000
AXPZ20 KNHC 282130
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC WED JUL 28 2010

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 
2030 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE IS ANALYZED ALONG A LINE FROM 
07N78W TO 12N100W TO 09N115W TO 11N132W TO 10N140W. A SURFACE 
TROUGH IS EMBEDDED IN THE ITCZ FROM 13N133W TO 07N135W. 
SCATTERED MODERATE CONVECTION LIES WITHIN 210 NM EITHER SIDE OF 
THE ITCZ AXIS BETWEEN 92W AND 100W AND WITHIN 120 NM EITHER SIDE 
OF THE ITCZ AXIS BETWEEN 106W AND 111W.

...DISCUSSION...

THE AXIS OF AN UPPER LEVEL TROUGH EXTENDS FROM A LOW WELL N OF 
THE FORECAST AREA TO 30N130W AND SW TO 22N138W. A 30-50 KT UPPER 
JET LIES WITHIN 520 NM OF THE E SIDE OF THIS AXIS S OF 30N. 
RIDGING ALOFT COVERS THE REMAINDER OF THE AREA N OF ABOUT 10N E 
OF 130W INTO MEXICO WITH THE RIDGE AXIS EXTENDING FROM AN 
ANTICYCLONE NEAR THE SOUTHERN BAJA PENINSULA AT 24N112W SW TO 
20N136W. 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 
17N11W TO 11N117W. SOUTHERLY SWELLS TO 9 FEET ARE LOCATED OVER 
THE TROPICS E OF 130W S OF 11N TO THE EQUATOR.

MODERATE EASTERLY TO NORTHEASTERLY WINDS ALOFT COVER THE EASTERN 
PART OF THE DISCUSSION AREA. WINDS WILL WEAKEN SLIGHTLY OVER THE 
NEXT TWO DAYS. A TROUGH HAS DEVELOPED ALONG 86W N OF 06N. 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. 
SCATTERED MODERATE CONVECTION LIES WITHIN 60 NM W AND 120 NM E 
OF THIS TROUGH FROM 07N TO 09N. OUTSIDE OF THE ITCZ...SCATTERED 
MODERATE CONVECTION LIES WITHIN 150 NM OF THE MEXICAN COAST FROM 
18N TO 22N.

$$
CAB/SCHAUER