000
AXPZ20 KNHC 111555
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC WED JAN 11 2012

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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH EXTENDS FROM 10N85W TO 05N92W TO 06N105W THEN 
ITCZ FROM 07N106W TO 07N140W.  NO SIGNIFICANT CONVECTION ALONG 
EITHER AXIS. 

...DISCUSSION...
DEEP LAYER CYCLONE AT 33N129W HAS TROUGH EXTEND TO 30N130W 
TO 22N140W.  VERY DRY AIR MASS NW OF TROUGH WHILE SW JET CORE 
ADVECTS ABUNDANT DEEP LAYERED MOISTURE ON W SIDE OF MID TO UPPER 
RIDGE WITH AXIS ALONG 114W.  RIDGE EXPECTED TO HOLD ITS GROUND 
AND SHIFT TROUGH NE ALONG WITH ITS MOISTURE INTO SOUTHERN HALF 
OF CALIFORNIA AND THE BAJA PENINSULA.  MODERATE DIVERGENCE 
COMBINES WITH COLD POOL ALOFT TO ENHANCE SCATTERED MODERATE 
CONVECTION FROM 14N TO 20N W OF 133W.  CYCLONE INTENSIFIES THU 
AND DEVELOPS SURFACE LOW PRES 1016 MB NEAR 29N131W THEN DRIFT NE 
APPROACHING SOUTHERN CALIFORNIA COAST LATE SUN OR EARLY MON WITH 
POSSIBLE EXCESSIVE RAINFALL EVENT.

AIR MASS REMAINS RELATIVELY DRY E OF 100W AND ACROSS BASIN S OF 
10N W OF 84W EVEN ALONG ITCZ/MONSOON TROUGH AXIS CURTAILING ANY 
SIGNIFICANT CONVECTION ACROSS REMAINING OF E PAC.   

ELSEWHERE AT LOW LEVELS...
BROAD HIGH PRES 1034 MB WELL N OF BASIN EXTENDS S WELL INTO E 
PAC AND BLOCK ANY FURTHER SOUTHERN ENCROACHMENT OF WEAK TROUGH 
...ASSOCIATED WITH UPPER LEVEL CYCLONE...EXTENDING FROM 30N130W 
TO 26N140W.  PRES GRADIENT WARRANTS FOR FRESH NE BREEZE TODAY 
AND THU THEN DIMINISHING FRI ALTHOUGH WEAK LOW PRES DEVELOPS 
NEAR 29N130W THU.  LONG PERIOD NW SWELL UP TO 8-10 FT SPREAD SE 
THROUGHOUT ENTIRE BASIN EXCEPT AREA FROM GULF OF TEHUANTEPEC TO 
COSTA RICA. 

COLD FRONT ENTERS GULF OF MEXICO TONIGHT EXPECTED TO REACH BAY 
OF CAMPECHE AND FUNNEL COLD AIR MASS ACROSS CHIVELA PASS THU 
SPILLING FRESH TO STRONG BREEZE INTO GULF OF TEHUANTEPEC 
STARTING LATE THU INTO FRI.  WINDS EXPECTED TO STRENGTHEN 
POSSIBLY REACHING NEAR GALE FORCE BEYOND FORECAST PERIOD.  

$$
WALLY BARNES