Austin / Travis County and South Central Texas Weather Update
Prepared by Incident Meteorologist Troy Kimmel (www.troykimmelweather.com)
550pm CT – Tuesday / 9 April 2013
… Slight Risk of Thunderstorms Later Tonight into the Morning Rush Hour Wednesday
For Areas Generally Northwest.. North and Northeast of Austin …
In the evening hours on this Tuesday.. an intense upper level low pressure system is over
southwestern Colorado and northwestern New Mexico. At the surface, a deepening surface
low pressure area extends from south central Kansas through western Oklahoma into west
Texas. A strong slow southeastward moving cold front extends through the surface low pressure from near Oklahoma City to just west of Wichita Falls westward to south of Lubbock.
The strength of this system and the attendant cold front can be seen in temperatures across the front. Currently, to the north of the front, Lubbock is reporting around 50 degrees while not very far away in Abilene.. southeast of the front.. it is 92 degrees. It should be noted that we’ve seen temperatures as warm as 108 at Laredo along the Rio Grande country of south Texas this afternoon.
Tonight, as the upper level low moves east northeastward, the surface cold front will be
reinforced in its movement southeastward and will likely move through our area a little after sunrise tomorrow morning with the colder air arriving during the day with overnight lows tonight ending up being very close to daytime highs tomorrow. Any rain chances will diminish quickly with the passage of the frontal boundary.
As the front moves across the area.. we’ll see instability and atmospheric lift increase across our area. Scattered rain showers and thunderstorms, likely in line formation, will develop to our north through northwest with south central Texas likely to remain on the south side of the best instability and lift. In addition, this front will be moving through the area at a time of the coolest temperatures of the day (overnight into the morning hours), which is a negative factor. I expect that we’ll see a line of rain showers and thunderstorms develop in the prefrontal environment after midnight with us being affected by the southern part of any line that does develop. My feeling, at this point, is that – in agreement with the NWS Storm Prediction Center day one severe weather outlook — the greatest risk of severe thunderstorms will be mainly northwest.. north and northeast of the Austin metro area proper. The main risks in these areas will be larger
hail and damaging straight line thunderstorm wind.
See the NWS/Storm Prediction Center Day 1 Outlook here (valid until 7am tomorrow):
http://www.spc.noaa.gov/products/outlook/day1otlk.html
Excessive rainfall will not be a problem with this system given the fast forward or progressive movement expected as the system surges across our part of the state. With this system, rainfall amounts.. where the rain occurs.. will average 1/4 up to 1/2 inch.
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.
I’ll continue to monitor this potential inclement weather event into the overnight hours.
tk
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Updated 845am CDT Tuesday / 9 April 2013
A Cold Front with a Chance of Thunderstorms Late Tonight into Tomorrow ….
Some Stronger Thunderstorms Possible Mainly Northeast of Austin ….
Cooler.. Drier and More Stable Weather Pattern Thursday into the Weekend ….
On this Tuesday morning…. surface high pressure is well off the east coast of the USA. A strong area of deepening low pressure is over eastern New Mexico with a cold front.. extending through the surface low.. from southeastern Nebraska into the Oklahoma panhandle and the northwest Texas panhandle and into northeastern New Mexico and then northwest into Colorado. Given this surface pressure pattern, surface winds are southerly across our area of Texas.
In the upper levels of the atmosphere…. a strong trough.. or line.. of upper level low pressure is over Utah and Arizona. Given this upper air pattern, winds over south central Texas and the Austin metro area about 18,000 feet above the ground are southwesterly 50 to 60 mph.
Southerly surface winds continue to return low level moisture back to the area with late night and early morning low clouds with some patchy fog and drizzle. With the strong and deepening surface and upper level low pressure area, to our distant west and northwest, we’ll see the more humid weather pattern continuing over the next 12 to 24 hours.
As the upper level low pressure area out west moves eastward, the surface low out west and the attendant surface cold front will surge southeastward through Texas tonight into tomorrow. At this point, I think it will move through our local area in the 8 to 11 am time frame tomorrow morning. As it approaches late tonight into tomorrow morning, scattered rain showers and thunderstorms with some storms possibly severe.. mainly north and east of Austin. The main risk will be larger hail and damaging straight line thunderstorm wind.
Once the front moved through, cooler and drier surface high pressure will settle southeastward into Texas tomorrow night into Thursday.
As surface high pressure moves eastward by late Friday into Friday night into Saturday.. a south southeasterly wind will redevelop with a slow return in low level moisture over the weekend into early next week.
Have a good Tuesday night and Wednesday…
Meteorologist Troy Kimmel
Contact me:
tkimmel@austin.utexas.edu
http://www.facebook.com/troykimmel