Austin / Travis County and South Central Texas Special Weather Briefing #1
Prepared by Incident Meteorologist Troy Kimmel (www.troykimmelweather.com)
530pm CT – Friday / 20 December 2013
… “Slight” Risk of Severe Thunderstorms Late Tonight into Saturday Morning…
… Upper Air Storm System and Associated Cold Front To Move Across Texas …
.. Synoptic / Forecast Discussion …
Late this Friday afternoon… warm, moist surface air continues to move northward across our
area on the heels of a moderate south southeasterly wind. A strong cold front has moved
very slowly south southeastward to just east of Paris, TX to north of Waco TX and to south
of San Angelo. Temperatures are in the 70s ahead of the front (70 in Waco) with
temperatures falling into the 40s and 30s behind the front (36 in Abilene).
Most importantly, a vigorous upper level low pressure disturbance/storm system is located
near Tucson, AZ and is moving eastward. As it continues to move eastward, with very cold
temperatures aloft, our atmosphere is quickly becoming more unstable with atmospheric
lift increasing as well. As it moves eastward, the cold front to our north should slow in its
southward movement as scattered to numerous rain showers and thunderstorms develop
to our west and march eastward.
By later tonight into the day Saturday, as the disturbance moves west-to-east north of our
area, the cold front will surge southeastward with a line of rain showers and stronger thunderstorms
building on the front. The NWS/Storm Prediction Center (SPC) has placed our area in a “slight”
risk area for severe thunderstorms for the 9pm to 9am time period tonight into Saturday morning
as atmospheric lift and instability is maximized. Here is a link to the SPC day one severe weather
outlook (valid now through 6am Saturday)..
Here is the link to the SPC day two severe weather outlook (valid 6am Saturday to 6am Sunday)..
The risk in our part of the outlook area is larger hail along with the possibility of strong
straight line thunderstorm wind. Rainfall amounts locally will be beneficial with 1/2″ to 1″
totals possible with isolated heavier amounts.
Once the upper air system passes off to our northeast and the surface cold front passes
through our area tomorrow, the threat of severe weather will end quickly with clouds and
post frontal precipitation lingering through tomorrow afternoon.
… ABIA Interests …
Scattered to numerous rain showers and thunderstorms will develop around and/or move through
the area.. including the ABIA aerodrome.. later tonight into the predawn hours Saturday. Frequent
deadly cloud-to-ground lightning will accompany any thunderstorms that develop and/or move into
the area with NWS issued airport weather warnings likely by late tonight into the morning hours
Saturday. There is also a “slight” risk of severe thunderstorms with larger hail and strong straight
line thunderstorm winds possible. The threat of severe weather and thunderstorms will end with the
wind shift to the west by tomorrow morning into midday.
DFW/DAL aerodromes will be affected by this storm system, with possible delays and diversions,
later tonight and perhaps for the morning hours Saturday. IAH/HOU aerodromes will be affected
by this system primarily tomorrow into tomorrow night with possible delays and diversions.
Here is the current KAUS Terminal Forecast (TAF) as issued by NWS/Austin-San Antonio
at 1pm CT today…
FTUS44 KEWX 201900 AAB TAFAUS TAF AMD KAUS 201928Z 2019/2124 17010KT P6SM SCT015 BKN035 TEMPO 2019/2022 BKN015 FM210200 15013KT P6SM OVC009 FM210600 17015G22KT P6SM OVC012 TEMPO 2111/2115 4SM TSRA OVC009CB FM211500 22012KT P6SM -SHRA BKN025 FM211800 24015KT P6SM BKN035=
I’ll continue to keep you informed on this weather event as it unfolds.
If you have a smart phone (iPhone, Android), I strongly recommend the use of the MyWarn App.. which operates in the background of your phone to let you know when there’s a general “heads up” risk of severe thunderstorms and/or tornadoes (day 1 and day 2 outlooks from the NWS/Storm Prediction Center in Norman, OK). As the risk becomes more immediate and tornado and severe thunderstorm watches from the NWS/Storm Prediction Center and flash flood watches from the NWS/Austin-San Antonio become necessary, you’ll be notified. Finally, when the weather becomes an imminent and urgent threat to life and to property and tornado, severe thunderstorm and flash flood warnings are issued from the NWS/Austin-San Antonio, you’ll be the first to know through this app whether you’re at your home or on the road in the USA. The GPS location feature of your phone tells the app where you are and you’re notified immediately whether you’re in Austin or Chicago. All the details can be found here.