000
AXPZ20 KNHC 310315
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC WED 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 5N77W 7N100W 9N130W 7N140W. NO SIGNIFICANT 
CONVECTION

...DISCUSSION...
UPPER LEVEL TROUGH WITH AXIS FROM 32N128W TO 25N140W. 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 27N125W TO 22N113W...WHERE WINDS 
DECREASE TO AROUND 50 KT. MID/UPPER LEVEL TROUGH E OF THE RIDGE 
EXTENDS FROM 32N120W TO 18N105W. UPPER LEVEL DIFFLUENT FLOW IS 
ENHANCING CONVECTIVE ACTIVITY FROM 14N-16N BETWEEN 118W-123W. SW 
UPPER LEVEL WINDS ARE ADVECTING MOISTURE FROM THIS CONVECTION 
INTO CENTRAL MEXICO. UPPER LEVEL CYCLONIC CIRCULATION IN THE 
DEEP TROPICS CENTERED NEAR 5N98W 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 323N135W TO 14N112W. BROKEN/OVERCAST 
STRATOCUMULUS CLOUDS BLANKETS THE AREA WITHIN THE RIDGE N OF 17N 
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