW FOR NE WINDS TO INCREASE TO 25-30 KT BY SUN EVENING OVER THESE WATERS WITH SEAS BUILDING TO 14 FT. THE HIGH THEN WEAKENS BY WED WITH WINDS AND SEAS SLOWLY DIMINISHING...BUT A TIGHT GRADIENT OVER THE FAR NE PART WILL ACCOUNT FOR NW FLOW OF 20-25 KT NEAR NRN BAJA CALIFORNIA AND SRN CALIFORNIA WITH SEAS 8-12 FT IN NW SWELL. THESE CONDITIONS SHOULD SUBSIDE BY THE END OF THE WEEK. AT THE SURFACE...A RIDGE AXIS EXTENDS THROUGH 32N128W TO 23N119W TO NEAR 17N112W. HIGH PRES IS PRESENT N OF 12N W OF 112W. A WEAK SURFACE TROUGH DRIFTING W EXTENDS FROM 8N122W TO 3N125W...AND IS ENHANCING ITCZ CONVECTION SOME BETWEEN 122W-126W. E OF 110W... BROAD MID/UPPER LEVEL ANTICYCLONIC FLOW GENERALLY COVERS THIS AREA WITH A MEAN RIDGE AXIS EXTENDING FROM NRN S AMERICA WNW THROUGH 7N82W 10N90W 12N104. A VERY MOIST FLOW PATTERN THROUGH ALL LEVELS OF THE ATMOSPHERE FOUND TO THE E OF 95W IS SUSTAINING NUMEROUS SHOWERS AND TSTMS THERE WITH THE ADDITIONAL ENHANCEMENT PROVIDED BY A 1006 MB LOW NEAR 8N88W. EXPECT THIS ACTIVITY TO CONTINUE THROUGH THE 24-36 HRS AS THE LOW MOVES SLOWLY WWD. GAP WINDS...LATEST NWP MODELS SUGGEST THAT WINDS IN THE GULF OF TEHUANTEPEC WILL INCREASE TO N AT 20 KT BEGINNING ON SUN AND INCREASE TO GALE FORCE BY EARLY SUN EVENING...POSSIBLY REACHING UP TO 40 KT...AS A RATHER STRONG COLD FRONT FOR THIS TIME OF YEAR PUSHES FAR S THROUGH MEXICO AND INTO THE NW CARIBBEAN LATE SUN INTO MON. WITH VERY PRONOUNCED HIGH PRES ESTABLISHING OVER SE MEXICO AND THE WRN GULF PROVIDING PROLONGING THE SURGE OF STRONG NLY WINDS...EXPECT GALE WINDS THROUGH THE GULF OF TEHUANTEPEC TO LAST INTO WED. THE COMBINATION OF THE LOW NEAR 8N88W AND STRONG HIGH PRES BUILDING S INTO THE NW CARIBBEAN IS EXPECTED TO BRING SURGES OF NE 20-25 KT WINDS THROUGH THE GULF OF PAPAGAYO BEGINNING MON MORNING AND LASTING THROUGH AT LEAST THU. $$ AGUIRRE