Upper atmosphere dictating the pattern; changes coming!

Ecmwf Deterministic Conus Z500 Anom 1day 2060000

For those who like hot summer weather, we apologize for this past week. For the rest of us, we’ll take whatever reprieve we can get in July! Summer-lovers, it’s not over though! We still have plenty of time for summerlike conditions, and to be honest, the heat and humidity combo meal will be served daily once again in the very near future!

Many times, the weather we feel down here at ground zero is reflective of surface-based features like cold and warm fronts, high and low pressure, etc. This past week though, the upper levels of the atmosphere have had much more to say about our cooler and wetter pattern, though surface features still play a major role in how the overall pattern is manifested to us.

To be more specific, we’ve been under the influence of lower pressures aloft this week (roughly at 15,000-20,000 feet). This upper level low pressure, when coupled with low level moisture, has meant mainly cloudy days, elevated rain chances, and thus cooler than average temperatures. The below average temperatures have reduced the amount of storm fuel (instability), so most of the precipitation this week -with a few exceptions – has been in the form of showers with little in the way of thunder and no severe storms. That pattern hangs on this weekend, so rain chances remain high, but is showing signs of falling apart by early this coming week.

Ecmwf Deterministic Conus Z500 Anom 1day 2060000
The European modeled upper level (18,000′) pressure anomalies from Friday show below average pressure (blues) over the southern Plains, edging into the Mid-South, resulting in clouds and below average temperatures. (WeatherBell)

As our sights shift to next week, the upper level pattern looks much more like typical summertime, with higher pressure building over the southern Plains and reaching east into the lower Mississippi Valley. That will result in more sunshine and warmer temperatures. At the surface, moisture remains in place (dewpoints in the 70s), so the hotter temperatures will combine with the elevated moisture and we’ll likely end up with heat alerts this week as heat indices climb above 105 each day, especially by Tuesday.

Ecmwf Deterministic Conus Z500 Anom 1day 2556800
The European modeled upper level (18,000′) pressure anomalies for Thursday, August 1, show above average pressure (yellow/orange) over most of the U.S. with the center of a heat dome in the ArkLaTex area to our west. This will result in hot temperatures and a cap on precipitation chances. (WeatherBell)

That upper level high pressure will also put a “cap” on the atmosphere, meaning little if any rain for the coming work week, other than maybe a few daytime thunderstorms Monday. This larger pattern looks to remain in place through the week before maybe relaxing a bit next weekend when small rain chances start to re-appear.

Ecmwf Deterministic Conus Z500 Anom 1day 2816000
The European modeled upper level (18,000′) pressure anomalies for Sunday, August 4, show above average pressure (yellow/orange) over the western U.S. with near average pressure and a hint of an upper level trough in the eastern U.S. south into the lower Mississippi Valley. This would result in more typical summertime weather. (WeatherBell)
610temp.new (1)
The temperature outlook for the first week of August indicates above average temperatures are likely for most of the nation, though slightly lower odds are in place from southern TX into the Deep South. (NOAA/CPC)

Recent Posts

Subscribe
Notify of
guest
0 Comments
Oldest
Newest Most Voted
Inline Feedbacks
View all comments