000
AXPZ20 KNHC 152116
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC MON JUN 15 2009

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

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE IS ALONG THE LINE...09N83W TO 
09N100W TO 06N115W TO 10N140W. SCATTERED MODERATE WITH ISOLATED 
STRONG CONVECTION IS WITHIN 90 NM OF THE POINT 06.5N90.5W.  
SCATTERED MODERATE CONVECTION IS WITHIN 90 NM OF THE POINT 
04N122W.

...DISCUSSION...

WELL DEFINED DEEP LAYER TROUGH EXTENDS FROM SOUTHERN CALIFORNIA 
AND OFFSHORE ABOUT 600 NM SOUTHWEST ACROSS THE AREA TO THE ITCZ 
WEST OF 130W. A WEAKENING PLUME OF UPPER LEVEL MOISTURE 
EMANATING FROM THE ITCZ IS ASSOCIATED WITH THE SOUTHERLY FLOW 
EAST OF THE TROUGH AXIS AND EXTENDS EAST OF A LINE FROM NEAR 
32N100W TO 20N120W TO 10N135W. WEST OF THIS LINE THE ATMOSPHERE 
IS MOSTLY DRY AND CLOUD FREE IN THE MIDDLE AND UPPER LEVELS WITH 
PATCHY STRATOCUMULUS IN THE LOWER LEVELS. THE EXCEPTION IS 
ASSOCIATED WITH A STRONG SHORTWAVE DROPPING INTO THE TROUGH FROM 
THE NORTHWEST WITH MULTI LEVEL BROKEN TO OVERCAST CLOUDS NORTH 
OF 29N FROM 120W TO 129W. EVEN THE MOISTURE PLUME IS CLOUD FREE 
IN THE MIDDLE AND UPPER LEVELS. THE TROUGH IS FORECAST TO REMAIN 
IN PLACE AND STRENGTHEN THROUGH MID WEEK AND TO BECOME A CUT-OFF 
LOW WEST OF BAJA CALIFORNIA LATER IN THE WEEK.

ANOTHER DEEP LAYER TROUGH IS OVER EASTERN MEXICO AND EXTENDS 
SOUTHWESTWARD OVER THE PACIFIC WITH A TROUGH AXIS FROM THE 
NORTHWEST PART OF THE YUCATAN PENINSULA TO THE ITCZ NEAR 100W. 
THE TROUGH IS MOVING WEST ABOUT 15 KNOTS AND IS FORECAST TO ONLY 
WEAKEN SLIGHTLY THROUGH MID WEEK THEN WEAKEN FURTHER. ASSOCIATED 
WITH THE TROUGH IS AN ACTIVE AREA OF CONVECTION WITH SCATTERED 
MODERATE WITH ISOLATED STRONG CONVECTION FROM 11N TO 15N FROM 
100W TO 105W. A BROAD AREA OF MULTI LEVEL CLOUDS IS OVER THE 
PACIFIC AREA EAST OF THE TROUGH WITHIN A BROAD AREA OF UPPER 
DIFFLUENCE.

REMAINDER OF THE MIDDLE AND UPPER LEVELS IS UNDER BROAD 
ANTICYCLONIC FLOW.

A WEAK SURFACE TROUGH IS ASSOCIATED WITH TROUGH OFF OF SOUTHERN 
CALIFORNIA AND IS ALONG A LINE THROUGH 32N123W TO 27N126W. 
ELSEWHERE NORTH OF 12N WEST OF 110W A WEAK SURFACE RIDGE IS 
ANALYZED. REMAINDER OF THE AREA IS ANALYZED AS A BROAD SURFACE 
TROUGH.
 
$$
LL