000
AXPZ20 KNHC 300311
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC TUE DEC 31 2008

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

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC.

...ITCZ...
ITCZ AXIS IS ALONG 5N78W 6N95W 5N110W 9N140W. NO SIGNIFICANT 
CONVECTION.

...DISCUSSION...
A BROAD FLAT UPPER LEVEL RIDGE COVERS THE DISCUSSION AREA W OF 
130W SOME UPPER LEVEL MOISTURE IS FLOWING THROUGH THE RIDGE  
FROM CONVECTION S OF HAWAII. A 90-95 KT JET STREAM EXTENDS FROM 
26N140W TO 20N124W...WHERE WINDS DECREASE TO AROUND 50 KT. 
MID/UPPER LEVEL TROUGH E OF THE RIDGE WITH AXIS FROM 32N128W TO 
20N113W. UPPER LEVEL DIFFLUENT FLOW IS ENHANCING CONVECTIVE 
ACTIVITY FROM 11N-15N BETWEEN 111W-115W. SW UPPER LEVEL WINDS 
ARE ADVECTING MOISTURE FROM THIS CONVECTION INTO CENTRAL MEXICO. 
UPPER LEVEL TROUGH IN THE DEEP TROPICS FROM 10N101W TO EQUATOR 
AT 92W. MID/UPPER LEVEL RIDGE EXTENDS FROM COLOMBIA ACROSS 
CENTRAL AMERICA TO THE YUCATAN PENINSULA. MODERATE/STRONG 
SUBSIDENCE WITH DRY STABLE AIR AT THE MID TO UPPER LEVELS OF THE 
ATMOSPHERE COVERS MUCH OF THE AREA S OF 20N E OF 105W.

A 1029 MB SURFACE RIDGE EXTENDS FROM A HIGH PRES CENTERED NEAR 
32N131W TO 20N115W. BROKEN/OVERCAST STRATOCUMULUS CLOUDS BLANKETS
THE AREA WITHIN THE RIDGE N OF 19N W OF 115W AND ALSO S OF THE 
ITCZ E OF 105W. 

HIGH PRES BUILDING BEHIND A COLD FRONT IN THE GULF OF MEXICO WILL
TIGHTEN THE GRADIENT OVER SOUTHERN MEXICO WITH GALE FORCE WINDS 
THROUGH THE GULF OF TEHUANTEPEC.

$$
DGS