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