000
AXPZ20 KNHC 122130
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC MON JAN 12 2009

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

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2030 UTC.

...ITCZ...
ITCZ IS ALONG 6N77W 8N84W 5N91W 9N112W 5N140W. NUMEROUS MODERATE 
TO SCATTERED STRONG CONVECTION FROM 6N TO 12N BETWEEN 99W AND 
110W. SCATTERED MODERATE CONVECTION FROM 6N TO 9N BETWEEN 100W 
TO 118W. ISOLATED MODERATE CONVECTION FROM 3N TO 8N E OF 86W. 

...DISCUSSION...
NARROW UPPER LEVEL TROUGH BETWEEN TWO UPPER RIDGES EXTENDS INTO 
THE FAR NW PORTION OF THE DISCUSSION AREA THROUGH 32N138W TO 
25N126W. THE UPPER RIDGE TO THE S OF THE TROUGH COVERS THE AREA 
W OF 129W. VERY BROAD UPPER HIGH IS TO THE NE OF THE UPPER 
TROUGH ANCHORED NEAR 40N127W COVERING THE AREA N OF 26N W OF 
110W. MODERATE TO STRONG SUBSIDENCE WITH DRY STABLE AIR COVERS 
THE AREA N OF 23N TO OVER BAJA PENINSULA AND NW MEXICO. AN UPPER 
LEVEL TROUGH OVER THE CENTRAL U.S. IS E OF THE BROAD UPPER HIGH 
AND EXTENDS S TO OVER N MEXICO. SLY UPPER FLOW S OF MEXICO E OF 
110W COMBINED WITH THE DIFFLUENCE ALOFT S OF THIS UPPER TROUGH 
IS SUPPORTING CONVECTION ASSOCIATED WITH THE ITCZ. 

A SURFACE RIDGE DOMINATES MUCH OF THE AREA N OF 15N BETWEEN 120W 
AND 145W ANCHORED BY A 1040 MB HIGH OFF THE NW U.S. COAST. A 
1032 MB SURFACE HIGH INLAND OVER N MEXICO IS MAINTAINING A 
STRONG PRES GRADIENT ACROSS SOUTHERN MEXICO AND WITH THE PASSAGE 
OF FRONT IN THE GULF OF MEXICO IS PRODUCING GALE FORCE WINDS 
CONTINUING THROUGH THE GULF OF TEHAUNTEPEC. 

$$
WALLACE