Area Forecast Discussion
Issued by NWS San Angelo, TX
FXUS64 KSJT 052301
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN ANGELO TX
601 PM CDT MON OCT 5 2015
Expect VFR conditions at the terminals for the next 24 hours. The
winds will be light.
.PREV DISCUSSION... /ISSUED 351 PM CDT MON OCT 5 2015/
(Tonight and Tuesday)
Mid level cloudiness was clearing this afternoon as a weak
shortwave moved north into Oklahoma, bringing subsidence in its
wake. Tonight, as surface high pressure builds into the region,
winds will become light. Light winds, along with the clearing
skies, will set up good radiational cooling conditions. Went
closer to the cooler NAM MOS guidance tonight, with lows in the
lower to mid 50s. It will be warmer and dry Tuesday, with mid
level clouds remaining east of the region and winds returning to
the southeast at 5 to 10 mph.
(Tuesday night through Monday)
Heavy rainfall will be possible later this week as the strong
closed low over the southwest CONUS approaches from the west.
Dry weather is anticipated Tuesday night before shortwave ridging
aloft shifts to our east. Overnight lows will be near or just
above climo, with min temps around 60 degrees. By 12z Wednesday,
model consensus has the aforementioned upper-level cyclone just to
the west of El Paso, with diffluent, southwesterly flow aloft over
west TX. Rain chances will begin over west TX on Wednesday and
were included west of an Abilene to San Angelo line. However, most
of this precipitation is expected to remain to our west through
00Z. Afternoon temperatures will warm into the mid 80s to near 90
degrees. Rain chances increase Wednesday night, although PoPs
remain below 50 percent.
An upper-level jet streak is progged to develop over the Big Bend,
extending into west central TX Thursday and Thursday night. Strong
synoptic scale forcing for ascent will overspread the region in
conjunction with an increase in mid-tropospheric moisture and the
arrival of a weak surface boundary. The 12z model runs are all
indicating significant rainfall across portions of the CWA
beginning as early as Thursday and continuing into the day Friday.
However, the mesoscale features that determine where the heaviest
rainfall will occur aren`t handled well by the models this far
out. We won`t have a good a handle on these smaller scale features
for a few more days.
At this time, it appears that widespread rainfall amounts
exceeding 1 inch are possible through Friday. Higher amounts are
anticipated over the southern and western portions of the CWA,
with localized amounts exceeding 3 inches. We haven`t seen a lot
of rainfall over the past few months, but rainfall amounts of this
magnitude may result in localized flooding concerns, especially in
urban and other poor drainage areas. With the widespread rainfall
and weak surface boundary in the area, temperatures are expected
to remain in the 70s across the area both Thursday and Friday.
By Friday morning, both the ECMWF and GEM begin to move the upper-
level cyclone off to the west southwest, while the GFS holds
position over the Big Bend until Friday night. Low PoPs were
retained on Saturday, favoring the southwest CWA with dry weather
Saturday night into Monday. Temperatures are expected to warm back
into the mid/upper 80s by the beginning of next week, although a
significant increase in soil moisture could limit the warm-up.
.PRELIMINARY POINT TEMPS/POPS...
Abilene 53 85 59 87 / 0 0 0 10
San Angelo 55 88 61 89 / 0 0 0 10
Junction 54 90 62 90 / 0 0 0 10