000
AXPZ20 KNHC 270518 CCA
TWDEP 

TROPICAL WEATHER DISCUSSION     
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SAT JAN 27 2007

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 
0345 UTC.

...ITCZ...
ITCZ AXIS ALONG 6N78W 8N114W 5N140W.  NO SIGNIFICANT CONVECTION.

...DISCUSSION...
WEAK UPPER LEVEL TROUGH FROM 32N107W TO 20N116W HAS FLATTENED 
CREST OF BROAD MID/UPPER LEVEL RIDGE THAT DOMINATES E PAC BASIN 
S OF 20N W OF 95W KEEPING MOSTLY ZONAL FLOW OVER RIDGE AREA.
STRONG JET CORE 145 KT SE OF TROUGH AXIS ADVECTS PLENTY OF 
TROPICAL MOISTURE NE IN OTHERWISE VERY DRY AIR MASS ALOFT.  
WATER VAPOR IMAGES SHOW MOISTURE CROSSING CENTRAL MEXICO INTO 
GULF OF MEXICO BUT LACK OF UPLIFTING MECHANISM MAINTAINS AREA 
DEVOID OF SIGNIFICANT WEATHER. 

AT THE SURFACE...HIGH PRES CENTER 1018 MB 27N121W BLOCK ANY 
FURTHER SRN ADVANCE OF WEAK COLD FRONT 32N123W TO 27N130W... 
WHICH SHOULD BECOME STATIONARY LATE TONIGHT AND DIFFUSE SAT AS 
UPPER LEVEL SUPPORT FIZZLES.

APPROACHING COLD FRONT NOW ALONG 142W SHOULD DENT ABOVE RIDGE 
AND DECREASE BRISK TRADES CAUSED BY HIGH PRES...BUT INCREASE S 
WINDS AHEAD OF FRONT N OF 28N.  FRONT SWINGS N OF AREA BUT 
LEAVES BEHIND LARGE LONG PERIOD SWELL REACHING DOWN TO 4N W OF 
130W.

GALE EVENT ACROSS ISTHMUS OF TEHUANTEPEC HAVE ENDED AS WEAK 
TROUGH OVER BAY OF CAMPECHE LOSES INTENSITY.  WINDS OVER GULF OF 
PAPAGAYO PERSIST THROUGH PERIOD AS COLOMBIAN LOW PRES 1009 MB 
MAINTAINS ITSELF LATENT. 

$$
WALLY BARNES