000
AXPZ20 KNHC 070918
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC WED SEP 07 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

...ITCZ/MONSOON TROUGH...
MONSOON TROUGH 15N93W 18N110W 10N130W 08N140W. SCATTERED 
MODERATE ISOLATED STRONG CONVECTION WITHIN 180 NM S OF AXIS FROM 
93W-96W, SCATTERED MODERATE TO STRONG CONVECTION WITHIN 120 NM N 
OF AXIS FROM 118W-125W.

...DISCUSSION...
BROAD UPPER LEVEL TROUGH N OF 28N BETWEEN 123W-130W CONTINUES TO 
WEAKEN AND LIFT TO THE NE. S OF THE TROUGH AND UPPER LEVEL 
ANTICYCLONIC CIRCULATION IS CENTERED NEAR 23N157W. A CYCLONIC 
CIRCULATION IS E OF THE ANTICYCLONE NEAR 24N121W. STRONG 
SUBSIDENCE WITH DRY STABLE AIR AT THE MIDDLE AND UPPER LEVELS IS 
N OF 15N W OF 115W. A LARGE UPPER LEVEL ANTICYCLONIC CIRCULATION 
IS OVER NORTHERN MEXICO NEAR 28N106W WITH A RIDGE AXIS EXTENDING 
SW ACROSS SOUTHERN BAJA CALIFORNIA TO 19N111W.

NE TO E FLOW ALOFT PERSISTS S OF THE UPPER LEVEL RIDGE MENTIONED 
ABOVE ACROSS THE MAJORITY OF THE REMAINDER OF THE DISCUSSION 
AREA. UPPER LEVEL DIFFLUENCE S OF THE RIDGE AXIS IS HELPING TO 
SUPPORT CONVECTION NEAR THE MONSOON TROUGH AS DESCRIBED ABOVE.

A BROAD SURFACE RIDGE COVERS THE AREA N OF 15N W OF 115W. WITH A 
WEAK PRES PATTERN IN PLACE TRADES REMAIN LESS THAN 20 KT ACROSS 
THE NE PACIFIC WATERS. AN AREA OF 20 KT SW WINDS EXISTS FROM 5N 
TO 19N BETWEEN 110W AND 130W WITH SEAS 9 TO 10 FT SEAS IN SW 
SWELL. BROKEN TO OVERCAST STRATOCUMULUS CLOUDS BLANKET THE AREA 
N OF 15N W OF 120W.

OTHERWISE LONG PERIOD CROSS EQUATORIAL SWELL OF 8 TO 10 FT 
CONTINUES TO DOMINATE THE REMAINDER OF THE AREA S OF 15N BETWEEN 
90W AND 130W. THESE SWELLS WILL NOT VARY MUCH THROUGH THE NEXT 
48 HOURS. 

$$
DGS