000
FXUS64 KSJT 251159
AFDSJT

Area Forecast Discussion
National Weather Service San Angelo TX
659 AM CDT Mon Sep 25 2017

.AVIATION...
/12Z TAFS/

Periods of showers and a few thunderstorms will affect the
terminals through tonight. For this morning, occasional MVFR
ceilings will affect the southern terminals, with IFR ceilings
expected at KSOA through mid morning. Expect temporary reductions
in visibility and ceilings at times associated with heavier
precipitation through the forecast period. Ceilings are expected
to lower to MVFR across most of the terminals after 06Z. Could
also see some IFR ceilings at times across the southern terminals
but confidence is too low to mention at this time.

&&

.PREV DISCUSSION... /issued 452 AM CDT Mon Sep 25 2017/

SHORT TERM...
(Today and Tonight)

A deep upper trough currently extends across the Rockies early this
morning, with an embedded closed low situated over Wyoming. This low
is progged to break away from the main upper trough and lift
northeast into the northern Plains by early Tuesday morning, while
energy on the back side of the trough closes off a second low over
the Great Basin on Tuesday. Deep mid and upper level southwest flow
will transport abundant moisture across the area through tonight.
Early morning satellite imagery shows a deep plume of moisture
extending from Tropical Storm Pilar also lifting northeast across
central Mexico into the Edwards Plateau. In the low levels,
southeast flow is transporting rich Gulf Moisture across the area.
This will contribute to precipitable water values between 1.5 and
2.0 inches across West Central Texas through tonight, with the
potential for moderate to locally heavy rainfall across mainly
the western half of the forecast area.

Regional radar imagery shows convection developing across the low
rolling Plains and the Permian Basin early this morning. Hi-Res
model data shows convection increasing in coverage across this area
this morning, then spreading east across West Central Texas today
into tonight. Going with high POPs for western sections, with lower
POPs over eastern sections. WPC has included a slight chance for
excessive rainfall generally west of a Hamlin to Junction line the
next 24 hours, with a better chance for significant rainfall
expected across the area Tuesday night and Wednesday. After
coordinating with surrounding offices, decided to hold off on
a Flash Flood Watch for now but this may be needed eventually.
Abundant cloud cover, along with precipitation will result in
cloudy skies and cooler temperatures today, with highs in the
lower and middle 80s. Lows tonight will be in the upper 60s to
around 70 degrees.

LONG TERM...
(Tuesday through Monday)

Looks like a wet period with the potential for some flooding this
week. The main ingredients will be a slow moving upper level
trough(a few strong disturbances in the flow aloft), a cold front
moving south across our area by Wednesday and some upper level jet
stream dynamics. In addition, expect overrunning over the front and
strong low level upslope flow, especially over the Northern Edwards
Plateau. The moisture will be plentiful with PW values of 1.75 to
2 inches. As a result, expect showers and thunderstorms across
much of West Central Texas for many days. Heavy rainfall is a good
possibility across parts of the area, especially Tuesday through
Thursday, with localized flooding possible. For now, the heaviest
rainfall amounts seem to be setting up across the western half of
the area. Will hold off issuing any Flash Flood Watch for now, but
this upcoming heavy rainfall event will need to be monitored
closely. Also, WPC is issuing a moderate risk for excessive
rainfall across mainly the Northern Edwards Plateau and Concho
Valley for mainly Wednesday and Wednesday night.

The rain chances will be decreasing by this weekend. Temperatures
will be much cooler due to the cloud cover, rainfall and weak low
level cold air advection mid to late week. Highs will be range
from the 70s to lower 80s for Tuesday through Saturday.

&&

.PRELIMINARY POINT TEMPS/POPS...
Abilene  83  69  77  62 /  50  70  80  80
San Angelo  82  69  78  65 /  70  80  80  80
Junction  85  71  79  67 /  50  50  80  80
Brownwood  86  71  80  66 /  40  40  60  60
Sweetwater  79  67  73  61 /  80  80  80  80
Ozona       79  68  75  64 /  80  80  80  80

&&

.SJT WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

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