000
AXPZ20 KNHC 051512
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC TUE OCT 05 2010

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 
1300 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE IS ANALYZED FROM 09N85W TO 
08N93W TO LOW PRES 10N106W TO LOW PRES 13N119W TO 10N140W. 
ISOLATED MODERATE CONVECTION LIES E OF 88W WITHIN 90 NM S OF THE 
ITCZ AXIS AND N OF THE ITCZ AXIS OVER FORECAST WATERS TO 11N. 

...DISCUSSION...

ALOFT...AN UPPER LOW OVER CALIFORNIA NEAR 37N120W HAS CUT OFF 
FROM THE POLAR JET AND EXTENDS A TROUGH SW TO 28N124W TO 
24N140W. THE SUBTROPICAL RIDGE IS DISPLACED FAR SOUTH OF ITS 
USUAL POSITION...WITH AN ANTICYCLONE NEAR 10N99W EXTENDING A 
RIDGE TO ITS NW TO 16N115W AND TO ITS NE TO 14N92W. AS A 
RESULT...WESTERLY WINDS COVER ALMOST THE ENTIRE FORECAST AREA N 
OF 15N. THIS PATTERN IS USUALLY FOUND MUCH LATER IN THE FALL OR 
EARLY WINTER INSTEAD OF EARLY OCTOBER. TO THE W OF THE 
ANTICYCLONE LIES A WEAK UPPER LOW NEAR 10N120W. 

SURFACE...CURRENT SATELLITE IMAGERY AND SCATTEROMETER DATA FROM 
OVERNIGHT INDICATE WEAK CYCLONIC CIRCULATIONS EMBEDDED IN THE 
ITCZ NEAR 10N106W AND 13N119W. 1033 MB HIGH PRESSURE N OF AREA 
NEAR 43N132W IS HELPING TO SUSTAIN TWO SEPARATE REGIONS OF 
HIGHER WINDS AND SEAS ASSOCIATED WITH THE PRESSURE GRADIENT 
BETWEEN THIS HIGH AND THE ITCZ W OF THE LOW NEAR 13N119W AS WELL 
AS ALONG THE COAST OF CALIFORNIA. SHIP DGDD NEAR 30N116W SHOWED 
NW WINDS AROUND 20 KT DIPPING INTO FAR NW WATERS AT 1200 UTC 
THIS MORNING. THE WINDS CAUSED BY THIS STRONG GRADIENT ALONG THE 
COAST OF CALIFORNIA HAS GENERATED SHORT PERIOD NW TO N SWELL 
THAT HAS BROUGHT SEAS TO THE 8 TO 10 FT RANGE OVER NE PART OF 
THE DISCUSSION AREA. THIS SWELL WILL CONTINUE OVER THE AREA N OF 
26N BETWEEN 117W AND 130W WED AND THU. CROSS-EQUATORIAL LONG 
PERIOD SWELL BETWEEN 92W AND 120W WILL CONTINUE INTO WED AND 
THEN BEGIN TO SUBSIDE. THE 0352 UTC ASCAT PASS SHOWS 20 KT WINDS 
IN THE N SEMICIRCLE OF THE LOW PRES SYSTEM NEAR 09N106W WHICH IS 
EMBEDDED IN THIS AREA OF SOUTHWESTERLY SWELL. THIS LOW IS 
FORECAST TO CONTINUE W AROUND 5 KT AND GRADUALLY DEEPEN OVER THE 
NEXT FEW DAYS.

GAP WINDS...MINIMAL GALE FORCE WINDS ARE BLOWING THROUGH THE 
GULF OF TEHUANTEPEC AND ARE EXPECTED TO PERSIST AT LEAST ANOTHER 
48 HOURS WITH LITTLE CHANGE EXCEPT FOR DIURNAL 
VARIABILITY...WITH THE STRONGEST WINDS EXPECTED IN THE EARLY 
MORNING HOURS. WINDS ARE FINALLY EXPECTED TO DROP BELOW GALE 
FORCE FRI AS WINDS WEAKEN IN THE GULF OF MEXICO.

$$
SCHAUER/MUNDELL