000
AXPZ20 KNHC 261557
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC MON NOV 26 2007

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

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1545 UTC.
 
...ITCZ...
INTERTROPICAL CONVERGENCE ZONE...AXIS ALONG 8N79W 6N86W 10N120W 
9N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION NOTED 
WITHIN 15 NM EITHER SIDE OF LINE 6N78W 7N96W AND ALSO WITHIN 30 
NM EITHER SIDE OF LINE 8N108W 9N113W 7N120W 8N134W. 

...DISCUSSION...
A PROGRESSIVE PATTERN DOMINATES THE UPPER LEVELS OF THE E PAC 
WITH A COUPLE OF UPPER SHORTWAVE TROUGHS EXTENDING INTO THE 
DISCUSSION AREA. THE FIRST TROUGH OVER THE NW PORTION EXTENDS 
ALONG 32N121W INTO AN UPPER CYCLONE AT 26N126W WITH THE TROUGH 
CONTINUING S TO A BASE AT 17N131W. DRY UPPER AIR IS NOTED W OF 
THE CYCLONE AND THE TROUGH. WELL TO THE NW OF THE DISCUSSION 
AREA AN UPPER RIDGE IS COLLAPSING SE WITH UPPER MOISTURE NOW 
SPILLING OVER THE AREA NW OF LINE 27N140W 32N130W. FURTHER E... 
THE SECOND SHORTWAVE TROUGH EXTENDS ALONG 32N94W 23N98W THROUGH 
A SMALL UPPER CYCLONE AT 13N109W WITH THE TROUGH CONTINUING SSE 
TO A BASE AT 3N107W. DRY UPPER AIR IS NOTED WITHIN 480 NM W OF 
LINE 30N90W 20N97W 9N110W.

BETWEEN THESE TWO UPPER TROUGHS AN UPPER RIDGE EXTENDS N ACROSS 
THE EQUATOR AT 136W...AND CONTINUES NE ALONG 18N120W TO A CREST 
OVER THE DESERT SW OF THE CONUS AT 36N110W. UPPER DEBRIS 
MOISTURE...ORIGINATING FROM ITCZ CONVECTION W OF THE AREA NEAR 
13N145W AND BETWEEN 122W AND 137W...IS ADVECTED N ALONG THE 
RIDGE WITHIN 300 NM EITHER SIDE OF LINE 14N140W 15N125W TO 
BEYOND 35N105W. UPPER SW FLOW DOMINATES THE UPPER LEVELS OF THE 
DISCUSSION AREA E OF 100W...WITH VERY DRY UPPER AIR SUPPRESSING 
ITCZ CONVECTION TO A VERY THIN LINE DESCRIBED ABOVE.   

AT THE LOW LEVELS...WEAK RIDGING EXTENDS FROM NEAR 32N140W TO 
10N110W.  

GAP WINDS...NE WINDS EXPECTED TO PULSE TO 20 KT WITH FETCH 
LIMITING SEAS HEIGHTS TO LESS THAN TO 8 FT OVER PAC WATERS IN 
AND DOWNSTREAM OF THE GULF OF PAPAGAYO FOR THE NEXT FEW DAYS.
N TO NE 20 KT WINDS EXPECTED SURGE INTO THE GULF OF TEHUANTEPEC 
LATER THIS MORNING AND GRADUALLY INCREASE TO A MINIMAL GALE IN 
ABOUT 24 HOURS...AND CONTINUE IN THE 25-35 KT RANGE INTO 48 
HOURS THEN DIMINISH.     
  
$$
NELSON