000
AXPZ20 KNHC 270405
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC TUE NOV 27 2007

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

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0330 UTC.
 
...ITCZ...
INTERTROPICAL CONVERGENCE ZONE...AXIS ALONG 8N82W 8N110W 10N125W 
9N140W. SCATTERED MODERATE WITHIN 120-180 NM EITHER SIDE OF AXIS 
BETWEEN 116W AND 122W...AND W OF 130W. SCATTERED MODERATE WITHIN 
45-60 NM OF THE AXIS BETWEEN 86W AND 90W. 

...DISCUSSION...
A PROGRESSIVE BUT AMPLIFIED PATTERN DOMINATES THE UPPER LEVELS 
OF THE E PACIFIC WITH A COUPLE OF UPPER SHORTWAVE TROUGHS 
EXTENDING INTO THE DISCUSSION AREA. THE FIRST TROUGH OVER THE NW 
PORTION EXTENDS ALONG 32N121W INTO AN ELONGATED UPPER CYCLONE 
NEAR 25N124W WITH THE TROUGH CONTINUING S TO A BASE NEAR 
16N127W. STRONG UPPER LEVEL SUBSIDENCE IS WRAPPING AROUND THE SW 
SIDE OF THE CYCLONE AND INTO 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 IS SHEARING OUT RAPIDLY 
TO THE NE ALONG 32N87W 22N98W THROUGH A SMALL UPPER CYCLONE NEAR 
15N106W WITH THE TROUGH CONTINUING SSE TO A BASE AT 3N107W. DRY 
UPPER LEVEL SUBSIDENCE IS NOTED WITHIN 480 NM W OF LINE 30N90W 
20N97W 9N110W.

BETWEEN THESE TWO UPPER TROUGHS AN TROPICAL UPPER RIDGE EXTENDS 
NWD FROM THE EQUATOR TO 14N ALONG 130W...AND WAS BECOMING 
FRACTURED FROM ANOTHER RIDGE EXTENDING NWD OVER NE MEXICO AND 
THE SW U.S. WITH AXIS ALONG 115W. AXIS OF SUBTROPICAL JTST ALONG 
17N140W EWD TO 15N125W...THEN TURNS NEWD THROUGH 20N121W THROUGH 
CENTRAL BAJA CALIFORNIA INTO THE SW CONUS AND SRN PLAINS. 
SATELLITE DERIVED WINDS INDICATED SPEEDS OF 90-100 KT NEAR 140W 
AND 70-80 KT ELSEWHERE. JTST WAS ADVECTING MID TO UPPER LEVEL 
MOISTURE ORIGINATING FROM ITCZ CONVECTION W OF THE AREA NEAR 
13N145W AND BETWEEN 122W AND 137W NEWD OVER 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 

AT THE LOW LEVELS...WEAK RIDGING DOMINATES THE AREA N OF 12N W 
OF 110W WITH A 1028 MB HIGH CENTER N OF THE AREA NEAR 36N129W.

GAP WINDS...0032 UTC QUIKSCAT PASS INDICATED NE WINDS PULSING 
TO 20 KT WITH FETCH LIMITED SEA HEIGHTS OF LESS THAN 8 FT OVER 
PAC WATERS DOWNSTREAM OF THE GULF OF PAPAGAYO. THESE CONDITIONS 
ARE EXPECTED OVER THE NEXT 24-36 HOURS WITH WINDS INCREASING 
TO 20-25 KT BY 48 HOURS. THE SAME QUIKSCAT PASS INDICATED NLY 
WINDS OF 25 KT...LOCALLY 30 KT IN THE GULF OF TEHUANTEPEC. THE 
WINDS ARE EXPECTED TO INCREASE FURTHER AND REACH GALE FORCE AS 
EARLY AS TUE MORNING AND CONTINUE IN THE 25-35 KT RANGE THROUGH 
48 HOURS.
  
$$
COBB