000 AXPZ20 KNHC 270953 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC SAT MAR 27 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 0830 UTC. ...ITCZ... AXIS ANALYZED ALONG 02N77W TO 08N88W TO 08N109W TO 05N125W TO 03N134W TO 03N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION WAS OCCURRING WITHIN 180 NM N AND 90 NM S OF AXIS W OF 98W. ...DISCUSSION... SUBTROPICS... A WEAK UPPER TROUGH OVER THE NW WATERS REMAINS SOMEWHAT CUT OFF FROM THE MEAN FLOW...NESTLED S OF A SHARP MID TO UPPER LEVEL RIDGE N OF 30N AND ALONG 131W. A L/W TROUGH ACROSS THE N PAC HAS CROSSED 150W AND WILL MOVE E DURING THE NEXT 24-36 HOURS AND REINFORCE THE WEAK UPPER TROUGH...WITH THE MERGED FEATURE TRACKING E TO 122W AND N OF 25N BY 1200 UTC SUN. THE RELATIVELY ZONAL SUBTROPICAL JET AXIS REMAINS W-SW TO E-NE ACROSS THE AREA EXTENDING FROM 16N140W INTO SRN BAJA CALIFORNIA AND WILL BE FORCED SE TO 10N140W TO CENTRAL BAJA BY SUN EVENING DUE TO THE ABOVE UPPER TROUGH. A WEAK COLD FRONT ASSOCIATED WITH THE DEEP LAYERED TROUGH WILL MOVE INTO NW WATERS SAT NIGHT AND WILL BRING A NEW SURGE OF NW SWELL INTO THE FORECAST AREA WITH SEAS REACHING AS HIGH AS 16 FT BY SUN AFTERNOON. THE PRESSURE GRADIENT BETWEEN THE ITCZ AND A 1026 MB HIGH LOCATED N OF AREA NEAR 38N127W IS MAINTAINING A BROAD AREA OF FRESH TO STRONG TRADE WINDS GENERALLY FROM 06N TO 22N AND W OF 125W...WHERE SEAS ARE RUNNING 8 TO 11 FT IN MIXED NE AND NW SWELL. THE HIGH PRES CENTER WILL WEAKEN SAT AND SHIFT SE AHEAD OF THE FRONT MOVING INTO THE NW WATERS. THIS WILL SIGNIFICANTLY 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 1026 MB HIGH AND LOWER PRES ALONG THE SIERRA NEVADA AND THE SIERRA MADRE OCCIDENTAL WILL MAINTAIN WINDS OF 20-25 KT FROM OFFSHORE OF SOUTHERN CALIFORNIA TO ALONG THE WEST COAST OF THE NORTHERN BAJA PENINSULA THROUGH LATE MORNING...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 SAT EVENING AND CONTINUE THROUGH THE FORECAST PERIOD. DOWNSLOPE FLOW AND FUNNELING WINDS COULD PRODUCE AREAS OF NLY WINDS TO 30 KT WITHIN THE GULF OF CALIFORNIA TONIGHT THROUGH SUN NIGHT...WITH SEAS BUILDING TO AROUND 8 FT. TROPICS... AFTER ENTERING SRN BAJA CALIFORNIA...WITH SUBTROPICAL RIDGE EXTENDS E ACROSS THE GULF OF MEXICO BETWEEN 23N AND 28N WITH WEAKENING WLYS ALOFT S TO 15N. TO THE S OF THIS...DEEP AND ACTIVE CNVTN ACROSS NRN S AMERICA AND ALONG THE EPAC ITCZ CONTINUES TO MAINTAINS A NARROW UPPER LEVEL RIDGE FROM SE VENEZUELA W-NW TO THE EPAC NEAR 11N92W THEN W-SW ALONG THE ITCZ AT 130W. TO THE NW LIES A BROAD NEGATIVELY TILTED UPPER TROUGH FROM 16N136W TO 04N134W. A LARGE POOL OF ABUNDANT MOISTURE IS CONVERGING ALONG BOTH SIDES OF THE ITCZ BETWEEN 105W AND 135W...YIELDING SCATTERED MODERATE ISOLATED STRONG CONVECTION INDICATED ABOVE. WAVE/PERTURBATIONS WERE MOVING W ALONG THE ITCZ AND LOCATED ALONG 110W AND 125/126W. MID TO UPPER CONVERGENCE ACROSS THE ITCZ BETWEEN 90W AND 97W WAS MAINTAINING LLVL DIFFLUENT FLOW...AND LIMITING ISOLATED CONVECTION TO E OF 90W. GAP WINDS... A PARTIAL 0044 UTC ASCAT PASS SUGGESTED WINDS THROUGH THE GULF OF TEHUANTEPEC HAD DIMINISHED TO 20-25 KT...POSSIBLY TO ONLY 20 KT...AND THE NLY FLOW IN EXCESS OF 20 KT SHOULD SHUT DOWN AT OR VERY SHORTLY AFTER 1200 UTC AS RETURN FLOW IN THE GULF OF MEXICO HAS ALREADY COMMENCED. STRONG NLY WINDS ARE EXPECTED TO BLAST THROUGH TEHUANTEPEC AGAIN SUNDAY EVENING AS ANOTHER COLD FRONT MOVES ACROSS THE GULF OF MEXICO...AND COULD YIELD GALE FORCE WINDS IN THE GULF OF TEHUANTEPEC BY 1200 UTC MON. THE COLD FRONT THAT BROUGHT STRONG N WINDS TO TEHUANTEPEC HAS STALLED ACROSS THE YUCATAN PENINSULA AND CHANNEL AND WILL NOT REACH NEAR THE GULF OF PAPAGAYO. HOWEVER IT HAS FORCED A WEAK RIDGE AXIS SOUTHWARD INTO THE NW CARIBBEAN AHEAD OF IT. AS A RESULT...THE PRES GRADIENT HAS BUILT BETWEEN THE RIDGE AXIS AND LOW PRES OVER COLOMBIA. THIS WILL INDUCE PULSING GAP WINDS THROUGH THE GULF OF PAPAGAYO BETWEEN 20 AND 25 KT THROUGH MON MORNING WITH THE ASSISTANCE OF NOCTURNAL DRAINAGE FLOW. SIMILARLY...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 $$ STRIPLING