000
AXPZ20 KNHC 010324
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC THU DEC 01 2011

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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0145 UTC.

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

THE MONSOON TROUGH AXIS EXTENDS FROM 08N83W TO 07N91W. ITCZ AXIS 
EXTENDS FROM 07N91W TO 08N110W TO 10N140W. SCATTERED MODERATE 
WITHIN 120 NM EITHER SIDE OF THE MONSOON TROUGH AXIS W OF 136W. 
 
...DISCUSSION...

THE UPPER PATTERN OVER THE FORECAST AREA WILL BECOME MORE 
AMPLIFIED THOUGH FRI EVENING AS A VIGOROUS UPPER TROUGH OVER 
CALIFORNIA DIGS INTO NW MEXICO AHEAD OF RIDGING BUILDING NEAR 
140W. AN UPPER LOW CENTERED NEAR 30N137W IS WEAKENING TO THE 
SOUTH OF A BUILDING UPPER ANTICYCLONE NEAR 38N138W. THE UPPER 
LOW WILL DISSIPATE THU AS THE UPPER TROUGH DIGS INTO THE 
NORTHERN BAJA AND NE MAINLAND MEXICO. THIS TROUGH IS SUPPORTING 
AN ASSOCIATED COLD FRONT THAT PASS S OF 30N BEFORE SUNRISE AND 
DISSIPATE OVER WATERS N OF 24N OVERNIGHT THU NIGHT. STRONG HIGH 
PRES BUILDING BEHIND THE FRONT WILL SUPPORT FRESH TRADES OVER 
WESTERN WATERS. FRESH TO STRONG N WINDS WILL FOLLOW THE FRONT 
THU ACCOMPANIED BY N SWELL WITH SIGNIFICANT WAVE HEIGHTS TO 15 
FT AND PERIODS TO 11 SECONDS PER WW3 AND ECWAVE GUIDANCE. 

ANOTHER UPPER TROUGH CURRENTLY LIES S OF 23N ALONG 115W WITH A 
LARGE STATIONARY ANTICYCLONE TO ITS E CENTERED OVER NICARAGUA. 
MEANWHILE...SHORTWAVE ENERGY ALOFT ASSOCIATED WITH A DISSIPATING 
COLD FRONT OVER THE WESTERN CARIBBEAN IS FUNNELING W INTO THE 
PACIFIC. THIS ENERGY IS EXPECTED TO REFLECT A SURFACE LOW ALONG 
THE MONSOON TROUGH THU AND FRI. DIFFLUENCE BETWEEN THE LEADING 
EDGE OF THE UPPER TROUGH AND THE ANTICYCLONE IS EXPECTED TO 
ENHANCE CONVECTION ALONG THE MONSOON TROUGH NEAR THIS DEVELOPING 
LOW PRES AT THE SURFACE. OVERNIGHT THU NIGHT...THE NORTHERN 
STREAM TROUGH DESCRIBED IN THE PARAGRAPH ABOVE WILL BEGIN TO 
COME IN PHASE WITH THIS UPPER TROUGH ALONG 115W...BUT THE MEAN 
TROUGH AXIS WILL REMAIN ALONG 115W.

GAP WINDS...
GULF OF CALIFORNIA...FRESH TO STRONG SW WINDS N OF 29N WILL 
PROCEED THE APPROACHING COLD FRONT OVER THE NORTHERN GULF 
BEGINNING EARLY THU MORNING AND SHIFT NW BEHIND THE FRONT THU. 
THE FRONT WILL WEAKEN FRI AS IT REACHES AS FAR S AS 28N BEFORE 
DISSIPATING. 

GULF OF TEHUANTEPEC...ALTHOUGH THE 1616 UTC ASCAT PASS ONLY 
SHOWED WINDS TO 30 KT...IT ONLY PARTIALLY HIT THE GULF OF 
TEHUANTEPEC AND A SLIGHT INCREASE IN WINDS IS EXPECTED OVERNIGHT 
DUE TO DRAINAGE IMPACTS. A GALE WARNING REMAINS IN EFFECT 
THROUGH THU MORNING AS A RESULT.

GULF OF PAPAGAYO...OVERNIGHT DRAINAGE WILL ALSO IMPACT THE GULF 
OF PAPAGAYO...WITH THE ADDED ENHANCEMENT OF STRONG GRADIENT FLOW 
OVER THE SW CARIBBEAN. FRESH TO STRONG NORTHEASTERLY GAP WINDS 
ARE EXPECTED TO BEGIN OVERNIGHT TONIGHT WITH BRIEF REPRIEVES IN 
THE LATE AFTERNOON/EARLY EVENING HOURS.

OF NOTE...
NOVEMBER 30 MARKED THE END OF THE TROPICAL CYCLONE SEASON IN THE 
EASTERN NORTH PACIFIC OCEAN. THE 2011 TROPICAL SEASON PRODUCED A 
TOTAL OF 11 TROPICAL STORMS OF WHICH 10 BECAME HURRICANES... 
INCLUDING 6 MAJOR HURRICANES. ADRIAN WAS THE FIRST SYSTEM OF THE 
SEASON AND HAD A PEAK INTENSITY AS A CATEGORY 4 HURRICANE. 
DORA...EUGENE...HILARY...JOVA AND KENNETH ARE THE OTHER 5 
HURRICANES THAT REACHED MAJOR HURRICANE STRENGTH. THERE WERE 
ALSO TWO TROPICAL DEPRESSIONS. 

$$
CHRISTENSEN/SCHAUER