Area Forecast Discussion
Issued by NWS San Angelo, TX
FXUS64 KSJT 200440
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN ANGELO TX
1140 PM CDT FRI SEP 19 2014
VFR conditions continue to prevail across West Central Texas
terminals late this evening, with most of the showers having
dissipated as well. Low cloud imagery starting to show the
formation of the expected MVFR/IFR ceilings across central Texas.
These should expand across much of the area before sunrise. Hard
to tell just how far cigs will drop, but should be in the same
general conditions as last night. High res models suggest showers
may redevelop near Abilene towards sunrise, in an hour where
satellite is showing a developing mid level cloud deck late this
evening. Will include a VCSH up there.
.PREV DISCUSSION... /ISSUED 638 PM CDT FRI SEP 19 2014/
VFR conditions should continue across West Central Texas terminals
for the remainder of the evening hours. Most of the showers and
storms have dissipated. Cant rule out a stray shower near a
terminal, but the odds are so small that we wont mention at this
time. With the loss of the showers, the low cloud formation looks
more likely. Previous forecasts based it partly on what happened
earlier this morning, and this seems like a good starting point
as well. However, without the disruption by the showers, should
be more widespread than it was today.
PREV DISCUSSION... /ISSUED 354 PM CDT FRI SEP 19 2014/
(Tonight and Saturday)
Scattered showers and a few thunderstorms are occurring this
afternoon across West Central Texas south of Interstate 20.
This convective activity is occurring in a very moist airmass, out
ahead of the remnant circulation of Odile over southeastern New
Mexico. Also have a weak surface boundary extending roughly along
the Interstate 10 corridor. Given how moist the airmass is
(precipitable water values of 1.8 to just over 2 inches) with
slow-moving convection, locally heavy rainfall is likely with a
possibility of localized flash flooding.
For tonight and tomorrow, will need to monitor the progress of what
is left of Odile, along with any mesoscale convective vorticies.
More organized heavy rainfall has occurred during the past 24-48
hours with these features. A MCV early this morning brought heavy
rain to West Texas, around and west of Midland/Odessa. Difficult to
discern in satellite imagery, but may have a MCV near Crane, TX
(about midway between Midland and Fort Stockton) at mid-afternoon,
moving east-southeast. A difficult forecast with the track of the
the weakening remnants of Odile, which is trapped beneath a weak
mid/upper level ridge over the southern Rockies and Southern Plains.
Additional showers and thunderstorms are expected tonight and
Saturday in West Central Texas. The higher PoPs and coverage are
expected to be across our western and northwestern counties, but
will need to monitor the presence and track of the aforementioned
features. Since the coverage of heavy rainfall during the past 1-2
days has been scattered, reluctant to issue a Flash Flood Watch for
our area at this time. However, could see the case for issuing a
Watch if trends indicate a more organized heavy rain threat. Lows
tonight and highs on Saturday are expected to be similar to what
(Saturday night through Monday)
Tropical moisture from remnants of Odile will continue to provide
rain chances through the start of next week. Unfortunately for most
of West Central Texas, models indicate areas of greatest rainfall
will be to the west or southwest of our area through Monday; only
a few of our western counties have any significant chance of
greater rainfall. Also, remnants of Odile will remain under an
upper ridge through Monday. Model precipitable water values remain
in the noteworthy 1.75 to 2.0 inches range, across our southern
counties Saturday night. Then, precipitable water values decrease
into the 1.25 to 1.50 inches range for Sunday through Monday. In
addition, models this cycle don`t bring the weak front into our
area, as previous model runs indicated. This lack of surface focus
will diminish the potential for widespread high rainfall amounts,
which would surely help increase stock tank and reservoir levels.
Nevertheless, some locations across the western half of our area
may receive an additional 1 to 2 inches through mainly Sunday
night. On Monday, drier air begins to move into Texas, and rain
chances decrease to 20 percent for all of West Central Texas.
(Monday night through Friday)
For Monday night through the end of the Long Term period, look for
dry conditions and temperatures close to seasonal normals. Models
begin to shift the upper-level ridge east early in the week.
Then, an upper trough moves over the Plains by mid week. Behind
this trough, an upper ridge builds over the eastern CONUS, by
week`s end. With high pressure dominating most of Texas next week,
surface winds will be mainly from the south and relatively light
for this time of year.
.PRELIMINARY POINT TEMPS/POPS...
Abilene 69 84 70 85 68 / 50 60 50 40 30
San Angelo 70 85 70 86 67 / 50 60 40 40 30
Junction 72 86 72 87 68 / 30 40 30 30 20