Area Forecast Discussion
Issued by NWS San Angelo, TX

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49
000
FXUS64 KSJT 291729
AFDSJT

Area Forecast Discussion
National Weather Service SAN ANGELO TX
1229 PM CDT SUN MAY 29 2016

.AVIATION...
/18Z TAFS/

VFR conditions prevail across West Central TX this afternoon with
south winds of 6-12 kts. A diurnal Cu field will develop across
the area, with scattered showers and thunderstorms developing
after 21z. This activity will remain scattered through early
evening, but is expected to consolidate into an MCS, moving east-
southeast across the CWA through the early morning hours.
Convection is likely at each forecast terminal this evening and
tonight, but the timing is still somewhat in question. Will carry
VCTS for most sites, with TS included at KABI. Tempo visibility
and ceiling restrictions are expected in an around thunderstorms,
along with gusty convective outflow winds. This will be covered in
subsequent updates as the timing becomes more apparent.

Low clouds are possible late tonight, mainly across the southeast
areas. No low clouds were included at KABI or KSJT tonight as
convection is expected to limit how far north low clouds will
form.

&&

.PREV DISCUSSION... /issued 700 AM CDT SUN MAY 29 2016/

AVIATION...
/12Z TAFS/

Some brief MVFR ceilings will be possible at KJCT through mid
morning, otherwise VFR conditions are expected through much of
the period. Scattered showers/isolated thunderstorms may
affect KBBD, KJCT and KSOA this morning. Convection is expected
to develop northwest of the area late this afternoon, with
activity moving southeast across the area later this evening.
KABI stands the best chance to see thunder on station this
evening and will include TS at the terminal for a couple of
hours. Also included VCTS at KSJT this evening but left the other
terminals alone for now due to coverage uncertainties. MVFR
ceilings expected after 09Z at the southern terminals.

PREV DISCUSSION... /issued 504 AM CDT SUN MAY 29 2016/

SHORT TERM...
(Today and Tonight)

An outflow boundary (from previous convection) has sagged south
into the southern third of our area early this morning. Behind
this boundary, scattered showers and thunderstorms are occurring
across the central third of our area, but this is much weaker than
what occurred across the Big Country earlier in the night.

The forecast concerns for this afternoon and tonight are on the
possibility for additional severe weather, and on heavy rainfall
and the associated possibility for flooding.

An upper low will move east across southern California and into far
western Arizona by Monday morning. With southwest flow aloft into
our area out ahead of the low, model indications are for an
embedded disturbance to enter southwest Texas by this evening,
continuing into our area overnight. Convection this morning will
gradually dissipate, and should have a decrease in cloud cover
this afternoon. While isolated thunderstorm development cannot be
ruled out this afternoon (especially along any residual outflow
boundaries), the main focus is what will occur with the approach/
arrival of the disturbance aloft. The models indicate increased
development that should grow upscale into a MCS, with a subsequent
track east/ southeast across at least part of west central Texas
later this evening and tonight. The 00Z NAM and TTU WRF show
convective development today across the Texas Panhandle, with
growth into a MCS and track southeast across at least the northern
third of our area. This is where we have the highest PoPs for
tonight. Could also have thunderstorm development along a dryline
in far west Texas, with some of the convection entering our area
from the west. Combination of moderate to strong instability and
sufficient vertical shear favor severe weather potential for much
of our area this afternoon into tonight. The severe weather
threats include large hail, damaging winds, and isolated
tornadoes.

With much of the Big Country area having received recent heavy
rainfall, concerns are for additional heavy rain which could lead
to runoff/flooding. Precipitable water values are forecast to be
around 1.5 inches, and with weak low-level jet development and
steep mid- level lapse rates, the factors favor sustaining a MCS
well into the overnight hours.

LONG TERM...
(Memorial Day through Saturday)

Our area will remain in southwest flow aloft through Tuesday
night, as the upper low and trough progress slowly east across
the southwestern state. Models indications are for additional
embedded disturbances to enter Texas, with moist and unstable air
remaining in place. With this setup, our area could have
additional rounds of showers and thunderstorms, with convective
development during the mid/late afternoons and expansion across
our area during the evening and nighttime hours. We are carrying
30-50 PoPs Monday through Tuesday. Large scale lift with the
incoming upper low and trough will support more widespread
coverage of showers and thunderstorms Tuesday night and Wednesday.
A weak cold front progged to move south across our area Wednesday
into Wednesday night would provide an additional focus.

Temperatures will be cooler following the frontal passage, and
rain chances should diminish Thursday night into Friday as drier
air filters in behind the slowly departing system.

&&

.PRELIMINARY POINT TEMPS/POPS...
Abilene  83  66  86  67 /  40  60  40  30
San Angelo  87  68  86  67 /  40  50  40  30
Junction  86  69  85  68 /  30  40  40  30

&&

.SJT Watches/Warnings/Advisories...
None.

&&

$$

Johnson



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.