Area Forecast Discussion
Issued by NWS San Angelo, TX
FXUS64 KSJT 290401
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN ANGELO TX
1101 PM CDT MON JUL 28 2014
A weak front is located along the interstate 10 corridor. Winds are
forecast to remain generally east to northeast, and light, through
the overnight hours. Isolated showers and thunderstorms will be
possible Tuesday afternoon, but coverage if forecast to remain
isolated, so no mention of thunder was included in the TAF package
at this time. VFR conditions are expected through the next 24 hours.
.PREV DISCUSSION... /ISSUED 617 PM CDT MON JUL 28 2014/
A cold front/outflow boundary was approaching KSJT. This feature
will result in brief northeast winds of 12 to 16 knots, with some
higher gusts. Overnight, winds will generally be east to southeast
at less than 10 knots. Isolated showers and thunderstorms will be
possible Tuesday afternoon, at mainly KABI, but coverage should
remain isolated enough to leave out any mention in the current TAF
PREV DISCUSSION... /ISSUED 359 PM CDT Mon Jul 28 2014/
The atmosphere is ripe for microbursts this afternoon. Model
soundings show good adiabatic layer up to around 700mb, a decent
moist layer between 700 and 750mb with inverted V sounding beneath
Late this afternoon, showers and thunderstorms were developing
along an outflow boundary across Interstate 20. The boundary was
headed slowly south southwest. With an agitated cu field to work
with along Interstate 29, continued storm development is expected
this afternoon and early evening.
Looking at the NAM and SPC Mesoanalysis, most unstable CAPE
values were between 1000-1500 j/kg this afternoon. NAM shows the
CAPE increasing to 2500 j/kg by tomorrow afternoon. For the most
part, convective inhibition will be less than 60 j/kg during the
day, and increasing to 100 j/kg overnight. For this reason we
expect showers and thunderstorm to taper off as the evening
progresses and we lose daytime heating. Scattered storms should
redevelop tomorrow afternoon along old outflow boundaries and the
weak cold front mainly along and north of a line from Sterling City
to San Angelo to San Saba.
Otherwise, lows tonight will drop down into the low to mid 70s
with afternoon highs tomorrow mainly in the mid 90s.
Outflow boundaries in the area will continue a chance for showers
and thunderstorms through Tuesday night mainly along and north of
a line from Sterling City to San Angelo to San Saba. On Wednesday
the chance of rain should retreat to the Big Country.
Models continue to weaken the upper high by Wednesday and bring
in a stronger cold front on Thursday. Went with chances for
showers and thunderstorms on Thursday. Much cooler temperatures
are expected from Thursday into the upcoming weekend.
.PRELIMINARY POINT TEMPS/POPS...
Abilene 74 92 74 97 71 / 30 20 20 10 30
San Angelo 74 97 73 100 72 / 20 10 20 10 20
Junction 73 97 72 99 74 / 10 5 5 5 10