000
AXPZ20 KNHC 280926
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC TUE APR 28 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 
0845 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE IS ALONG THE LINE...04N77W TO 
04N100W TO 05N120W TO 02N140W. THERE ARE ONLY SMALL ISOLATED 
AREAS OF CONVECTION ALONG THE ITCZ.
 
...DISCUSSION...

MODERATE WEST TO SOUTHWEST WINDS ARE NORTH OF A LINE FROM SOUTH 
TEXAS ACROSS NORTHERN MEXICO AND SOUTHERN BAJA CALIFORNIA TO 
NEAR 20N140W. THIS PATTERN WILL CONTINUE THROUGH THE NEXT COUPLE 
OF DAYS WITH THE WINDS SPEED GRADUALLY DECREASING. A STRONG 
TROUGH WEST OF THE AREA WITH AN AXIS ALONG 150W WILL SLOWLY MOVE 
EAST REACHING TO ALONG 140W THURSDAY. ASSOCIATED WITH THE WEST 
TO SOUTHWEST WINDS A LARGE PLUME OF DEEP LAYER MOISTURE WITH 
BROKEN MULTI LEVEL CLOUDS IS WITHIN ABOUT 500 NM SOUTHEAST OF A 
LINE FROM NEAR 30N110W TO 18N140W. THIS PLUME OF MOISTURE SHOULD 
CONTINUE TO ADVECT NORTHEASTWARD THROUGH THE NEXT COUPLE OF 
DAYS. IN ADDITION AS THE TROUGH WEST OF THE AREA MOVES EAST 
INCREASING MOISTURE AND CLOUDINESS WILL SPREAD OVER THE 
NORTHWEST PART OF THE AREA DURING THE NEXT COUPLE OF DAYS.

A MAINLY UPPER TOUGH EXTENDS OVER THE EASTERN PART OF THE AREA 
THROUGH THE GULF OF HONDURAS TO THE ITCZ NEAR 105W. A PLUME OF 
DEEP LAYER MOISTURE AND BROKEN TO OVERCAST MAINLY HIGH CLOUDS 
EXTENDS ABOUT 400 NM SOUTHEAST OF THE TROUGH. THE TROUGH IS 
SUPPORTING ISOLATED THUNDERSTORMS OVER EASTERN MEXICO AND OVER 
THE PACIFIC WITHIN THE MOISTURE PLUME.

REMAINDER OF THE AREA IS UNDER BROAD DEEP LAYER ANTICYCLONIC 
FLOW.

MODERATE SURFACE RIDGE IS NORTH OF 10N WEST OF 112W. THIS 
FEATURE IS FORECAST TO WEAKEN AS A SURFACE TROUGH ASSOCIATED 
WITH THE STRONG TROUGH WEST OF THE AREA APPROACHES THE AREA. 
ELSEWHERE BROAD SURFACE TROUGH IS ANALYZED.

NORTHEAST TO EAST GAP WINDS OF 20 TO OCCASIONALLY 25 KNOTS IN 
THE GULF OF PAPAGAYO REGION WILL CONTINUE FOR ABOUT 48 HOURS 
BEFORE DIMINISHING.

$$
LL