000
AXPZ20 KNHC 220923
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC THU OCT 22 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.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 10N85W TO 
12N110W TO 12N130W TO 07N140W. SCATTERED MODERATE WITH ISOLATED 
STRONG CONVECTION IS WITHIN 120 NM OF THE POINT 10N87W. 
SCATTERED MODERATE CONVECTION IS WITHIN 60 NM OF THE POINT 
10N105.5W. SCATTERED MODERATE TO STRONG CONVECTION IS WITHIN 60 
NM OF THE POINT 13N109.5W. SCATTERED MODERATE TO STRONG 
CONVECTION IS WITHIN THE AREA FROM 05N TO 09N WEST OF 130W.

...DISCUSSION...

DEEP LAYER TROUGH WILL CONTINUE OVER THE NORTHEAST PART OF THE 
PACIFIC OCEAN REGION AND NORTHERN MEXICO. THIS FEATURE WILL LAST 
AT LEAST THROUGH THE NEXT SEVERAL DAYS. AT THIS TIME THERE IS 
LITTLE WEATHER ASSOCIATED WITH THE TROUGH. THE MIDDLE AND UPPER 
LEVELS ARE MOSTLY DRY WITH SOME UPPER MOISTURE OCCASIONALLY 
ALONG AND NORTH OF 30N. OVERCAST STRATOCUMULUS CLOUDS ARE NORTH 
OF 20N WEST OF 120W. THE SOUTHERLY FLOW EAST OF THE TROUGH IS 
ADVECTING DEEP LAYER MOISTURE EMANATING FROM ITCZ CONVECTION 
NORTHEASTWARD ACROSS CENTRAL MEXICO TO THE WESTERN GULF OF 
MEXICO. 

ANOTHER TROUGH WHICH HAS ALSO LASTED FOR A FEW DAYS IS OVER 
NORTHERN CENTRAL AMERICA. A SURFACE LOW JUST OFFSHORE NORTHERN 
COSTA RICA IS PRODUCING AN AREA OF CONVECTION MENTIONED IN THE 
ITCZ SECTION. THE CONVECTION DOES SEEM TO BE ORGANIZED AND HAS 
INCREASED SOME DURING THE LAST SIX HOURS. THE COMPUTER FORECAST 
MODEL LEAVES THE LOW STATIONARY AND WEAKENS IT VERY SLOWLY. THE 
DEEP LAYER TROUGH ALSO REMAINS STATIONARY AND WEAKENS IN THE 
COMPUTER FORECAST.

THE WESTERN PART OF THE ITCZ IS VERY DIFFLUENT ALOFT AND A LARGE 
AREA OF CONVECTION WITH MULTI LEVEL CLOUDS IS WEST OF 130W. NO 
LOW LEVEL FEATURE IS IN THIS AREA AND THE CONVECTION IS NOT 
ORGANIZED BY ANY LOW LEVEL CIRCULATION.

MODERATE SURFACE RIDGE IS NORTH OF 13N WES OF 115W. ELSEWHERE 
EXCEPT FOR THE LOW OFFSHORE NORTHERN COSTA RICA A BROAD TROUGH 
IS ANALYZED AT THE SURFACE.

$$
LL