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fxus64 ksjt 220920 
afdsjt

Area forecast discussion
National Weather Service San Angelo Texas
420 am CDT Tue Aug 22 2017

Short term...
(today and tonight)

An upper trough will move east across the Great Lakes today, and
trailing portion of associated cold front will push south across
much of Oklahoma and the Texas Panhandle. South of this front across
our area, highs today will be in the mid to upper 90s with clear to
partly cloudy skies. Weak northerly flow aloft will develop over our
area, as an upper high becomes centered over far northern Mexico
just south of El Paso this afternoon and tonight. With weak
northerly flow aloft and expected convective development along
the cold front, the boundary will make southward progress into our
northern counties (big country area) tonight. The models differ
on the timing/progress of the front with the NAM faster and
farther south than the GFS. Prefer a blended solution at this
time, which takes the front south into the Big Country after
midnight. Anticipate that the front will be just north of the I-20
corridor by sunrise Wednesday.

The GFS and NAM both show disturbances embedded in weak northerly
flow aloft entering our area overnight. With these indications for
surface and upper support, the chance for showers and thunderstorms
will increase tonight across most of the northern half of our area.
May have loosely organized convection moving into our area from the
north/northwest by or after 10 PM. We are carrying chance pops
across the area generally north of a Sterling City to Baird line.

A few storms may be accompanied by gusty winds and frequent
lightning. With precipitable water values increasing to between 1.5
and 2 inches, locally heavy rainfall will also be possible. Lows
tonight are expected to be in the lower to mid 70s.

19



Long term...
(wednesday through thursday)

Models continue to show the cool front moving into the Concho
Valley on Wednesday. The European model (ecmwf) model is wetter compared to the
GFS for rainfall. Split the difference between the two models and
went with a 40 to 50 percent chance for much of west central Texas
on Wednesday. Chance of rain drops off on Thursday to 20 to 30
percent.

(Friday through next monday)

Chances of rain continue through the weekend as the remnants of Harvey
emerge into the Bay of Campeche. NHC is thinking this system has
a good chance of becoming a tropical depression by Wednesday. Some
of the moisture from this storm could reach west central Texas
and interact with the old frontal boundary Friday and Saturday,
but it is very early to know for sure. The better chance of rain
should be across the Northwest Hill country Friday through Sunday.

Afternoon high temperatures will remain in the mid to upper 80s
through next Tuesday. Chances of rain decrease next Monday into
Tuesday.

&&

Preliminary point temps/pops...
Abilene 96 73 88 70 / 5 30 50 20
San Angelo 98 74 91 70 / 5 10 50 20
Junction 97 73 93 72 / 5 5 40 20
Brownwood 96 73 90 71 / 5 10 40 30
Sweetwater 95 72 86 69 / 10 40 50 20
Ozona 96 72 90 70 / 5 10 40 20

&&

Sjt watches/warnings/advisories...
none.
&&

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