000
AXPZ20 KNHC 072205
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SUN DEC 07 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 
2145 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 6N78W 8N90W 8N105W 8N120W 9N130W
8N140W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN
180 NM S OF THE AXIS BETWEEN 114W-119W.

...DISCUSSION...

A WELL-DEFINED CUT-OFF MIDDLE/UPPER LEVEL CYCLONIC 
CIRCULATION...ABOUT 5 DEG IN DIAMETER...IS NEARLY STATIONARY 
NEAR 22N138W WITH A TROUGH EXTENDING SSW TO 12N139W. A JET STREAM
BRANCH WITH MAXIMUM WINDS OF 50-90 KT ENTERS THE ROUNDS THE BASE
OF THE TROUGH FROM 12N140W NE TO 20N128W TO 25N120W TO ACROSS 
FAR SOUTHERN CALIFORNIA AND NORTHERN BAJA CALIFORNIA...AND 
DIVES SEWD ACROSS THE SW UNITED STATES AND INTO CENTRAL MEXICO.
DUE TO THE CURRENT SET UP OF LOW AND TROUGH WITH STRONG SW WINDS
ACCOMPANYING THE JET STREAM...AMPLE MID AND UPPER LEVEL 
SUB-TROPICAL MOISTURE IN THE FORM OF MIDDLE AND HIGH BROKEN TO 
OVERCAST CLOUDS WILL CONTINUE TO BE CHANNELED NORTHEASTWARD FROM 
THE CENTRAL PACIFIC NE TOWARDS MUCH OF MEXICO...INCLUDING BAJA 
CALIFORNIA AND SOUTHERN CALIFORNIA THROUGH THE NEXT 48 HOURS AS 
THE LOW THEN DRIFTS E. AT THE SURFACE...A TROUGH IS ANALYZED IN 
THE VICINITY OF THE LOW ALONG 138W FROM 20N-25N. SCATTERED 
SHOWERS ARE POSSIBLE WITHIN 30 NM EITHER SIDE OF THE TROUGH.

TO THE E OF THE LOW AND TROUGH...MID/UPPER LEVEL RIDGING IS 
NOTED OVER THE AREA S OF 25N BETWEEN 106W-124W WITH A MEAN AXIS
ROUGHLY ALONG 115W. WHERE THE JET STREAM MAKES ITS TURN TO THE 
NE AT 128W...A SPLIT FLOW PATTERN EXISTS WITH ANOTHER BRANCH OF 
THE JET STREAM DIVING SE THROUGH 19N114W TO 10N106W. A ZONE 
UPPER LEVEL DIFFLUENCE CONTINUES TO ENHANCE THE AREA OF CLOUDS 
FROM 13N-20N BETWEEN 128W-135W. SCATTERED MODERATE/ISOLATED 
STRONG CONVECTION IS EMBEDDED WITHIN THIS AREA WITHIN 30-45 NM 
EITHER SIDE OF A LINE FROM 13N134W TO 15N132W TO 18N132W. A 
SURFACE TROUGH IS ANALYZED WITHIN THIS AREA ALONG 121W FROM 
6N-12N. MODERATE SUBSIDENCE WITH DRY STABLE IS ENTERING THE FAR
WESTERN PORTION OF THE AREA BEHIND THE UPPER LOW AND TROUGH.
STRONG SUBSIDENCE AND RATHER STABLE CONDITIONS ARE PRESENT OVER 
THE EASTERN PORTION OF THE AREA W OF 104W. SURFACE RIDGE EXTENDS
FROM 32N127W TO 20N109W.

$$
AGUIRRE