East Pacific Tropical Weather Discussion

000
AXPZ20 KNHC 260959
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC THU NOV 26 2009

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 
0815 UTC.

...ITCZ...

AXIS ANALYZED FROM 09N78W TO 7.5N89W TO 06N95W TO 07.5N115W TO 
08N130W TO 6.5N140W. NUMEROUS MODERATE SCATTERED STRONG 
CONVECTION WITHIN 160 NM EITHER SIDE OF AXIS BETWEEN 116W AND 
138W. ABUNDANT CONVECTION IN THE ITCZ IS BEING ENHANCED BY 
SEVERAL LOW LEVEL PERTURBATIONS. 


...DISCUSSION...
WEAKENING HIGH PRESSURE 1023MB CENTERED N OF THE AREA NEAR 
33.5N131.5W. THE PRESSURE GRADIENT BETWEEN THIS HIGH AND LOW 
PRESSURE IN THE VICINITY OF THE ITCZ HAS MAINTAINED 20 KT WINDS 
ACROSS THE WESTERN PORTION OF THE FORECAST AREA W OF 128W. THIS 
HIGH PRESSURE WILL DISSIPATE TODAY AS A COLD FRONT SHIFTS INTO 
THE FAR N PORTION OF THE AREA. BEHIND THIS COLD FRONT...EVEN 
STRONGER HIGH PRESSURE 1033 MB CURRENTLY NEAR 36N154.5W SHIFTS 
EASTWARD AND EVENTUALLY N OF THE AREA BY SATURDAY AS THE COLD 
FRONT DISSIPATES. THIS WILL EXPAND THE FRESH TO STRONG TRADES 
ACROSS THE AREA N OF 10N AND WEST OF 117W. LONG PERIOD NW SWELLS 
HAVE SPREAD INTO THE FAR NW PORTION OF THE AREA. THESE SWELLS 
WILL SPREAD SOUTH AND EAST OVER THE NEXT 48 HOURS. BY 
SAT...THESE SWELLS WILL MIX WITH NE SWELLS GENERATED FROM THE 
STRONG TRADES RESULTING IN CONFUSED SEAS IN THE WESTERN PORTION 
N OF 10N. 

...GAP WINDS...
A 0330 ASCAT PASS WAS JUST TO THE WEST OF THE GULF OF 
TEHUANTEPEC REPORTED 30 KT WINDS. WITH THE STRONGEST AREA OF 
WINDS EXPECTED TO BE JUST TO THE EAST OF THIS PASS...IT IS 
LIKELY THAT GALE CONDITIONS ARE OCCURRING NOW. 925 MB WINDS OF 
50 KT ARE EXPECTED BY TONIGHT...AND WITH THE UNSTABLE 
STRATIFICATION OVER THE GULF OF TEHUANTEPEC...THESE WINDS WILL 
EASILY BE MIXED TO THE SURFACE. THUS...WE ARE EXPECTING MINIMAL 
STORM CONDITIONS IN THIS AREA BY TONIGHT...DECREASING TO GALE 
CONDITIONS FRI NIGHT/SAT MORNING. 

STRONG HIGH PRESSURE OVER THE NW CONUS COMBINED WITH A LOW 
PRESSURE TROUGH ALONG THE BAJA PENINSULA IS MAINTAINING A TIGHT 
PRESSURE GRADIENT RESULTING IN STRONG NORTHERLY WINDS IN THE 
NORTHERN GULF OF CALIFORNIA N OF 28N. 0500 UTC ASCAT PASS 
DETECTED 25 KT WINDS IN THIS AREA. THE HIGH PRESSURE WILL WEAKEN 
OVER THE NEXT 18 HOURS WHICH WILL RELAX THE PRESSURE GRADIENT 
AND DIMINISH THE WINDS BELOW 20 KT. 

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

$$

AL