000
AXPZ20 KNHC 171605
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC WED SEP 17 2008

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

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1600 UTC.

...TROPICAL WAVES...
TROPICAL WAVE ALONG 83W SOUTH OF 20N...PASSING THROUGH
THE BORDER OF EASTERN HONDURAS/NORTHEASTERN NICARAGUA
TO THE COSTA RICA/PANAMA BORDER AND BEYOND...MOVING WEST
10 KT. SCATTERED MODERATE TO STRONG SHOWERS AND
THUNDERSTORMS FROM 7N TO 8N BETWEEN 83W AND 84W.

TROPICAL WAVE ALONG 93W/94W SOUTH OF 18N MOVING WEST 10 KT.
ITCZ SHOWERS AND THUNDERSTORMS.

TROPICAL WAVE ALONG 115W/116W SOUTH OF 18N MOVING WEST 15 KT.
NO SIGNIFICANT ORGANIZED CONVECTIVE PRECIPITATION.

A SURFACE TROUGH IS ALONG 130W/131W FROM 10N TO 16N. ITCZ
SHOWERS AND POSSIBLE THUNDERSTORMS ARE FROM 9.5N TO 11.5N
BETWEEN 130W AND 136W.

...ITCZ...
9N84W 10N95W 12N115W 10N124W 11N137W 10N140W. SCATTERED
MODERATE TO STRONG SHOWERS AND THUNDERSTORMS FROM 7N TO 8N 
BETWEEN 83W AND 84W...FROM 4N TO 9N BETWEEN 88W AND 100W...
AND WITHIN 30 NM TO 60 NM ON EITHER SIDE OF 9N88W 11N93W...
AND FROM 12N TO 15N BETWEEN 94W AND 98W. DISORGANIZED
ISOLATED MODERATE SHOWERS FROM 6N TO 16N BETWEEN 110W
AND 140W. 

...DISCUSSION...
MIDDLE TO UPPER LEVEL TROUGH MOVING ACROSS THE FAR NORTHWESTERN
CORNER OF THE DISCUSSION AREA HAS FLATTENED THE RIDGE THAT HAS 
BEEN OVER THE AREA DURING THE LAST SEVERAL DAYS. THE TROUGH 
EXTENDS FROM 32N132W TO 27N140W. AN UPPER LEVEL ANTICYCLONIC 
CIRCULATION CENTER NEAR 22N119W WITH AN EAST-TO-WEST RIDGE
EXTENDING ALONG 22N. ANOTHER ANTICYCLONIC CIRCULATION CENTER
IS IN CENTRAL MEXICO NEAR 22N99W. STRONG SUBSIDENCE WITH DRY 
STABLE CONDITIONS COVER THE AREA NORTH OF 15N WEST OF 115W.

ANOTHER UPPER LEVEL ANTICYCLONIC CIRCULATION OVER THE NW 
CARIBBEAN JUST OFF THE COAST OF HONDURAS. DIFFLUENT FLOW S OF 
THE ANTICYCLONIC CIRCULATION IS ENHANCING CONVECTIVE ACTIVITY 
ACROSS CENTRAL AMERICA AND THE PACIFIC N OF 4N W OF 95W. A WEAK 
TROUGH SEPARATES THE CARIBBEAN AND MEXICO ANTICYCLONES.

SURFACE RIDGE WITH AXIS EXTENDING FROM A 1022 MB HIGH PRES 
CENTER NEAR 29N133W TO 19N123W. BROKEN/OVERCAST STRATOCUMULUS 
CLOUDS COVER THE AREA N OF 20N W OF 115W. SURFACE TROUGH IS 
ANALYZED ALONG THE ITCZ FROM 7N-15N ALONG 130W. A FEW SHOWERS 
ARE ALONG THE TROUGH AXIS. 

$$
MT