000
AXPZ20 KNHC 201509
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC MON JUL 20 2009

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 
1500 UTC.

...TROPICAL WAVES...
TROPICAL WAVE FROM 6N TO 14N ALONG 114W MOVING W 10-15 KT.
UPPER LEVEL DIFFLUENT FLOW IS ENHANCING CONVECTION WITH THE WAVE 
MAINLY ALONG THE ITCZ.
 
TROPICAL WAVE FROM 7N-16N ALONG 136W MOVING W 10-15 KT. ONLY 
ISOLATED SHOWERS ASSOCIATED WITH THE WAVE.

...ITCZ...
AXIS IS ALONG 7N78W 9N105W 7N125W 9N140W. NUMEROUS STRONG 
CONVECTION N OF 3N E OF 83W. SCATTERED MODERATE TO STRONG 
CONVECTION WITHIN 240 NM S AND 60 NM  N OF AXIS FROM 104W-111W 
AMD WITHIN 150 NM N OF AXIS FROM 112W-117W AND WITHIN 360 NM N 
OF AXIS FROM 123W-129W.

...DISCUSSION...
WELL DEFINED CYCLONIC CIRCULATION NW OF THE DISCUSSION AREA WITH
TROUGH EXTENDING THROUGH 32N135W TO 24N130W. A 45-55 KT WIND MAX 
IS S OF THE TROUGH AXIS FROM 24N140W 26N135W TO 32N130W. 
MODERATE TO STRONG SUBSIDENCE WITH DRY AIR AT THE MID/UPPER 
LEVELS OF THE ATMOSPHERE IS NW OF THE WIND MAX...WITH SCATTERED 
TO BROKEN HIGH CLOUDS WITHIN 180 NM SE OF THE WIND MAX. A BROAD 
UPPER LEVEL ANTICYCLONIC CIRCULATION IS W OF THE AREA NEAR 
15N150W WITH RIDGE EXTENDING EWD TO 17N140W 22N131W. E OF THE 
RIDGE IS A CYCLONIC CIRCULATION CENTERED AT 19N126W...UPPER
LEVEL DIFFLUENT FLOW SE OF THE CYCLONIC CIRCULATION IS ENHANCING 
CONVECTIVE ACTIVITY ALONG THE ITCZ.

AN UPPER LEVEL ANTICYCLONIC CIRCULATION OVER THE NORTHERN GULF 
OF CALIFORNIA NEAR 31N114W. THE AIRMASS AT THE MID AND UPPER 
LEVELS IS MOIST E OF 120W. AN UPPER LEVEL TROUGH WITH AXIS FROM 
THE W COAST OF THE YUCATAN PENINSULA ACROSS SOUTHERN MEXICO TO
13N102W. AN AREA OF STRONG UPPER LEVEL DIFFLUENCE IS PRODUCING
A LARGE AREA OF STRONG CONVECTION OFF THE W COAST OF COLOMBIA TO 
THE GULF OF PANAMA...N OF 3N E OF 83W.

A WEAK SURFACE TROUGH FROM 32N135W TO 23N133W IS EMBEDDED IN A 
RIDGE THAT COVERS THE AREA N OF 17N W OF 117W. BROKEN/OVERCAST
STRATOCUMULUS CLOUDS BLANKET THE AREA N OF 22N W OF 115W.

$$
DGS