Area Forecast Discussion
Issued by NWS San Angelo, TX
FXUS64 KSJT 110912
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN ANGELO TX
412 AM CDT TUE MAR 11 2014
(Today and Tonight)
...Dangerous fire weather conditions this afternoon and very
windy tonight behind a cold front...
A surface trough will move through West Central Texas around
noon, sweeping low level moisture eastward and bringing breezy
downslope westerly winds. Critical fire Weather conditions are
likely across the Big Country, extending southward into the Concho
Valley this afternoon. Added couple degrees to GFS MOS highs to
account for downslope warming.
A cold front with very strong winds behind it will affect the
region tonight. The front should enter Haskell and Throckmorton
counties around 7 PM...be along the I-20 corridor 9-10 PM...San
Angelo to Brownwood 11 PM-Midnight...and I-10 corridor around 2
AM. There is still some uncertainty on timing. Expected wind
speeds will be 25 to 35 mph with gusts to 45 mph. Winds will
likely shift to the northwest a couple hours before the front.
Despite the very strong winds, temperatures should stay above the
freezing mark due to strong mixing behind the front. The Big
country should see lows in the upper 30s, with lows near 40
farther south. A wind advisory will be issued for tonight.
(Wednesday through next Monday)
...Generally dry and mild conditions for the long term...
Wednesday will start off windy as colder air finishes moving into
the area behind a strong cold front. A quick punch of colder than
normal temperatures will invade following the front for Wednesday,
with highs only expected to get into the upper 50s to near 60. An
upper level low develops near Las Vegas on Wednesday, and will
approach Texas Thursday, moving across the caprock area near
Lubbock Friday into Friday night. The system will not have enough
time to pull significant moisture into west central Texas, and the
core of the low will be north of our area, so we will leave the
forecast dry for now. Temperatures will warm back into the 60s by
Thursday, and into the 70s for Friday and Saturday. Elevated fire
weather conditions will affect the area Thursday through Saturday,
mainly for areas west of a Throckmorton to Sonora line due to
gusty winds and low relative humidity values.
Another shortwave trough will drop south through the region
Saturday night into Sunday. However, medium range models differ
significantly on the exact track of this low as it moves south.
Precipitation is likely to develop to the east of the main low as
the next cold front moves through. However, have low confidence in
any one solution at this point, so have only introduced slight
chance PoPs along our extreme eastern border at this time.
Temperatures will be cooler Sunday behind the front, and may need
to be cooled more if precipitation/clouds look more certain.
Expect temperatures to warm back up into he 70s to near 80
degrees by Tuesday.
...Red Flag Warning this afternoon for the Big Country and Concho
A surface trough will move across West Central Texas midday with
winds shifting to the southwest by mid morning, and west by noon.
This will sweep surface moisture with dew points in the 50s
eastward midday. RH values should fall below 20 percent between
Noon and 1 PM in the Concho Valley and Big Country. Minimum RH
values across West Central Texas will fall into the 7-15 percent
range. Twenty foot winds of 20 mph will bring critical fire
weather conditions to the Big Country and Concho Valley,
especially in the range of hills south of Sweetwater and Abilene.
Farther south along the I-10 corridor and along and east of a
Brownwood to Junction line, wind speeds should stay below critical
values, however fire weather conditions will be elevated with very
Strong, gusty north winds are expected to follow a cold frontal
passage tonight. North wind gusts of 45 mph could occur. Fire
fighters working any fires that start this afternoon should be
alert for the wind direction changes and the increase in wind
speeds. The front should enter Haskell and Throckmorton counties
around 7 PM...be along the I-20 corridor 9-10 PM...San Angelo to
Brownwood 11 PM-Midnight...and I-10 corridor around 2 AM. Winds
should shift northwest a couple hours before frontal passage. It
is possible that Red Flag Conditions may be exceeded for an hour
in the evening, in the very dry air along the front.
Elevated fire weather conditions are expected again on Wednesday,
due to gusty north winds continuing into early afternoon. Relative
humidity values will drop to between 20 and 25 percent in the
afternoon. It will be cooler with highs in the upper 50s.
.PRELIMINARY POINT TEMPS/POPS...
Abilene 88 38 57 32 65 / 0 0 0 0 0
San Angelo 87 40 59 31 66 / 0 0 0 0 0
Junction 87 42 60 30 65 / 0 0 0 0 0
RED FLAG WARNING from Noon today to 8 PM CDT this evening FOR
THE FOLLOWING ZONES: Callahan...Coke...Coleman...Fisher...
WIND ADVISORY from 7 PM this evening to 7 AM CDT Wednesday FOR
THE FOLLOWING ZONES: Brown...Callahan...Coke...Coleman...