000
AXPZ20 KNHC 121600
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC THU JAN 12 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 04N77W TO 07N85W TO 04N92W THEN ITCZ TO 
08N113W TO 06N119W TO 07N126W TO BEYOND 07N140W.  NO SIGNIFICANT 
CONVECTION.

...DISCUSSION...
DEEP LAYER CYCLONE AT 30N130W HAS MID TO UPPER LEVEL TROUGH 
EXTEND TO 18N140W WITH VERY DRY AIR MASS ALONG AND NW OF AXIS. 
BROAD MID TO UPPER LEVEL RIDGE BARELY HOLDING ITS GROUND WITH 
TROUGH FORCING IT E AS TROUGH DIGS FURTHER S.  LARGE AMOUNTS OF 
MOISTURE ALOFT CARRIED TOWARDS BAJA CALIFORNIA BY WEAK 60 KT SW 
JET CORE.  LARGE AREA OF UPPER LEVEL DIVERGENCE AND POOL OF COLD 
AIR ENHANCES MODERATE CONVECTION ACROSS BROAD REGION OF BASIN. 

RIDGE HAS BUDGED EASTWARD WITH AXIS NOW ALONG 106W.  SHARP 
LONGWAVE TROUGH HAS AXIS ALONG 83W COULD BLOCK ANY FURTHER RIDGE 
MIGRATION EFFECTIVELY FORCING CYCLONE OF W SIDE TO SHIFT NE INTO 
SOUTHERN CALIFORNIA AND BAJA PENINSULA. 

...ELSEWHERE AT LOWER LEVELS...
REFLECTION OF UPPER CYCLONE ON SURFACE IS 1018 MB LOW PRES 
CENTER AT 30N130W PRESENTLY DRIFTING S.  LOW PRES MAINTAINS 
FRESH NE WINDS AND 8-9 FT SEAS OVER NW CORNER OF BASIN.  LOW 
PRES CENTER WEAKEN BY SAT AS UPPER LEVEL SUPPORT SHIFTS NE.  
LONG PERIOD NW SWELLS SPREAD ACROSS E PAC N OF 08N W OF 120W 
THROUGH FORECAST PERIOD. 

GULF OF TEHUANTEPEC...STRONG COLD FRONT MOVED OFF TEXAS COAST 
EARLIER TODAY WILL PUSH ACROSS GULF OF MEXICO THROUGH FRI.  COLD 
AIR FORCED THROUGH CHIVELA PASS TONIGHT EXPECTED TO BRING STRONG 
WINDS UNTO GULF OF TEHUANTEPEC AND TO REACH MINIMAL GALE FORCE 
EARLY FRI PERSISTING THROUGH SAT. 

CARIBBEAN FRESH TO STRONG NE TRADES FINDING THEIR WAY THROUGH 
CENTRAL AMERICA MOUNTAIN GAPS IN COSTA RICA AND PANAMA.  
AFOREMENTIONED COLD FRONT REINFORCES WINDS CROSSING INTO GULF OF 
PAPAGAYO AND INCREASE WINDS WHILE FRESH N BREEZE IN GULF OF 
PANAMA DIMINISHES.

$$
WALLY BARNES