000
AXPZ20 KNHC 141538
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SAT JAN 14 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 
1330 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH AXIS FROM 07N77W TO 03N85W TO 05N100W. ITCZ AXIS 
FROM 05N100W TO 05N112W TO 08N120W TO 08N140W. SCATTERED 
MODERATE ISOLATED STRONG FROM 03N TO 08N E OF 84W. SCATTERED 
MODERATE WITHIN 90 NM S AND 30 NM N OF AXIS W OF 138W.

...DISCUSSION...
A MID/UPPER LEVEL CYCLONIC CIRCULATION IS CENTERED NEAR 31N129W. 
A SOUTHWESTERLY JET WITH TROPICAL ORIGINS IS TRANSPORTING 
MOISTURE S AND E OF THE LOW...WITH SCATTERED SHOWERS FOUND IN A 
BAND ALONG 128W N OF 19N NEAR A SURFACE TROUGH FROM 24N128W TO 
20N131W. SHOWERS E OF THE LOW ARE ALSO FOUND IN A SECOND BAND 
CURRENTLY OVER THE GULF OF CALIFORNIA WHERE AN UPPER RIDGE IS 
ENHANCING ATMOSPHERIC LIFT. A DEEP LAYER TROUGH MOVING INTO THE 
U.S. PACIFIC NW IS FORECAST TO OVERTAKE THE LOW SUN...BUT BROAD 
UPPER TROUGHING SHOULD LINGER OVER NORTHERN WATERS THROUGH MON. 
THERE IS SOME DISAGREEMENT ON THE STRENGTH OF THIS TROUGH AMONG 
THE FORECAST MODELS. HOWEVER...THE MAJORITY OF THE MODELS KEEP 
THE WINDS BELOW 20 KT AND SEAS BELOW 8 FT INTO MON. 

A STRONGER UPPER LOW LIES N OF THE HAWAIIAN ISLANDS ALONG 30N. 
THIS LOW HAS GENERATED NW SWELL THAT IS MOVING THROUGH THE NW 
PORTION OF THE FORECAST AREA WITH SEAS TO 9 FT. THIS LOW WILL 
WEAKEN AS IT IS OVERTAKEN BY A TROUGH APPROACHING FROM THE W 
LATER TODAY. SWELLS ARE EXPECTED TO SUBSIDE BELOW 8 FT BY SUN 
MORNING OVER THE FORECAST AREA.

GAP WINDS...
GULF OF CALIFORNIA...THE 0456 UTC ASCAT PASS SHOWED NW WINDS TO 
20 KT IN THE GULF OF CALIFORNIA. THE PASS ONLY COVERED THE 
REGION S OF 27N...WITH MODEL GUIDANCE SHOWING WINDS TO 20 KT IN 
THE NORTHERN GULF. THESE WINDS ARE EXPECTED TO DIMINISH LATER 
TODAY AS THE IMPETUS HIGH PRES OVER THE INTERIOR WESTERN U.S. IS 
WEAKENED BY THE APPROACHING TROUGH CURRENTLY OVER THE U.S. 
PACIFIC NW. 

GULF OF TEHUANTEPEC...1029 MB HIGH PRES OVER THE NW GULF OF 
MEXICO IS EXPECTED TO CHANGE LITTLE THROUGH SUN MORNING...WITH 
WINDS CONTINUING TO FUNNEL THROUGH THE ISTHMUS OF TEHUANTEPEC. 
THE 0314 UTC ASCAT PASS SHOWED NEAR GALE FORCE WINDS...BUT 
MISSED THE AREA NEAR THE COAST WHERE STRONGER WINDS ARE LIKELY. 
A GALE WARNING IS IN EFFECT UNTIL EARLY MON MORNING.

GULF OF PAPAGAYO...SHIP PHSG REPORTED 26 KT NE WINDS AT 1200 UTC 
NEAR 11.5N89W...DOWNWIND OF PAPAGAYO. THE HIGH PRES OVER THE NW 
GULF OF MEXICO DRIVING THE GALE IN THE GULF OF TEHUANTEPEC WILL 
ALSO KEEP WINDS FRESH TO STRONG DOWNWIND OF PAPAGAYO. AS THIS 
HIGH SHIFTS E AND INTENSIFIES LATE SUN INTO MON...THE PRES 
GRADIENT WILL INCREASE OVER THE GULF OF PAPAGAYO ALLOWING FRESH 
TO STRONG WINDS TO SPREAD AS FAR WEST AS 98W BY MON MORNING.

$$
SCHAUER