000
AXPZ20 KNHC 010917
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SAT AUG 01 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 
0000 UTC.

...TROPICAL WAVES...
TROPICAL WAVE ENTERED E PACIFIC N OF THE EQUATOR TO COAST OF 
PANAMA THEN CONTINUES N INTO THE CARIBBEAN ALONG 82W MOVING W 20 
KT. NO SIGNIFICANT CONVECTION ASSOCIATED WITH THE WAVE.

TROPICAL WAVE FROM 5N-14N ALONG 109W MOVING W 15 KT.  A CLUSTER 
OF STRONG CONVECTION IS FROM 11N-13N WITHIN 180 NM E OF THE WAVE,

TROPICAL WAVE FROM 19N125W TO 3N126W MOVING W 15 KT. A 1013 MB
LOW IS ANALYZED ALONG THE N PORTION OF THE WAVE NEAR 17N125W.
ONLY ISOLATED SHOWERS ARE ALONG THE WAVE.

...ITCZ...
AXIS ALONG 7N81W 10N105W 10N120W 8N140W. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION WITHIN 120 NM N OF AXIS FROM 97W-110W 
AND WITHIN 90 NM S OF AXIS FROM 131W-138W.

...DISCUSSION...
AN UPPER LEVEL TROUGH EXTENDS FROM A CYCLONIC CIRCULATION N OF 
THE AREA TO 32N130W 25N131W. ASSOCIATED SURFACE TROUGH WITH AXIS 
FROM 32N128W TO 28N131W. A 75-90 KT JETSTREAM IS MOVING ACROSS 
THE BASE OF THE TROUGH FROM 32N136W TO 30N128W WHERE WINDS 
DECREASE TO 40-15 KT. SW OF THE TROUGH IS AN UPPER LEVEL 
ANTICYCLONIC CIRCULATION CENTERED NEAR 20N136W WITH RIDGE FROM 
THE CIRCULATION TO 23N120W. UPPER LEVEL MOISTURE FROM CENTRAL 
PACIFIC TROPICAL STORM LANA IS MOVING TO THE N OF THE 
ANTICYCLONIC CIRCULATION. OTHERWISE MODERATE TO STRONG 
SUBSIDENCE WITH DRY STABLE AIR AT THE MIDDLE AND UPPER LEVELS OF 
THE ATMOSPHERE IS WITHIN 300 NM EITHER SIDE OF THE RIDGE AXIS.

AN UPPER LEVEL CYCLONIC CIRCULATION IN THE DEEP TROPICS IS 
CENTERED NEAR 13N119W. ANOTHER DEEP TROPICS CYCLONIC CIRCULATION 
IS SW OF THE FIRST ONE NEAR 9N135W. UPPER LEVEL DIFFLUENT FLOW 
SW OF THE CYCLONIC CIRCULATION IS ENHANCING CONVECTIVE ACTIVITY 
ALONG THE ITCZ W OF 135W.

A LARGE UPPER LEVEL ANTICYCLONIC CIRCULATION IS OVER NORTHERN
MEXICO NEAR 27N105W. CLUSTERS TO TSTMS ARE WITHIN THE ANTICYLONES
UPPER LEVEL DIFFLUENCE. AN UPPER RIDGE EXTENDS FROM THE 
ANTICYCLONIC CIRCULATION SW TO TO THE TIP OF BAJA CALIFORNIA TO 
12N105W. AN INVERTED UPPER LEVEL TROUGH EXTENDS FROM CENTRAL 
MEXICO TO NICARAGUA.

SURFACE RIDGE WITH AXIS FROM 27N126W TO 19N108W. BROKEN TO 
OVERCAST STRATOCUMULUS CLOUDS BLANKET THE AREA N OF 20N W OF 
120W. SURFACE TROUGH IS ANALYZED ALONG THE ITCZ FROM 14N96W TO 
6N95W. NUMEROUS MODERATE TO STRONG CONVECTION MAINLY ASSOCIATED 
WITH UPPER LEVEL DIFFLUENCE IS WITHIN 210 NM FROM THE COAST OF 
TEHUANTEPEC. OTHERWISE SCATTERED SHOWERS ARE WITHIN 60 NM E OF 
THE TROUGH. THE NEXT ROUND OF SW SWELL WILL BE CROSSING THE 
EQUATOR LATER TODAY.

$$
DGS