000
AXPZ20 KNHC 181000
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC TUE DEC 18 2007

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

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.
 
...ITCZ...
INTERTROPICAL CONVERGENCE ZONE AXIS IS CENTERED ALONG 8N82W 
6N90W 9N120W 7N140W. SCATTERED MODERATE TO STRONG CONVECTION 
WITHIN 60 NM EITHER SIDE OF AXIS FROM 120W-123W. SCATTERED 
MODERATE ISOLATED STRONG CONVECTION WITHIN 80 NM S OF AXIS FROM 
124W-127W.

...DISCUSSION...
MID/UPPER TROUGH EXTENDS FROM 32N120W TO 21N140W. AN 80-95 KT 
SUBTROPICAL JETSTREAM WITH AXIS FROM 18N140W TO 21N130W WHERE 
WINDS INCREASE TO 100-110 KT THEN NE INTO CENTRAL BAJA 
CALIFORNIA TO SW TEXAS. MODERATE TO STRONG SUBSIDENCE IS WITHIN 
420 NM N OF THE JET AXIS W OF 125W...WITH DRY AND CLOUD FREE IN 
THE MIDDLE AND UPPER LEVELS.  A 660 NM WIDE PLUME OF UPPER LEVEL 
MOISTURE AND BROKEN TO OVERCAST MULTI LEVEL CLOUDS IS ADVECTING 
NE S OF THE JET.

AN UPPER LEVEL RIDGE EXTENDS FROM AN ANTICYCLONIC CIRCULATION 
OVER GUATEMALA WWD ACROSS THE PACIFIC TO 11N120W. MODERATE TO 
STRONG SUBSIDENCE HAS SUPPRESSED ITCZ CONVECTION E OF 115W WITH 
DRY AIR S OF 17N E OF 115W.

WEAK RIDGE IS NORTH OF THE ITCZ WEST OF 110W. REMAINDER OF THE 
AREA IS ANALYZED AS A BROAD TROUGH.

HIGH PRES RIDGE OVER THE GULF OF MEXICO AND SOUTHERN MEXICO WILL
KEEP GALE FORCE WINDS IN THE GULF OF TEHUANTEPEC THROUGH ABOUT 
ANOTHER 12 HOURS THEN FALL BELOW GALE FORCE.

$$
DGS