000
AXPZ20 KNHC 031005
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SUN OCT 03 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 08N91W TO 10N101W TO LOW PRES NEAR 10N137W. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 90 NM S OF 
AXIS BETWEEN 84W AND 90W.

...DISCUSSION...

UPPER LEVEL LOW OFF THE SOUTHERN CALIFORNIA COAST WITH A TROUGH 
EXTENDING SSW TO 25N121W IS LIFTING N. THE ASSOCIATED MOISTURE 
AND PRECIPITATION REMAINS OVER SOUTHERN CALIFORNIA WITH A SMALL 
BATCH OVER NORTHERN BAJA CALIFORNIA. THIS AREA OF MOISTURE WILL 
LIFT N WITH THE CYCLONIC CIRCULATION TODAY AS A LARGE UPPER 
TROUGH CROSSING THE FAR NW PORTION OF THE AREA PRESSES EASTWARD. 
AN UPPER RIDGE OVER THE SW U.S. EXTENDS SW ACROSS NW MEXICO AND 
SOUTHERN BAJA CALIFORNIA TO AN ANTICYCLONE NEAR 16N115W WITH 
ANOTHER RIDGE EXTENDING FROM THE ANTICYCLONE WNW TO 17N131W. AN 
UPPER TROUGH EXTENDS FROM WESTERN GULF OF MEXICO ACROSS CENTRAL 
MEXICO THEN SW TO NEAR 14N108W. NLY WINDS BEHIND THE TROUGH WILL 
HAMPER ANY DEEP CONVECTION THAT ATTEMPTS TO FORM NEAR OR ALONG 
THE ITCZ THROUGH THE NEXT 48 HOURS. SE OF THE TROUGH...A MID 
LEVEL RIDGE EXTENDS FROM THE N CENTRAL CARIBBEAN SW ACROSS 
CENTRAL AMERICA. STRONG ELY FLOW ON SOUTHERN PERIPHERY OF THE 
RIDGE IS ADVECTING UPPER LEVEL DEBRIS MOSITURE FROM CLUSTERS OF 
DEEP CONVECTION OVER THE SW CARIBBEAN SEA WESTWARD TO NEAR 110W.

CROSS-EQUATORIAL S TO SW WINDS INTO A WEAKER MONSOON TROUGH HAVE 
DIMINISHED TO LESS THAN 20 KT. SEAS EXPECTED TO BUILD TO NEAR 10 
FT IN MIXED SW AND NW SWELL S OF 15N BETWEEN 102W AND 130W...AND 
IN SW SWELL BETWEEN 92W AND 125W IN ABOUT 24 HOURS....THEN S OF 
15N BETWEEN 92W AND 120W IN 48 HOURS.

N WINDS OF 20 TO 25 KT ARE OCCURRING WITHIN 60 NM EITHER SIDE OF 
A LINE FROM 16N94.5W TO 14N95W...INCLUDING THE ISTHMUS OF 
TEHUANTEPEC...WITH SEAS TO 9 FT. UNSEASONABLY STRONG SURFACE 
RIDGE BUILDING SOUTHEASTWARD ACROSS MEXICO WILL TIGHTEN THE 
PRESSURE GRADIENT OVER THE ISTHMUS OF TEHUANTEPEC RESULTING IN 
AN EARLY SEASON GALE EVENT...WITH WINDS INCREASING TO 30 TO 35 
KT WITHIN 30 NM OF LINE 16N94.5W TO 14N95W AND SEAS BUILDING 9 
TO 12 FT WITHIN 6 HOURS. GALE FORCE WINDS ARE EXPECTED TO 
INCREASE TO 40 KT LATE TONIGHT...WITH SEAS BUILDING TO 12-16 FT. 
BY 48 HOURS...WINDS ARE FORECAST TO DIMINISH BACK TO 30 TO 35 KT 
WITH SEAS OF 12-15 FT. 

HIGH PRES WILL STRENGTHEN OVER THE WESTERN PORTION OF THE AREA 
AND INCREASE THE PRES GRADIENT BETWEEN IT AND A 1010 MB LOW NEAR 
101N38W ALLOWING NE TO E TRADES OF 20 KT TO DEVELOP FROM 12N TO 
22N W OF 132W IN 36-48 HOURS...WITH SEAS BUILDING TO 11 FT IN NW 
SWELL. 11 FT SEAS WILL SPREAD ACROSS THE NW WATERS IN 24 HOURS 
THEN SLOWLY SUBSIDE TO 10 FT BY 48 HOURS.

$$
MUNDELL