000
AXPZ20 KNHC 020931
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SUN DEC 2 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 
0900 UTC.
 
...ITCZ...

ITCZ AXIS ALONG 9N77W 8N86W 6N99W 7N111W 6N122W 9N140W. ISOLATED 
MODERATE CONVECTION NEAR 6N89W 9N99W 11N111W 8N118W AND 10N133W. 

...DISCUSSION...

STRONG ZONAL FLOW N OF 27N TONIGHT EJECTING REMNANT OF SHORTWAVE 
OVER SW CONUS. SRN BRANCH OF WESTERLIES TRYING TO SET UP S OF 
20N WITH A MODERATE SHORTWAVE TROUGH ALONG 130W. MID LEVEL RIDGE 
OVER CENTRAL MEXICO EXTENDS NE. ON THE SURFACE THIS EARLY 
MORNING INCREASING PRES GRADIENT OVER NW SECTION AHEAD OF A NEW 
COLD FRONT WITH WINDS 20 TO 25 KT AND BUILDING SEAS. PACIFIC 
HIGH NEAR 28N121W AT 1023 MB WITH WINDS ALONG THE BAJA COAST 5 
TO 10 KT N OF PT EUGENIO AND 10 TO 15 KT S OF THE PT. NE TRADES 
15 TO 20 KT S OF RIDGE BETWEEN 10N AND 20N FROM 110W TO 130W. 
GAP WINDS TO 20 KT W OF PAPAGAYO OTHERWISE LIGHT. CROSS 
EQUATORIAL SLY WINDS TO 20 KT S OF 5N W OF 110W ACCORDING TO 
SSMI IMAGERY. 

LATER DAY 1 MID LEVEL HEIGHTS CONTINUE TO FALL OVER THE NW 
PORTION AS A STRONG TROUGH APPROACHES FROM THE NW. WEAKENING 
SHORTWAVE IN SRN BRANCH HAVING TROUBLE MOVING OUT OF THE AREA 
DUE TO A BLOCKING MID LEVEL RIDGE OVER CENTRAL MEXICO EXTENDING 
W TO 128W. ON THE SURFACE LATER DAY 1 GALE CONDITION OVER NW 
SECTION N OF 25N W OF 132W WITH INCREASING NW SWELL 15 TO 18 FT. 
PACIFIC RIDGE MOVES TO 30N120W STRENGTHENS SOME WITH INCREASE IN 
NE TRADES 20 KT BETWEEN 10N AND 20N W OF 110W. GAP WINDS CHANGE 
LITTLE. CROSS EQUATORIAL SLY WINDS MOSTLY 10 TO 15 KT.

FOR DAY 2 BLOCKING MID LEVEL RIDGE SETS UP ALONG 115W. STRONG 
SHORTWAVE TROUGH NW OF AREA HEADS EWD AND MID LEVEL HEIGHTS 
BEGIN TO RISE OVER NW SECTION. WEAK MID LEVEL SHORTWAVE TROUGH 
WORKS IT'S WAY AROUND BLOCKING RIDGE AND MOVES SE TO NW MEXICO. 
ON THE SURFACE DAY 2 WINDS OVER NW SECTOR BEGIN TO WEAKEN BUT 
STILL GUSTY S TO SW 25 TO 30 KT. NW SWELL OF 18 TO 27 FT 
CONTINUES N OF 26N W OF 130W. PACIFIC RIDGE CHANGES LITTLE AND 
NE TRADES REMAIN ABOUT THE SAME. WINDS ALONG THE BAJA COAST NLY 
15 KT. GAP WINDS THROUGH TEHUANTEPEC INCREASE SOME TO 20 KT KT 
WITH SEAS TO 7 FT. CROSS EQUATORIAL SLY WINDS REMAIN 10 TO 15 
KT.  

$$
RRG