000
AXPZ20 KNHC 072130
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC THU DEC 07 2006

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG...5N78W 5N90W 4N100W 5N110W 8N123W 
7N120W 7N140W. SCATTERED MODERATE WITH ISOLATED STRONG 
CONVECTION IS WITHIN 60 NM EITHER SIDE OF THE AXIS BETWEEN 116W 
AND 120W...AND WITHIN 30 NM EITHER SIDE OF THE AXIS BETWEEN 
127.5W AND 132W.

...DISCUSSION...

MIDDLE AND UPPER LEVELS...

MIDDLE AND UPPER LEVEL TROUGH WITH EMBEDDED CYCLONIC CIRCULATION 
EXTENDS ALONG LINE 32N106W TO CYCLONIC CENTER NEAR 28N111.3W AND 
CONTINUES TO 21N112W.  THIS SYSTEM IS MOVING EAST AND IS CAUSING 
MIDDLE AND UPPER LEVEL UPWARD MOTION OVER MOST OF MEXICO NORTH 
OF 20N WITH MULTI LAYER CLOUDS OVER THE AREA. THE AREA NEAR THE 
ARIZONA AND CALIFORNIA BORDER AND BAJA CALIFORNIA ARE WEST OF 
THIS UPWARD MOTION AND ARE CLOUD FREE.  A LARGE AREA OF DRY AND 
CLOUD FREE AIR IS NORTH OF 20N EAST OF 122W.  

ANOTHER MIDDLE AND UPPER LEVEL TROUGH IS OVER THE NORTHWEST PART 
OF THE AREA AND IS NORTHWEST OF A LINE 32N32N135W TO 23N140W.  
CLOUDINESS ASSOCIATED WITH THIS SYSTEM IS MOSTLY NORTH OF 32N.  
A STRONG COLD FRONT ASSOCIATED WITH THIS SYSTEM IS OVER THE 
NORTHWEST PART ALONG LINE 32N138.5W TO 30N140W. ASSOCIATED GALE 
CONDITIONS ARE NORTH OF 30N.

ANOTHER MIDDLE AND UPPER LEVEL TROUGH WITH AN EMBEDDED CYCLONIC 
CIRCULATION IS ALONG LINE 20N135W TO 10N140W.  THE EMBEDDED 
CYCLONIC CIRCULATION IS LOCATED NEAR 18N139W.  AN AREA OF WIDELY 
SCATTERED MODERATE CONVECTION IS LOCATED WITHIN 60 NM OF 
17.3N137.4W.  

THE REMAINDER OF THE MIDDLE AND UPPER LEVELS IS COVERED BY A 
BROAD RIDGE.

SURFACE...
COLD FRONT THROUGH 32N138W TO 30N140W WITH ASSOCIATED TROUGH 
NORTH OF 25N WEST OF 135W.  WEAK RIDGE ELSEWHERE NORTH OF 13N 
WEST OF 115W.  ELSEWHERE BROAD TROUGH IS 
ANALYZED.

GAP WINDS...
NE WINDS IN THE 20-30 KT RANGE OVER THE GULF OF TEHUANTEPEC AS
OBSERVED IN A MORNING QUIKSCAT PASS ARE EXPECTED TO INCREASE ONCE
AGAIN TO GALE FORCE IN 18 HOURS AS THE GRADIENT OVER MEXICO 
TIGHTENS. SEAS IN THE GULF OF TEHUANTEPEC CURRENTLY TOPPING UP 
TO 13 FT WILL CHANGE LITTLE THROUGH THE NEXT 18 HOURS THEN 
INCREASE SLIGHTLY ONCE THE EVENT BEGINS. THIS NEXT GALE EVENT IS 
EXPECTED TO CONTINUE TO POSSIBLY INTO SUN AFTERNOON.

NE WINDS OF 20 KT ACROSS THE GULF OF PAPAGAYO ARE EXPECTED TO 
DIMINISH TO LESS THAN 20 KT WITHIN THE NEXT 18 HOURS.

$$
LL