000
AXPZ20 KNHC 290327
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC THU JUL 29 2010

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 
0045 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE IS ANALYZED ALONG A LINE FROM 
09N87W TO 12N100W TO 10N115W TO 10N133W TO 09N140W. SCATTERED 
MODERATE CONVECTION IS WITHIN 210 NM N OF THE ITCZ AXIS BETWEEN 
102W AND 110W AND WITHIN 75 NM EITHER SIDE OF THE ITCZ AXIS 
BETWEEN 110W AND 113W. A TROUGH IS EMBEDDED IN THE ITCZ ALONG 
86N N OF 06N. SCATTERED MODERATE CONVECTION IS WITHIN 60 NM W 
AND 90 NM E OF THE TROUGH AS WELL AS WITHIN 45 NM OF THE CENTRAL 
AMERICAN COAST BETWEEN 87W AND 90W. A SECOND TROUGH IS EMBEDDED 
IN THE ITCZ FROM 13N133W TO 07N135W. SCATTERED MODERATE 
CONVECTION IS WITHIN 150 NM E OF THE TROUGH FROM 09N TO 11N.


...DISCUSSION...

THE AXIS OF AN UPPER LEVEL TROUGH EXTENDS FROM A LOW WELL N OF 
THE FORECAST AREA TO 30N132W AND SW TO 22N138W. A 30-50 KT UPPER 
JET LIES WITHIN 520 NM OF THE E SIDE OF THIS AXIS BETWEEN 25N 
AND 30N. RIDGING ALOFT COVERS THE REMAINDER OF THE AREA N OF 10N 
E OF 130W INTO WESTERN MEXICO WITH THE RIDGE AXIS EXTENDING FROM 
AN ANTICYCLONE NEAR THE BAJA PENINSULA AT 25N116W SW TO 20N135W. 
THE PATTERN IS EXPECTED TO RETROGRADE SLIGHTLY WESTWARD OVER THE 
NEXT TWO DAYS. WATER VAPOR IMAGERY INDICATES STRONG SUBSIDENCE 
NW OF A LINE FROM 10N140W TO 28N114W. MODERATE EASTERLY WINDS 
ALOFT ARE LOCATED S OF 20N TO THE EQUATOR E OF 125W. AT THE 
SURFACE...A BROAD RIDGE IS LOCATED OVER THE SUBTROPICS N OF 18N 
W OF 115W. A SURFACE TROUGH IS LOCATED FROM 16N113W TO 11N116W. 
SOUTHERLY SWELLS TO 9 FEET ARE LOCATED NEAR THIS TROUGH AND OVER 
THE TROPICS W OF 95W S OF 10N TO THE EQUATOR.

MODERATE EASTERLY TO NORTHEASTERLY WINDS ALOFT COVER THE EASTERN 
PART OF THE DISCUSSION AREA. A SURFACE TROUGH IS EMBEDDED IN 
THE ITCZ ALONG 86W N OF 06N. CONVECTION NEAR THE TROUGH IS NOTED 
IN THE ITCZ SECTION ABOVE. THE 1515 UTC ASCAT PASS INDICATES 20 
KT WINDS ON THE NW SIDE OF THE TROUGH. THIS TROUGH IS EXPECTED 
TO SLOWLY MOVE W OVER THE NEXT TWO DAYS. SOME OF THE COMPUTER 
MODEL GUIDANCE SUGGESTS THAT A LOW MAY DEVELOP ALONG THIS TROUGH 
OVER THE NEXT 48 HOURS AS SHORTWAVE ENERGY ASSOCIATED WITH A MID 
LEVEL TROUGH NEAR THE COAST OF THE BAY OF CAMPECHE SEEPS 
SOUTHWARD THROUGH THE GULF OF TEHUANTEPEC INTO THE W SIDE OF 
THIS PACIFIC TROUGH. THE PASSAGE OF THIS SHORTWAVE ENERGY IS 
EXPECTED TO INDUCE 20 TO 25 KT N TO NE WINDS AT THE SURFACE 
THROUGH THE GULF OF TEHUANTEPEC BY TOMORROW MORNING.

$$
SCHAUER