Sunday, July 31, 2022

Much-needed rain closes out a hot two-month start to summer 2022

Today closes out what will go into the record books as the hottest June/July on record in Memphis, ironically with one of the coolest days in the two-month record! Until this past Friday, not a single day since June 11 had failed to reach 90 degrees, and most of them were in the mid 90s or higher. Sixteen days have seen the high reach 100 degrees! Not only will the average temperature (average of all highs and lows) be the hottest on record, so will the average high temperatures, eclipsing 95 degrees for only the third time on record (including 1952 and 1954). 


That heat has been exacerbated by, and with some likely contribution from, the lack of precipitation. Until a wetter pattern started on Friday, total precipitation for the past two months has been more than five inches below the norm of around nine inches. This has resulted in flash drought conditions as shown below. The drought allows the temperatures to be even hotter because there is less moisture fed back into the low atmosphere from the ground, allowing it to heat more than usual. 

A comparison of the drought index from June 14, when summer was starting pretty decent, to this past week, when we were all crying "mercy" following a brutal six weeks of heat. This weekend's rain should help things improve on the drought side when this week's index is released. (U.S. Drought Monitor)

But this weekend has provided a reprieve, as a front finally stalled over the area and moisture from the southwest streamed in, allowing multiple rounds of precipitation to fall over the entire region. While the ground eagerly soaks up the welcome rainfall, the clouds and precip are holding high temperatures below normal on consecutive days for the first time in a month. Muggy conditions, featuring dewpoints in the mid 70s, are keeping morning lows warm, but anything below 80 degrees is likely ruled a win right now!


Looking ahead, the upper level trough that resulted in this welcome pattern shifts to the east to start the week. We'll likely see elevated rain chances into Monday afternoon before high pressure at the surface and upper levels builds back in for the next several days. This pattern will mean a return of more typical summertime conditions. In case you've forgotten what is "expected" in summer, it isn't 100 degrees and parched earth! We're looking at highs in the low to mid 90s, enough humidity to kick heat indices just above 100, lows in the mid 70s, and small thunderstorm chances during the afternoon hours that will probably miss more of you than they will rain on. But we can't rule them out! 

The Sunday morning European model ensemble average of mid-level height anomalies for the coming week. Basically, high pressure aloft centered over the Southwest U.S. will control most of the country this week with slightly above average pressure over the Mid-South contributing to summerlike weather conditions. (WeatherBell)

So while August will be hot, it should start off not-as-hot as we had for much of the month of July, which will be the second hottest July on record behind only the benchmark of 1980.

Erik Proseus
MWN Meteorologist

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MWN is a NOAA Weather Ready Nation Ambassador Meteorologist Erik Proseus is an NWA Digital Seal Holder

Sunday, July 17, 2022

Comparing the summers of 2022 and 1980, and what's ahead for the coming week

July 1980 vs. 2022

It's no secret that heat has been a major story locally, and also for much of the country, this summer. If you've seen the daily climate summaries we post on social media each evening, you may be seeing a lot of record highs from the year 1980. Those who have spent all or most of their lifetime in the area will be glad to tell you about ridiculously hot that summer was. 

With 13 days that have reached the century mark so far this summer, and more likely to come, some comparisons are being drawn to the benchmark for Memphis summers. I decided to do a quick comparison of the two summers, in particular the months of July. Here's what I found when running the numbers for the first half of July 2022 versus the month of July 1980:


As you can see, if the pace we have set in the first half of the month continues (and none of us want it to of course), the average temperature for the month will fall within a degree of 1980. The average high temperature for the month is actually higher for the first half of July 2022 than it was for July 1980, while the overnight lows this month have been a couple of degrees cooler than they were in 1980. Through the 16th though, both months had the same number of 100 degree days so far in their respective summers. However, 1980 went on to reach the century mark 20 more times! I sincerely hope that is not what we have in store this year!

This heat is partially due to the lack of precipitation... and that lack of precipitation, particularly over the past month, has resulted in a rapid-onset drought. Comparing the Mid-South drought maps for mid-June versus just four weeks later in mid-July tells the tale:



Rain chances with a "not so hot" front

High pressure ridging that has dominated for much of the first half of July is taking a brief rest in our area the next couple of days as it repositions to the west. That is allowing a front to move into the area, bringing decent precipitation chances over the next 24 hours. The highest probability will be tonight as what appears to be a semi-organized system moves in from the northwest ahead of the cold front. Showers and thunderstorms will be likely, with heavy rain for some and perhaps a few strong wind gusts roughly north of I-40. 

With the front lingering across north MS on Monday, rain chances could linger into the morning, then we'll have another chance of a few thunderstorms in the afternoon and evening too. Clouds will keep high temperatures closer to average as local thermometers take a break from the 100 degree mark. While today's high will be mid to maybe upper 90s, Monday should be in the lower half of the 90s.

The Sunday morning HRRR forecast radar from 7am Sunday to 7am Tuesday shows highest rain chances, accompanied by thunderstorms, Sunday evening/overnight, then lingering chances Monday into Monday night as the front stalls out. (WeatherBell)


Heat returns by mid-week

As we head towards mid-week though, upper level high pressure will start building back into the Mid-South from the west. Temperatures soaring well above 100 in the southern Plains are a harbinger of the heat to come as the ridge noses over the area, squashing rain chances. Look for daily high temps at or just above the century mark Wednesday into next weekend. And since the early week front never really moves all the way through the area, drier air will remain to our north, so humidity will make it feel even hotter than the temperature would indicate. Look for Heat Advisories once again while heat indices climb above 105. 

There are hints of a weak front late Wednesday, but at most it will bring an isolated shower then maybe ever-so-slightly drier air to end the week. Unfortunately, we appear destined for more 100 degree days this month, adding to the total for 2022. Continue to exercise caution in the hot weather and always look before you lock!

The National Weather Service "Blend" model forecasts the excessive heat to pick back up where it left off by the middle of this week, and continue for probably another week. (NWS via WeatherModels.com)

Erik Proseus
MWN Meteorologist

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Complete MWN Forecast: MemphisWeather.net on the mobile web or via the MWN mobile app
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MWN is a NOAA Weather Ready Nation Ambassador Meteorologist Erik Proseus is an NWA Digital Seal Holder

Saturday, July 9, 2022

June 2022 Climate Report for Memphis, TN

June Climate Recap

The first third of the month of June was overall relatively decent, with seven of the first 11 days featuring temperatures below average and about an inch of rain falling. However, the pattern changed starting on the 12th. From that day through the end of the month, there were only three days that high temperatures did not reach the mid 90s, six days with highs at or above 100 (second most for the month of June on record), only two days with slightly below average temperatures, and no rainfall officially recorded. Temperature records were set on multiple days. Thus the month ended well above average temperature-wise (7th warmest on record) and well below average from a precipitation perspective (10th driest on record), totaling under an inch of rain. 


Drought conditions started to set in by the end of the month as well. There was one Severe Thunderstorm Warning issued in the metro in June, for Tunica County on the 8th, and no reports of storm damage during the month.

Comparison of the Drought Index from the start to end of the month of June shows the results of a lack of precipitation for the month. Conditions would worsen in early July as rainfall remained scarce. (U.S. Drought Monitor)


Memphis International Airport, Memphis, TN

Temperature 
Average temperature: 83.2 degrees (3.3 degrees above average) 
Average high temperature: 93.4 degrees (4.0 degrees above average) 
Average low temperature: 72.9 degrees (2.5 degrees above average) 
Warmest temperature: 102 degrees (22nd) 
Coolest temperature: 64 degrees (3rd, 4th) 
Heating Degrees Days: 0 (0.0 above average)
Cooling Degree Days: 553 (106 above average) 
Records set or tied: Multiple daily high temperature records were set or tied in June, including the 16th (100), 17th (100), 21st (101), 22nd (102), and 25th (101). In addition, a daily record warm minimum temperature was set on the 17th (80), which also is the warmest low temperature on record for the month of June.
Comments: 21 days saw high temperatures meet or exceed 90 degrees, which is 5.5 above normal. Six days met or exceeded 100 degrees, second most on record behind 1953 (nine). The average temperature for the month ranked 7th warmest June on record.

Precipitation 
Monthly total: 0.88 " (3.11" below average) 
Days with measurable precipitation: 6 (2.9 days below average) 
Wettest 24-hour period: 0.50" (6th) 
Snowfall: 0.0"
Records set or tied: None
Comments: The precipitation total for the month resulted in the 10th driest June on record. 

Miscellaneous 
Peak wind: Southwest/43 mph (6th) 
Average wind: 7.2 mph 
Average relative humidity: 59%
Average sky cover: 38%

 Click here for a daily statistical recap for Memphis International Airport.
 

Cirrus Weather Solutions / MemphisWeather.net, Bartlett, TN

Temperature 
Average temperature: 78.9 degrees 
Average high temperature: 91.4 degrees 
Average low temperature: 67.6 degrees 
Warmest temperature: 100.4 degrees (22nd) 
Coolest temperature: 57.3 degrees (4th) 
Comments: None 

Precipitation 
Monthly total: 1.25" (automated rain gauge), 1.34"(manual CoCoRaHS rain gauge) 
Days with measurable precipitation: 8
Wettest date: 0.75" (6th) (via automated gauge) 
Snowfall: 0.0"
Comments: None

Miscellaneous 
Peak wind: Southwest/21 mph (30th)
Average relative humidity: 70% 
Average barometric pressure: 29.99 in. Hg
Comments: None

Click here for a daily statistical recap for Bartlett, TN.
 

MWN Forecast Accuracy

MWN average temperature error: 1.97 degrees 
MWN forecast temperatures within 2 degrees of actual: 66% 
MWN average dewpoint error: 1.66 degrees 
MWN forecast dewpoints within 2 degrees of actual: 76% 

MWN's forecasts extend out five periods (2.5 days, or roughly 60 hours). Historical accuracy statistics can be found here.

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Complete MWN Forecast: MemphisWeather.net on the mobile web or via the MWN mobile app 
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MWN is a NOAA Weather Ready Nation Ambassador Meteorologist Erik Proseus is an NWA Digital Seal Holder

Sunday, July 3, 2022

Typical Independence Day weather as excessive heat builds back this week

How we got here...

Before we dig into the forecast, a quick recap of June. Everything was going along just dandy for the first 10 days or so of the month - near average temperatures and a few rainmakers. Then, the midsummer heat dome developed... and basically never left. The month ended as the 7th warmest on record with SIX days that reached 100 degrees (second most on record). Rain chances also dropped off under unrelenting high pressure and the month ended as the 10th driest on record with less than an inch of rain officially recorded.

Where we are...

As we ended turned the calendar from June to July, upper level high pressure eased just a bit and some were lucky enough to get some much-needed precipitation from scattered thunderstorms. But many were not. And as he head into the Independence Day holiday, the weather is shaping up to be much like you would expect - hot and humid with a very small rain chance - as the heat dome rebuilds for the week ahead. 

4th of July Forecast

An upper level disturbance (the faint remnants of a tropical low that deluged parts of the upper TX coast late last week), is weakening over Arkansas and rain chances are dwindling with it today. That sets the stage for high pressure aloft to rebuild heading into the holiday and week ahead. Temperatures have remained hot the past few days, but with the disturbance less of a factor, there won't be a lot of cloud cover to shield the sun's rays and we'll easily be back in the mid 90s for July 4th. In addition, humidity has started to return as dewpoints climb into the low to mid 70s, resulting in heat indices that climb back to near the danger level of 105 degrees. A Heat Advisory has been issued for Monday. Only a very small chance of a shower exists in the afternoon, but Independence Day celebrations in the evening should be unaffected and the weather will feel uncomfortably like July. 



Where we're headed...

Heading into the week, as high pressure at the surface and aloft dominate, looks for continued heat and humidity with almost no chance of rain. Highs soar to near 100 by Wednesday and stay there through the end of the week, while overnight lows only drop below 80 outside of the city, and even there just barely. It's a persistence forecast through Friday unfortunately, so expect Heat Advisories, and possibly Warnings, to continue throughout the week.. Next weekend, there are signs of an approaching cold front, though I'm not sure (and the models aren't either) that it'll actually make it here. What it should do is increase rain chances a bit for Saturday, though highs remain in the upper half of the 90s all weekend it appears. 

The European model forecast for pressure trends at about 18,000 feet shows anomalously high pressure building over the Mid-South early this week and continuing until next weekend, when some relief is forecast. This means very hot weather and a strong "lid" on upward motion that causes precipitation to form. Basically - very hot and dry. (WeatheBell)

It looks like summer is here to stay, and it won't be kind for the foreseeable future! Please ensure that you are practicing good heat safety, drinking plenty of water, staying cool in the hottest part of the day, and checking on those that need your assistance - the young, old, and your pets. The longer the heat lasts, the more likely it is to succumb to heat exhaustion or heat stroke if proper precautions are not taken. 


Erik Proseus
MWN Meteorologist

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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