000
AXPZ20 KNHC 300908
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC WED SEP 30 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.

...SPECIAL FEATURES...
A BROAD LOW PRES CENTERED NEAR 19N112W MOVING WNW 10 KT.
THE LOW COULD POSSIBLY DEVELOP INTO A TROPICAL CYCLONE OVER THE 
NEXT 48 HOURS. DIFFLUENT FLOW ALOFT IS ENHANCING CONVECTIVE 
ACTIVITY WITH THE LOW...SCATTERED MODERATE TO STRONG CONVECTION
IS FROM 12N-21N BETWEEN 108W-120W.

...TROPICAL WAVE...
TROPICAL WAVE FROM 14N-6N ALONG 100W MOVING W 15 KT. SCATTERED 
AND ISOLATED TSTMS ARE WITHIN 100 NM EITHER SIDE OF THE WAVE.

...ITCZ...
AXIS ALONG 8N78W 11N105W 13N120W TO 10N140W. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION WITHIN 300 NM S OF AXIS FROM 
102W-105W. SCATTERED TO NUMEROUS MODERATE TO STRONG CONVECTION 
WITHIN 180 NM N OF AXIS FROM 111W-125W.

...DISCUSSION...
MID/UPPER LEVEL TROUGH EXTENDS FROM A BROAD CYCLONIC CIRCULATION
CENTERED NEAR 29N132W TO 24N140W. A 75-95 KT JETSTREAM E OF THE 
TROUGH EXTENDS FROM 29N123W TO SOUTHERN CALIFORNIA...WHERE WINDS 
INCREASE TO 100 KT. MODERATE TO STRONG SUBSIDENCE WITH DRY 
STABLE AIR IN THE MIDDLE AND UPPER LEVELS OF THE ATMOSPHERE IS 
WITHIN 300 NM EITHER SIDE OF THE TROUGH AXIS. DOWNSTREAM A WELL 
PRONOUNCED UPPER LEVEL ANTICYCLONIC CIRCULATION IS JUST OFF THE 
W COAST OF MEXICO NEAR 21N107W. A RIDGE EXTENDS SE FROM THE 
ANTICYCLONE ACROSS SOUTHERN MEXICO TO NICARAGUA...WITH ANOTHER 
RIDGE EXTENDING NWD ACROSS NORTHERN MEXICO TO THE BIG BEND OF 
TEXAS. UPPER LEVEL DIFFLUENT FLOW S OF THE ANTICYLONE IS 
ENHANCING CONVECTION ASSOCIATED WITH THE LOW DESCRIBED ABOVE.

AN INVERTED TROUGH IN THE DEEP TROPICS WITH AXIS FROM 19N117W
TO A CYCLONIC CIRCULATION CENTERED NEAR 11N119W. UPPER LEVEL
DIFFLUENT FLOW W OF THE CYCLONIC CIRCULATION IS ENHANCING 
CONVECTION ALONG THE ITCZ FROM 111W-127W.

SURFACE HIGH PRES RIDGE COVERS THE AREA N OF 20N W OF 120W. 
BROKEN TO OVERCAST STRATOCUMULUS CLOUDS BLANKET THE AREA N OF 
20N W OF 125W. A COUPLE OF SURFACE LOWS ARE ANALYZED ALONG THE
ITCZ. A 1008 MB LOW IS CENTERED NEAR 14N121W. A LARGE CLUSTER OF
STRONG CONVECTION IS WITHIN 240 NM E OF THE LOW. ANTHER WEAKER
...1010 MB...LOW IS NEAR 14N135W. ONLY A FEW SHOWERS ARE NEAR 
THE LOW CENTER.

$$
DGS