TK’s Special Weather Update #1 – Troy Kimmel Weather

Austin / Travis County and South Central Texas Special Weather Briefing (Update #1)
Prepared by Incident Meteorologist Troy Kimmel (www.troykimmelweather.com)
545pm CDT – Saturday / 09 March 2013

… Thunderstorm Risk Tonight with Cold Front Moving Through the Area …
… Remember Also, the Time Change CST to CDT Occurs at 2am Sunday Morning (“Spring Ahead”) …

.. Synoptic / Forecast Discussion …

Late this Saturday afternoon… a strong upper level low pressure disturbance is over far northwest Texas
and eastern New Mexico.. and is within a broad and deep trough.. or line.. of upper air low pressure
that extends south southwestward from the northern plains through the southwestern USA. At the surface,
a deepening area of low pressure is located over southwestern Kansas and southeastern Colorado with
a dry line and Pacific cold front extending southward through west and southwest Texas. Another cold
front extends from the Kansas surface low southwestward into the Oklahoma/Texas panhandles into
northeastern New Mexico and souther Colorado.

By later today into tonight.. atmospheric lift and instability will overspread our area as the initial dry line
and Pacific cold front progresses eastward over the area. Scattered to numerous rain showers and
thunderstorms will develop and/or move through the area as this occurs. Some thunderstorms may become
severe.. mainly north of the area.. in the 9pm CST to 4am CDT time period with the mail risks locally being
larger hail and damaging thunderstorm wind. The initial dry line/front should move east of the IH35 corridor..
with a wind shift to the west.. by 4am CDT Sunday morning with the threat of severe thunderstorms diminishing
rapidly thereafter and rain chances decreasing as well.

GENERAL WEATHER THREATS LATER TODAY INTO TONIGHT…

The NWS/Storm Prediction Center (SPC) is forecasting a “slight” risk of severe thunderstorms locally
tonight. You can see the day one severe weather outlook from the SPC at…
http://www.spc.noaa.gov/products/outlook/day1otlk.html

Latest NWS QPF guidance suggests that rainfall locally will be one inch or less. Other than urban
flooding in passing heavier thunderstorms, I do not anticipate flooding problems. Even though flooding
is not expected, you should always remember.. “Turn Around, Don’t Drown”.. which is the
National Weather Service safety campaign to get people to recognize flood dangers and to avoid
low water crossings when they are flooded.

As in all anticipated severe/inclement weather events, no matter where you are, please continue
to stay “weather aware” and please check to make sure that your NOAA All Hazard Weather Radios
are operational and are set to alarm in case of severe and inclement weather watches and/or warnings.

AVIATION INFORMATION…

.. FOR THE AUSTIN BERGSTROM INTERNATIONAL (AUS) AIRPORT AERODROME …
Scattered to numerous rain showers and thunderstorms are expected in the 9pm CST to 4am CDT time
period this Saturday night/Sunday morning with the strongest storms after 11pm CST. There is a risk
of severe thunderstorms with hail and strong straight line thunderstorm winds with these thunderstorms.
NWS issued Airport Weather Warnings are likely as thunderstorms develop over or approach the
ABIA aerodrome. With the Saturday night minimum (“X7”) in commercial air traffic, the local effect
should be a bit more minimal than it would be any other night of the week.

..AUS Terminal Aerodrome Forecast (TAF).. Just Issued by the NWS at 2300z…

KAUS 092332Z 1000/1106 17015G25KT P6SM SCT029 OVC045
FM100300 17012KT P6SM OVC020
TEMPO 1006/1010 3SM TSRA BKN008 OVC020CB
FM101000 30015G30KT P6SM BKN025 PROB30 1010/1012 31015G35KT 2SM
TSRA OVC025CB
FM101200 34012G22KT P6SM -RA OVC025
FM101400 35015G25KT P6SM BKN250=

.. FOR OUR DAL/DFW HUB AERODROMES …
A severe thunderstorm watch is already in effect for the area as a line of strong to severe thunderstorms
progresses over the metroplex and the DAL/DFW aerodromes. Delays.. diversions and FAA traffic
management programs are likely into tonight with numerous thunderstorms impact the individual
aerodromes and, of course, the FAA/Fort Worth center airspace. With the Saturday
night minimum (“X7”) in commercial air traffic, the effect perhaps should be a little less than it would be
any other night. The front will clear these aerodromes by midnight with weather improving thereafter.

.. FOR OUR HOU/IAH HUB AERODROMES …
The threat of strong thunderstorms will be after midnight into the mid and late morning hours tomorrow
(Sunday). We should expect some delays and FAA traffic management programs as well as some diversions
into the morning hours on Sunday as a line of thunderstorms directly impact the individual IAH/HOU hub
aerodromes and, of course, the FAA/Houston Center airspace.

FAA National Airspace Status can always be found at…
http://www.fly.faa.gov/ois/

FOLLOWUP STATEMENTS…

I will continue to keep you informed of this severe/inclement weather threat event.
Any questions, please let me know at tkimmel@mail.utexas.edu .

GENERAL WEATHER INFORMATION LINKS…

For the Austin area…
Austin – San Antonio NWS Office web site:
http://www.srh.noaa.gov/ewx/

For the Bryan – College Station area…
Houston / Galveston NWS Office web site:
http://www.srh.noaa.gov/hgx/

To see all current real time weather warnings/statements for NWS offices, please see…
http://kamala.cod.edu/svr/
For the Austin and LaGrange areas, it’s the “NWS/Austin-San Antonio office”… for the
Bryan/College Station area, it’s the “NWS/Houston-Galveston office.”
The list is national in scope and the bulletins are all listed in chronological order with the most recent
statements/warnings at the top (you scroll down to go back in time). Click on the NWS Office name
to see the warning… and click on the the four letter ID after that to see any follow up statements to
the warnings. This web page “auto refreshes” every two (2) minutes.

During the severe/inclement weather episode, please consult the NWS / Storm Prediction Center
website regularly at..
http://www.spc.noaa.gov/products/md/ ..
for the latest mesoscale convective updates as these are usually the “heads up” on impending
severe weather watches.

Troy Kimmel Weather

Forecasting Austin and South Central Texas Weather Since 1984