Austin / Travis County and South Central Texas Weather Statement #2
Prepared by UT University/Incident Meteorologist Troy Kimmel
800am CT – Friday / 20 March 2015

.. Upper Level Low Pressure Storm System Moves Overhead Through Saturday Night..
.. Three or More Inches of Rainfall Possible Today through Saturday Night ..
.. NWS Austin-San Antonio has, Before Becoming Effective, Redefined the Time of Flash
Flood Watch For All of the Local Area Effective 1pm Today (Instead of 4pm) through
7pm Saturday ..

On this Friday morning…. a cold front is moving southeastward from south of Tyler to south
of Waco to south of Junction. In the upper levels of the atmosphere.. a strong upper level
low pressure disturbance is located over northwestern Mexico.

The strong upper level disturbance.. to our distant west.. will be approaching the area by later
today into tonight and through Saturday with abundant atmospheric moisture in place across
the area. The approaching upper level storm will combine with the advancing cold front to
create abundant atmospheric lift resulting in widespread rain and even thunderstorm activity by this
afternoon into Saturday night and early Sunday.

As mentioned, above, given cooler temperatures aloft/atmospheric instability, there will be some
embedded thunderstorms as the system passes. As seen below (first map).. forecast precipitation
amounts, in both the manual NWS national guidance as well as the atmospheric model output..
continue with upwards of 3 or more inches of rain possible from now through Saturday night and
until 7am Sunday. Reference the second and third maps below, the NWS Weather Prediction
Center in Washington has all of our area in a “slight” risk area for exceeding flash flood values
7am today through 7am Sunday.

NWS Austin-San Antonio meteorologists.. who had already issued, at mid morning yesterday, a
FLASH FLOOD WATCH to be effective at 4pm today for all of our area..  have already revised
that watch to become effective at 1pm today with an earlier onset of heavier precipitation expected.
As originally issued, the watch will be valid until 7pm Saturday. They continue to suggest that some
isolated spots may see as much as 6 to 8 inches of rain. Make no mistake… rainfall amounts of 3 to
8 inches will cause flooding issues across the area. Local interests throughout south central Texas..
especially with numerous events going on around the area.. are strongly encouraged to monitor the
latest information regarding this potential heavy rain/flood event for tomorrow into the upcoming
weekend. As we make our way through the next several days, it’ll likely pay to remember the NWS
Slogan… “Turn Around.. Don’t Drown.”

Another factor, as the upper level low pressure area approaches the area today, the front to our
immediate north will surge southeastward across the area resulting in cooler temperatures beginning
later this afternoon into the weekend.

After rain chances decrease Saturday night into early Sunday, clouds will break a bit Sunday into
Monday.

I will continue to monitor this situation.
tk