Austin / Travis County and South Central Texas Weather Update #1
Prepared by Incident Meteorologist Troy Kimmel (www.troykimmelweather.com)
730am CT – Monday / 12 May 2014
…. Strong Cold Front Due Late Tonight ….
…. Rain Showers and Thunderstorms Expected.. Some Heavy and Possibly Severe ….
…. Flash Flood Watch in Effect for the IH35 Corridor 6pm Tonight Until Noon Tomorrow ….
. Weather Discussion ..
Early this Monday morning, a strong cold front is oriented from eastern Kansas south
southwestward into western Oklahoma and far west Texas /south of Lubbock/ then west
northwestward into eastern/northern New Mexico. In the upper levels of the atmosphere..
a strong/vigorous eastward moving upper level low pressure disturbance and trough
extends south southwestward from western Colorado into northwestern Mexico and the
Baja Peninsula.
As the cold front moves southeastward into the area by a little after midnight tonight and
the upper air disturbance approaches the area from the west.. atmospheric lift and instability
will be maximized. As a result, I expect a round of thunderstorms by later today into tonight.
There will be a “slight” risk of severe thunderstorms along with the possibility of periods of
heavy rain.
The upper level disturbance out west will lag behind the cold front; as a result, rain showers
and even some thunderstorms will continue to “overrun” the much cooler surface air for about
12 to 18 hours (through the day tomorrow into tomorrow night) following the cold frontal passage.
The NWS Storm Prediction Center has placed most of the local area is a “SLIGHT”
risk area this afternoon into tonight for severe thunderstorms (see map below) with the primary
hazards locally being larger hail and damaging straight line thunderstorms wind.
For the entire day one outlook and text discussion, see this web page…
http://www.spc.noaa.gov/products/outlook/day1otlk.html
Forecast rainfall amounts late today into tonight and Tuesday are generally expected to be in the
one to two inch range with isolated heavier totals to 3 or more inches possible. Current flash flood
guidance for Travis County… very rough estimates of what it would take to initiate flash flooding
in a given period… is 3.1 inches in a one hour period, 4.0 inches in a three hour period and 5.2
inches for a six hour period. Flash or urban/small stream flooding is going to be a risk in areas
where heavier thunderstorms occur. As well, flash flooding is a possibility, as indicated by the
NWS’ flash flood watch. Remember the NWS slogan, “turn around, don’t drown.”
Bottom line.. let’s be weather aware again today into tonight and Tuesday… first thing this morning,
please check your NOAA/NWS All Hazards Weather Radios to make sure that the radio is in
the “stand by” mode so that they’ll automatically alarm if and when the NWS Storm Prediction
Center and/or NWS Austin-San Antonio issues watches and warnings across the area today into
early tonight.
I’ll continue to keep you updated.
Troy