000
AXPZ20 KNHC 210323
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SAT AUG 21 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 
0300 UTC.

...SPECIAL FEATURE...
AT 21/0300 UTC...TROPICAL DEPRESSION EIGHT-E IS CENTERED NEAR 
20.2N 110.3W MOVING W-NW OR 300 DEGREES AT 11 KT. ESTIMATED 
MINIMUM CENTRAL PRESSURE IS 1004 MB. MAXIMUM SUSTAINED WIND 
SPEED IS 30 KT WITH GUSTS TO 40 KT. SEE LATEST NHC 
FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP3/WTPZ23 KNHC 
FOR MORE DETAILS. THE CENTER OF THE DEPRESSION CONTINUES TO BE 
EXPOSED TO THE NE DENSE CLOUD COVER WITH NO ASSOCIATED DEEP 
CONVECTION. 

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE AXIS IS ALONG 12N108W TO 
11N120W TO 13N128W THEN RESUMES AT 11N131W TO 09N140W. SCATTERED 
MODERATE CONVECTION IS SEEN FROM 10N TO 13N BETWEEN 129W AND 
132W. THIS ACTIVITY IS ASSOCIATED WITH A 1011 MB LOW PRES 
EMBEDDED WITHIN THE ITCZ. SIMILAR CONVECTION IS ALSO NOTED NEAR 
10N111W.  

...DISCUSSION...

ALOFT...A DEEP-LAYER RIDGE...ANCHORED ON AN UPPER LEVEL HIGH 
LOCATED OVER SW TEXAS NEAR 31N104W...DOMINATES THE MAJORITY OF 
THE NORTHERN FORECAST WATERS...PARTICULARLY N OF 20N. MODERATE 
TO STRONG SUBSIDENCE AND DRY AIR ALOFT IS INDICATED BY WATER 
VAPOR IMAGERY MAINLY N OF 18N W OF 122W UNDER THE INFLUENCE OF 
THIS RIDGE. T.D. EIGHT-E IS MOVING W-NW AROUND THE SOUTHERN 
PERIPHERY OF THIS SYSTEM. NE TO E FLOW ALOFT IS NOTED OVER THE 
DEEP TROPICS WITH SIGNIFICANT MID/UPPER LEVEL MOISTURE E OF 
120W.  

AT THE SURFACE...A SURFACE RIDGE COVERS THE AREA N OF 20N W OF 
120W. A 1011 MB LOW PRES IS EMBEDDED WITHIN THE ITCZ NEAR 
11N131W. MARINE GUIDANCE SUGGESTS SOME INCREASE IN WINDS AND 
SEAS IN ASSOCIATION WITH THIS FEATURE DURING THE UPCOMING 
WEEKEND. 

A BROAD AREA OF LOW PRESSURE LOCATED ABOUT 130 NM S-SE OF THE 
GULF OF TEHUANTEPEC IS PRODUCING DISORGANIZED SHOWERS AND 
THUNDERSTORMS.  ENVIRONMENTAL CONDITIONS APPEAR FAVORABLE FOR 
SOME GRADUAL DEVELOPMENT OF THIS SYSTEM AS IT DRIFTS ERRATICALLY 
DURING THE NEXT COUPLE OF DAYS. THERE IS A LOW CHANCE OF THIS 
SYSTEM BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS.

CROSS EQUATORIAL S SWELL CONTINUES TO SPREAD N WITH SEAS TO 12 
FT OVER S CENTRAL WATERS AND SE WATERS TO THE COAST OF MEXICO 
AND W PANAMA. THIS LONG PERIOD SWELL IS EXPECTED TO BRING SEAS 
OF 8 TO 10 FT TO THE REMAINDER OF THE COAST S OF 20N BY EARLY 
SAT MORNING. AT THE SAME TIME...A NEW BATCH OF LONG PERIOD 
SWELLS FROM THE S WILL AFFECT THE SW WATERS.

$$
GR/PAW