000
AXPZ20 KNHC 300943
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

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

TROUGH 09N84W TO 06N90W TO 10N100W. ITCZ FROM 10N100 TO 08N120W 
TO 10N128W THEN RESUMES AT 10N134W TO BEYOND 09N140W. SCATTERED 
MODERATE FROM 08N TO 10N W OF 137W. 
 
...DISCUSSION...

AN UPPER-LEVEL LOW IS SPINNING OVER THE FAR NW PORTION OF THE 
AREA NEAR 27N138W. AN ASSOCIATED BROAD SURFACE TROUGH LIES N OF 
15N BETWEEN 140W AND THE HAWAIIAN ISLANDS. SCATTEROMETER PASSES 
SHOWED FRESH ELY FLOW OVER THE W PORTIONS OF THE FORECAST AREA 
BETWEEN THE TROUGH AND 1040 MB SURFACE HIGH PRES CENTERED WELL N 
OF THE REGION NEAR 44N137W. WINDS INCREASE TO 25 KT N OF 25N W 
OF 130W WHERE THE PRES GRADIENT IS STRONGER. FRESH E WINDS ARE 
ALSO NOTED BETWEEN THE HIGH AND A TROUGH EXTENDING FROM 14N128W 
TO 9N132W. 

FURTHER E...A SHARP UPPER TROUGH EXTENDS FROM N CENTRAL MEXICO 
TO AN UPPER LOW NEAR 19N115W THEN TO 00N114W. UPPER DIFFLUENCE 
ON THE E SIDE OF THE TROUGH IS ENHANCING ISOLATED MODERATE 
CONVECTION FROM 12N TO 16N BETWEEN 108W AND 111W. AN UPPER 
ANTICYCLONE IS CENTERED NEAR THE COSTA RICA/NICARAGUA BORDER  
AND EXTENDS A RIDGE ACROSS SE MEXICO AND NORTHERN CENTRAL 
AMERICA WHERE STRONG UPPER LEVEL SUBSIDENCE AND IMPLIED DRY AIR 
MASS IS SEEN. SW FLOW BETWEEN THIS ANTICYCLONE AND THE SHARP 
UPPER TROUGH WILL TRANSPORT ITCZ MOISTURE ACROSS SW MEXICO.

LOOKING AHEAD...AN UPPER TROUGH WILL DIG INTO SOUTHERN 
CALIFORNIA TONIGHT. AN ASSOCIATED COLD FRONT WILL MOVE S OF 30N 
THU...EXTENDING FROM 30N112W TO 25N120W BY THU NIGHT. THE FRONT 
WILL USHER IN FRESH TO STRONG NORTHERLY FLOW WITH N SWELL 
QUICKLY BUILDING SEAS TO 15 FT IN WATERS BEHIND THE FRONT. 

GAP WINDS...
GULF OF TEHUANTEPEC...PRES GRADIENT BETWEEN AN INTENSIFIED HIGH 
PRES TO THE N AND LOWER PRES ASSOCIATED WITH THE MONSOON TROUGH 
TO THE S HAS ONCE AGAIN BROUGHT WINDS TO GALE FORCE IN THE GULF 
OF TEHUANTEPEC ACCORDING TO MODEL GUIDANCE. THE HIGH PRES WILL 
WEAKEN SLIGHTLY AS IT SINKS S TODAY AND THEN WEAKEN MORE RAPIDLY 
AS IT SHIFTS E TONIGHT...WITH WINDS EXPECTED TO DROP BELOW 
GALE FORCE THU MORNING AFTER THE PEAK DRAINAGE FLOW DISSIPATES. 

GULF OF PAPAGAYO...STRONG GRADIENT FLOW OVER THE WESTERN 
CARIBBEAN THAT HAS ALLOWED WINDS TO PULSE IN EXCESS OF 20 KT 
THROUGH THE GULF OF PAPAGAYO DURING THE LATE NIGHT AND EARLY 
MORNING HOURS. THE 0342 ASCAT PASS PROVIDED OBSERVATIONS OF 
THESE WINDS. THIS WEATHER PATTERN IS FORECAST TO PERSIST AS THE 
AFOREMENTIONED HIGH PRES SYSTEM TO THE N SHIFTS EASTWARD 
ALLOWING THE PRES GRADIENT TO BECOME STRONGER OVER CENTRAL 
AMERICA BETWEEN THE HIGH AND DEVELOPING LOW PRES ALONG THE 
MONSOON TROUGH. A WEAK LOW IS EXPECTED TO DEVELOP NEAR 08N91W IN 
ABOUT 24 HOURS. THIS SYSTEM WILL MOVE WWD ALONG THE MONSOON 
TROUGH PRODUCING SOME INCREASE IN WINDS AND SEAS. 

GULF OF CALIFORNIA...STRONG SOUTHWESTERLY WINDS ARE EXPECTED TO 
DEVELOP TONIGHT AS A DEEP LAYER TROUGH DIGS INTO SOUTHERN 
CALIFORNIA. THE ASSOCIATED COLD FRONT WILL REACH THE NORTHERN 
GULF OF CALIFORNIA THU...WITH FRESH TO STRONG WINDS SHIFTING NW 
BEHIND THE FRONT. THE FRONT WILL CUT ACROSS THE GULF OF 
CALIFORNIA FROM FROM 31N112W TO 25N120W BY THU NIGHT.

OF NOTE...NOVEMBER 30 MARKS THE END OF THE TROPICAL SEASON IN 
THE EASTERN 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 WAS ALSO 
TWO TROPICAL DEPRESSIONS. JOVA AFFECTED MEXICO.

$$
GR