000
AXPZ20 KNHC 131603
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1545 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

MONSOON TROUGH EXTENDS FROM 7N78W TO 5N92W TO 5N105W WHERE
LOW LEVEL WINDS SUGGEST THE ITCZ BEGINS AND EXTENDS TO 7N120W
TO 6N130W TO 6N140W. SCATTERED STRONG CONVECTION EXISTS FROM 
3N-6N E OF 80W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS 
WITHIN 60 NM N OF THE ITCZ AXIS BETWEEN 86W-90W.

...DISCUSSION...

A STATIONARY CUT-OFF WELL DEFINED MID/UPPER LEVEL CYCLONIC 
CIRCULATION IS LOCATED AT 29N132W WITH A TROUGH EXTENDING SE TO 
22N126W TO 15N122W TO NEAR 12N116W. THE LOW IS TO THE S OF A 
LARGE AMPLITUDE RIDGE N OF THE AREA MAINTAINING WHAT APPEARS TO 
BE A REX-TYPE BLOCKING PATTERN OVER THE EASTERN PACIFIC REGION N 
OF THE DISCUSSION AREA. A NARROWING UPPER RIDGE IS ALONG 140W. 
ISOLATED SHOWERS ARE POSSIBLE WITHIN 120 NM OF THE LOW. 
SATELLITE WATER VAPOR IMAGERY SHOWS MODERATE SUBSIDENCE AND 
ASSOCIATED DRY AND STABLE AIR W OF THE TROUGH AXIS WHERE THE 
NARROWING RIDGE BECOMES BROADER S OF ABOUT 26N. TO THE E OF THE 
TROUGH...AMPLE DEEP ATMOSPHERIC MOISTURE IN THE FORM OF OVERCAST 
TO BROKEN MOSTLY MID AND UPPER CLOUDINESS IS NOTED. SCATTERED 
SHOWERS AND WEAK ISOLATED TSTMS UNDER UPPER LEVEL DIVERGENCE ARE 
POSSIBLE WITHIN THIS AREA OF MOISTURE. MODERATE TO STRONG SW 
UPPER LEVEL WINDS ARE ADVECTING THE UPPER LEVEL MOISTURE IN THE 
FORM OF SCATTERED TO BROKEN CLOUDS ACROSS MUCH OF CENTRAL AND 
SRN BAJA CALIFORNIA...AND TO ACROSS MEXICO TO AS FAR NE AND AS 
THE CENTRAL GULF OF MEXICO AND SRN U.S. WHERE IT COMES INTO 
PHASE WITH NRN STREAM ENERGY PLUNGING SEWD FROM POLAR LATITUDES.

AT THE SURFACE...WEAK RIDGING IS PRESENT N OF 16N W OF 115W 
WHERE THE MODERATE SUBSIDENCE ALOFT IS SUPPRESSING ANY DEEP
CONVECTION FROM FORMING THERE. THE SURFACE LOW OF 1016 MB IS 
COLLOCATED WITH THE UPPER LOW AT 29N132W. A TROUGH EXTENDS FROM 
THE LOW S TO 23N123W. ANOTHER TROUGH IS ALONG 135W FROM 14N TO 
20N. THE LOW IS FORECAST TO WEAKEN TO A TROUGH WITHIN THE NEXT
24-30 HRS.

WITH RESPECT TO MARINE ISSUES...LARGE NW SWELLS RESULTING IN SEAS
UP TO 11 FT ARE PRESENT NW OF A LINE FROM 30N128W TO 22N129W
TO 16N140W. THESE SWELLS ARE FORECAST BY MARINE GUIDANCE 
MODELS TO GRADUALLY SUBSIDE OVER THE NEXT 24 TO 36 HRS.

GAP WINDS...
STRONG HIGH PRES BUILDING ACROSS THE GULF OF MEXICO BEHIND A 
COLD FRONT HAS TIGHTENED THE PRES GRADIENT OVER SOUTHERN MEXICO. 
THIS HAS INDUCE GALE FORCE NLY WINDS THROUGH INTO THE GULF OF 
TEHUANTEPEC WITH WINDS OF UP TO 40 KT. THESE WINDS WILL SLOWLY
ABATE THROUGH THE NEXT 48 HRS.

NLY WINDS TO 20 KT IN THE GULF OF PANAMA WILL DECREASE TO LESS
THAN 20 KT SAT AFTERNOON.

NE GULF OF PAPAGAYO WINDS OF 20 KT WILL INCREASE TO 20-25 KT IN 
24 HRS...AND CONTINUE WITH LITTLE CHANGE THROUGH SUN. 

$$
AGUIRRE