"Real" summer is underway, and here to stay, across the Mid-South

Summer 2021 so far

While we saw some above normal temperatures in the month of June, the overall average for the month was 1.0 degrees below normal and the highest temperature recorded (officially) in Memphis was 94 degrees. July typically features highs in the low 90s and low in the mid 70s. Through the 23rd, we had only observed two days with above average temperatures and both were a single degree above average. Sixteen days were below average. So while it was hot, it wasn't abnormal, nor excessive.

Weather records for the first 24 days of July. The temperature departures from normal for each day are in the red box. The warmest temperature, relative to normal, so far this month was yesterday. (NWS)

That changed on Saturday. The high of 95 degrees was the hottest so far this year and today will likely meet or exceed that. Combined with dewpoints in the mid 70s, which is sultry and means there is a great deal of moisture in the air that makes it harder to sweat off the heat, the first Heat Advisory of the summer was issued. Today was the second. Tomorrow will be the third. Heat indices are making it to 105 degrees or higher in the afternoons. But how long will this hotter pattern last?

Early this week - scattered relief

A weak front (I almost hesitate to call it that) will move into northern sections of the Mid-South. So while we will start Monday on track for similar conditions to this weekend (disgusting upper 70s for low temps), clouds will increase and scattered showers and thunderstorms are expected mainly in the afternoon. We'll still reach the low 90s for highs, but there's a good chance many areas will get some relief as thunderstorms form - whether it be from actual rain or rain-cooled air spreading out from nearby thunderstorms. With the front nearby, dewpoints will likely "pool," meaning they build-up just ahead of the front. Since the front will not move through, we'll basically just sit in the soup. Expect extremely muggy conditions where rain or outflows are not helping a bit.

HRRR model radar simulation from Monday morning through Monday evening shows the likelihood of scattered showers and thunderstorms during the warmest part of the day. Exact storm location is not predictable, but overall coverage in a region is. Model ≠ gospel. (WeatherBell)

Tuesday will be fairly similar to Monday with warm and muggy conditions to start the day, heat building into the low 90s and afternoon scattered storms, though maybe a few less than Monday, as the front washes out to our north. Both days will likely see heat indices reach 105 or worse, at least until rain-cooled air invades an area. These are the invasions we root for.

Wednesday-Friday - more heat

As high pressure aloft builds back over the area from the west by Wednesday and for the rest of the week, oppressive conditions return as any shower than tries to form in the heat will be squashed quickly by the downward motion of air under the ridge aloft. Very little relief is expected overnight with lows in the mid to upper 70s. Afternoon highs should have no trouble reaching the mid 90s, and could touch the upper 90s late in the week in spots. Wind will be light. Sweat will be plentiful. Feels like temperatures will exceed 105, thus Heat Advisories are likely.

The European model ensemble shows a massive ridge of high pressure aloft over all but the northeast portion of the country between Wednesday-Sunday. The center of the high is over the central Plains and stretches southeast into the Mid-South. Warm colors indicate anomalously high (or warm) values. A 5-day average of 594 (or 5,940 meters) is very strong high pressure. (WeatherBell)

Next weekend

Another front looks to try and make a push towards the region from the north. The best we can hope for now is scattered showers of relief in the afternoons, but highs remain probably toward the middle range of the 90s. Further in voodoo land, a summer frontal passage is shown in long-range models early the following week. That is about like seeing snow 8-10 days out on the models in the winter. Don't get your hopes up just yet, even though the weather crap apps on your phone may show 80s ten days out.

Heat caution

Heat is rough on a person's body, and it gets worse with time. The more consecutive days with little relief, the more it takes a toll. It hasn't been this hot yet this summer. Please take it easy. Frequent breaks, plenty of non-alcoholic beverages (especially water or sports drinks), and shade as much as possible if you have to be out. Watch out for those pets too. They need lots of water and shade if they can't come in. And finally, you would never do it on purpose, but check the back seat before exiting your vehicle. We don't want any unnecessary deaths from children left in vehicles!

Heat exhaustion and heat stroke is also real - I have recent experience with a healthy, young relative who passed out while driving after working outside all day and totaled his truck when he drove it into a telephone pole. (Thankfully, he was fine other than recuperating from the heat!) It's not worth pushing it "just a little bit longer."

Erik Proseus

MWN Meteorologist

----
Follow MWN on Facebook and Twitter for routine updates and the latest info!
Complete MWN Forecast: MemphisWeather.net on the mobile web or via the MWN mobile app
Download our iPhone or Android apps, featuring StormWatch+ severe weather alerts!

MWN is a NOAA Weather Ready Nation Ambassador

Meteorologist Erik Proseus is an NWA Digital Seal Holder