Updated 915am CT – Monday / 27 July 2015
.. Little Change For Now as a Dry and Stable Weather Pattern Continues ..
.. Slim Rain and Thunderstorm Chances by Friday and Saturday ..
On this Monday…. a trough.. or line.. of low pressure extends southward from a surface low over eastern Colorado southward through eastern New Mexico and southwest Texas. Surface high pressure is over the southeastern USA and the central and western Gulf of Mexico. As a result of this surface weather pattern, our local surface winds are southerly.
In the upper levels of the atmosphere.. an upper level high pressure area.. acting like a “lid” on the atmosphere.. is centered from west Texas northeastward into Oklahoma. An upper level low pressure trough extends south southwestward from eastern Washington into southern California. Another upper level low pressure trough is over the northeastern USA. As a result, our upper air winds at about 18,500 feet, are light northeasterly.
As we’ve seen over the last few weeks, a typical summer weather pattern continues with a moist and tropical air mass holding across the area.
In the past 24 hours, with the upper level high pressure area settling a little more to our west, we’ve had a slug of mid and upper air moisture work into the area fro the east. Although the overall effect of this moisture will be minimal, I think it’ll keep us a degree or two below the century mark locally for today and tomorrow.
The upper level high pressure area will settle a little more overhead of our area Wednesday and Thursday with probably the best chance of a 100 degree temperatures here along the IH35 corridor.
By Friday into the upcoming weekend, the upper level high pressure.. and the “lid” effect it has on the atmosphere.. will retreat westward more over the southwestern USA and the four corners region. As this occurs and we find ourselves east of the high pressure area, we’ll see a more pronounced northerly wind aloft along with a slightly more unstable atmosphere. A weakening cold front.. supported by this more northerly wind aloft.. will move southeastward into northern Texas before pulling up stationary just to the north and northeast of the Austin area. Given the forecast instability as well as increased low level moisture, I will call for widely scattered rain showers and thunderstorms for the Friday through the weekend time period. With the increased cloud cover, daytime high temperatures will be down a few degrees as well.
Have a good Monday….
Meteorologist Troy Kimmel