Area Forecast Discussion
Issued by NWS San Angelo, TX
FXUS64 KSJT 080425
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN ANGELO TX
1025 PM CST Sat Dec 7 2013
See update discussion below.
Have updated zones and grids to remove freezing drizzle from the
Northern Big Country. The regional radars indicate light returns now
well east of our CWA and the boundary layer remains quite dry across
this area. Besides minor tweaks to low temperatures, will make no
other changes to current forecast.
.PREV DISCUSSION... /ISSUED 538 PM CST SAT DEC 7 2013/
MVFR ceilings are currently observed at all forecast terminals
excluding KABI. However, recent ceilometer trends are suggesting
that these low clouds will be overtaking KABI soon. I expect
generally 1200-2500 ft ceilings through most of the night but clouds
are forecast to begin eroding by 12z. I did hang on to MVFR flight
restrictions through mid-morning in a few areas but improving
conditions are anticipated by late morning with only a few high
clouds expected after 18z. light north to northeast winds this
evening will veer to the south overnight, becoming predominantly
southwesterly at 7-10 kts Sunday afternoon.
Patchy freezing drizzle does remain a possibility tonight, mainly at
KABI. However, the boundary layer remain quite dry (as evidenced by
the dewpoints of 10F or less along/north of I-20). This may preclude
the development of said freezing drizzle altogether. With confidence
waning, I did remove FZRA from the prevailing weather group and will
amend as necessary.
PREV DISCUSSION... /ISSUED 350 PM CST SAT DEC 7 2013/
(Tonight and Sunday)
A few flurries or patchy freezing drizzle possible this evening in
the Big Country, as mid levels moisten with approach of a weak upper
shortwave from the west. Weak up slope NE-E winds in West Central
Texas otherwise will become south by morning.
Subsidence conditions, with decreasing clouds, are expected Sunday
as shortwave passes east. Went below GFS MOS guidance Sunday (about
5 degrees for areas south of I-20), as models probably do not take
into account energy needed to melt sleet and ice on ground.
(Sunday Night through Saturday)
Another strong cold front will affect the area on Monday with warmer
temperatures expected towards the end of next week.
A potent upper level trough will move across the Central and
northern Plains Sunday night and Monday, sending another strong
cold front across the area. Latest models are in decent agreement
concerning the timing of the front which will enter the Big Country
late Sunday night and will clear the I-10 corridor by mid morning
on Monday. No precipitation is expected with the front but we
will see temperatures back in the 20s and 30s for daytime highs on
Monday. Monday night will be cold with lows in the upper teens and
low 20s. Surface high pressure settles into the area Tuesday and
Wednesday with moderating temperatures as we see more sunshine and
low level flow becomes easterly by Wednesday.
Models still indicate an upper level trough developing over the
Desert Southwest by midweek, with the trough swing across the area
by Friday. Could see some rain showers with this system primarily
over eastern sections Thursday night and Friday and have kept the
inherited slight pops intact this forecast cycle. Temperatures will
moderate further through the end of the week with highs warming into
the 50s Friday and Saturday, with lows mainly in the 30s.
.PRELIMINARY POINT TEMPS/POPS...
Abilene 16 38 19 28 18 / 10 5 5 10 10
San Angelo 18 46 23 35 20 / 10 5 5 10 10
Junction 19 53 25 41 23 / 10 5 5 20 10