000
AXPZ20 KNHC 080929
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SAT DEC 08 2007

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 
0845 UTC.
 
...ITCZ...
INTERTROPICAL CONVERGENCE ZONE AXIS ALONG 7N78W 7N95W 12N117W 
9N131W 8N140W. ISOLATED MODERATE CONVECTION NEAR 6N79W AND 
9N122W.  

OTHER MODERATE CONVECTION ALONG A LINE FROM 19N111W TO 16N117W 
TO 12N121W.

...DISCUSSION...

LARGE POOL OF COLD AIR SPILLING SWD AT MID LEVELS ALONG 120W. 
GFS MODEL IN GOOD AGREEMENT WITH LATEST WATER VAPOR IMAGERY. OLD 
MID LEVEL CYCLONIC CENTER ALSO HANDLED WELL BY GFS MODEL. 
POSITION NEAR SW BAJA COAST ACCORDING TO WATER VAPOR IMAGERY. 
BROAD MID LEVEL RIDGE COVERING MOST OF AREA WEAKENING BETWEEN 
110W AND 130W AS COLD AIR ALOFT SPILLS SWD. WRN RIDGE CENTER 
ALONG 140W BUILDING NWD. ON THE SURFACE TONIGHT PACIFIC RIDGE 
HAS STRENGTHENED WITH MID LEVEL RIDGE OVERHEAD..THUS NE TRADES 
20 TO 25 KT W OF 130W. RIDGE ALSO SUPPORTING GOOD NLY FLOW 20 TO 
25 KT BETWEEN 120W AND 130W N OF 25N. WINDS ALONG THE BAJA COAST 
REMAIN LIGHT BUT WINDS WILL INCREASE ALONG N COAST NEXT 12 HR. 
GAP WINDS MOSTLY LIGHT WITH WEAK PRES GRADIENT. CROSS EQUATORIAL 
SLY WINDS TO 20 KT NOTED IN LATEST SSMI IMAGERY S OF 5N W OF 
110W..OTHERWISE MOSTLY 10 TO 15 KT.

LATER DAY 1 STRONG UPPER TROUGH OVER SRN CA WILL CONTINUE TO 
LOWER MID LEVEL HEIGHTS N OF 20N BETWEEN 105W AND 130W. MID 
LEVEL RIDGE REMAINS IN PLACE ALONG 140W. ON THE SURFACE LATER 
DAY 1 PACIFIC RIDGE REMAINS IN PLACE BUT EXTENDS TO COAST OF 
BAJA THEREFORE NW WINDS INCREASE 15 TO 20 KT. LITTLE CHANGE TO 
NE TRADES. GAP WINDS BEGIN TO INCREASE W OF PAPAGAYO TO 20 KT AS 
HIGH PRES BUILDS OVER THE WRN CARIBBEAN. CROSS EQUATORIAL SLY 
WINDS REMAIN ABOUT THE SAME WITH 15 TO 20 KT S OF 5N W OF 110W.

FOR DAY 2 GFS MODEL SHOWS NEW SURGE OF COLD AIR ALOFT DIVING SWD 
ALONG 115W STILL LOWERING MID LEVEL HEIGHTS N OF 20N BETWEEN 
105W AND 130W. MID LEVEL RIDGE REMAINS IN PLACE ALONG 140W BUT 
WEAKENS SOME. ON THE SURFACE DAY 2 THE PACIFIC RIDGE REMAINS IN 
PLACE BUT WEAKENS 3 TO 4 MB THUS NE TRADES DIMINISH TO 15 TO 20 
KT. WINDS ALONG THE BAJA COAST WEAKEN ALSO TO 10 TO 15 KT. GAP 
WINDS THROUGH PAPAGAYO REMAIN ABOUT THE SAME AT 15 TO 20 KT. 
CROSS EQUATORIAL SE WINDS S OF 5N W OF 110W DECREASE TO 10 TO 15 
KT.  

$$
RRG