000
AXPZ20 KNHC 292155
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC FRI OCT 29 2010

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

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 2100 UTC.

...ITCZ...
AXIS FROM 09N84W TO 09N101W TO 11N108W TO 10N117W TO 13N126W TO 
09N140W.  ISOLATED MODERATE CONVECTION WITHIN 90 NM OF AXIS E OF 
92W.  SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 120 
NM OF AXIS FROM 105W TO 120W.

...DISCUSSION...
HIGHLY AMPLIFIED UPPER LEVEL TROUGH EXTEND FROM 32N127W TO 
2N140W USHERING COLD FRONT INTO NW PORTION OF BASIN.  TROUGH 
LIFT NE SAT ALLOWING FRONT TO STALL SAT AND DISSIPATE SUN. 
PLENTY OF TROPICAL MOISTURE ADVECTED N RIDING ON 125 KT JET CORE 
IN THE PATH OF HEALTHY 1007 MB SURFACE LOW PRES APPROACHING 
SOUTHERN CALIFORNIA.  SIGNIFICANT AMOUNT OF RAINFALL COULD BE 
EXPECTED OUT OF THIS ENCOUNTER.  ELSEWHERE...OVERCAST TO BROKEN 
LOW AND MID CLOUDS WITH ISOLATED SHOWERS WITHIN 90 NM W OF 
FRONTAL BOUNDARY.  ONLY LIGHT TO MODERATE WINDS ON EITHER SIDE 
OF FRONT.  HOWEVER MAIN PROBLEM IS LARGE NW SWELLS UP TO 15 FT 
BEHIND FRONT SPREADING SE THROUGH FORECAST PERIOD SUBSIDE BY 
LATE SUN.

SURFACE LOW PRES 1013 MB EMBEDDED IN ITCZ AT 14N124W HAS SURFACE 
TROUGH EXTENDING TO 18N123W.  FRESH NE WINDS WITH 60 NM W OF 
TROUGH AND WITHIN 120 NM NE QUADRANT OF LOW PRES.  LOW PRES 
FORECAST TO DISSIPATE IN 24 HOURS AS WEAK 1015 MB RIDGE IS 
FORCED SE BY COLD FRONT.  RIDGE REBUILDS LATE SUN AS COLD FRONT 
DISSIPATE AND ALLOWS FOR WEAK TRADES TO CONTINUE.

BROAD UPPER LEVEL ANTICYCLONE MOVING E OVER FAR W TEXAS ALLOWS 
TROPICAL MOISTURE TO INTRUDE INTO E PAC ALONG ITCZ LATITUDE WITH 
CONVECTIVE ACTIVITY INCREASING E OF 121W.  ELSEWHERE...VERY DRY  
AIR PREVALENT UNDER RIDGE N OF 15N FROM 110W TO 120W.

GAP WINDS...
NORTHERLY WINDS SURGING ACROSS SOUTHERN GULF OF MEXICO THROUGH 
CHIVELAS PASS INTO GULF OF TEHUANTEPEC.  GALE FORCE WINDS BEGAN 
EARLIER LAST NIGHT EXPECTED TO PEAK AT 40 KT TONIGHT INTO SAT 
MORNING THEN DIMINISH TO LESS THAN GALE FORCE LATE SAT NIGHT. 
SEAS FORECAST TO BUILD TO 14 FT TONIGHT INTO SAT MORNING THEN 
SUBSIDE LATER SAT NIGHT AND SUN.

$$
WALLY BARNES