Troy Kimmel Weather

Forecasting Austin and South Central Texas Weather Since 1984

…. TEMPERATURES HOLDING STEADY ABOVE FREEZING IN METRO AREA ….

145am CT – Thursday / 5 March 2015

… Model Guidance Suggests Precipitation Tapers Off Before Daybreak …
… IH35 Metro Temperatures Steady and Holding Above the Freezing Mark …

At 130am… NWS Doppler weather radar suggests that one of the last waves of
precipitation is currently moving eastward across the IH35 corridor. Some lighter
precipitation may linger into wake of this current band into the 4 to 5am hour.

Our problem is that temperatures have been just a few degrees too warm.. as usual
right on the edge. After a steady fall into mid and late evening, the temperatures have
held rather steady about 2 to 3 degrees above freezing throughout the Austin metro and
the IH35 corridor metro areas over the last few hours. Keep in mind that temperatures
will still drop a few degrees before sunrise and even if precipitation ends, residual
moisture on elevated structures.. bridges.. overpasses and fly overs could freeze
even after precipitation tapers off
.

Some areas of western Hays.. western Travis and western Williamson counties.. in areas
from west of Dripping Springs to Spicewood to Lake Travis and northward to Liberty Hill
are or have been at or just below freezing as precipitation falls so it is likely that some
patchy ice may have formed or will form in those areas before daybreak on elevated
structures.. bridges.. overpasses and fly overs in those areas
.

A good source for current temperature data is the LCRA Hydromet…
http://hydromet.lcra.org/full.aspx
(Select “Austin Area” forĀ  map depiction and “Current Temperatures” for data. Good
idea, too, to click show county lines.)

Meanwhile, we need to continue to be weather aware. The NWS issued WINTER STORM
WARNING and WINTER WEATHER ADVISORY remains in effect until 12 noon today
or until we are notified otherwise by the NWS
.

The NWS/Austin-San Antonio is looking at the situation as they prepare their forecast
update for the 3 to 4am hour..

tk

…. WINTER STORM WARNING BEGINS AT 10PM …..

Updated 935pm CT – Wed / 4 March 2015

…. Winter Storm Warnings 10pm Tonight to 12 Noon Friday for
IH35 Corridor Counties ….
…. Winter Weather Advisory 10pm Tonight to 12 Noon Friday for
Row of Counties to Immediate East Southeast of IH35 Corridor Counties ….

NWS WATCHES / ADVISORIES / WARNINGS:
NWS / Winter Storm Warning (Valid 10pm Tonight until 12 Noon Thu/05Mar2015)
Counties Included.. Travis (Metro Austin).. Williamson.. Hays
Sleet/Ice accumulations to 1/10th Inch or Slightly More

NWS / Winter Weather Advisory (Valid 10pm Tonight until 12 Noon Thu/05Mar2015)
Counties Included.. Bastrop.. Caldwell.. Lee
Sleet/Ice accumulations less than 1/10th Inch

SYNOPTIC/FORECAST REASONING:
Temperatures are falling through the 30s from north to south now across
the area. Between now and midnight, temperatures will fall closer to the freezing
mark. After midnight and through the morning hours on Thursday, temperatures are
expected to be below the freezing mark.

As the relatively shallow arctic cold air slides southward over the area, several
upper air low pressure disturbances will move across the area tonight into Thursday.
This will produce an overrunning clouds and light to occasionally moderate precipitation
which will pick up tonight and persist through Thursday morning. There is some instability
noted aloft so there is even the chance of a thunderstorm or two tonight as well. A mixed
liquid/freezing/frozen precipitation or even a complete change over to freezing/frozen
winter precipitation will likely occur over south central Texas based on the latest
guidance. NWS advises that ice accumulations locally may be 1/10th inch or perhaps a
little more in areas where precipitation after midnight becomes more moderate in some
areas. Please understand that this is enough to create very hazardous/dangerous driving
conditions locally and to have major local impacts.

Gusty northerly winds.. in excess of 30 mph at times.. will potentially cause some problems
overnight in association with ice accumulations on trees and power lines.

Ice that does form tonight, based on the current forecast, will not completely melt away
from surfaces until Thursday after the noon hour.

While we will likely see some breaks in the clouds by tomorrow into Friday, the
cloudy overrunning pattern is likely to kick back in by Friday night into the weekend
with temperatures only slowly warming.

I will continue to keep you advised with shorter updates through the night with temperature
and weather reports from local officials and the National Weather Service.

tk