000
AXPZ20 KNHC 302159
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC TUE AUG 30 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... 
A 1004 MB SURFACE LOW CENTERED NEAR 16N101W IS EXPECTED TO 
SLOWLY INTENSIFY AND MOVE TO NEAR 18N104W WED EVENING AND NEAR 
19N106W THU EVENING WITH THE POSSIBILITY OF TROPICAL CYCLONE 
FORMATION. CURRENTLY SCATTERED MODERATE CONVECTION IS OCCURRING 
WITHIN 150 NM OF THE LOW CENTER.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH IS ALONG 10N86W TO THE DEVELOPING 1004 MB 
SURFACE LOW AT 16N101W TO 19N113W TO 16N126W TO 10N140W. 
SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS WITHIN 150 
NM OF THE SPECIAL FEATURES LOW. SCATTERED MODERATE CONVECTION IS 
N OF 13N BETWEEN 93W AND 96W. SIMILAR CONVECTION IS FROM 10N TO 
12N BETWEEN 120W AND 126W AND FROM 08N TO 10N BETWEEN 126W AND 
130W.

...DISCUSSION...
AN UPPER LEVEL TROUGH EXTENDS SW FROM VANCOUVER CANADA TO AN 
UPPER LEVEL CYCLONE CUTTING OFF N OF THE HAWAIIAN ISLANDS 
CENTERED NEAR 26N157W. AN UPPER LEVEL ANTICYCLONE OVER WEST 
TEXAS HAS AN UPPER RIDGE EXTENDING SW ACROSS THE NORTHERN BAJA 
CALIFORNIA PENINSULA THROUGH 18N134W...TO A CREST NEAR 10N151W. 
AN UPPER LEVEL TROUGH DISSECTS THE GULF OF MEXICO FROM NE TO SW 
AND CONTINUES SW THROUGH AN UPPER LEVEL CYCLONE AT 23N105W. 
STRONG SUBSIDENCE AND DRY UPPER LEVEL AIR IS INDICATED OVER THE 
ENTIRE AREA N OF 20N...AND FROM 10N TO 20N W OF 125W. AN UPPER 
LEVEL ANTICYCLONE IS OVER THE NW CARIBBEAN AND YUCATAN PENINSULA 
WITH A RIDGE W TO NEAR 14N117W RESULTING IN NORTHEASTERLY UPPER 
LEVEL FLOW DOMINATING MOST OF TROPICS E OF 115W.

AT THE SURFACE...A BROAD RIDGE DOMINATES THE PACIFIC WATERS N OF 
20N W OF 120W. THE RIDGE IS PRESENTING THE TIGHTEST PRESSURE 
GRADIENT AND THEREFORE STRONGEST TRADES N OF 27N BETWEEN 122W 
AND 132W WITH N TO NE WINDS AT 20 KT. THIS AREA WAS INDICATED BY 
AN EARLIER ASCAT PASS AT 30/1756 UTC. ELSEWHERE...LONG-PERIOD 
CROSS EQUATORIAL SOUTHWESTERLY SWELL IS NOTED S OF 14N BETWEEN 
96W AND 110W AND S OF 20N BETWEEN 110W AND 140W RESULTING IN 
SEAS TO 11 FT. THESE SOUTHERLY SWELLS WILL PROPAGATE NE AND 
IMPACT THE FORECAST WATERS S OF 27N THROUGH THE OVERNIGHT 
HOURS...REACHING THE NORTHERN BAJA PENINSULA AND SOUTHERN 
CALIFORNIA COAST BY EARLY WED INTO THE AFTERNOON HOURS.

$$
HUFFMAN