East Pacific Tropical Weather Discussion

000
AXPZ20 KNHC 100326
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC WED FEB 10 2010

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...

AXIS ANALYZED ALONG 04N77W TO 03N82W TO 05N92W TO 06N111W TO 
05N128W TO 07N134W TO 03N140W.  ISOLATED TO SCATTERED MODERATE 
CONVECTION WAS OCCURRING WITHIN 150 NM N AND 60 S OF AXIS W OF 
115W. SCATTERED MODERATE CONVECTION WAS OCCURRING WITHIN 60 NM 
EITHER SIDE OF LINE FROM 07N85W TO 02.5N82W.

...DISCUSSION...

WELL DEFINED MIDDLE TO UPPER LEVEL CYCLONIC VORTEX AT 35N122W 
DRIFTING SE HAS DEEP LAYER TROUGH EXTENDING S THEN SW TO 
WEAKENING/FILLING MID LEVEL LOW NEAR 17N137W...THEN CONTINUES SW 
THEN W TO 11N147W. THIS WEAKENING MID LEVEL LOW CONTINUED TO DIG 
S INTO THE BACKSIDE...AND BECOME ABSORBED...INTO A BROAD UPPER 
TROUGH PERSISTING ACROSS THE AREA FOR THE PAST SEVERAL DAYS S OF 
30N BETWEEN 123W AND 145W. THIS NEW MERGED TROUGH IS FORECAST TO 
MOVE ESE DURING THE NEXT FEW DAYS...WITH THE VORTEX MOVING INTO 
SRN CALIFORNIA TO BECOME DECOUPLED AND EXIT TO THE E...WHILE THE 
SRN PORTIONS DIGS INTO THE TROPICAL EPAC THROUGH THU...THEN 
WEAKENS AND MOVES ENE INTO MEXICO OVER THE WEEKEND. CURRENTLY... 
A VERY BROAD ZONE OF SWLY FLOW ALOFT E OF THIS TROUGH WAS 
ADVECTING MULTILAYERED MID AND UPPER CLOUDS FROM NEAR 
130W...NEWD TO BAJA CALIFORNIA AND MUCH OF OLD MEXICO...WITH JET 
CORE SPEEDS OF 150-170 KT DEPICTED IN SATELLITE DERIVED WINDS.  
N OF 30N...A WELL SUPPORTED SURFACE TROUGH MOVING INTO THE 
CENTRAL CALIFORNIA COAST IS EXPECTED TO COUPLE WITH ADVECTED 
MOISTURE TO PRODUCE SIGNIFICANT RAINS N OF 25N WED NIGHT AND 
THU. 

UPPER LEVEL ANTICYCLONIC FLOW E OF 120W WILL KEEP FAIR WEATHER 
CONDITIONS ACROSS THIS REGION...WHILE A DEEP MID LEVEL TROUGH 
ACROSS CENTRAL AMERICA ALONG 83W WILL COMBINE TO PRODUCE 
SUBSIDING AIR S OF 16N E OF 105W NEXT 24 HOURS. 

ELSEWHERE AT THE SURFACE...
HIGH PRES CENTER 1025 MB NEAR 30N136W HAS BEEN PRESSING AGAINST 
BAJA CALIFORNIA COAST PROMPTING FRESH NW WINDS WITHIN 120 NM OF 
COAST THROUGHOUT THE DAY...BUT THE INFLUENCE OF THE DEEP LAYERED 
LOW OFF THE COAST OF SRN CALIFORNIA APPEARS TO BE BACKING WINDS 
MORE W TO SW AND DIMINISHING THE FLOW ALONG THE BAJA COAST. THE 
DIGGING MID LEVEL LOW ACROSS W PORTIONS OF THE AREA IS ALLOWING 
THE SURFACE RIDGE TO THE NW TO SHIFT INTO N PORTIONS OF THE 
AREA...WITH THE ASSOCIATED PRES GRADIENT YIELDING A VERY BROAD 
ZONE OF FRESH TO STRONG NE TRADES. ALTHOUGH HINTED AT RECENTLY 
BE MODEL GUIDANCE...AN 1834 UTC ASCAT PASS REVEALED A ZONE OF 
NEAR GALE FORCE WINDS N OF THE ITCZ FROM 06N TO 12N BETWEEN 122W 
AND 132W...AND A GALE WARNING HAS BEEN ISSUED FOR THIS AREA. 
THIS AREA OF GALES MAY PULSE DURING THE NEXT FEW DAYS BUT SHOULD 
GRADUALLY SLIDE E AND NE AS THE ITCZ LIFT N ACROSS PORTIONS E OF 
125W...AND MAINTAINS A VERY TIGHT PRES GRADIENT. THIS LARGE AREA 
OF FRESH TO STRONG TRADES WILL PERSIST THROUGH T36-48 HOURS AND 
COMBINE WITH THE PREVAILING LONG PERIOD NW SWELL TO PRODUCE SEAS 
OF 15 TO 18 FT AND POSSIBLY HIGHER WITHIN 5 TO 6 DEGREES N OF 
THE ITCZ BETWEEN 115W AND 130W THROUGH 48 HOURS. VARIOUS 
SCENARIOS HAVE BEEN DEPICTED BY THE MODELS WITH THIS EVOLVING 
SITUATION...AND HAVE OPTED TO GO WITH THE ECMWF/UKMET/CANADIAN 
CONSENSUS.

GAP WINDS...
A STRONG COLD FRONT IN GULF OF MEXICO HAS REACHED THE YUCATAN 
PENINSULA AND WILL FORCE STRONG NLY WINDS ACROSS CHIVELAS PASS 
INTO GULF OF TEHUANTEPEC WITHIN THE NEXT 6 HRS AND BLAST INTO 
THE EPAC AS GALES. ALTHOUGH INITIALLY THIS GALE WARNING WAS 
EXPECTED TO BE SHORT LIVED...AS THE COLD FRONT MOVES QUICKLY E 
AND WINDS ACROSS THE ISTHMUS WILL VEER BEFORE THE END OF 
FORECAST PERIOD. HOWEVER...RECENT GUIDANCE SUGGESTS THE GALES 
MAY CONTINUE 24-36 HOURS. THE COLD FRONT WILL REACH THE NW 
CARIBBEAN AND PROMOTE FRESH GAP WINDS ACROSS THE GULF OF 
PAPAGAYO LASTING THROUGH THE ENTIRE FORECAST PERIOD.

STRONG CARIBBEAN TRADES ALONG THE NW COAST OF COLOMBIA WILL 
ENHANCE NORTHERLY FLOW INTO GULF OF PANAMA WITH FRESH N WINDS 
STARTING WED NIGHT AND CONTINUE THROUGH LATE FRI. 

FOR ADDITIONAL INFORMATION PLEASE VISIT 
HTTP://WWW.HURRICANES.GOV/MARINE

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STRIPLING