000
AXPZ20 KNHC 041617
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC THU DEC 04 2008

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

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

...ITCZ...
FROM 07N78W TO 06N100W TO 09N116W TO 09N130W TO 07N140W. 
SCATTERED MODERATE CONVECTION WITHIN 60 NM OF AXIS E OF 86W AND 
WITHIN 90 NM N OF AXIS FROM 93W-101W.  SCATTERED MODERATE 
ISOLATED STRONG WITHIN 90 NM OF 08N130W.

...DISCUSSION...
DEEP LAYER TROUGH EXTENDS FROM CENTRAL MEXICO ALONG 102W TO THE 
EQUATOR MAINTAINING DRY AIR MASS WITHIN 5 DEG W OF AXIS DUE TO 
MODERATE TO STRONG SUBSIDENCE. BROAD MID/UPPER LEVEL RIDGE COVER 
ENTIRE E PAC W OF 107W WITH ANTICYCLONIC FLOW ADVECTING LARGE 
AMOUNTS OF TROPICAL MOISTURE N OF 06N W OF 112W.  WEAK 90 KT JET 
CORE HAS SMALL AREA OF UPPER LEVEL DIFFLUENCE ENHANCING DEEP 
CONVECTION NEAR 08N130W.  APPROACHING CYCLONIC VORTEX NOW AT 
21N142W LIKELY TO BRING CHANGES INTO W PART OF E PAC WITHIN NEXT 
24-36 HRS. 

MID/UPPER LEVEL RIDGE WITH ANTICYCLONE CENTERED AT 15N70W BRINGS 
ANOTHER SWATH OF TROPICAL MOISTURE E OF AFOREMENTIONED DEEP 
LAYER TROUGH MAINLY E OF 101W FEEDING ITCZ CONVECTION.  

AT THE SURFACE...
GULF OF PAPAGAYO STRONG WINDS CAUSED BY FRONTAL BOUNDARY OVER 
WRN CARIBBEAN AS 20-30 KT NE WINDS SPILL INTO E PAC.  WINDS 
EXPECTED TO LAST THROUGH FORECAST PERIOD. 

SHORT LIVED GALE FORCE WINDS EXPECTED ACROSS ISTHMUS OF 
TEHUANTEPEC AS FAST MOVING COLD FRONT CROSSES GULF OF MEXICO 
BRINGING COLD AIR MASS INTO BAY OF CAMPECHE WITHIN 12 HRS.  
GALE EVENT EXPECTED TO LAST ONLY 12-18 HRS AS HIGH PRES FORCES 
FRONT EASTWARD QUICKLY.  

$$
WALLY BARNES