000
AXPZ20 KNHC 100951
TWDEP 

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

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 
MONSOON TROUGH EXTENDS FROM 08N82W TO 06N95W. ITCZ AXIS EXTENDS 
FROM 06N95W TO 09N132W TO 08N140W. SCATTERED MODERATE STRONG 
CONVECTION WITHIN 120 NM N OF AXIS BETWEEN 131W AND 135W.

...DISCUSSION...
A SHARP TROUGH EXTENDING FROM 22N146W TO 05N138W IS SUPPORTING 
ACTIVE ITCZ CONVECTION NW OF 130W. SOME CONTINUED DEEP CONVECTION
SHOULD BE EXPECTED AS THE UPPER TROUGH AND ITCZ INTERACT DURING 
THE NEXT TWO DAYS WITH LITTLE CHANCE OF LOW PRES DEVELOPMENT DUE 
TO STRONG VERTICAL SHEAR AND LACK OF PREEXISTING SURFACE TROUGH. 
ELSEWHERE THE TROPICAL NE PACIFIC IS DOMINATED BY AN ANTICYCLONE 
CENTERED NEAR 11N111W...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 A HIGH NEAR 32N140W TO NEAR 22N121W.
THE COMBINATION OF THE RIDGE WITH ITCZ ASSOCIATED LOW PRESSURE 
IS SUSTAINING FRESH E-NE WINDS FROM 10N TO 20N W OF 130W. HIGHER 
THE GRADIENT NOT EXPECTED TO VARY MUCH OVER THE NEXT COUPLE OF 
DAYS...WITH LITTLE CHANGE IN EXPECTED WINDS S OF 20N W OF 125W.

WINDS THROUGH THE GULF OF TEHUANTEPEC ARE FORECAST TO INCREASE 
UP TO MINIMAL GALE FORCE LATER THIS MORNING AS THE LOCAL SURFACE 
PRESSURE GRADIENT OVER AND JUST INLAND THE GULF OF TEHUANTEPEC 
TIGHTENS. BASED ON LATEST MODEL GUIDANCE...IT APPEARS THIS EVENT 
WILL PERSIST SEVERAL DAYS WITH LITTLE CHANGE OTHER THAN DIURNAL 
VARIABILITY. THIS WILL BE SMALLER IN SCALE THAN THE TYPICAL GULF 
OF TEHUANTEPEC WIND EVENTS...WITH THE EFFECTS CONFINED MOSTLY TO 
THE GULF ITSELF N OF 14N WITH WIND-DRIVEN SEAS SPREADING OVER A 
LIMITED STRETCH OF OPEN OCEAN TO AROUND 12N97W. FORECAST REFLECTS
DOMINANT CONDITIONS EXPECTED THERE AND NOT DIURNAL FLUCTUATIONS.

A TROUGH DIGGING SOUTHWARD ALONG THE COAST OF SOUTHERN CALIFORNIA
SUN THROUGH MON IS EXPECTED TO BRIEFLY DEEPEN INTO A CLOSED LOW 
NEAR SAN DIEGO MON EVENING WITH A TRAILING COLD FRONT EXTENDING 
INTO NE PORTION MON NIGHT AND TUE. PRES GRADIENT BETWEEN THIS LOW
AND HIGH PRES 25N140W WILL INDUCE FRESH TO STRONG NORTHERLY WINDS
N OF 25N MAINLY BETWEEN 120W AND 135W WITH N SWELLS SWEEPING INTO
THE AREA AS WELL...WITH SEAS TO 14-15 FT EXPECTED BY MON NIGHT.

$$
MUNDELL