000 AXPZ20 KNHC 271525 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC SAT MAR 27 2010 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1500 UTC. ...ITCZ... THE ITCZ AXIS IS ANALYZED ALONG 05N77W TO 06N85W TO 04N100W TO 06N120W TO 03N140W. CLUSTERS OF MODERATE TO STRONG CONVECTION ARE OCCURRING FROM 02N TO 05N BETWEEN 126W AND 136W. SCATTERED MODERATE CONVECTION IS WITHIN AROUND 200 NM N OF AXIS FROM 110W TO 120W. ...DISCUSSION... SUBTROPICS... A WEAK UPPER-LEVEL TROUGH IS OVER THE NW WATERS EXTENDING FROM 31N131W TO 22N140W. A LONG WAVE TROUGH ACROSS THE NE PACIFIC IS APPROACHING 140W AND WILL REINFORCE THE WEAK UPPER TROUGH... WITH THE MERGED FEATURE TRACKING E TO 122W AND N OF 25N BY 1200 UTC SUN. A JET-STREAM BRANCH REMAINS ACROSS THE AREA EXTENDING FROM 17N140W TO S-CENTRAL BAJA CALIFORNIA INTO NORTHERN MEXICO. A WEAK COLD FRONT ASSOCIATED WITH THE DEEP LAYERED TROUGH WILL MOVE INTO NW WATERS THIS EVENING BRINGING A NEW SURGE OF NW SWELL INTO THE FORECAST AREA WITH SEAS REACHING AS HIGH AS 17 FT BY SUN MORNING. THE PRESSURE GRADIENT BETWEEN THE ITCZ AND A 1024 MB HIGH LOCATED N OF AREA NEAR 35N125W IS MAINTAINING A BROAD AREA OF FRESH TO STRONG TRADE WINDS GENERALLY FROM 06N TO 20N AND W OF 125W... WHERE SEAS ARE RUNNING 8 TO 12 FT IN MIXED NE AND NW SWELL. OVER THE NEXT 24 HOURS...THE HIGH PRES CENTER WILL SLIGHTLY WEAKEN AND SHIFT SE AHEAD OF THE FRONT MOVING INTO THE NW WATERS. THIS WILL REDUCE THE AREAL COVERAGE OF FRESH TO STRONG TRADES. BY SUN EVENING THIS NEXT COLD FRONT WILL BEGIN TO DISSIPATE AND THE HIGH WILL BEGIN TO MERGE WITH HIGH PRES NW OF THE FRONT... ALLOWING FOR TRADES TO BEGIN TO EXPAND AGAIN TO THE N. IN ADDITION...THE PRES GRADIENT BETWEEN THE HIGH AND LOWER PRES ALONG THE SIERRA NEVADA AND THE SIERRA MADRE OCCIDENTAL WILL MAINTAIN NW WINDS OF 20-25 KT FROM OFFSHORE OF SOUTHERN CALIFORNIA TO ALONG THE WEST COAST OF THE NORTHERN BAJA PENINSULA THROUGH LATE TODAY...THEN WEAKEN ACROSS THE PACIFIC WATERS BUT GRADUALLY INCREASE TO 20-25 KT THROUGHOUT THE ENTIRE LENGTH OF THE GULF OF CALIFORNIA FROM THIS EVENING THROUGH THE FORECAST PERIOD...WITH SEAS BUILDING TO AROUND 8 FT. TROPICS... AN ANTICYCLONIC CIRCULATION CENTERED NEAR 12N92W EXTENDS A RIDGE W-SW TO NEAR 8N123W. TO ITS W LIES A NEGATIVELY TILTED UPPER TROUGH FROM 13N134W TO AN UPPER-LEVEL LOW CENTERED NEAR 1N125W. THE DIFFLUENT PATTERN ALOFT BETWEEN THE WESTERN SIDE OF THE RIDGE AND THE NEGATIVELY TILTED UPPER TROUGH IS HELPING TO INDUCE SCATTERED TO NUMEROUS MODERATE TO STRONG CONVECTION ALONG THE ITCZ AXIS BETWEEN 126W AND 136W. A PAIR OF SFC TROUGHS ARE MOVING WWD ALONG THE ITCZ...LOCATED ALONG 111/112W AND 125/126W. SCATTERED MODERATE CONVECTION IS WITHIN AROUND 150 NM EITHER SIDE OF THE EASTERNMOST TROUGH AXIS AND N OF THE ITCZ. GAP WINDS... WINDS HAS DIMINISHED BELOW 20 KT ACROSS THE GULF OF TEHUANTEPEC. STRONG NLY WINDS ARE EXPECTED TO BLAST THROUGH THIS AREA AGAIN SUNDAY EVENING AS ANOTHER COLD FRONT MOVES ACROSS THE GULF OF MEXICO. BASED ON THE NAM MODEL...WINDS COULD REACH GALE FORCE BY MON EVENING. PULSING GAP WINDS OF 20 TO 25 KT ARE EXPECTED THROUGH THE GULF OF PAPAGAYO OVER THE NEXT 48 HOURS. WINDS ARE GREATEST DURING THE OVERNIGHT AND EARLY MORNING HOURS WITH THE ASSISTANCE OF NOCTURNAL DRAINAGE FLOW. N TO NE WINDS WILL ALSO INCREASE TO 20 KT IN THE GULF OF PANAMA BY THIS EVENING. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GR