000
AXPZ20 KNHC 211553
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC WED JAN 21 2009

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 ALONG 04N78W TO 06N110W TO 04N130W TO 06N140W. SCATTERED 
MODERATE FROM 04N TO 06N BETWEEN 102W AND 105W.

...DISCUSSION...
A BROAD UPPER LEVEL RIDGE IS OVER THE WESTERN PORTION OF THE 
DISCUSSION AREA WITH AXIS FROM 32N136W TO 10N140W. ANTICYCLONIC 
FLOW COVERS THE AREA W OF 130W. MODERATE TO STRONG SUBSIDENCE 
WITH DRY STABLE AIR AT THE MIDDLE AND UPPER LEVELS OF THE 
ATMOSPHERE IS W OF 125W. A 90-100 KT JET STREAM IS OVER THE TOP 
OF THE RIDGE FROM 32N140W TO 30N130W. MID TO UPPER LEVEL TROUGH 
IS E OF THE RIDGE FROM 32N123W TO 25N118W TO A CYCLONIC 
CIRCULATION CENTERED NEAR 15N117W. MID/UPPER LEVEL RIDGE WITH 
AXIS FROM EASTERN ARIZONA IS ACROSS WESTERN MEXICO TO 15N100W. 
MODERATE TO STRONG SUBSIDENCE COVERS THE AREA S OF 20N E OF 
100W...WITH MOSTLY CLEAR SKIES EXCEPT FOR BROKEN TO OVERCAST 
STRATOCUMULUS CLOUDS S OF THE ITCZ.

A 1009 MB SURFACE LOW IS W OF BAJA CALIFORNIA NEAR 27N125W WITH 
TROUGH EXTENDING S FROM LOW CENTER TO 16N125W. DISSIPATING COLD 
FRONT IS W OF THE TROUGH EXTENDING FROM 32N127W TO 27N125W TO 
18N132W. OVERCAST LOW TOP CLOUDS WITH AREAS OF LIGHT RAIN ARE 
BETWEEN THE TROUGH AND THE FRONT N OF 18N. HIGH PRES CENTERS ARE 
ANALYZED ON EITHER SIDE OF THE LOW. ONE 1020 MB HIGH IS NEAR 
25N140W AND ANOTHER 1017 MB HIGH IS NEAR 24N114W. ELSEWHERE... 
HIGH PRESSURE GRADIENT OVER SOUTHERN MEXICO IS PRODUCING GALE 
FORCE WINDS THROUGH THE GULF OF TEHUANTEPEC. ALSO 20-25 KT WINDS 
ARE ALSO OVER THE GULF OF PAPAGAYO TO 88W.

$$
MRF