000
AXPZ20 KNHC 202141
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC TUE JUL 20 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 1945 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE WAS ANALYZED FROM 11N87W TO 
12N99W TO 10N109W TO 12N126W TO 08N140W. SCATTERED MODERATE WITH 
ISOLATED STRONG CONVECTION IS WITHIN 150 NM S OF THE ITCZ AXIS E 
OF 89W. SCATTERED MODERATE CONVECTION IS WITHIN 120 NM S OF THE 
ITCZ AXIS BETWEEN 100W AND 110W AS WELL AS S OF THE ITCZ AXIS TO 
09N BETWEEN 113W AND 122W.

...DISCUSSION...

AN UPPER LEVEL RIDGE ENTERS THE AREA FROM 25N140W TO 30N135W 
WITH VERY DRY AIR IN PLACE W OF 135W. AN UPPER LEVEL TROUGH IS 
CENTERED FROM 30N128W TO 17N134W WITH MID TO UPPER LEVEL 
MOISTURE EVIDENT N OF 21N BETWEEN 125W AND 135W. THIS UPPER 
TROUGH IS EXPECTED TO REMAIN NEARLY STATIONARY DURING THE NEXT 
48 HOURS. AN UPPER LEVEL ANTICYCLONE IS POSITIONED NEAR 22N117W 
WITH A RIDGE SW TO NEAR 15N125W. AN UPPER LEVEL CYCLONE IS JUST 
E OF THIS ANTICYCLONE NEAR THE SOUTHERN TIP OF BAJA CALIFORNIA 
DRIFTING TO THE W. DEEP LAYERED MOISTURE IS MOVING N OF THIS 
UPPER CYCLONE UP THE GULF OF CALIFORNIA AND ACROSS BAJA 
CALIFORNIA AND NW MEXICO. OTHERWISE THE REMAINDER OF THE UPPER 
LEVEL FLOW PATTERN IS DOMINATED BY E-NE WINDS WITH ABUNDANT 
MOISTURE ADVECTING FROM CARIBBEAN SEA INTO THE E PAC FEEDING 
SCATTERED MODERATE CONVECTION ALONG AND JUST OFFSHORE OF MUCH OF 
THE MEXICAN AND CENTRAL AMERICAN COAST S OF 20N.

1037 MB HIGH PRES AT THE SURFACE IS CENTERED WELL NW OF THE 
DISCUSSION AREA NEAR 46N151W WITH A RIDGE AXIS EXTENDING TO 
30N127W AND TO 16N115W WITH VERY DRY AND STABLE AIR UNDERNEATH 
IT. A WEAK TROUGH...THE REMNANTS OF T.D. SIX-E...LINGERS FROM 
21N126W TO 17N130W WITH LIMITED MOISTURE EVIDENT WITH THIS 
FEATURE. REGENERATION OF THIS SYSTEM IS NOT ANTICIPATED.

GALE FORCE WINDS ALONG THE PACIFIC NW COAST OF THE U.S. CONTINUE 
TO GENERATE NORTHERLY SWELL TO 9 FT WHICH IS PROPAGATING INTO 
THE DISCUSSION AREA N OF 23N BETWEEN 118W AND 130W. THIS SWELL 
WILL CONTINUE TO BRING SEAS TO 9 FT PRIMARILY IN THE AREA N OF 
25N BETWEEN 120W AND 135W OVER THE NEXT 48 HOURS.

LONG PERIOD CROSS EQUATORIAL SOUTHERLY SWELL OF 8-10 FT LIES 
ACROSS A LARGE PORTION OF THE REMAINDER OF THE BASIN S OF 15N 
BETWEEN 90W AND 135W WITH SW SWELL TO 8 FT IN THE FAR SE 
PORTION. THIS SWELL WILL GRADUALLY DECAY OVER THE NEXT TWO 
DAYS...BUT SE TO S WINDS ARE EXPECTED TO INCREASE TO 20 KT WED 
AND THU IN S CENTRAL WATERS. THIS WILL KEEP SEAS ABOVE 8 FT IN 
MUCH OF THE REGION S OF 06N.

$$
SCHAUER