000
AXPZ20 KNHC 130317
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC FRI JAN 13 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH EXTENDS FROM 09N77W TO 09N90W TO 05N100W THEN  
ITCZ TO BEYOND 07N140W. NO SIGNIFICANT CONVECTION NOTED.

...DISCUSSION...
A DEEP LAYER CYCLONE IS CENTERED NEAR 30N130W WITH AN ASSOCIATED 
WEAK 1017 MB SURFACE LOW CENTERED NEAR 29N131W. THE UPPER RIDGE 
WILL BREAK DOWN AHEAD OF A SHORT WAVE TROUGH MOVING EAST OUT OF 
THE N CENTRAL PACIFIC THROUGH FRI...ALLOWING THE STALLED DEEP 
LAYERED TROUGH TO LIFT OUT TO THE NE AND THE AREA OF 20 KT 
NORTHERLY WINDS TO DIMINISH. THE ONLY SENSIBLE SURFACE WEATHER 
OF INTEREST REMAINS AN AREA OF 20 KT NORTHERLY WINDS N OF 29N W 
OF 130W...AS NOTED BY AN ENV ALTIMETER PASS FROM 1919 UTC. THIS 
CONTINUES A WEAK PRES PATTERN W OF 110W...WITH FRESH TRADES 
LIMITED TO AN AREA FROM 17N TO 21N W OF 135W AS NOTED BY AN 
EARLIER WINDSAT PASS. SHIP AND ALTIMETER DATA SHOW MUCH OF THE 
NW SWELL THAT PREVIOUSLY COVERED THE AREA W OF 110W HAS 
DIMINISHED BELOW 8 FT. ANOTHER TRAIN OF NW SWELL IS PUSHING INTO 
THE NW CORNER OF THE DISCUSSION AREA...AND WILL COVER THE REGION 
N OF 08N W OF 120W BY 48 HOURS. 

GULF OF CALIFORNIA...HIGH PRES BUILDING OVER THE GREAT BASIN 
WILL SUPPORT NW WINDS TO 20 KT DOWN THE LENGTH OF THE GULF OF 
CALIFORNIA STARTING EARLY FRI MORNING...AND LASTING INTO SAT.

GULF OF TEHUANTEPEC...A COLD FRONT WILL PUSH THROUGH THE WESTERN 
GULF OF MEXICO TONIGHT AND FRI. COLD AIR ADVECTION OVER THE 
WESTERN GULF BEHIND THE FRONT WILL PROMPT GAP WIND FLOW THROUGH 
THE CHIVELA PASS LATE TONIGHT...REACHING GALE FORCE OVER THE 
GULF OF TEHUANTEPEC FRI MORNING WITH THE AID OVERNIGHT 
DRAINAGE...THEN PUSH TO GALE FORCE AGAIN LATER ON FRI AND SAT 
NIGHT AS HIGH PRES BUILDS OVER THE WESTERN GULF OF MEXICO IN THE 
WAKE OF THE COLD FRONT.

GULFS OF PAPAGAYO AND PANAMA...OVERNIGHT DRAINAGE EFFECTS WILL 
ALLOW WINDS TO REACH 20 KT BRIEFLY DURING THE EARLY MORNING 
HOURS ON FRI. THIS WILL BE REINFORCED AS TRADE WIND FLOW OVER 
THE SW CARIBBEAN INCREASES FRI AND SAT. THE STRONGER TRADE WINDS 
OVER THE CARIBBEAN WILL ALSO ALLOW 20 KT NORTHERLY WINDS INTO 
THE GULF OF PANAMA OVERNIGHT. THIS WILL DIMINISH BY LATE FRI AS 
THE NORTHERLY WINDS VEER MORE EASTERLY OVER THE SW CARIBBEAN.

$$
CHRISTENSEN