000
AXPZ20 KNHC 230253
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC MON DEC 22 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 IS CENTERED ALONG 7N77W 6N100W 10N130W 07N140W. SCATTERED 
MODERATE ISOLATED STRONG WITHIN 150 NM N OF AXIS FROM 123W TO 
135W.

...DISCUSSION...
DEEP LAYERED CUT OFF LOW CENTERED NEAR 19N140W. ASSOCIATED 
INVERTED SURFACE TROUGH IS A FEW DEGREES TO THE E OF THIS DEEP 
LAYERED LOW EXTENDING FROM 10N-21N ALONG 134W. LOW-LEVEL 
CONVERGENCE COMBINED WITH INSTABILITY AND DIFFLUENCE ALOFT IS 
MAINTAINING A LARGE AREA OF SCATTERED MODERATE/ISOLATED STRONG 
CONVECTION FROM 15N-20N BETWEEN 126W-136W. 

BROAD MID/UPPER LEVEL TROUGH OVER THE N PORTION OF THE 
DISCUSSION AREA IS ALONG THE W COAST OF THE U.S. WITH AXIS 
32N121W TO 23N125W. A 90-95 KT JET STREAM EXTENDS FROM 28N125W
ACROSS CENTRAL BAJA CALIFORNIA INTO NORTHERN MEXICO. WEAK UPPER 
LEVEL RIDGE WITH AXIS FROM BAY OF CAMPECHE ACROSS MEXICO TO 
8N109W. UPPER LEVEL TROUGH EXTENDS FROM THE YUCATAN PENINSULA 
10N93W TO THE EQUATOR AT 83W. A LARGE AREA OF SUBSIDENCE 
WITH DRY STABLE AIR AT THE MIDDLE AND UPPER LEVELS OF THE 
ATMOSPHERE COVERS THE AREA S OF 20N E OF 110W.

A COLD FRONT ENTERS THE AREA AT 32N118W TO 29N130W TO 30N135W. 
NO SIGNIFICANT WEATHER ASSOCIATED WITH THE FRONT. A SURFACE 
TROUGH ANALYZED ALONG THE ITCZ FROM 7N-11N ALONG 106W. SCATTERED 
SHOWERS ARE WITHIN 90 NM EITHER SIDE OF TROUGH. HIGH PRES 
BUILDING N OF A FRONT IN THE GULF OF MEXICO HAS TIGHTENED THE 
GRADIENT OVER SOUTHERN MEXICO WITH GALE FORCE WINDS BLOWING 
THROUGH THE GULF OF TEHUANTEPEC. THE WINDS WILL DECREASE BELOW 
GALE FORCE LATER TONIGHT.

$$
DGS