000
AXPZ20 KNHC 272122
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC TUE OCT 27 2009

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

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1530 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE IS CENTERED ALONG...05N77W TO 
11N100W TO 11N120W TO 08N130W TO 08N140W. SCATTERED MODERATE TO 
STRONG CONVECTION IS WITHIN 150 NM OF THE POINT 06N78.5W. 
SCATTERED MODERATE TO STRONG CONVECTION IS WITHIN 150 NM OF THE 
POINT 12N98.5W. SCATTERED MODERATE WITH ISOLATED STRONG 
CONVECTION IS WITHIN 60 NM EITHER SIDE OF THE ITCZ AXIS W OF 
130W.

...DISCUSSION...

DEEP LAYER LONGWAVE TROUGH AXIS EXTENDS FROM THE MOUTH OF THE 
RIO GRANDE TO 18N107W TO 15N123W TO 11N127W TO 10N140W. MOST OF 
THE AREA NORTHWEST OF THE TROUGH AXIS IS DRY AND CLOUD FREE IN 
THE MIDDLE AND UPPER LEVELS. OVERCAST STRATOCUMULUS IS N OF 19N 
W OF 120W WITH CLEAR SKIES IN THE LOWER LEVELS ELSEWHERE 
NORTHWEST OF THE TROUGH AXIS. THE EXCEPTION TO THIS IS MOSTLY 
HIGH BROKEN CLOUDS OVER THE UNTIED STATES FROM WEST TEXAS 
WESTWARD. THIS AREA IS DOMINATED BY A LARGE ANTICYCLONE CENTERED 
NEAR 33N141W.
THE DEEP LAYER TROUGH IS CONFINED TO OVER THE NORTHEAST PART OF 
THE PACIFIC OCEAN AREA AND MEXICO NORTH OF 20N. THIS PATTERN IS 
FORECAST TO REMAIN WITH THE TROUGH STRENGTHENING SOME AND THE 
RIDGE WEAKENING SOME.

TO THE SOUTHEAST OF THE TROUGH AXIS A MOIST REGION EXTENDS 
ABOUT 360 NM SOUTH OF THE TROUGH AXIS WEST OF 110W. SOME OF 
THIS AREA IS THE ITCZ. EAST OF 110W TO 90W THE ATMOSPHERE IS 
MOIST IN THE DEEP LAYER NORTH OF THE ITCZ WITH MULTI LEVEL 
OVERCAST CLOUDS WITH EMBEDDED AREAS OF CONVECTION. FROM ABOUT 
82W TO 90W THE ATMOSPHERE IS DRY IN THE MIDDLE AND UPPER LEVELS 
WITH SCATTERED TO BROKEN CUMULUS IN THE LOWER LEVELS.

STRONG RIDGE IS NORTH OF 15N WEST OF 117W. NORTHEASTERLY WINDS 
OF 20 TO 25 KT ARE OVER THE NORTHWEST QUARTER OF THE PACIFIC 
OCEAN REGION DUE TO THE STRONG HIGH PRESSURE. WINDS WILL GUST TO 
30 KNOTS NEAR 30N WITH GALE CONDITIONS FURTHER NORTH OFF THE 
CALIFORNIA COAST. AS THE RIDGE WEAKENS THESE WINDS WILL BEGIN TO 
DIMINISH LATER WEDNESDAY. ELSEWHERE A BROAD TROUGH IS ANALYZED 
AT THE SURFACE CENTERED AROUND THE ITCZ.
 
$$
LL