000
AXPZ20 KNHC 302158
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC WED NOV 30 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2115 UTC.

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

THE MONSOON TROUGH AXIS EXTENDS FROM 09N84W TO 06N97W. ITCZ AXIS 
EXTENDS FROM 06N97W TO 09N130W TO 09N140W. SCATTERED MODERATE 
CONVECTION LIES WITHIN 120 NM N AND 75 NM S OF THE ITCZ AXIS. 
 
...DISCUSSION...

THE UPPER PATTERN IS BECOMING MORE AMPLIFIED N OF 32N AS A 
VIGOROUS UPPER TROUGH DIGS INTO CALIFORNIA AHEAD OF RIDGING 
BUILDING NEAR 140W. AN LOW CENTERED NEAR 30N137W IS 
WEAKENING TO THE SOUTH OF THE BUILDING UPPER ANTICYCLONE NEAR 
37N137W. THE UPPER LOW WILL DISSIPATE BY THIS TIME TOMORROW AS 
THE UPPER TROUGH DIGS INTO THE NORTHERN BAJA AND NE MAINLAND 
MEXICO. THIS TROUGH IS SUPPORTING AN ASSOCIATED COLD FRONT THAT 
WILL REACH AS FAR S AS 24N E OF 125W BY LATE THU. STRONG HIGH 
PRES BUILDING BEHIND THE FRONT WILL SUPPORT FRESH TRADES OVER 
WESTERN WATERS. FRESH TO STRONG N WINDS WILL FOLLOW THE FRONT 
ACCOMPANIED BY N SWELL WITH SIGNIFICANT WAVE HEIGHTS TO 15 FT 
AND PERIODS TO 11 SECONDS PER WW3 AND ECWAVE GUIDANCE. THE FRONT 
WILL DRIFT S AND DISSIPATE THROUGH LATE FRI.

ANOTHER UPPER TROUGH CURRENTLY LIES S OF 22N 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 NEXT 24-48 HOURS. OVERNIGHT THU 
NIGHT...THE NORTHERN STREAM TROUGH DESCRIBED IN THE PARAGRAPH 
ABOVE WILL BEGIN TO COME IN PHASE WITH THIS UPPER TROUGH ALONG 
115W. 

GAP WINDS...
GULF OF CALIFORNIA...FRESH TO STRONG SW WINDS WILL PROCEED THE 
FRONT OVER THE NORTHERN GULF N OF 29N THROUGH THU MORNING AND 
SHIFT NW BEHIND THE FRONT. THE FRONT WILL WEAKEN AS IT REACHES 
AS FAR S AS 28N BY FRI AFTERNOON. 

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 IS IN EFFECT THROUGH THU 
MORNING AS A RESULT.

GULF OF FONSECA...OVERNIGHT DRAINAGE FLOW WILL CONVERGE TO 
PRODUCE WINDS TO 20 KT BRIEFLY DURING THE EARLY MORNING.

GULF OF PAPAGAYO...OVERNIGHT DRAINAGE WILL ALSO IMPACT THE GULF 
OF PAPAGAYO...WITH THE ADDED ENHANCEMENT OF STRONG GRADIENT FLOW 
OVER THE SW CARIBBEAN. 

OF NOTE...
NOVEMBER 30 MARKS 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