000
AXPZ20 KNHC 160414
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC FRI NOV 16 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 
0300 UTC.

...ITCZ...
ITCZ AXIS CENTERED ALONG  9N83W  6N94W  9N113W  10N140W.  
ISOLATED MODERATE CONVECTION WITHIN 90 NM N OF AXIS FROM 90W-98W 
SCATTERED MODERATE CONVECTION WITHIN 120 NM N OF AXIS W OF 123W.

...DISCUSSION...
BROAD UPPER LEVEL RIDGE SPANS ACROSS ENTIRE REGION E OF 110W 
WITH MINOR TROPICAL MOISTURE AVAILABLE OVER CENTRAL AMERICA FROM 
HONDURAS TO PANAMA.  SCATTERED CONVECTION AS OVER PANAMA...COSTA 
RICA AND NICARAGUA AS RESULT OF WIND CONVERGING OVER EAST SIDE 
OF MOUNTAIN RANGE.  REMAINDER AREA E OF 110W IS UNDER RIDGE 
MODERATE TO STRONG SUBSIDING AIR MASS AND IS VERY DRY.

MID/UPPER LEVEL SHORT WAVE TROUGH AT 32N114W SHIFTING ITS TRACK 
NE AS DOWNSTREAM RIDGE BLOCKS ANY FURTHER SE INTRUSION.  LARGE 
AMPLITUDE LONGWAVE TROUGH DIGS S FROM SHORTWAVE TO 15N120W THEN 
SE TO 7N112W.  ENTIRE AREA N OF 20N W OF 115W REMAINS VERY DRY 
AS MID/UPPER LEVEL RIDGE BUILDS BEHIND SHIFTING SHORTWAVE.

SECOND UPPER LEVEL TROUGH ENTERS E PAC ON NW CORNER EXTENDING 
FROM 32N129W TO 22N140W.  TROUGH OF LITTLE IMMEDIATE CONSEQUENCE 
...BUT EVENTUALLY WILL ADVECT SOME SUBTROPICAL MOISTURE INTO 
REGION BY END OF FORECAST PERIOD. 

AT THE SURFACE...
HIGH PRES 1022 MB AT 30N132W EXTENDS RIDGE TO 15N105W.  LOW PRES 
1013 MB OVER N GULF OF CALIFORNIA...SUPPORTED BY UPPER LEVEL 
SHORTWAVE...CREATES PRES GRADIENT INCREASING NW WINDS ALONG BAJA 
CALIFORNIA COAST.  LOW PRES WEAKENS AND LIFTS NE WITHIN 6 HRS 
RELAXING GRADIENT AND HENCE DIMINISH WINDS.  HIGH PRES ALSO 
MAINTAINS NE TRADES W OF 122-125W FROM 10N-20N. 

STRONG COLD FRONT OVER GULF OF MEXICO MASSING UP WINDS ACROSS 
BAY OF CAMPECHE ENHANCING N FLOW ACROSS GULF OF TEHUANTEPEC TO 
GALE FORCE.  EVENT SHORT LIVED AS HIGH PRES QUICKLY MOVES E OF 
GULF AND WINDS RETURN TO EASTERLIES.  SIMILARLY...GULF OF 
PAPAGAYO NE WINDS INCREASE TO 20-25 KT THROUGH PERIOD AS HIGH 
PRES AFFECTS NW CARIBBEAN SEA.   

$$
WALLY BARNES