000
AXPZ20 KNHC 111614
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC TUE DEC 11 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 
1445 UTC.
 
...ITCZ...
INTERTROPICAL CONVERGENCE ZONE ALONG...7N78W  9N108W  7N124W  
9N140W.  SCATTERED MODERATE TO STRONG CONVECTION WITHIN 60 NM OF 
11N107W.  ISOLATED MODERATE CONVECTION WITHIN 90 NM OF AXIS W OF 
132W.

...DISCUSSION...
UPPER LEVELS...
DEEP LAYER CYCLONIC VORTEX NOW MOVING N-NE AS WELL ANCHORED MID-
UPPER LEVEL RIDGE CENTERED OVER GUATEMALA BLOCKED ANY FURTHER 
SE DISPLACEMENT.  ASSOCIATED UPPER LEVEL TROUGH NOW DIGS TO 
16N115W THEN TO THE EQUATOR AT 97W.  JET CORE 125 KT ON LEE SIDE 
OF TROUGH ADVECTING LARGE AMOUNTS OF TRPCL MOISTURE ACROSS 
CENTRAL MEXICO.  HOPEFULLY THIS SOURCE OF WATER WILL BE OUT OF 
THE WAY BY THE TIME THE REMNANTS OF SUBTRPCL STORM OLGA APPROACH 
CENTRAL AMERICA LATE FRI. 

UPSTREAM...LARGE AMPLITUDE BUT NARROW RIDGE ALONG 132W ALSO 
ADVECTING LARGE AMOUNTS OF MOISTURE INTO E PAC W OF ITS AXIS.  
NO IMMEDIATE MECHANISM TO PROMPT DEEP CONVECTION AT THIS TIME 
BUT FORMATION OF LOW PRES ON SURFACE NEAR 108W COULD BECOME MORE 
CRITICAL IF OR WHEN THESE TWO INGREDIENTS COLLIDE.  GLOBAL 
MODELS APPEAR TO TAKE THIS LIGHTLY WITH LOW PRES OPENING UP TO A 
TROUGH BY LATE FRI...BUT STILL COULD BE ENOUGH LIFTING MECHANISM 
TO CAUSE DEEP CONVECTION. 

SURFACE...
HIGH PRES CENTER 1027 MB AT 32N137W HAS RIDGE EXTEND TO 22N120W 
TIGHTENING GRADIENT WITH LOW PRES NOW AT 9N108W.  TRADES 
INCREASE IN STRENGTH AND COVERAGE THROUGH FORECAST PERIOD. 
ITCZ SHORTCHANGED OF MOISTURE ALONG MOST OF ITS AXIS EXCEPT W OF 
132W WHERE UPPER RIDGE SUPPLIES IT AND WITHIN 90 NM OF LOW PRES 
CENTER 1010 MB.  

GAP WINDS...STRONG CARIBBEAN WINDS EXPECTED TO DIMINISH WITHIN 
36 HRS AS SUBTROPICAL STORM OLGA APPROACHES BRINGING PRES 
GRADIENT DOWN.   

$$
WALLY BARNES