Troy Kimmel Weather

Forecasting Austin and South Central Texas Weather Since 1984

TK’s Special Weather Updates / Sun 31Mar2013

440pm CT – Sunday / 31 March 2013

…. Severe Weather Risk Diminishing from the North ….

As the cold front drifts southward across the area.. the severe thunderstorm threat is slowly diminishing north-to-south across the area.

The NWS has now dropped the following counties from the Severe Thunderstorm Watch…
Williamson.. Burnet.. Milam

So far.. pretty quiet. At 440pm, the strongest thunderstorms are from distant west through northwest of San Antonio with lighter rain showers northeastward to Austin and Georgetown and northeastward toward Cameron and Rockdale.

The Severe Thunderstorm Watch continues in effect for the following counties…
Travis /including Metro Austin/.. Hays.. Blanco.. Caldwell.. Bastrop and Lee.

I’ll continue to monitor.. tk

141 pm CT – Sun/31Mar2013

…. Authority / NWS Austin – San Antonio ….

NOTE: Risk of Quarter Size Hail / Damaging Straight Line Winds
Moving toward North/Northwest Austin Metro Area …

BULLETIN – EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
138 PM CDT SUN MAR 31 2013

THE NATIONAL WEATHER SERVICE IN AUSTIN SAN ANTONIO HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR…
EXTREME SOUTH CENTRAL BURNET COUNTY…
NORTHWESTERN TRAVIS COUNTY…

* UNTIL 215 PM CDT.

* AT 132 PM CDT…NWS METEOROLOGISTS HAVE DETECTED A SEVERE
THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL…AND DAMAGING
WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR
SPICEWOOD…OR 11 MILES SOUTHEAST OF MARBLE FALLS…AND MOVING EAST
AT 25 MPH.

* SOME LOCATIONS IN THE WARNING INCLUDE LAGO VISTA AND LAKEWAY.

125pm CT – Sunday / 31 March 2013

…. Severe Thunderstorm Watch Issued for All of the Area Until 10pm ….

The NWS/Storm Prediction Center has issued Severe Thunderstorm Watch #73
valid for all of our area until 10pm tonight…

See… http://www.spc.noaa.gov/products/watch/ww0073.html .. for details.

I’ll continue to monitor… tk

Austin / Travis County and South Central Texas Special Weather Briefing
Prepared by Incident Meteorologist Troy Kimmel (www.troykimmelweather.com)
1125am CDT – Sunday / 31 March 2013

.. Slight Risk of Severe Thunderstorms Later This Afternoon into Tonight …
.. Main Risks are Larger Hail and Damaging Straight Line Thunderstorm Wind …

.. Synoptic / Forecast Discussion …
On this Easter Sunday morning on our surface weather map… a weakening cold front is moving southward along a line from northeastern Arkansas southwestward into the ArkLaTex region to near Waco to near San Angelo. At the same time, in the upper levels of the atmosphere, there is an eastward moving¬† low pressure disturbance over southern New Mexico.

By later today into tonight.. the front will continue southward into our area about the time that the upper level disturbance is passing. Both of these systems will phase to combine with daytime heating to create abundant atmospheric lift in what will be an increasingly unstable atmosphere. Scattered rain showers and thunderstorms will develop.. likely in a general west to east band along and ahead of the front.. and move southward through the area. Some of the thunderstorms may become severe with large hail (over
1″ in diameter) along with damaging straight line thunderstorm winds over 58 mph. This event will taper off after about 8pm as the disturbance moves east of the area and we lose daytime heating. The severe weather threat should end by 10 pm at the latest.

GENERAL WEATHER THREATS LATER TODAY INTO TONIGHT…

The NWS/Storm Prediction Center (SPC) is forecasting a “slight” risk of severe thunderstorms for all of our area. You can see the day one severe weather outlook from the SPC at…
http://www.spc.noaa.gov/products/outlook/day1otlk.html

As well, during the potential severe/inclement weather episode, please consult the NWS / Storm Prediction Center website regularly at.. http://www.spc.noaa.gov/products/md/ ..
for the latest mesoscale convective updates as these are usually the “heads up” on impending severe weather watches.

Latest QPF guidance suggests that rainfall will be in the 1/4 to 1/2 inch range so flooding should not, given our current significant drought conditions, be anything of a problem other than in very localized, mainly urban, areas where localized heavier amounts occur.

Even though flooding is not expected, you should always remember.. “Turn Around, Don’t Drown”..
which is the National Weather Service safety campaign to get people to recognize flood
dangers and to avoid low water crossings when they are flooded.

All users, as in all anticipated severe/inclement weather events, no matter where you are, please continue to stay “weather aware” and please check to make sure that your NOAA All Hazard Weather Radios are operational and are set to alarm in case of severe and inclement weather watches and/or warnings.

AVIATION INFORMATION…

.. FOR THE AUSTIN BERGSTROM INTERNATIONAL (AUS) AIRPORT AERODROME …
Scattered rain showers and thunderstorms will occur in the 3pm to 8pm time frame this afternoon into tonight. There is a risk of severe thunderstorms.. including the possibility of larger hail above 1″ in diameter and straight line thunderstorm winds of 58 mph or higher. NWS issued Airport Weather Warnings will be issued later today into tonight as thunderstorms develop over or approach the ABIA aerodrome. NWS rain chance today for the ABIA aerodrome is about 60% decreasing to 30% for tonight.

..AUS Terminal Aerodrome Forecast (TAF).. Issued by the NWS at 1100z…

KAUS 311124Z 3112/0118 20008KT P6SM OVC010
FM311500 19010KT P6SM BKN014 BKN150
FM311700 20008KT P6SM SCT040CB BKN150
TEMPO 3119/3123 01015G25KT TSRA BKN030CB
FM010000 02006KT P6SM FEW040 SCT250
FM010800 03003KT P6SM BKN012
FM011100 01004KT 1/2SM FG SCT002 BKN010
FM011500 05004KT 6SM BR SCT012=

.. FOR OUR DAL/DFW HUB AERODROMES …
Even though included in the SPC “slight risk” area. being north of the frontal boundary, the
strongest thunderstorm activity should remain south of the DFW/DAL hub aerodromes
over the southern part of the FAA/Fort Worth center airspace this afternoon. NWS rain
chance for the aerodromes today into early tonight are around 20% and are specifically
mentioned as a “few sprinkles” by the NWS Fort Worth office.

.. FOR OUR HOU/IAH HUB AERODROMES …
As the front approaches the area from the north and northwest by later this afternoon into
tonight, scattered rain showers and thunderstorms will move into southeast Texas area and specifically approach the IAH/HOU aerodromes. NWS rain chance for the area increases to 50% this afternoon decreasing to 40% by tonight. There is a risk of severe thunderstorms.. including the possibility of larger hail above 1″ in diameter and straight line thunderstorm winds of 58 mph or higher. Delays and FAA traffic management programs as well as diversions are possible with these thunderstorms later this afternoon into tonight as the line of thunderstorms directly impact the individual aerodromes and, of course, the FAA/Houston Center airspace.

FAA National Airspace Status can always be found at…
http://www.fly.faa.gov/ois/

FOLLOWUP STATEMENTS…

I will continue to keep you informed of this severe/inclement weather threat event.
Any questions, please let me know at tkimmel@mail.utexas.edu .

GENERAL WEATHER INFORMATION LINKS…

For the Austin area…Austin – San Antonio NWS Office web site: http://www.srh.noaa.gov/ewx/

For the Bryan – College Station area… Houston / Galveston NWS Office web site:
http://www.srh.noaa.gov/hgx/

To see all current real time weather warnings/statements for NWS offices, please see…
http://kamala.cod.edu/svr/
For the Austin and LaGrange areas, it’s the “NWS/Austin-San Antonio office”… for the
Bryan/College Station area, it’s the “NWS/Houston-Galveston office.”
The list is national in scope and the bulletins are all listed in chronological order with the most recent statements/warnings at the top (you scroll down to go back in time). Click on the NWS Office name to see the warning… and click on the the four letter ID after that to see any follow up statements to the warnings. This web page “auto refreshes” every two (2) minutes.

As in all anticipated severe/inclement weather events, no matter where you are, please continue to stay “weather aware” and please check to make sure that your NOAA All Hazard Weather Radios are operational and are set to alarm in case of severe and inclement weather watches and/or warnings.

tk