000
AXPZ20 KNHC 150301
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SUN AUG 15 2010

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN
FROM THE EQUATOR TO 32N...EAST OF 140W.

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 0245 UTC.

...TROPICAL WAVE...

A TROPICAL WAVE IS ALONG 89W/90W N OF 10N. THERE IS LIMITED 
SHOWER ACTIVITY ASSOCIATED WITH THIS TROPICAL WAVE OVER THE 
EASTERN PACIFIC.

...ITCZ...

THE ITCZ IS ALONG 10N120W TO 09N125W TO 10N140W. ISOLATED 
MODERATE SHOWERS ARE FROM 08N TO 10N BETWEEN 120W AND 132W.

...DISCUSSION...

AN UPPER LEVEL RIDGE EXTENDS FROM BAJA CALIFORNIA NEAR 30N115W 
TO 22N136W. AN UPPER LEVEL ANTICYCLONE IS CENTERED NEAR 25N105W 
WITH RIDGE EXTENDING SW TO 15N117W. BETWEEN THESE TWO RIDGES 
LIES AN INVERTED TROUGH. 

A 1008 MB LOW PRESSURE CENTER IS NEAR 17N109W. SCATTERED 
MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS ARE WITHIN 120 
NM WEST OF THE LOW. SCATTERED MODERATE SHOWERS ARE WITHIN 180 NM 
E OF THE LOW. THE LOW IS EMBEDDED IN THE MONSOON TROUGH WHICH 
EXTENDS FROM 12N118W TO 18N103W. THE FRESH TO STRONG MONSOONAL 
FLOW SOUTH OF THE LOW IS HELPING KEEP SEAS IN THE 8 TO 10 FT 
RANGE FROM 09N TO 17N BETWEEN 105W AND 112W AND FROM 08N TO 12N 
BETWEEN 112W AND 118W IN SOUTHWESTERLY SWELL. THE LOW CENTER IS 
FORECAST TO SHIFT SLOWLY NORTHEASTWARD DURING THE WEEKEND.

A SURFACE RIDGE RUNS FROM 26N115W TO BEYOND 30N140W. THE 
PRESSURE GRADIENT BETWEEN THIS RIDGE AND TROUGHING IN THE GULF 
OF CALIFORNIA CONTINUES TO RESULT IN NORTH TO NORTHWESTERLY 
WINDS REACHING 20 KT NEAR THE WESTERN COAST OF BAJA CALIFORNIA 
NORTH OF 25N. 

TROUGHING IN THE SOUTHWESTERN U.S.A. WILL DEEPEN SUNDAY AS A 
COLD FRONT DIVES TO THE SOUTH OF THE FOUR CORNERS REGION. THE 
SURFACE PRESSURE GRADIENT WILL INCREASE IN THE NORTHERN GULF OF 
CALIFORNIA AND INCREASE SOUTHERLY WINDS TO 20 KT SUNDAY NIGHT. 

$$
AL