000
AXPZ20 KNHC 310926
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC FRI OCT 31 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...
ITCZ AXIS IS CENTERED ALONG 08N78W TO 07N92W TO 11N117W TO 
11N134W TO 09N140W. SCATTERED MODERATE TO STRONG CONVECTION IS 
FROM 06N TO 09N BETWEEN 87W AND 99W. SCATTERED MODERATE 
CONVECTION IS WITHIN 60 NM OF THE AXIS BETWEEN 134W 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. WHILE THIS FEATURE 
WILL BE DRAGGING A COLD FRONT ACROSS THE NW CORNER OF THE AREA 
THIS WEEKEND...IT IS EXPECTED TO WEAKEN QUICKLY AS THE LOWS 
CONSOLIDATE AND 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 SFC TROUGH IS PERTURBING THE ITCZ ALONG 118W FROM 10N-16N.  
MODERATE CONVECTION IS SCATTERED WITHIN 90 NM W AND 270 NM E OF 
THE TROUGH AXIS. STRONG S TO SW MID-UPPER FLOW IS LIMITING 
SIGNIFICANT ORGANIZATION AND SPREADING DEBRIS CLOUDINESS THROUGH 
CENTRAL MEXICO. THIS FEATURE WILL LIKELY CONTINUE W AS A WEAK 
TROUGH OVER THE NEXT FEW DAYS. ANOTHER WEAK LOW-LEVEL TROUGH IS 
EMBEDDED IN THE ITCZ ALONG 95W...ENHANCING SCATTERED MODERATE TO 
STRONG CONVECTION (OUTLINED ABOVE). 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 FUNNELING THRU 
THE GULF OF TEHUANTEPEC. A QSCAT PASS AROUND 00Z 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.

$$
CANGIALOSI