000
AXPZ20 KNHC 102204
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SAT DEC 10 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 
21450 UTC.

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

MONSOON TROUGH EXTENDS FROM 09N84W TO 06N92W WHERE LOW LEVEL
WINDS SUGGEST THAT THE ITCZ BEGINS AND EXTENDS TO 06N100W TO
07N110W TO 07N121W TO 11N140W. SCATTERED MODERATE CONVECTION 
IS WITHIN 120 NM N OF THE AXIS BETWEEN 117W AND 121W...AND
ALSO FROM 03N TO 06N E OF 79W.

...DISCUSSION...

A SHORT WAVE TROUGH EXTENDS FROM 17N137W SE TO 08N133W. IT 
IS MOVING RAPIDLY EASTWARD WHILE SUPPORTING ACTIVE ITCZ BETWEEN 
117W AND 121W. SOME CONTINUED DEEP CONVECTION SHOULD BE EXPECTED 
AS THE UPPER TROUGH AND ITCZ INTERACT TODAY WITH LITTLE CHANCE 
OF TROPICAL CYCLONE DEVELOPMENT DUE TO STRONG VERTICAL SHEAR AND 
LACK OF PRE-EXISTING SURFACE TROUGH. BY SUNDAY...THE TROUGH 
SHOULD LIFT OUT TO NE AND THE DEEP CONVECTION SHOULD LIKELY 
DIMINISH.  ELSEWHERE THE TROPICAL NE PACIFIC IS DOMINATED BY AN 
ANTICYCLONE CENTERED NEAR 10N111W...PROMOTING SUBSIDENCE AND DRY 
CONDITIONS IN EASTERN PORTION AS WELL AS ADVECTING UPPER LEVEL 
MOISTURE AND CLOUDINESS FROM WESTERN PORTION TOWARD NW MEXICO.

A SURFACE RIDGE EXTENDS FROM 30N140W TO NEAR 22N112W. THE 
COMBINATION OF THE RIDGE WITH ITCZ ASSOCIATED LOW PRESSURE IS 
SUSTAINING FRESH E-NE WINDS FROM 15N TO 23N W OF 130W. THE 
PRES GRADIENT NOT EXPECTED TO VARY MUCH OVER THE NEXT COUPLE OF 
DAYS...WITH LITTLE CHANGE IN EXPECTED WINDS.

GULF OF TEHUANTEPEC...MINIMAL N TO NE GALE FORCE WINDS ARE 
SURGING SWD THROUGH THE GULF AS A STRONG PRES GRADIENT HAS SET 
UP OVER SORN MEXICO AND JUST INLAND THE GULF. SEAS OF UP TO 12 FT
ARE VERY POSSIBLE IN THE GULF...AND ARE EXPECTED TO BUILD UP TO 
14 FT BY EARLY SUN AT WHICH TIME WINDS MAY BRIEFLY PEACK AT 40 KT
PER LATEST REGIONAL NAM MODEL GUIDANCE BEFORE SLOWLY SUBSIDING 
BACK TO MINIMAL GALE FORCE LATER ON SUN.

A VIGOROUS TROUGH DIGGING SOUTHEASTWARD TOWARD THE COAST OF 
SOUTHERN CALIFORNIA AND NW MEXICO SUNDAY AND MONDAY IS EXPECTED 
TO BRIEFLY DEEPEN INTO A CLOSED LOW OFFSHORE SRN CALIFORNIA
BY EARLY MONDAY EVENING WITH A WEAKENING COLD SW TO NEAR 
20N125W. THE PRES GRADIENT BETWEEN THIS LOW AND A HIGH OF 1029 MB
NEAR 35N140W WILL INDUCE W TO NW WINDS OF 20 TO 25 KT N OF 
23N W OF FRONT WITH NW SWELLS LEADING TO 10 TO 14 FT BY MON 
AFTERNOON. ELSEWHERE W OF FRONT WINDS ARE EXPECTED TO BE N TO NE
AT 20 KT WITH SEAS 8 TO 10 FT IN NW TO N SWELL. SW TO W WINDS OF
20 KT ARE FORECAST TO THE E OF THE FRONT AND S OF THE LOW ON MON 
WITH SEAS 8 TO 10 FT IN A NW SWELL.

GULF OF PAPAGAYO...NE WINDS OF 20 KT ARE EXPECTED TO PULSATE
UP AND DOWN PRIMARILY DURING THE LATE NIGHT AND EARLY MORNING
IN DRAINAGE FLOW OFF THE LAND. HOWEVER...THESE WINDS ARE NOT 
EXPECTED TO COVER A LARGE ENOUGH AREA FOR MENTION IN THE NE
PACIFIC HIGH SEAS FORECAST.

$$
AGUIRRE