Area Forecast Discussion
Issued by NWS San Angelo, TX

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FXUS64 KSJT 271233 AAA
AFDSJT

Area Forecast Discussion...UPDATED
National Weather Service SAN ANGELO TX
733 AM CDT FRI MAY 27 2016

.UPDATE...

Increased POPs across southeast counties this morning.

.DISCUSSION...
POPs were increased across far southeast counties for this
morning. Showers and thunderstorms with heavy rainfall continue
across mainly Coleman and Brown counties early this morning. This
activity will linger through mid morning per latest HRRR, before
moving off to the east. The heaviest rainfall is affecting Brown
county, where hourly rainfall amounts are averaging between 1 and
3 inches. An Urban and Small Stream Flood advisory has been issued
for the city of Brownwood due to the ongoing heavy rainfall and
precip trends will be monitored closely for additional flooding
potential, as storms train over the same area. No other changes
needed this update.

&&

.PREV DISCUSSION... /issued 648 AM CDT FRI MAY 27 2016/

AVIATION...
/12Z TAFS/

MVFR ceilings will affect KJCT, KBBD and possibly KSJT through
mid morning. VFR conditions are then expected across the terminals
for much of the forecast period, as drier air filters into the
area. Low level moisture will make a comeback tonight, with some
MVFR stratus developing at KJCT and KBBD after 10Z.

PREV DISCUSSION... /issued 454 AM CDT FRI MAY 27 2016/

SHORT TERM
(Today and Tonight)

Showers and thunderstorms are occurring across far east and
southeast counties early this morning. Most of this activity will
exit the CWA by sunrise but some lingering showers and isolated
thunderstorms will be possible generally east of a Throckmorton to
Junction line through the early morning hours.

A short wave trough will lift northeast from the southern Rockies
and into the Central Plains by tonight and will allow the dryline to
push east across most of the area this morning and early afternoon.
Exactly where the dryline ends up is still somewhat uncertain but
should be situated along our far eastern counties during peak
heating. Will maintain 20 to 30 POPs along and east of a
Throckmorton to Junction line for this afternoon, with slight
POPs lingering over far southeast counties through early evening.
Could see an isolated strong to severe storm across this area later
this afternoon but the bulk of any severe weather should remain off
to our east today. Skies will be mostly sunny today, with afternoon
high in the upper 80s and lower 90s. Clear to partly cloudy skies
will prevail tonight, with lows in the 60s.

24

LONG TERM...
(Saturday through Thursday)

The unsettled pattern will continue Saturday through the middle
of next week, with increasing uncertainty in the pattern evolution
thereafter. As a shortwave trough lifts northeast out of the
Central Plains on Saturday, another trough will develop over
California to just west of the Baja Peninsula. With this setup,
southwest flow aloft will redevelop across our area, and low-level
moisture will return with south-southeasterly low-level flow.
Instability will also increase, and may have an approach with a
disturbance aloft. The main chance for showers and thunderstorms
Saturday will be during the afternoon, across the southern third
to half of our area.

The aforementioned upper trough will move slowly east across the
southwestern states Sunday through Tuesday. Could have several
embedded disturbances entering our area in southwest flow aloft
ahead of the main trough. Strong instability is indicated each
afternoon with surface dewpoints remaining in the 60s. Rain chances
will depend on the strength of the cap, low-level convergence along
a sloshing dryline, presence of outflow boundaries and timing/
placement of disturbances embedded in the southwest flow aloft. We
are carrying PoPs mostly in the 30-50 percent range, with the more
favored timing from the afternoon into the overnight hours.

The 00Z GFS and ECMWF have notable differences Wednesday into Friday
with the specific developments in the upper pattern for our area.
On Wednesday and Wednesday night, the GFS indicates some phasing
with a trough digging south out of the northern and central
Plains, and the southwestern trough moving out of New Mexico and
into Texas. A weak cold front is progged by the GFS to push south
across west central Texas Wednesday night. This setup would favor
a continued chance of showers and thunderstorms, followed by
cooler temperatures Thursday along with diminishing rain chances.
The ECMWF develops a closed low with the upper trough moving into
Texas from New Mexico, and lingers the system over our area
through at least Friday and possibly beyond. A consensus blend
has temperatures at least a few degrees cooler across our area by
Thursday, with lingering low rain chances. Model trends and
consistency will be monitored with forecast adjustments
anticipated.

19

&&

.PRELIMINARY POINT TEMPS/POPS...
Abilene  89  62  91  68 /  10   5  20  30
San Angelo  93  61  92  68 /  10   5  30  30
Junction  93  65  92  68 /  20  10  30  30

&&

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

$$

99/99


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