000
AXPZ20 KNHC 010917
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC THU OCT 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 
0900 UTC.

...SPECIAL FEATURE...
A BROAD LOW PRES CENTERED NEAR 19N117W MOVING WNW 10 KT. THE LOW 
COULD POSSIBLY DEVELOP INTO A TROPICAL CYCLONE OVER THE NEXT 48 
HOURS. CONVECTION NEAR THE CENTER OF THE LOW HAS DECREASED 
CONSIDERABLY WITH JUST SCATTERED MODERATE ISOLATED STRONG 
CONVECTION NEAR THE CENTER. AN AREA OF STRONG CONVECTION IS WELL 
S OF THE LOW FROM 14N-17N BETWEEN 113W-118W.

...TROPICAL WAVE...
TROPICAL WAVE FROM 16N-6N ALONG 106W MOVING W 10-15 KT. ISOLATED
SHOWERS ARE WITHIN 80 NM E OF WAVE FROM 11N-15N.

...ITCZ...
AXIS IS ALONG 8N78W 13N105W 15N120W 12N125W 11N140W. SCATTERED 
STRONG CONVECTION WITHIN 90 NM S OF AXIS FROM 78W-82W. SCATTERED 
MODERATE TO STRONG CONVECTION FROM 13N-17N BETWEEN 113W-120W. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 90 NM S OF 
OF AXIS FROM 123W-128W.

...DISCUSSION...
MID/UPPER LEVEL TROUGH EXTENDS FROM 32N130W TO A BROAD CYCLONIC 
CIRCULATION CENTERED NEAR 28N140W. A 75-95 KT JETSTREAM SE OF 
THE TROUGH EXTENDS FROM 23N136W TO NORTHERN BAJA CALIFORNIA. 
MODERATE TO STRONG SUBSIDENCE WITH DRY STABLE AIR IN THE MIDDLE 
AND UPPER LEVELS OF THE ATMOSPHERE COVERS THE AREA N OF 25N W OF 
118W. DOWNSTREAM UPPER LEVEL ANTICYCLONIC CIRCULATION IS 
CENTERED NEAR 23N119W...WITH RIDGE N TO THE NORTHERN COAST OF 
THE BAJA PENINSULA. UPPER LEVEL DIFFLUENT FLOW S OF THE 
ANTICYCLONIC CIRCULATION IS ENHANCING CONVECTIVE ACTIVITY FROM 
13N-18N BETWEEN 112W-119W. ANOTHER ANTICYCLONIC CIRCULATION
IS OVER WESTERN MEXICO CENTERED NEAR 23N105W. 

AN INVERTED TROUGH IN THE DEEP TROPICS WITH AXIS FROM THE 
EQUATOR AT 98W TO NEAR THE COAST OF NICARAGUA NEAR 11N188W. 
MODERATE TO STRONG SUBSIDENCE IS WITH THE TROUGH S OF 6N
E OF 100W.

SURFACE HIGH PRES RIDGE COVERS THE AREA N OF 24N W OF 120W. THE 
RIDGE COMBINED WITH THE LOW PRES DESCRIBED ABOVE HAS TIGHTENED 
THE
PRES GRADIENT BETWEEN THE TWO RESULTING IN BRISK NE WINDS.  

$$
DGS