000
AXPZ20 KNHC 211601
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC FRI JAN 21 2011

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...ITCZ...
AXIS IS ALONG 6N78W 4N90W 7N115W 6N140W. NO SIGNIFICANT 
CONVECTION.

...DISCUSSION...
AN UPPER LEVEL CYCLONIC CIRCULATION OVER THE FAR WESTERN PORTION 
OF THE DISCUSSION AREA IS CENTERED NEAR 25N139W MOVE TO THE WSW. 
AN UPPER LEVEL ANTICYCLONIC CIRCULATION IS WELL N OF THE AREA 
WITH AN UPPER RIDGE COVERING THE AREA N OF 25N BETWEEN 
110W-115W. MODERATE TO STRONG SUBSIDENCE WITH DRY STABLE AIR AT 
THE MIDDLE AND UPPER LEVELS IS N OF 25N W OF 110W. AN UPPER 
LEVEL TROUGH EXTENDING FROM THE SOUTHWESTERN U.S. THROUGH 
NORTHERN MEXICO TO SOUTHERN BAJA CALIFORNIA. A BROAD UPPER LEVEL 
RIDGE EXTENDS FROM AN ANTICYCLONIC CIRCULATION OVER COLOMBIA 
ACROSS CENTRAL AMERICA.

IN THE DEEP TROPICS AN UPPER LEVEL TROUGH EXTENDS FROM 15N107W 
TO EQUATOR AT 110W. MODERATE TO STRONG SUBSIDENCE S OF 15N E OF  
110W AND S OF 10N W OF 110W HAS SUPPRESSED CONVECTION ALONG THE
ITCZ.

SURFACE HIGH PRES IS LOCATED WELL TO THE N OF THE AREA WITH A 
RIDGE EXTENDING SEWD TO 32N140W TO 22N127W. THE PRES GRADIENT 
ON THE SOUTHERN PERIPHERY OF THE RIDGE IS PRODUCING NE TO E 
WINDS 20 KT N OF 10N W OF 130W. THE RIDGE WILL WEAKEN AND THE 
WINDS ARE EXPECTED TO DECREASE TO BELOW 20 KT ON SAT. LARGE NW 
SWELL WITH SEAS UP TO 15 FT WILL MOVE INTO THE FAR NW PORTION OF 
THE AREA LATER TODAY AND SPREADING SE SAT AND SUN.

HIGH PRES BUILDING IN THE GULF OF MEXICO BEHIND A COLD FRONT WILL
TIGHTEN THE PRES GRADIENT ACROSS SOUTHERN MEXICO RESULTING IN 
20-30 KT WINDS THROUGH THE GULF OF TEHUANTEPEC LATER THIS 
AFTERNOON. THIS EVENT SHOULD BE SHORT LIVED AND WINDS WILL 
DECREASE TO BELOW 20 KT BY EARLY SUN.

A SURFACE TROUGH IS ANALYZED ALONG THE ITCZ FROM 7N88W TO 
3N90W. A FEW LOW TOP SHOWERS ARE WITHIN 90 NM W OF THE 
TROUGH.

$$
DGS