000
AXPZ20 KNHC 291522
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC THU JUL 29 2010

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 
1500 UTC.

...ITCZ...
THE INTERTROPICAL CONVERGENCE ZONE IS ANALYZED ALONG A LINE FROM 
05N77W TO 15N103W TO 10N115W TO 10N140W. SCATTERED MODERATE AND 
ISOLATED STRONG CONVECTION IS FROM 06N TO 12N BETWEEN 89W AND 
96W. ISOLATED MODERATE CONVECTION IS WITHIN 180 NM OF THE AXIS 
BETWEEN 99W AND 107W. A TROUGH IS EMBEDDED IN THE ITCZ ALONG 89W 
N OF 07N. ISOLATED MODERATE CONVECTION IS WITHIN 90 NM E AND 120 
NM W OF THE TROUGH.

...DISCUSSION...

AN UPPER LEVEL TROUGH AXIS PASSES THROUGH 32N135W TO 26N140W. A 
30-50 KT UPPER LEVEL JET STREAM IS WITHIN 300 NM TO THE EAST OF 
THE TROUGH AXIS FROM 25N TO 30N. UPPER LEVEL ANTICYCLONIC FLOW 
COVERS THE REST OF THE AREA TO THE NORTH OF 10N TO THE EAST OF 
140W. THIS PATTERN IS EXPECTED TO RETROGRADE SLIGHTLY WESTWARD 
DURING THE NEXT COUPLE OF DAYS WITH AN UPPER LEVEL LOW TO 
DEVELOP NW OF THE AREA NEAR 34N145W. DRY AIR IN SUBSIDENCE IS 
WITHIN AT LEAST 360 NM ON EITHER SIDE OF THE LINE THAT PASSES 
THROUGH 32N119W TO 18N140W. BROAD SURFACE ANTICYCLONIC FLOW 
COVERS THE AREA TO THE NORTH OF 18N TO THE WEST OF 115W. A 
SURFACE TROUGH IS ANALYZED FROM 14N114W TO 12N117W. SOUTHERLY 
SWELLS TO 9 FEET ARE LOCATED NEAR THIS TROUGH AND IN GENERAL TO 
THE SOUTH OF 15N BETWEEN 96W AND 120W AND SOUTH OF 12N TO THE 
WEST OF 120W.

MODERATE EASTERLY TO NORTHEASTERLY WINDS ALOFT COVER THE EASTERN 
PORTION OF THE DISCUSSION AREA. A SURFACE TROUGH IS EMBEDDED IN 
THE ITCZ FROM 12N88W TO 07N89W. ANY NEARBY PRECIPITATION IS 
MIXED IN WITH ITCZ PRECIPITATION. AN EARLIER ASCAT PASS AROUND  
29/0406 UTC INDICATED 20 KT WINDS ON THE WESTERN SIDE OF THE 
TROUGH. THIS TROUGH IS EXPECTED TO DRIFT SLOWLY WESTWARD OVER 
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...IMPACTING THE GULF OF TEHUANTEPEC 
REGION LATE TONIGHT INTO EARLY FRIDAY.

$$
HUFFMAN