000
AXPZ20 KNHC 201537
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC TUE JUL 20 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 1500 UTC.

...ITCZ...

ITCZ AXIS ALONG 14N91W TO 10N100W TO 08N110W TO 14N127W TO 
07N140W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS 
WITHIN 90 NM OF THE AXIS BETWEEN 99W AND 109W...AND WITHIN 90 
NM N OF THE AXIS BETWEEN 114W AND 116W. SCATTERED MODERATE TO 
STRONG CONVECTION IS WITHIN 120 NM S OF THE AXIS BETWEEN 117W 
AND 121W...AND WITHIN 90 NM OF THE AXIS BETWEEN 128W AND 132W.

...DISCUSSION...

AN UPPER LEVEL RIDGE ENTERS THE AREA FROM 23N140W TO 32N134W 
WITH VERY DRY AIR IN PLACE W OF 134W. AN UPPER LEVEL CYCLONE IS 
CENTERED NEAR 25N130W WITH MID TO UPPER LEVEL MOISTURE EVIDENT N 
OF 21N BETWEEN 120W AND 134W. THE UPPER CYCLONE 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 10N127W. ANOTHER UPPER LEVEL CYCLONE IS JUST E OF THE 
ANTICYCLONE NEAR THE SOUTHERN TIP OF BAJA CALIFORNIA DRIFTING TO 
THE W. MONSOONAL MOISTURE IS N OF THIS UPPER CYCLONE ACROSS BAJA 
CALIFORNIA AND NW MEXICO. OTHERWISE THE REMAINDER OF THE UPPER 
LEVEL FLOW PATTERN IS DOMINATED BY TYPICAL E-NE WINDS WITH 
ABUNDANT MOISTURE ADVECTING FROM CARIBBEAN SEA INTO THE E PAC 
FEEDING SCATTERED MODERATE ISOLATED STRONG DEEP CONVECTION ALONG 
AND JUST OFFSHORE OF THE MAJORITY OF THE MEXICAN AND CENTRAL 
AMERICA COASTS S OF 22N.

AT THE SURFACE...
1037 MB HIGH PRES IS CENTERED WELL NW OF THE DISCUSSION AREA 
WITH A RIDGE AXIS EXTENDING INTO THE N PORTION TO NEAR 24N119W 
WITH VERY DRY AND STABLE AIR UNDERNEATH IT. A WEAK TROUGH...THE 
REMNANTS OF T.D. SIX-E...LINGERS FROM 21N127W TO 16N129W WITH 
LIMITED MOISTURE EVIDENT WITH THIS FEATURE. REGENERATION OF THIS 
OLD SYSTEM IS NOT ANTICIPATED.

GALE FORCE WINDS ALONG THE CALIFORNIA COAST N OF POINT 
CONCEPTION CONTINUE TO GENERATE NORTHERLY SWELLS OF 8 FT WHICH
IS PROPAGATING INTO THE DISCUSSION AREA N OF 23N BETWEEN 119W 
AND 124W. THIS SWELL WILL EXPAND TO BETWEEN 120W AND 135W AND 
BUILD SLIGHTLY TO 9 FT BY 48 HOURS.

LONG PERIOD CROSS EQUATORIAL SOUTHERLY SWELLS OF 8-10 FT ARE 
ACROSS A LARGE PORTION OF THE REMAINDER OF THE BASIN S OF 23N 
BETWEEN 90W AND 136W WITH SW SWELL TO 8 FT IN THE FAR SE 
PORTION. THIS SWELL WILL GRADUALLY DECAY WITH HEIGHTS OF 8-10 FT 
BECOMING CONFINED S OF 18N IN 24 HOURS AND THEN S OF 11N IN 48 
HOURS.

$$
LEWITSKY