000
AXPZ20 KNHC 152205
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC THU NOV 15 2007

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 
2100 UTC.

...ITCZ...
ITCZ AXIS IS CENTERED ALONG  8N77W 9N83W 7N105W 10N130W 9N140W.  
SCATTERED MODERATE CONVECTION FROM 6N-14N BETWEEN 105W-114W. 
SCATTERED MODERATE CONVECTION WITHIN 120 NM OF AXIS W OF 130W.

...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 CUT-OFF CYCLONIC VORTEX AT 30N115W SHIFTING ITS 
TRACK NE AS DOWNSTREAM RIDGE BLOCKS ANY FURTHER SE INTRUSION.  
LARGE AMPLITUDE TROUGH DIGS S 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 CYCLONIC VORTEX.  

SECOND UPPER LEVEL TROUGH ENTERS E PAC ON NW CORNER EXTENDING 
FROM 32N131W 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 1023 MB AT 31N132W EXTENDS RIDGE TO 15N105W.  LOW PRES 
1013 MB OVER N BAJA CALIFORNIA...REFLECTION OF UPPER LEVEL 
VORTEX...CREATES PRES GRADIENT INCREASING NW WINDS ALONG BAJA 
CALIFORNIA COAST.  LOW PRES WEAKENS AND LIFTS NE WITHIN 12 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