000
AXPZ20 KNHC 260918
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SUN JUL 26 2009

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

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

...TROPICAL WAVES...
TROPICAL WAVE N OF 5N ALONG 86W/87W MOVING W 15 KT. NO
SIGNIFICANT CONVECTION ASSOCIATED WITH THE WAVE.

TROPICAL WAVE N OF 4N ALONG 98W MOVING W 15 KT. SCATTERED TO 
NUMEROUS STRONG CONVECTION E OF THE WAVE OVER AND SE OF THE GULF 
OF TEHUANTEPEC IS MAINLY DUE TO UPPER LEVEL DIFFLUENT FLOW.
 
TROPICAL WAVE FROM 4N TO 17N ALONG 111W MOVING W 15 KT.
SCATTERED MODERATE ISOLATED STRONG CONVECTION IS FROM 7N-14N
BETWEEN 110W-114W.

TROPICAL WAVE FROM 3N TO 14N ALONG 119W MOVING W 10-15 KT.
ISOLATED SHOWERS ARE ALONG THE WAVE.

...ITCZ...
AXIS IS ALONG 8N81W 9N110W 6N125W 9N140W. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION FROM 7N-14N BETWEEN 110W-114W.

...DISCUSSION...
AN UPPER LEVEL CYCLONIC CIRCULATION N OF THE DISCUSSION AREA 
NEAR 34N138W WITH TROUGH SE OF THE CIRCULATION TO 25N138W. 
MIDDLE AND HIGH LEVEL MOISTURE IS ROTATING AROUND THE CYCLONIC 
CIRCULATION AND TROUGH. ANOTHER POORLY DEFINED UPPER LEVEL 
CYCLONIC CIRCULATION IS CENTERED NEAR 18N126W. MODERATE TO 
STRONG SUBSIDENCE WITH DRY STABLE AIR AT THE MIDDLE AND UPPER 
LEVELS OF THE ATMOSPHERE IS WITHIN THE CIRCULATION N OF THE ITCZ 
TO 25N BETWEEN 117W-130W.
 
AN UPPER ANTICYCLONIC CIRCULATION IS CENTERED OVER NORTHERN 
MEXICO NEAR THE SOUTHERN NEW MEXICO BORDER NEAR 31N108W WITH A 
RIDGE EXTENDING S TO THE SOUTHERN TIP OF BAJA CALIFORNIA THEN 
INTO THE PACIFIC TO 11N108W. 

A SHARP UPPER LEVEL TROUGH WITH AXIS THAT EXTENDS FROM THE N 
CENTRAL GULF OF MEXICO ACROSS CENTRAL MEXICO TO NEAR PUERTO
VALLARTA. AN UPPER LEVEL ANTICYCLONIC CIRCULATION HAS MOVED
OVER NORTHERN GUATEMALA NEAR 16N89W. DIFFLUENT FLOW ALOFT 
BETWEEN THE UPPER TROUGH AND THE ANTICYCLONIC CIRCULATION IS 
ENHANCING STRONG CONVECTIVE ACTIVITY ALONG AND SE OF THE GULF OF 
TEHUANTEPEC.

SURFACE RIDGE WITH AXIS FROM 32N133W TO 22N115W. BROKEN/OVERCAST 
STRATOCUMULUS CLOUDS COVER THE AREA N OF 20N W OF 115W. SURFACE
TROUGH ANALYZED ALONG THE ITCZ FROM 16N133W TO 6N140W. A FEW 
SHOWERS ARE ALONG THE TROUGH. 

LARGE SOUTHERLY SWELLS THAT HAVE BEEN CROSSING THE EQUATOR FROM 
THE SOUTHERN HEMISPHERE THE PAST SEVERAL DAYS OVER THE SE 
PORTION OF THE DISCUSSION AREA ARE STARTING TO SUBSIDE.

$$
DGS