Troy Kimmel Weather

Forecasting Austin and South Central Texas Weather Since 1984

TK’s Special Briefing….

Austin / Travis County and South Central Texas Winter Weather Update #3
Prepared by Incident Meteorologist Troy Kimmel (www.troykimmelweather.com)
835pm CT – Monday / 27 January 2014

… Precipitation Now Developing to our West … Moving Eastward ….
… Temperatures Locally Still Above Freezing ….
… Possible Winter Weather Event Late Tonight into Tomorrow Morning ….

Current Area NWS Watches/Advisories/Warnings:

NWS Austin-San Antonio continues a WINTER WEATHER ADVISORY for the following
counties from 12 midnight tonight through noon tomorrow (Tuesday)…
Burnet.. Blanco.. Williamson.. Travis (Metro Austin).. Hays.. Caldwell.. Bastrop.. and Lee.
Current NWS precipitation probabilities have most recently been updated to 30% for tonight
and 20% for tomorrow. They continue to think that ice/snow accumulations will be light
with isolated one to two tenths of an inch accumulations primarily east of the IH35 corridor.

NWS Fort Worth has upped their precipitation probabilities to about 40% to 50% for frozen
precipitation and has indicated “little or no accumulation” for the Temple/Belton areas of
Bell County and the Rockdale/Cameron areas of Milam County. They have not issued any
winter weather watches/advisories/warnings for Bell and Milam Counties as of this moment.

NWS Houston-Galveston has upgraded to a WINTER STORM WARNING for most all of
southeast Texas including the Houston area/aerodromes.. to the east of our area.. for the 3am
Tuesday morning through 12 midnight Tuesday night time period. This warning includes
counties just to the east of our area including Brazos.. Burleson.. Washington.. Austin and
Colorado counties. Current precipitation probabilities for Bryan/College Station is 40% to
50% with snow/ice accumulations up to 1″ expected.

…. My Meteorological Thoughts ….

First.. a temperature round up at 8pm…
Austin City/Camp Mabry… 42F
Austin Bergstrom International Airport… 41 F
Austin Executive Airport / Pflugerville… 39 F
Georgetown Airport…. 39 F
Lago Vista Rusty Allen Airport… 38 F

At this point, my confidence has increased that we’re going to see wintry precipitation over next
12 to 15 hours.. I am raising my precipitation probability for the overnight hours resulting in
a this being more of a moderate probability event.. with a potential moderate to high impact locally.

We’re seeing a marked increase in precipitation on radar to the west of our area. Keep in mind,
however, that the surface based cold arctic air mass in this area is causing much of the precipitation to
evaporate before reaching the ground
. However, the process overall is moistening the atmospheric
column and as a result, it will become increasingly likely that this precipitation will start to reach the
ground within the next few hours as the area moves across the IH35 corridor. Based on the latest
radar presentation, as mentioned above, I’m raising my precipitation probability for the Austin area
from the current 20% to up to 40% for tonight and will keep my current forecast probabilities (40%)
for Tuesday morning into midday.

As the precipitation moves toward the IH35 corridor, we’ll likely, due to the very dry lower levels of
the atmosphere, see some evaporative cooling which should result in temperatures falling to near freezing
as the precipitation begins locally around or just after midnight.

It is likely that on-and-off light sleet and light snow.. and perhaps even some patchy light freezing rain..
will continue through the predawn hours and through the rush hour and as late as midday tomorrow as
temperatures rise to slightly above freezing.

Based on what we’re seeing now, I think we could see impacts during the morning rush hour Tuesday with
accumulations ranging from a dusting (a trace) to 1/4″ of ice and snow on some exposed bridges and
overpasses.  I agree with the NWS that the heavier accumulations will be generally along and east of the
IH35 corridor.

This weather system is still slated to move east of the area by late tomorrow into tomorrow night; clouds
will break and precipitation will end quickly by the late afternoon into evening hours tomorrow. Sunshine
and warmer temperatures are in store on Wednesday (40s to near 50 F) through the remainder of the
week (60s).

That’s it as of the 8pm hour tonight… I’ll continue to keep you advised.

tk