000
AXPZ20 KNHC 291002
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC THU JUL 29 2010

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.

...THE ITCZ...
09N83W 08N93W 12N106W 08N119W 10N130W 10N140W. NUMEROUS STRONG 
SHOWERS AND THUNDERSTORMS ARE FROM 9N TO 10.5N BETWEEN 93W AND 
94W. SCATTERED MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS 
ARE FROM 07N TO 10N BETWEEN 80W AND 91W...AND FROM 11N TO 12N 
BETWEEN 87W AND 91W.

NUMEROUS STRONG SHOWERS AND THUNDERSTORMS ARE WITHIN 30 NM
ON EITHER SIDE OF THE LINE FROM 21N106W TO 18N108W.

SCATTERED STRONG SHOWERS AND THUNDERSTORMS ARE FROM 16N TO 18N 
BETWEEN 101W AND 104W. SCATTERED MODERATE SHOWERS TO ISOLATED 
STRONG FROM 13N TO 15N BETWEEN 100W AND 106W.

SCATTERED STRONG SHOWERS ARE FROM 13N TO 14N BETWEEN 93W AND 94W.

A SURFACE TROUGH GOES FROM 15N113W TO 12N118W. SCATTERED STRONG
SHOWERS AND THUNDERSTORMS ARE FROM 12N TO 13N BETWEEN 117W AND 
119W.

...DISCUSSION...

AN UPPER LEVEL TROUGH PASSES THROUGH 31N135W TO 27N140W.
A 30-50 KT UPPER LEVEL JET STREAM IS WITHIN 520 NM TO THE EAST
OF THE TROUGH FROM 25N TO 30N. UPPER LEVEL ANTICYCLONIC FLOW
COVERS THE REST OF THE AREA TO THE NORTH OF 10N TO THE EAST
OF 130W. THE PATTERN IS EXPECTED TO RETROGRADE SLIGHTLY WESTWARD 
DURING THE NEXT TWO DAYS. DRY AIR IN SUBSIDENCE IS WITHIN AT 
LEAST 360 NM ON EITHER SIDE OF THE LINE THAT PASSES THROUGH 
32N121W TO 27N126W TO 19N140W. BROAD SURFACE ANTICYCLONIC FLOW
COVERS THE AREA TO THE NORTH OF 19N TO THE WEST OF 115W.
A SURFACE TROUGH IS LOCATED FROM 15N113W TO 12N118W. SOUTHERLY 
SWELLS TO 9 FEET ARE LOCATED NEAR THIS TROUGH AND IN GENERAL
TO THE SOUTH OF 17N TO THE WEST OF 90W.

MODERATE EASTERLY TO NORTHEASTERLY WINDS ALOFT COVER THE EASTERN 
PART OF THE DISCUSSION AREA. A SURFACE TROUGH IS EMBEDDED IN THE 
ITCZ ALONG 88W FROM 06N TO 12N. ANY NEARBY PRECIPITATION IS 
MIXED IN WITH ITCZ PRECIPITATION. THE 28/1515 UTC ASCAT PASS 
INDICATED 20 KT WINDS ON THE NORTHWESTERN SIDE OF THE TROUGH.
HIS TROUGH IS EXPECTED TO MOVE WESTWARD SLOWLY DURING THE NEXT
TWO DAYS. SOME OF THE COMPUTER MODEL GUIDANCE SUGGESTS THAT
A LOW PRESSURE CENTER MAY DEVELOP ALONG THIS TROUGH DURING THE
NEXT 48 HOURS AS SHORTWAVE ENERGY ASSOCIATED WITH A MIDDLE LEVEL 
TROUGH NEAR THE COAST OF THE BAY OF CAMPECHE SEEPS SOUTHWARD 
THROUGH THE GULF OF TEHUANTEPEC INTO THE WESTERN SIDE OF THIS
PACIFIC OCEAN TROUGH. THE PASSAGE OF THE SHORTWAVE ENERGY IS 
EXPECTED TO INDUCE 20 TO 25 KT WINDS FROM THE NORTH AND NORTHEAST
AT THE SURFACE...PASSING THROUGH THE GULF OF TEHUANTEPEC BY
TOMORROW MORNING.

$$
MT