000 AXPZ20 KNHC 120356 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC SAT FEB 12 2011 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0315 UTC. ...ITCZ... THE INTERTROPICAL CONVERGENCE ZONE AXIS IS CENTERED ALONG 3N78W 2N90W 5N105W 6N119W 8N127W...THEN RESUMES NEAR 7N131W TO 5N140W. SCATTERED MODERATE CONVECTION IS WITHIN 120 NM N OF THE AXIS BETWEEN 119W-124W. ...DISCUSSION... ALOFT...A STRONG POSITIVELY TILTED MID TO UPPER LEVEL TROUGH AXIS EXTENDS FROM SE ARIZONA TO 26N123W TO 25N131W AND TO AN ELONGATED CYCLONIC CIRCULATION NEAR 21N138W. A SUBTROPICAL JET STREAM BRANCH WITH CORE SPEEDS IN THE RANGE OF 60-80 KT E OF THE TROUGH CONTINUES TO ADVECT MID TO UPPER LEVEL MOISTURE FROM THE DEEP TROPICS NORTHEASTWARD TO ACROSS SOUTHERN BAJA CALIFORNIA PENINSULA AND TO OVER MUCH OF NORTHERN AND CENTRAL MEXICO. TO THE N OF THE TROUGH...N OF THE AREA...A LARGE ANTICYCLONE MOVING E IS IDENTIFIED NEAR 34N127W WITH ALLOWING FOR A BROAD AREA OF ANTICYCLONIC FLOW TO EXIST OVER THIS PORTION OF THE AREA N OF THE TROUGH. MODERATE SUBSIDENCE IS KEEPING A RATHER STABLE AND DRY ATMOSPHERIC ENVIRONMENT IN PLACE OVER MUCH OF THE AREA N OF THE TROUGH AS NOTED BY THE BROKEN STRATOCUMULUS CLOUD FIELD LOCATED N OF 20N AND W OF 120W...AND CLEAR SKIES N OF 20N AND E OF 120W. OVER THE CENTRAL PORTION OF THE AREA...A MID TO UPPER LEVEL TROUGH EXTENDS FROM 20N136W SE TO 13N129W TO NEAR 9N123W. THIS TROUGH DEVIATES THE UPPER LEVEL FLOW SOME WITH THE ABOVE JET STREAM SE TOWARDS 100W RESULTING IN A ZONE OF UPPER LEVEL DIFFLUENCE FROM 3N TO 14N BETWEEN 110W-121W. WELL TO THE NW OF THE DISCUSSION IS A RATHER ROBUST DEEP LAYER TROUGH QUICKLY MOVING E. THIS TROUGH IS FORECAST TO CLIP THE FAR NW CORNER OF THE AREA LATE SAT INTO SUN AS THE BROAD AREA OF ANTICYCLONE AHEAD OF IT MOVES INLAND THE WESTERN AND CENTRAL U.S. THIS FEATURE SHOULD PUSH A COLD FRONT TOWARDS THE FAR NW CORNER OF THE AREA BY SAT EVENING...THEN ACROSS THE NW WATERS LATER ON SAT...REACHING A LINE FROM 30N135W TO NEAR 26N140W BY EARLY SUN NIGHT. S TO S WINDS INCREASE TO 20 KT N OF 27N W OF 137W IN 24 HOURS...AND TO 20 TO 25 KT N OF 27N E OF THE FRONT IN ABOUT 48 HOURS. AT THE SURFACE...A STRONG 1031 MB HIGH LOCATED N OF THE AREA NEAR 35N127W MAINTAINS ITS DOMINANCE OF THE REGION'S WEATHER REGIME FOR THE TIME BEING AS IT EXTENDS A RIDGE SE TO JUST W OF THE AREA NEAR 24N143W. THE HIGH AND RIDGE AXIS WILL MIGRATE SLOWLY E THROUGH THE NEXT 24 HOURS AS THE UPPER LEVEL ANTICYCLONE SHIFTS E. A SURFACE TROUGH ANALYZED FROM 9N130W TO 4N135W IS MOVING W ABOUT 10 KT. UPPER LEVEL DIFFLUENCE ASSOCIATED WITH THE ABOVE DESCRIBED MID/UPPER LEVEL TROUGH IS HELPING TO ENHANCE THIS ACTIVITY. THE INTERACTION BETWEEN THE SURFACE TROUGH AND THE ZONE OF HIGH PRES TO ITS N IS MAINTAIN A TIGHT PRES GRADIENT MAINLY W OF THE TROUGH WHERE NE TO E 20 TO 25 KT ARE EVIDENT WITHIN 180 W OF THE TROUGH...AND E OF THE TROUGH FROM 9N TO 15N BETWEEN 114W AND THE TROUGH. THE AREA OF STRONGER TRADES WILL GRADUALLY SHIFT NE AS THE TROUGH SLIDES WESTWARD OVER THE NEXT 48 HOURS. GAP WINDS... GULF OF TEHUANTEPEC...COLD AIR CONTINUES TO SURGE THROUGH THE CHIVELA PASS ACROSS THE ISTHMUS OF TEHUANTEPEC WITH WINDS REPORTED BY THE IXTEPEC OBSERVATIONS ALREADY IN THE GALE FORCE RANGE OF 30-40 KT...AND IN THE 25-35 KT RANGE IN THE GULF OF TEHUANTEPEC. HIGH PRES OVER SE TEXAS IS FORECAST TO INTENSIFY SAT AFTERNOON INTO SAT EVENING SENDING A REINFORCING SURGE OF COLD AIR THROUGH ISTHMUS INDUCING WINDS IN THE STORM FORCE RANGE OF 40 TO 50 KT AS THE PRES GRADIENT OVER SOUTHEASTERN MEXICO TIGHTENS. A SLIGHT LESSENING OF THE GRADIENT DURING SUN AFTERNOON SHOULD ALLOW FOR THE WINDS TO DIMINISH TO JUST UNDER THE STORM THRESHOLD. SEAS ARE FORECAST BY SOME OF THE WAVEWATCH GUIDANCE MODELS TO BUILD UP TO 18 OR 19 FT IN 30 HOURS IN THE GULF...THEN ONLY SUBSIDE SLIGHTLY IN 48 HOURS. GULF OF PAPAGAYO...WINDS WILL CONTINUE TO PULSE TO 20 KT DURING THE NEXT 24 HOURS WITH ENHANCED DRAINAGE FLOW OFF THE CENTRAL AMERICA LANDMASS. EASTERLY TRADE WINDS WILL INCREASE IN THE WESTERN CARIBBEAN SEA BY EARLY SAT WHICH WILL ALLOW FOR WINDS TO INCREASE TO 20 TO 25 KT IN THE GULF OF PAPAGAYO THROUGH THE REMAINDER OF THE FORECAST PERIOD. GULF OF PANAMA...EASTERLY TRADE WINDS IN THE CARIBBEAN SEA ARE ALREADY FILTERING THROUGH THE ISTHMUS OF CENTRAL AMERICA INTO THE FAR EASTERN PACIFIC AS NLY FLOW THROUGH THE GULF OF PANAMA AS 20 KT N WINDS. THESE WINDS ARE CONFINED TO N OF 6N BETWEEN 78W AND 80W...AND ARE EXPECTED TO CONTINUE THROUGH SUN WITH LITTLE CHANGE. GULF OF CALIFORNIA...A TIGHT PRES GRADIENT BETWEEN HIGH PRES OVER THE U.S. INTERMOUNTAIN WEST AND SURFACE TROUGHING OVER NW MEXICO IS GENERATING 20 KT NW TO N WINDS WHICH ARE FUNNELING THROUGH THE GULF OF CALIFORNIA. WINDS ARE EXPECTED TO INCREASE BY EARLY SAT TO 25 KT AS THE HIGH OVER THE U.S. STRENGTHENS SLIGHTLY...THEN DIMINISH ON THE SUN AFTERNOON. $$ AGUIRRE