Friday, July 10, 2020

Summer high pressure ridge to take hold, bring very hot temperatures

Overview

Over the past week or so we have been under a repetitive pattern with below or near average temperatures and pop up thunderstorms. As we move into the middle of July, we will really be feeling a 'dog days of summer' vibe with much lower rain chances and above average temperatures. This is due to something we know all too well from past years, the dreaded summer ridge. By the beginning of next week a high pressure ridge will move in and situate itself over the eastern U.S. This will allow  afternoon highs to reach the mid to upper 90s for most of next week. High pressure is also notorious for squishing out any rain chances due to sinking motion of the air under a high. That will definitely be the case heading into mid July!

European model ensemble data showing a high pressure in the mid levels situated over much of the US, including the southeast, beginning by mid-week next week. The color shading represents departure from normal pressure values, so this ridge is "anomalously strong." (WeatherBell)

The European model ensemble shows extremely low rain chances, as often found with a ridge, for the middle part of July. The top half of the graph shows rainfall over time for each member of the ensemble system, while the bottom shows the mean, or average, of the individual members. (WeatherBell)



Saturday - Sunday

This time of year is often referred to as ' MCS', or Mesoscale Convective System, season as most of our rain and thunderstorm activity is produced by these fast-moving complexes. These systems will bring us our last few rain chances on Saturday and Sunday before we dry out next week. Saturday will consist of partly sunny skies afternoon highs in the low 90s, much like Friday. However, due to northwesterly flow, an MCS in northwest Arkansas could approach the area during the afternoon time. This would likely bring a chance of thunderstorms across the metro but whether or not this complex will fall apart as it approaches remains uncertain. [ Saturday morning UPDATE: thunderstorm chances this afternoon will indeed be very minimal. ]

Our best rain chance for the next several days will come early Sunday morning. Most of Saturday night will be dry with lows in the mid 70s but a secondary system will move through the area bring another potential round of thunderstorms. If it materializes and moves through, Sunday would start off wet but throughout the day skies will become partly cloudy with afternoon highs warming into the low 90s once again.  

The Friday mid-day high-resolution NAM model "forecast radar" from Saturday morning through Sunday afternoon shows the first potential MCS Saturday falling apart to our west, while another Sunday morning has a better chance of bringing us rain. Model are challenged with these types of systems though, so this likely will change! (WeatherBell.com)


Monday- Tuesday

After the rain chances on Sunday, the dry pattern begins to take hold for early next week as the western ridge begins making its way toward the eastern half of the US. Monday morning will start off in the lower 70s and will be our coolest point for a while as overnight lows stay in the mid to upper 70s over the coming week. The warming trend continues with afternoon highs warming into the lower 90s. Tuesday will be more of the same with plenty of sunshine and afternoon highs in the mid 90s. This makes for early next week to be perfect pool weather! 



Wednesday- Friday

By Wednesday, the high pressure ridge will be fully in place thus continuing the dry pattern but bringing extremely hot temperatures across the metro. A daily pattern of mostly sunny skies with afternoon highs in the mid-upper 90s and lows in the upper 70s is what we expect through late next week. Afternoon highs may even reach 100 Thursday and Friday! Heat indices will also be extremely high, reaching well above 100 and possible reaching the 110s. This will likely prompt heat advisories or warnings. While working out in the extreme heat this coming week, there are a few key things to remember in order to stay safe. Make sure to take frequent breaks from the heat. Drink plenty of water and wear sunscreen! Overnight lows that barely drop below 80 will make the heat even less bearable as there will be little relief overnight.

Forecast temperatures for the third week of July from the European model ensemble. (WeatherBell.com)























Allison Paige
MWN Meteorologist Intern

----
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

No comments: