000
AXPZ20 KNHC 302107
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC TUE DEC 30 2008

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 
2100 UTC.

...ITCZ...
ITCZ AXIS IS ALONG 06N77W TO 08N130W TO 07N140W. NO SIGNIFICANT 
CONVECTION.

...DISCUSSION...
UPPER LEVEL TROUGH WITH AXIS FROM 32N131W TO 26N140W. A BROAD 
FLAT UPPER LEVEL RIDGE IS SE OF THE TROUGH...SOME UPPER LEVEL 
MOISTURE IS FLOWING THROUGH THE RIDGE. A 70-85 KT JET STREAM 
EXTENDS FROM 26N135W TO 19N113W...WHERE WINDS DECREASE TO AROUND 
50 KT. MID/UPPER LEVEL TROUGH E OF THE RIDGE EXTENDS FROM 
32N120W TO 18N107W. UPPER LEVEL DIFFLUENT FLOW IS ENHANCING 
CONVECTIVE ACTIVITY FROM 13N-16N BETWEEN 113W-122W. SW UPPER 
LEVEL WINDS ARE ADVECTING MOISTURE FROM THIS CONVECTION INTO 
CENTRAL MEXICO. UPPER LEVEL CYCLONIC CIRCULATION IN THE DEEP 
TROPICS CENTERED NEAR 6N99W WITH TROUGH FROM THE CIRCULATION 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.

SURFACE RIDGE EXTENDS FROM A 1028 MB HIGH PRES CENTERED JUST N 
OF THE DISCUSSION AREA NEAR 33N135W TO 25N120W. BROKEN/OVERCAST 
STRATOCUMULUS CLOUDS BLANKETS THE AREA WITHIN THE RIDGE N OF 19N 
W OF 120W. 

HIGH PRES ACROSS MEXICO HAS TIGHTENED THE GRADIENT OVER SOUTHERN 
MEXICO WITH GALE FORCE WINDS THROUGH THE GULF OF TEHUANTEPEC
WHICH ARE EXPECTED TO DECREASE BELOW GALE FORCE BY EARLY WED.

$$
DGS