Updated 915am CT – Tuesday / 28 July 2015
.. Little Change For Now as a Dry and Stable Weather Pattern Continues ..
.. Slim Rain and Thunderstorm Chances Continue for Friday and Saturday ..
On this Tuesday…. a trough.. or line.. of low pressure extends southward from a surface low over eastern Colorado southwestward through northeastern New Mexico and into southwestern New Mexico. Surface high pressure is over the southeastern USA and the northern 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 southwestward from southern Canada into northeastern Montana into the southwestern USA. Another upper level low pressure trough extends southward from east of Hudson Bay to Maine and the western Atlantic. As a result, our upper air winds at about 18,500 feet, are light east 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.
The upper level high pressure area.. which is a little to the northwest of our area.. will settle a little more overhead of our area tomorrow and Thursday with probably the best chance of a 100 degree temperatures here along the IH35 corridor.
By later in the week 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.
Beyond the weekend, upper level high pressure appears to rebuild over the area with rain chances dropping from the forecast.
Have a good Tuesday….
Meteorologist Troy Kimmel