East Pacific Tropical Weather Discussion

000
AXPZ20 KNHC 261607
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC THU NOV 26 2009

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 
1415 UTC.

...ITCZ...
AXIS ANALYZED ALONG 08N77W TO 07.5N86W TO 06N91W TO 05N99W TO 
08N116W TO 08N130W TO 06N140W. ISOLATED MODERATE CONVECTION WAS 
WITHIN 90 NM OF AXIS E OF 93W. SCATTERED MODERATE ISOLATED 
STRONG CONVECTION WAS WITHIN 180 NM EITHER SIDE OF AXIS W OF 
113W.   

...DISCUSSION...
WEAKENING HIGH PRESSURE PREVIOUSLY CENTERED N OF THE AREA NEAR 
33.5N131.5W APPEARS TO HAVE COLLAPSED AND IS NOW PART OF HIGH 
PRES RIDGE ACROSS CENTRAL PACIFIC BRIDGING ACROSS AN APPROACHING 
COLD FRONT. HOWEVER...THE PRESSURE GRADIENT BETWEEN THIS 
COLLAPSED HIGH AND LOW PRESSURE IN THE VICINITY OF THE ITCZ HAS 
MAINTAINED A SHRINKING 20-25 KT WIND FIELD ACROSS THE WESTERN 
PORTION OF THE FORECAST AREA FROM 24N S TO THE ITCZ AND W OF 
127W. ALSO...SUFFICIENT GRADIENT PERSISTS ACROSS THE NRN GULF OF 
CALIFORNIA FOR 20-25 KT NLY WINDS WITHIN THE GULF N OF 28N THIS 
MORNING...BUT ARE EXPECTED TO DIMINISH BY LATE 
AFTERNOON/EVENING. THE APPROACHING COLD FRONT IS FORECAST TO 
SLIDE SE INTO THE FAR N PORTION OF THE AREA THIS AFTERNOON.  
BEHIND THIS COLD FRONT...STRONG HIGH PRESSURE...1033 MB 
CURRENTLY NEAR 38N149W...WILL SHIFT EASTWARD AND EVENTUALLY PASS 
N OF THE AREA BY SATURDAY AS THE COLD FRONT GRADUALLY WEAKENS 
INTO A SHEAR AXIS. THIS WILL AGAIN EXPAND THE AREA OF FRESH TO 
STRONG TRADES ACROSS THE AREA N OF 10N AND WEST OF 127W...WHILE 
NLY WINDS TO 30 FT WILL PREVAIL N OF 24N W OF 117W. LONG PERIOD 
NW SWELLS CURRENTLY DOMINATE MOST OF THE AREA W OF 
100W...YIELDING SEAS OF 8 TO 12 FT...AND UP TO 15 FT WITH THE 
FRONT ACROSS FAR NW PORTIONS. A NEW PULSE OF NW SWELL ASSOCIATED 
WITH THIS COLD FRONT IS CURRENTLY MOVING INTO THE FAR NW 
PORTIONS OF THE AREA. THIS PULSE WILL SPREAD SOUTH AND SOUTHEAST 
OVER THE NEXT 48 HOURS...AND YIELD SEAS OF 10 TO 15 FT W OF 
115W...WITH THIS NW SWELL MIXING WITH NE WIND SWELL GENERATED 
FROM THE STRONG TRADES...RESULTING IN CONFUSED SEAS ACROSS  
THE WESTERN PORTION N OF 10N. 

...GAP WINDS...
A 0330 ASCAT PASS LAST NIGHT WAS JUST TO THE WEST OF THE GULF OF 
TEHUANTEPEC AND INDICATED 30 KT WINDS. GALE CONDITIONS OCCURRING 
NOW ARE EXPECTED TO GRADUALLY INCREASE TODAY AND REACH 50 
KT...OR STORM CONDITIONS BY 00Z TONIGHT...AND CONTINUE THROUGH 
NEARLY 00Z SAT...WITH GALES FORECAST TO CONTINUE THROUGH AT LEST 
MIDDAY SATURDAY.  

EASTERLY TRADES IN THE W CARIBBEAN WILL CONTINUE TO FUNNEL 
THROUGH THE GULF OF PAPAGAYO AND DOWNSTREAM OF THE GULF OF 
PAPAGAYO TO NEAR 89W FOR THE NEXT FEW DAYS MAINTAINING FRESH TO 
STRONG WINDS THERE. 

$$

STRIPLING