000
AXPZ20 KNHC 311533
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC FRI OCT 31 2008

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 1500 UTC.

...ITCZ...
ITCZ AXIS IS CENTERED ALONG 08N78W TO 07N104W TO 14N120W TO 
10N140W. SCATTERED MODERATE TO ISOLATED STRONG FROM 04N TO 08N 
BETWEEN 77W AND 86W...AND FROM 04N TO 09N BETWEEN 92W AND 100W. 
SCATTERED MODERATE FROM 10N TO 14N BETWEEN 118W AND 121W...AND 
FROM 10N TO 13N BETWEEN 131W AND 136W.

...DISCUSSION...

A LARGE AND COMPLEX DEEP LAYER LOW PRESSURE SYSTEM IS CENTERED N 
OF THE ZONE OFF THE WEST COAST OF THE U.S. THIS SYSTEM HAS AN 
ASSOCIATED COLD FRONT THAT WILL BE OVER THE NW CORNER OF THE 
AREA WITHIN 24 HOURS. THE FRONT IS EXPECTED TO WEAKEN QUICKLY AS 
THE LOW CENTERS TURN NWD. THE MAIN EFFECT WILL BE THE LONG 
PERIOD NW SWELL WHICH IS FORECAST TO ELEVATE SEAS TO 15 FT 
ACROSS THE FAR NW WATERS THIS WEEKEND THEN SLOWLY SUBSIDE BUT 
SPREAD SW INTO EARLY NEXT WEEK. 

A SURFACE TROUGH IS NEAR THE ITCZ ALONG 135W FROM 08N TO 15N. 
SCATTERED MODERATE CONVECTION IS FROM 10N TO 13N BETWEEN 131W 
AND 136W. A ANOTHER SURFACE TROUGH IS PERTURBING THE ITCZ ALONG 
119W FROM 10N TO 16N.  SCATTERED MODERATE CONVECTION IS FROM 10N 
TO 14N BETWEEN 118W AND 121W. WIDELY SCATTERED MODERATE 
CONVECTION IS FURTHER N FROM 14N TO 17N BETWEEN 115W TO 119W. 
STRONG S TO SW MID-UPPER FLOW IS LIMITING SIGNIFICANT 
ORGANIZATION AND SPREADING DEBRIS CLOUDINESS THROUGH CENTRAL 
MEXICO. THIS FEATURE WILL LIKELY CONTINUE TO MOVE W AS A WEAK 
TROUGH OVER THE NEXT FEW DAYS. A THIRD WEAK LOW-LEVEL TROUGH IS 
EMBEDDED IN THE ITCZ ALONG 95W PRODUCING SCATTERED MODERATE TO 
ISOLATED STRONG FROM 04N TO 09N BETWEEN 92W AND 100W. THIS 
FEATURE IS LIKELY BEING ENHANCED BY ADDED VORTICITY ASSOCIATED 
WITH THE GAP OF TEHUANTEPEC AND PAPAGAYO WIND REGIMES.

THE COMBINATION OF STRONG SFC HIGH PRES CENTERED OVER THE 
SOUTHEAST U.S. AND A STALLED FRONTAL TROUGH OVER THE NW 
CARIBBEAN CONTINUES TO PRODUCE GALE FORCE N WINDS THROUGH THE 
GULF OF TEHUANTEPEC. A QSCAT PASS REVEALED MAX WINDS NEAR 
40 KT IN THE GAP AND A MORE RECENT ASCAT PASS SHOWED MAX WINDS 
NEAR 35 KT...BOTH SUPPORTING WARNING CRITERIA. LITTLE CHANGE IS 
EXPECTED OVER THE NEXT COUPLE OF DAYS AS THE LARGE SCALE PATTERN 
HOLDS.

$$
FORMOSA