000
AXPZ20 KNHC 200318
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC FRI NOV 20 2009

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

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC.

...ITCZ...
AXIS IS ALONG 5N77W 6N90W 5N100W 7N1114W 8N140W. SCATTERED 
MODERATE TO STRONG CONVECTION WITHIN 150 NM N OF AXIS FROM 
127W-130W AND WITHIN 120 NM N OF AXIS W OF 136W. 


...DISCUSSION...
AN UPPER LEVEL TROUGH IS APPROACHING THE FAR NW PORTION OF THE 
DISCUSSION AREA WITH AXIS FROM 32N135W TO 28N140W. OTHERWISE A 
BROAD UPPER LEVEL RIDGE COVERS THE AREA W OF 110W. THE RIDGE 
AXIS EXTENDS FROM AN ANTICYCLONIC CIRCULATION CENTERED NEAR 
11N117W N TO 32N120W...ANOTHER RIDGE EXTENDS FROM THE 
ANTICYCLONIC CIRCULATION NE TO 16N106W. A 90-100 KT JET STREAM  
ENTERS THE AREA AT 23N140W TO 27N120W THEN SE ACROSS SOUTHERN 
BAJA CALIFORNIA THEN INTO CENTRAL MEXICO. MODERATE TO STRONG 
SUBSIDENCE WITH DRY STABLE AIR AT THE MIDDLE AND UPPER LEVELS IS 
N OF THE JET. BROKEN TO OVERCAST HIGH CLOUDS ARE WITHIN 420 NM S 
OF THE JET AXIS FROM 140W-125W. DOWNSTREAM MID/UPPER LEVEL 
TROUGH EXTENDS FROM A CYCLONIC CIRCULATION OVER THE SOUTHERN 
ROCKIES ACROSS NW MEXICO TO THROUGH THE SOUTHERN BAJA PENINSULA. 
AN UPPER LEVEL TROUGH E OF THE ANTICYCLONIC CIRCULATION IN THE 
DEEP TROPICS WITH AXIS FROM 14N102W TO 5N103W. EXCEPT FOR AN 
AREA OF MODERATE CONVECTION ASSOCIATED WITH A SURFACE TROUGH 
ALONG THE ITCZ MODERATE TO STRONG SUBSIDENCE S OF 15N E OF 120W 
HAS SUPPRESSED CONVECTION ALONG THE ITCZ IN THIS AREA.

THE PRES GRADIENT HAS WEAKENED ACROSS SOUTHERN MEXICO AND THE 
WINDS HAVE DECREASED TO 20 KT IN THE GULF OF TEHAUNTEPEC AND 
WILL CONTINUE TO DECREASE THROUGH THE NEXT 24 HOURS. A 1020 MB 
SURFACE HIGH PRES CENTERED NEAR 29N130W IS PRODUCING A STRONG 
ENOUGH GRADIENT FOR WINDS TO REACH 20 TO 25 KT FROM 10N TO 20N W 
OF 120W. BROKEN TO OVERCAST STRATOCUMULUS CLOUDS COVER THE AREA 
N OF 20N BETWEEN 115W-135W.

A SURFACE TROUGHS IS ANALYZED ALONG THE ITCZ FROM 14N110W TO 
4N109W. SCATTERED MODERATE CONVECTION IS FROM 6N-8N WITHIN 150 
NM E OF TROUGH.

$$
DGS