000
AXPZ20 KNHC 290950
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SAT DEC 29 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 
0945 UTC.
 
...ITCZ...
INTERTROPICAL CONVERGENCE ZONE AXIS ALONG 8N78W 9N85W 5N100W 
8N115W 5N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS 
NOTED WITHIN 90 NM EITHER SIDE OF LINE 10N111W 10N121W AND 
WITHIN 30 NM EITHER SIDE OF LINE 9N128W 6N137W.

...DISCUSSION...
A LONGWAVE TROUGH DOMINATES CENTRAL N AMERICA WITH AN ASSOCIATED 
SHORT WAVE TROUGH EXTENDING SW INTO THE REGION ALONG 32N105W 
24N118W 21N127W 22N140W. A BAND OF UPPER DRY AIR IS NOTED WITHIN 
ROUGHLY 150 NM EITHER SIDE OF LINE 31N103W 24N120W 22N130W 
22N140W. AN UPPER ANTICYCLONE IS AT 32N144W WITH A RIDGE E TO A 
SHARP CREST AT 33N122W. UPPER LEVEL MOISTURE IS NOTED ALONG THE 
RIDGE BUT APPEARS TO EVAPORATING S OF 30N. 

A TROPICAL ANTICYCLONE IS OVER E CUBA WITH ITS ENVELOPE OF 
ANTICYCLONIC FLOW EXTENDING W OVER THE DISCUSSION AREA E OF 
100W. CONVECTION ALONG THE E PAC ITCZ IS ENHANCED BETWEEN 110W 
AND 138W...WITH THE RESULTANT DEBRIS MOISTURE ADVECTED N MERGING 
INTO A TROPICAL PLUME WITHIN 180 NM EITHER SIDE OF LINE 13N140W 
18N115W TO BEYOND 32N90W.

AT THE LOW LEVELS HIGH PRES DOMINATES THE AREA N OF THE ITCZ W 
OF 110W WITH THE EASTERLY TRADES S OF THE RIDGE IN THE 20-30 KT 
RANGE BUT EXPECTED TO DIMINISH TO 20 IN ABOUT 48 HOURS AS A 
STRONG COLD FRONT APPROACHES THE NW PORTION.

GAP WINDS TO ABOUT 20 KNOTS WILL CONTINUE FOR ANOTHER DAY OR SO 
THROUGH IN AND DOWNSTREAM OF THE GULF OF PAPAGAYO. EXTENDED 
OUTLOOK...A MAJOR WIND EVENT IS SETTING UP FOR THE GULF OF 
TEHUANTEPEC GAP IN THE WAKE OF A STRONG COLD FRONT IN THE GULF 
OF MEXICO TUE EVENING.

NORTHWEST WINDS IN THE GULF OF CALIFORNIA WILL FLUCTUATE AROUND 
20 KT DURING THE NEXT 48 HOURS.

$$
NELSON