000
AXPZ20 KNHC 312151
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC WED AUG 31 2011

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2115 UTC.

...SPECIAL FEATURES...
TROPICAL DEPRESSION EIGHT-E IS CENTERED NEAR 18.5N 102.9W AT 
31/2100 UTC OR ABOUT 50 NM NW OF LAZARO CARDENAS MEXICO MOVING 
N-NW AT 6 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1003 MB. 
MAXIMUM SUSTAINED WIND SPEED IS 25 KT WITH GUSTS TO 35 KT. THE 
DEPRESSION REMAINS UNDER A DIFFLUENT MIDDLE TO UPPER LEVEL 
ENVIRONMENT DUE TO AN UPPER LEVEL ANTICYCLONE NOTED ON WATER 
VAPOR IMAGERY CENTERED OVER SOUTHERN MEXICO NEAR 20N97W. THE 
UPPER LEVEL RIDGE AXIS EXTENDS W-SW OVER THE DEPRESSION TO NEAR 
16N110W. THIS IS ENHANCING SCATTERED MODERATE AND ISOLATED 
STRONG CONVECTION OCCURRING WITHIN 90 NM OF THE CENTER. WHILE 
THE DEPRESSION IS NOW LOCATED INLAND ALONG THE COAST OF WESTERN 
MEXICO...RAINFALL ASSOCIATED WITH THE DEPRESSION MAY PRODUCE 
LIFE-THREATENING FLASH FLOODING AND MUD SLIDES IN AREAS OF STEEP 
TERRAIN THROUGH THE EVENING AND OVERNIGHT HOURS. SEE LATEST NHC 
FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP3/WTPZ23 KNHC 
FOR MORE DETAILS.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH IS ALONG 09N84W TO TROPICAL DEPRESSION 
EIGHT-E NEAR 18N103W THEN TO 18N120W TO 10N140W. SCATTERED 
MODERATE AND ISOLATED STRONG CONVECTION IS NEAR 16N108W.  
SCATTERED MODERATE CONVECTION IS WITHIN 50 NM S OF LINE FROM 
FROM 11N108W TO 13N114W.

...DISCUSSION...
AN UPPER LEVEL TROUGH IS SWINGING SOUTHEASTWARD INTO THE NW 
PORTION OF THE DISCUSSION AREA WITH AXIS FROM NORTHERN 
CALIFORNIA NEAR 39N121W TO 28N138W. AN UPPER LEVEL ANTICYCLONE 
CENTERED OVER SE OKLAHOMA EXTENDS AN UPPER LEVEL RIDGE AXIS SW 
ACROSS NW MEXICO AND THE BAJA CALIFORNIA PENINSULA TO 25N117W. 
WHILE THE RIDGING IS DISRUPTED ALOFT BECAUSE OF THE UPPER LEVEL 
TROUGH SWINGING SOUTHEASTWARD...AN UPPER LEVEL ANTICYCLONE IS 
CENTERED OVER WESTERN PORTIONS OF THE AREA NEAR 18N139W. THE 
UPPER LEVELS APPEAR VERY DRY ON WATER VAPOR IMAGERY NW OF A LINE 
FROM 10N140W TO 25N112W. 

AN UPPER LEVEL LOW CENTERED OFF THE EASTERN US SEABOARD 
STRETCHES NARROWLY AS A TROUGH AXIS SW ACROSS THE NORTHERN GULF 
OF MEXICO THROUGH AN UPPER CYCLONE AT 29N92W THEN ACROSS 
NORTHERN MEXICO AND INTO THE TROPICAL PACIFIC NEAR 22N114W. 
IMMEDIATELY SE OF THIS TUTT IS UPPER LEVEL RIDGING...ORIENTATED 
NE TO SW WHICH AS MENTIONED ABOVE IS LOCATED ALOFT OVER TROPICAL 
DEPRESSION EIGHT-E.

AT THE SURFACE...A RIDGE DOMINATES THE NW CORNER OF THE FORECAST 
AREA WITH N TO NE WINDS AT 15 TO 20 KT SPREADING SE OVER THE 
PACIFIC WATERS W OF A LINE FROM 32N120W TO 10N140W. THE 
ASSOCIATED NORTHERLY SWELL IS MIXING WITH CROSS EQUATORIAL 
SOUTHERLY SWELL RESULTING IN COMBINED SEAS TO 9 FT. THE 
NORTHERLY WINDS WILL DIMINISH BELOW 20 KT S OF 32N ON THU...BUT 
OPPOSING SWELL WILL CONTINUE OVER THE ENTIRE WATERS N OF 
20N...AND FROM 12N TO 20N TO THE W OF 130W THROUGH THU NIGHT.
 
THESE LONG PERIOD CROSS EQUATORIAL SOUTHERLY SWELLS WILL ALSO 
SPREAD NE TO THE CENTRAL AMERICAN COAST S OF 20N WITH SEAS TO 11 
FT IN THE AREAS OF ENHANCED SOUTHWESTERLY MONSOON FLOW...JUST TO 
THE S OF TROPICAL DEPRESSION EIGHT-E.

$$
HUFFMAN