000
AXPZ20 KNHC 310927
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SUN OCT 31 2010

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...
AXIS FROM 09N84W TO 08N90W TO 10N110W TO 08N120W TO 11N130W TO 
10N140W. NO SIGNIFICANT CONVECTION NOTED. 

...DISCUSSION...
W OF 105W...
THE 06Z SURFACE MAP SHOWS 1021 MB HIGH PRES CENTERED NEAR 
30N124W...N OF WEAK LOW PRES ALONG THE ITCZ. ASCAT DATA AND SHIP 
OBSERVATIONS SHOW LIGHT TO MODERATE TRADE WIND FLOW BETWEEN 
THESE FEATURES. SHIP OBSERVATIONS AND JASON ALTIMETER DATA ALSO 
SHOW NW SWELL OF 8 TO 10 FT PUSHING THROUGH THE AREA N OF 10N. 
ALOFT...A SHORT WAVE TROUGH IS DIGGING INTO THE REGION N OF 15N 
W OF 130W AND WILL CUT OFF NEAR 20N140W TODAY. THE RESULTANT 
ZONAL UPPER PATTERN WILL BECOME MORE AMPLIFIED STARTING TONIGHT 
THROUGH TUE AS MID TO UPPER LEVEL RIDGING BUILDS OVER THE 
WESTERN U.S. BETWEEN DEEPENING TROUGHS OVER THE CENTRAL N 
PACIFIC AND CENTRAL PLAINS. THIS WILL ALLOW THE SURFACE HIGH 
PRES TO BUILD NEAR 30N125W...RESULTING FRESH TRADE WIND FLOW 
FROM 10N TO 25N W OF 115W AND ALONG THE N BAJA COAST FROM LATE 
TODAY THROUGH EARLY NEXT WEEK. LOOKING AHEAD...NW SWELL OF 10 
TO 20 FT WITH PERIODS OF 15 TO 20 SECONDS WILL PUSH INTO THE 
DISCUSSION AREA BY LATE MON SWEEP TO THE SE TUE. GIVEN THE 
HEIGHT AND LONG PERIOD OF THIS SWELL...THERE IS POTENTIAL FOR 
HAZARDOUS SURF AS THE SWELL REACHES THE BAJA COAST BY LATE TUE.

E OF 105W...
A HIGH RESOLUTION ASCAT PASS FROM 0316Z SHOWED 25 KT 
WINDS THROUGH THE GULF OF TEHUANTEPEC. GIVEN THIS AND WEAKENING 
AND EASTWARD MOVING SURFACE HIGH PRES OVER THE GULF OF 
MEXICO...THE GALE WARNING FOR THE GULF OF TEHUANTEPEC HAS BEEN 
LOWERED. A JASON ALTIMETER PASS FROM ROUND 11Z YESTERDAY SHOWED 
SEAS OF 8 TO 9 FT WITHIN 300 NM S OF TEHUANTEPEC. THE FRESH TO 
STRONG WINDS AS WELL THE ASSOCIATED SEAS WILL DIMINISH THROUGH 
TODAY AS THE PATTERN WEAKENS. FURTHER S...A SHIP REPORTED WINDS 
TO 25 KT IN THE GULF OF PAPAGAYO A FEW HOURS AGO. THIS IS ON THE 
NORTH SIDE OF A VERY BROAD AREA OF LOW PRES THAT IS STARTING TO 
SHOW UP ON SATELLITE IMAGERY NEAR 08N88W. GFS/ECMWF/UKMET SHOW A 
WEAK SURFACE LOW FORMING IN THIS AREA...BUT FILLING THROUGH 
TONIGHT AS IT SHIFTS E. THE PAPAGAYO GAP FLOW WILL PERSIST AT 
LEAST INTO TONIGHT...ALONG WITH ENHANCED SW FLOW OFF WESTERN 
PANAMA. INCREASED SW FLOW WILL RETURN TO THIS SAME AREA BY TUE 
AS HURRICANE TOMAS SHIFTS FURTHER W INTO THE CENTRAL CARIBBEAN. 

$$
CHRISTENSEN