Updated 915am CT – Tuesday / 28 August 2018
… Air Mass Turns A Bit More Unstable as Upper Level High Shifts Eastward …
… Isolated Rain Showers and Thunderstorms to our Southeast Next Day or So …
On the Weather Map…
On the surface map… surface high pressure, with clockwise wind circulation, is over the southeastern USA with another located over the four corners region to our distant northwest. Between the two areas of high pressure, a trough, or line, of surface low pressure, with counter clockwise wind rotation, extends southward from a low pressure and associated cold front over southwestern Kansas into the Texas panhandle and southeastern New Mexico and far west Texas. As a result of this surface weather pattern, our surface winds over south central Texas are southerly.
On the upper air map… an area of eastward moving upper level low pressure area is located south central and southwestern Canada into Montana and the intermountain west. General upper air high pressure, acting like a “lid” on the atmosphere, continues from the southwestern US and northern Mexico east northeastward over the southeastern USA and Appalachians with the main upper level high pressure centers within this area over the Appalachians and over northwestern Mexico. As a result of this upper air weather pattern, the 30,000 foot winds over our local area are easterly about 15 to 20 mph.
What I am Seeing As I Look Ahead…
The main upper level high pressure center has continued to settle more east northeast of Texas over the Appalachians with another one to our west over northwestern Mexico. We are now finding ourselves in a slightly more unstable air mass and short range high resolution model guidance now more confident that a few afternoon rain showers and thunderstorms could develop today and over the next few days in the coastal plains an move northwestward in the more unstable Gulf of Mexico flow. While the chances are very slim, I will include them in the forecast today and tomorrow. Any rainfall, in limited areas to our east, would average 1/10th inch or less with most areas receiving no rainfall.
For Thursday into the weekend, the rain chances will remain minimal and guidance suggests that I’m safe in keeping them out of the forecast for now.
A more unstable situation does spread (finally) into south central Texas by late in the holiday weekend into Labor Day and the early half of next week. I will include widely scattered to scattered rain showers and thunderstorms in the forecast with an associated lightning risk. Rainfall, at this point, of up to a 1/4 inch is possible for this time period.
Afternoon high temperatures will continue to be well above seasonal averages but falling back a little closer to seasonal averages (but still above average) by late week through the weekend into next week with the increased cloud cover.
Have a good Tuesday..
Meteorologist Troy Kimmel
Contact me:
tkimmel@austin.utexas.edu
troy@troykimmelweather.com
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@troykimmelwx (Twitter)
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Updated 845am CT… Tuesday / 28 August 2018
TODAY…. Mostly sunny. An isolated mid and late afternoon rain shower and/or thunderstorm, with an associated lightning risk, in areas east of the IH35 corridor. A 10% chance of rain; where rainfall occurs, it will average 1/10th inch or less. High 101. Southerly wind 5 to 10 mph except strong, gusty and variable around any thunderstorm.
TONIGHT…. An isolated early evening rain shower and/or thunderstorm, with an associated lightning risk, in areas east of the IH35 corridor. A 10% chance of rain; where rainfall occurs, it will average 1/10th inch or less. Mostly clear. Low 76. South southeasterly wind 5 to 10 mph.
WEDNESDAY…. Mostly sunny. An widely scattered mid and late afternoon rain shower and/or thunderstorm, with an associated lightning risk, in areas east of the IH35 corridor. A 20% chance of rain; where rainfall occurs, it will average 1/10th inch or less. High 100. Southerly wind 5 to 10 mph.
WEDNESDAY NIGHT…. An widely scattered early evening rain shower and/or thunderstorm, with an associated lightning risk, in areas east of the IH35 corridor. A 20% chance of rain; where rainfall occurs, it will average 1/10th inch or less. Mostly clear. Low 76. South southeasterly wind 5 to 10 mph.
THURSDAY…. A few morning low clouds.. otherwise mostly sunny. High 100. Southerly wind 5 to 10 mph.
THURSDAY NIGHT…. Mostly clear. Low 76. South southeasterly wind 5 to 10 mph.
FRIDAY…. A few morning low clouds.. otherwise mostly sunny. High 100. Southerly wind 5 to 10 mph.
FRIDAY NIGHT…. Mostly clear. Low 75. South southeasterly wind 5 to 10 mph.
SATURDAY…. A few morning low clouds.. otherwise mostly sunny. High 99. Southerly wind 5 to 10 mph.
SATURDAY NIGHT…. Mostly clear. Low 75. South southeasterly wind 5 to 10 mph.
SUNDAY…. A few morning low clouds.. otherwise partly cloudy with widely scattered rain showers and thunderstorms with an associated lightning risk. A 20% chance of rain; rainfall, where it occurs, will average less than 1/4 inch. High 98. Southerly wind 5 to 10 mph.
SUNDAY NIGHT…. Partly cloudy early becoming mostly cloudy after midnight. Low 75. South southeasterly wind 5 to 10 mph.
MONDAY /LABOR DAY/…. Morning low clouds.. otherwise partly cloudy with scattered rain showers and thunderstorms with an associated lightning risk. A 30% chance of rain; rainfall, where it occurs, will average 1/4 inch or less. High 96. South southeasterly wind 5 to 12 mph.
NATIONAL WEATHER SERVICE / 8 TO 14 DAY OUTLOOK
Valid Tuesday / 04 September 2018 through Monday / 10 September 2018…
Temperatures… Above Average
Precipitation… Above Average
AUSTIN SUNSET/SUNRISE TIMES…..
Sunrise this morning (28Aug)………………………………………. 7:06 am
Sunset this evening (28Aug)………………………………………… 7:58 pm
Sunrise tomorrow (29Aug)…………………………………………… 7:06 am
Sunset tomorrow (29Aug)……………………………………………. 7:57 pm