000
AXPZ20 KNHC 080925
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC THU NOV 08 2012

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0845 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

MONSOON TROUGH FROM 09N84W TO 07N98W. ITCZ FROM 07N98W TO 
09N110W TO 05N135W TO 06N140W. SCATTERED MODERATE CONVECTION 
WITHIN 270 NM N OF AXIS BETWEEN 105W AND 112W. 

...DISCUSSION...

AN UPPER CYCLONE THAT WAS CENTERED NEAR 26N123W HAS OPENED INTO 
A TROUGH AND IS LIFTING NE AS A LONG WAVE TROUGH N OF THE AREA 
DIGS EASTWARD TOWARD THE WEST COAST OF THE UNITED STATES. 
CLUSTERS OF SHOWERS AND THUNDERSTORMS N OF 25N E OF 120W ARE 
STARTING TO DIMINISH. A WEAK COLD FRONT ASSOCIATED WITH THE 
DEEPENING FRONT EXTENDS FROM CENTRAL CALIFORNIA TO NEAR 30N140W. 
THE WESTERN PORTION OF THE FRONT WILL DISSIPATE W OF 125W AS IT 
MOVES INTO THE DISCUSSION AREA THROUGH 24 HOURS...WITH THE 
EASTERN PORTION CONTINUING THROUGH SOUTHERN CALIFORNIA AND 
MOVING INTO NORTHERN BAJA AND THE NORTHERN PORTION OF THE GULF 
OF CALIFORNIA THROUGH 48 HOURS AS THE SUPPORTING UPPER TROUGH 
DIGS FARTHER INTO THE WESTERN UNITED STATES. PORTIONS OF THE 
GULF OF CALIFORNIA N OF 30N MAY SEE SW WINDS TO 20 KT BY FRI AS 
THE FRONT MOVES THROUGH THE AREA.  

A SHARP MID TO UPPER LEVEL RIDGE BUILDS BEHIND THE UPPER TROUGH 
THROUGH 24 HOURS...WITH AN ASSOCIATED 1028 MB SURFACE HIGH PRES 
AREA SETTLING NEAR 36N140W THROUGH 48 HOURS. THE BUILDING RIDGE 
WILL ALLOW A BROAD SWATH OF MODERATE TO FRESH TRADES TO DEVELOP 
MAINLY N OF 10N W OF 125W THROUGH LATE FRI. LONG PERIOD 
NORTHERLY SWELL WILL PROPAGATE INTO THE DISCUSSION AREA THROUGH 
FRI...WITH SEAS 8 TO 11 FT EXTENDING N OF 26N BETWEEN 118W AND 
135W BY LATE FRI. 

A BROAD UPPER TROUGH REMAINS INTACT FROM 24N119W TO 10N111W. 
THIS HAD BEEN SUPPORTING A WEAK SURFACE TO LOW LEVEL TROUGH 
EXTENDING FROM 20N116W TO 14N118W. AN AREA OF THUNDERSTORMS 
PERSISTS NEAR THE NORTHERN PORTION OF THE TROUGH. THE TROUGH 
WILL MAKE SLOW PROGRESS WEST THROUGH 48 HOURS BEFORE DISSIPATING 
BY 72 HOURS AS IT DECOUPLES FROM ITS SUPPORTING UPPER TROUGH. 
ONGOING DIVERGENCE ALOFT TO THE SW OF THE TROUGH ALONG WITH WEAK 
LOW LEVEL CONVERGENCE IS SUPPORTING SCATTERED MODERATE 
CONVECTION WITHIN 270 NM OF THE ITCZ AXIS.

GAP WINDS...HIGH RESOLUTION ASCAT DATA IMAGERY DATA FROM 0330 
UTC SHOWED NEAR GALE FORCE WINDS WITHIN 150 NM OF THE COAST OF 
TEHUANTEPEC. IT IS PLAUSIBLE THAT WINDS TO GALE FORCE ARE 
ONGOING AND A GALE WARNING REMAINS IN PLACE THROUGH THE NEXT 24 
TO 36 HOURS OVER THE GULF OF TEHUANTEPEC. THE COLD AIR ADVECTION 
IS ABATING ALREADY...AND PULSES OF WINDS TO GALE FORCE EMERGING 
OUT OF TEHUANTEPEC WILL DIMINISH IN INTENSITY AND FREQUENCY BY 
LATE FRI. THE ONGOING GALE EVENT HAS PRODUCED A LONG AREA OF 
SEAS OF 8 TO 14 FT AS FAR W AS 100W...MIXING WITH DECAYING 
REMNANTS OF CROSS-EQUATORIAL SW SWELL. MEANWHILE WIND PULSES 
THROUGH THE GULF OF PAPAGAYO ARE REACHING 25 KT...AS NOTED IN 
SCATTEROMETER DATA FROM NEAR 06 UTC. THE SAME PASS INDICATED 
WINDS NEAR THE GULF OF FONSECA HAVE DROPPED TO BELOW 20 KT. THE 
PAPAGAYO WINDS WILL PERSIST THROUGH 48 HOURS...PRIMARILY IN THE 
EARLY MORNINGS. 

$$
CHRISTENSEN