Austin / Travis County and South Central Texas Weather Update #2
Prepared by UT University/Incident Meteorologist Troy Kimmel
615pm CT – Saturday / 21 January 2017
.. Little Change in My Forecast Thought from Statement Yesterday …
.. Vigorous Upper Level Low Pressure Storm System Approaching …
.. As the Upper Level Disturbance Passes, a Surface Cold Front Will Move
Through Our Area with Strong Northwesterly Winds Developing …
NWS / Austin-San Antonio Upgrading Fire Weather Watch to a Red Flag Warning …
NWS / Austin-San Antonio Issues Wind Advisory …
Strong Gradient (Non-Thunderstorm) Wind Event for Tonight into Sunday …
Make Preparations Now …
As you’ve undoubtedly noticed, a pretty chaotic mid and high level cloud pattern
(including virga – precipitation evaporating before reaching the ground largely) and
even a few sprinkles here on the ground have been present over the past few hours
over the IH35 corridor. This is indicative – in fact, a textbook case – of a strong
and dynamic upper level low pressure storm system and current cold front that is
approaching us from the west on this Saturday evening. Because of the lack of surface
moisture, we’re seeing little in the way of lower clouds and precipitation from this
system.
Even so, I expect we’ll continue to see a few sprinkles here at the ground with, given
the dynamic nature of the system, even the possibility of a few lightning strikes over
the next few hours.
By later tonight, as the system passes overhead, the skies will clear and the atmospheric
pressure gradient will tighten considerably with a strong northwesterly surface wind
developing area wide. When this occurs, which I expect we’ll see in the evening
hours, northwest surface winds of 18 to 28 mph will develop with some wind
gusts to 35 to 40 mph.
By daybreak tomorrow, sustained northwesterly winds of 25 to 35 mph will be common
with some gusts as high as 45 to 50 mph possible.
Winds should slowly diminish by afternoon tomorrow.
In short, make preparations now. Secure loose objects that may be easily blown about
such as garbage cans, lawn furniture, etc. It is also reasonable to expect that with the
strong winds that there may be some power outages in some areas.
In addition, please be aware of the wildfire threat (as indicated by the NWS / Red Flag Warning).
Vegetation. which is dormant due to the season and the hard freezes we’ve seen this winter,
has dried out since our rains earlier in the week and wildfires will be easily spread by the
strong northwesterly wind.
I’ll continue to keep you informed.. tk
tk