Saturday, September 23, 2023

Recent and forecast weather trends as autumn officially begins

A pretty wild and stormy summer has transitioned to much drier conditions of late, with temperatures generally near to slightly below average over the past month or so. Comparing the departure from normal precipitation for the past 90 days (in the first image below) to the past 30 days (second image) really shows how the northern metro received plentiful precipitation earlier this summer, but more recently, most of the area has dried up. 

Precipitation departure from average for the past 90 days shows the effect of summertime storms across west TN and northeast AR from late June through July. Most of those missed the Mississippi Delta, setting the stage for drought later in the summer. (NWS/WPC)

Precipitation departure from average for the past month is evidence of much drier conditions for the Mid-South once the summer storm track moved north. The only areas with above average precipitation are in far northwest MS and Crittenden Co, due mainly to storms earlier this week. (NWS/WPC)

We also see drought conditions expanding in north Mississippi in the past 30 days, since that area started the summer with much less rainfall than west TN.

Drought Index for the Mid-South as of this week. The Mississippi Delta is running well below normal for precipitation this summer. (U.S. Drought Monitor)

As summer officially turns to fall today (at 1:50am this morning), we're starting pumpkin spice season off with above average temperatures. Afternoon temperatures will flirt with the 90 degree mark, which is not completely unusual since our typical last 90 degree day is September 19. (And recall clast year, when mid-September featured multiple 100 degree days!) But it doesn't FEEL much like fall out there! Thank goodness for humidity levels that are early-autumn-like.


A frontal system will approach the area on Sunday, bringing more clouds which will temper the warmth. It will also introduce scattered shower and thunderstorm chances, especially Sunday afternoon and night into Monday morning. However, the HRRR model (below) is more bullish on storms in Arkansas than areas east of the Mississippi River, thanks to high pressure to our east causing precipitation to fall apart as it approaches.

 
Once we get past Monday, another dry spell sets up for the rest of the week it appears, with temperatures just slightly above normal. It'll be a rinse-and-repeat pattern with partly cloudy to mostly sunny skies, high temperatures in the mid 80s and morning lows in the mid 60s. Normal highs this time of year run about 82-84 degrees. 

If you are waiting for visible signs of fall (not Starbucks advertising signs for PSL's!), fall colors are still about a month off in the Mid-South. Any leaves changing color at this point are more likely due to trauma from lack of precipitation than true fall color setting in! 


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

Friday, September 8, 2023

August 2023 Climate Report for Memphis, TN

August Climate Recap

The month of August generally saw temperatures waver every few days from slightly above to slightly below normal. The exception was a string of hot days in the third week of the month, which resulted in four days hitting the century mark and nearly a week of average temperatures 5-10 degrees above normal. Multiple warm temperature records were also set during that late summer heat wave and a string of four consecutive days with temperatures no lower than 80 degrees (August 22-26) tied for fifth longest on record and is the latest (in the year) occurrence of a streak of three or more such days on record. The periodically cooler weather tempered the overall average for the month, which ended slightly above normal. An interesting note though was that that average was driven almost entirely by the overnight lows, which were more than a degree above normal. Average high temperatures for the month were right at average for August. For the period of meteorological summer (June-August), the average temperature for the three-month period of 81.4 degrees ended in the top 25% of all years (period of record: 149 years).


A wet summer to date continued for portions of the Memphis area as multiple rounds of heavy rain tracked across the northern metro during the month, resulting in over eight inches of precipitation in Bartlett. However, southern Shelby County and north MS missed out on much of this, with the airport recording just under three inches of rain for the month (much of that falling during storms on the 9th and 10th). The dry weather in the MS Delta region during both July and August resulted in drought conditions setting in mid-month in those agricultural areas. For the period of meteorological summer (June-August), total precipitation of 16.84" ended in the top 10% of all years (period of record: 152 years).

Departure from average rainfall for the Mid-South in August 2023. The precipitation disparity between northern and southern areas of the metro was stark, as evidenced by 8"+ of rainfall in Bartlett and less than 3" at Memphis Int'l in south Memphis. By the middle of the month, drought conditions had developed in the Mississippi Delta. (NOAA)

An active summer severe weather pattern continued into early August with severe thunderstorms resulting in wind damage on afternoon of the 5th, followed by another round of midday storms on the 9th that brought large hail, damaging wind, and areas of flash flooding in Shelby County. A few strong storms also occurred mainly in Crittenden County on the evening of the 26th as the heat wave was broken by a cold front. 

Memphis International Airport, Memphis, TN

Temperature 
Average temperature: 82.6 degrees (0.5 degrees above average) 
Average high temperature: 91.4 degrees (0.1 degrees below average) 
Average low temperature: 73.8 degrees (1.2 degrees above average) 
Warmest temperature: 102 degrees (25th, 26th) 
Coolest temperature: 63 degrees (31st) 
Heating Degrees Days: 0
Cooling Degree Days: 553 (25 above  average) 
Records set or tiedAugust 22, (80°, tied record warm low), August 23, (81°, set record warm low), August 24 (100°, tied record high), August 25 (102°, set record high; 80°, set record warm low), August 26 (80°, set record warm low). 
Comments: 18 days reached 90°, which is 2.2 days below average for the month of August

Precipitation 
Monthly total: 2.82" (0.55" below average) 
Days with measurable precipitation: 8 (0.4 days above average) 
Wettest 24-hour period: 2.17" (9th-10th) 
Snowfall: None
Records set or tied: N/A
Comments: More than three-fourths of the total rain for the month fell in a 24-hour period over the 9th-10th. 

Miscellaneous 
Peak wind: North-northwest/51 mph (9th) 
Average wind: 6.8 mph 
Average relative humidity: 69%
Average sky cover: 42%

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

MemphisWeather.net Headquarters, Bartlett, TN

Temperature 
Average temperature: 79.6 degrees 
Average high temperature: 90.5 degrees 
Average low temperature: 70.8 degrees 
Warmest temperature: 99.8 degrees (5th) 
Coolest temperature: 58.8 degrees (31st) 
Comments: None 

Precipitation 
Monthly total: 8.20" (automated rain gauge), 8.09" (CoCoRaHS rain gauge) 
Days with measurable precipitation: 8
Wettest date: 3.33" (9th) (via automated gauge) 
Snowfall: None
Comments: Bartlett received over five inches more rain than fell at the airport, or almost 300% of the airport total. In fact, more rain fell on August 9 in Bartlett than the airport received for the entire month. The July-August total for Bartlett was well over 16 inches.

Miscellaneous 
Peak wind: Southwest/28 mph (5th)
Average relative humidity: 79% 
Average barometric pressure: 29.95 in. Hg
Comments: None

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

MWN Forecast Accuracy

MWN average temperature error: 1.99 degrees 
MWN forecast temperatures within 2 degrees of actual: 76% 
MWN average dewpoint error: 1.70 degrees 
MWN forecast dewpoints within 2 degrees of actual: 72% 

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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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

Sunday, August 20, 2023

Late-summer heat and dry weather this week; tropical update

The wet and stormy pattern from late July through mid-August has evaporated as we head through the latter half of August. Several very comfortable days last week had most of us grateful for the arrival of #FalseFall. But a massive ridge of high pressure above us (a.k.a., a Heat Dome) will dominate a large portion of the country from the Rockies to the east coast, including the Mississippi Valley this week. 

The European model ensemble data shows a gargantuan high pressure system aloft over the easter two-thirds of the nation midday Tuesday. This high will result in hot weather and dry conditions for most of the coming week. (WeatherBell)

That will mean very hot temperatures under little cloud cover and increasing humidity this week. We'll likely see our first string of 100-degree temperatures since July 2022 as #SecondSummer arrives with a vengeance. 

Fortunately, it appears that a cold front will move through next weekend as the high pressure ridge is suppressed to the south, allow temperatures to drop back to near average values around 90 degrees in about a week.  Even with the cold front arriving, precipitation chances look to be very low, and on Saturday.

With heat indices near 110 degrees for a good part of the week, heat safety will be a necessity, especially with morning lows near 80 degrees providing little overnight relief. Heat Advisories will likely become Heat Warnings before it cools down a bit next weekend. Avoid the outdoors in the hottest part of the day, stay hydrated, take frequent breaks if you must be outdoors, and check on neighbors, the young and elderly, and your pets too!



Tropical action

Meanwhile, the Atlantic Ocean tropical basin has sprung to life after a month of quiet conditions, and just as we begin the peak of the Atlantic hurricane season. Fortunately, only minor impacts are expected in the next several days as developing storms well out to sea will not affect the U.S. or Caribbean. A little closer to home, a system in the eastern Gulf of Mexico doesn't have optimal atmospheric conditions for development, but could become a tropical depression or weak storm as it moves towards south Texas in the next few days. That area of the country could use rainfall though, so rain would be beneficial in that region. Another system worth watching in the Caribbean is heading towards Hispaniola (Haiti and the Dominican Republic) and is likely to become Tropical Storm Franklin within the next day. It appears to miss Florida on an eventual track north.


Finally, you've likely heard about now-Tropical Storm Hilary, which is moving into southern California this evening and dissipating tomorrow, but not without catastrophic flooding impacts across that region, extending north into Nevada. Many desert areas of southern California will receive as much rain in 48 hours as they typically see in an entire year. The current Tropical Storm Warning for San Diego and other areas of southern CA is the first ever issued for the state!

Sunday afternoon forecast map for Tropical Storm Hilary (NHC)


Flash flood potential is high across southern CA into southwest NV. (NHC)

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

Tuesday, August 8, 2023

Details on the severe weather threat for Wednesday

As if we needed even more proof that this one of the busiest Mid-South summers for severe weather, yet another threat presents itself on Wednesday. And this one could be muti-pronged. 

This calendar for June and July shows the severe weather risk level by day for the Mid-South. 35 days in June and July presented some degree of severe weather risk. The trend is continuing into August unfortunately! (via Iowa Environmental Mesonet)

The unknown is a given...

The first thing to know about tomorrow is that there is simply a lot we do not know yet, even the night before. We are looking at the potential for multiple rounds of thunderstorms crossing the Mid-South, but believe there will be two main "windows" for severe weather. However, within those, multiple storms are possible. 

One of the reasons for the uncertainty is that each wave could have an effect on what happens in its wake. If predicted storms do not materialize, or are brief, it could keep open the possibility of the next one being a bit stronger. However, if a larger complex of storms were to move through early, then it could stabilize the atmosphere in its wake and result in a weaker round later. 


...but honestly it is, Mitch. So let's talk about what we know and what we think we know.

What we know

The Storm Prediction Center believes that the threat of damaging wind is high enough (as of Tuesday evening) between 7am Wednesday and 7am Thursday to include areas roughly north of the TN/MS line in an Enhanced Risk of severe weather, level 3 out of 5. Areas south of the state line are in a Slight Risk (level 2). 



Damaging wind is the main threat with any storms that move through tomorrow. Yes, again. By now you know how to prepare for that - secure it, stow it, and charge it. Heavy rain and lightning are also likely, probably multiple times. If storms move over an area repeatedly, flash flooding could result. It's not likely from a single storm, but a couple back-to-back could overwhelm storm drains or small creeks and tributaries. Secondary threats, which are not as likely but also cannot be ruled out, include hail and an isolated tornado. Tornadoes in August?? Do I have to remind you this is not your typical summer? Yes, it is in the realm of possibility that the strongest storms could be capable of spinning one up. Not likely, but not zero chance.

The probability of severe wind (58+ mph) occurring within 25 miles of Memphis is about 30%. (SPC)

The probability of a tornado occurring within 25 miles of Memphis is about 5%. (SPC)

What we think we (might) know

There will likely be multiple windows when storms are expected, but the two main ones appear to be mid-morning through early afternoon and evening through the early overnight hours. In Shelby County and immediate vicinity, we think that means about 9am-2pm and about 5pm-2am. But check back again regularly tomorrow because that could, and probably will, change! 

A 24-hour forecast loop of simulated radar from the Tuesday mid-day HRRR model, starting at 7am Wednesday and ending at 7pm Thursday. Times don't matter a whole lot, because this isn't exactly right. But you can see how there are multiple waves, and the stronger storms tend to be mainly north of Memphis. Take it with a grain of salt and prepare as you should. (WeatherBell)


In addition, the potential for the strongest storms appears to be with the last wave to move through, which we think will be around midnight or shortly thereafter. That is, if the atmosphere is not so worked over that the storm fuel is tapped out. Additional showers and probably thunderstorms will be possible even after that, but we believe that by then, the severe threat will be quickly declining.

 Most of the strongest storms will probably be north of the TN/MS state line, in northern AR and west TN. Memphis sits on the southern edge of the Enhanced Risk and while there is little the high-resolution models agree on, one is that the best severe parameters currently are north of Memphis. However, again, that could change. All it takes is one butterfly to flap its wings, or one big mean supercell, to change that. And we know that a Slight Risk is not nothing. How many trees and power lines have been downed in Slight Risk or lower this summer?


How we prepare

By now, we hope that everyone has learned their lesson. It's not like we haven't seen this before, recently, multiple times. Charge devices and auxiliary power banks overnight tonight and keep them charged tomorrow. Anything outside that could lift-off without so much as a countdown clock should be tied down or brought in. That might include Fifi the poodle, and it certainly includes lawn furniture, patio cushions, etc. If you have a place to park under cover, use it. Program whatever devices you use for severe weather notifications as well.



And of course stay plugged in, not just to your outlets, but to your no-hype weather peeps. They'll keep you sane and informed. If storms move through and the sun comes right back out, expect the next round could be severe. We'll keep social media posts going regularly throughout the day starting early tomorrow morning with the latest adjustments to the forecast as needed. Be prepared, not scared.


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

Sunday, August 6, 2023

July 2023 Climate Report for Memphis, TN

July Climate Recap

July started and ended with above average temperatures, but the majority of the middle of the month was cooler than typical. So on average, the mean for the entire month ended just below average, much like June. Still, the number of days in which the high temperature met or exceeded 90 degrees was just one day below normal at 21 days. The below average temperature for the month was driven by the average high temperature being just over one degree below average. Overnight low temperatures actually ended just slightly above normal. 


July precipitation was well above normal, and in fact almost record-breaking. The month ended as the 4th wettest July on record, almost four inches above normal. 


Training storms on one particular day (the 21st) resulted in 94% of an average July's precipitation in a single day. That particular day ended as the second wettest July day on record. The Bartlett observing site also recorded over 2.5" of rain on the 21st, but both sites experienced multiple days of heavy rain and storms, resulting in over 8" of rain for the month. However, not far away in southern Crittenden Co and the Mississippi Delta, rainfall was actually below normal for the month.

Departure from average rainfall for the Mid-South in July 2023. Much of the metro finished 2-4" above normal for the month. (NOAA)

As far as severe weather, July was abnormally active. Nearly a month of repeat storms in northwest flow started with the June 25 wind storm and continued for the first few of weeks of July, culminating in severe storms and very heavy rain on the 21st (described above). Multiple wind storms resulted in mass power outages due to downed trees and power poles, including - to varying degrees - the 2nd, 3rd, and 5th, followed by two larger-scale events on the 18th and 21st. In all, hundreds of thousands of electrical customers lost power at some point in the month, many on multiple occasions. Tree and utility infrastructure damage was extensive, resulting in clean-up from one storm rolling right into clean-up from the next. After the 21st, the severe weather pattern calmed as heat built back in under upper level high pressure.

Memphis International Airport, Memphis, TN

Temperature 
Average temperature: 82.3 degrees (0.5 degrees below average) 
Average high temperature: 90.7 degrees (1.2 degrees below average) 
Average low temperature: 73.8 degrees (0.2 degrees above average) 
Warmest temperature: 96 degrees (1st) 
Coolest temperature: 68 degrees (10th, 11th and 23rd) 
Heating Degrees Days: 0
Cooling Degree Days: 543 (7 below average) 
Records set or tied: Record high minimum tied (81 degrees on the 1st)
Comments: 21 days reached 90 degrees, which is 1.1 days below average for the month of July

Precipitation 
Monthly total: 8.62" (3.80" above average) 
Days with measurable precipitation: 14 (4.5 days above average) 
Wettest 24-hour period: 4.53" (21st) 
Snowfall: None
Records set or tied: 4.53" on the 21st set a daily rainfall record and was also the 2nd wettest July day and the 17th wettest overall day on record
Comments: July 2023 ranked as the 4th wettest July on record

Miscellaneous 
Peak wind: Northwest/69 mph (5th) 
Average wind: 6.6 mph 
Average relative humidity: 73%
Average sky cover: 52%

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

MemphisWeather.net Headquarters, Bartlett, TN

Temperature 
Average temperature: 81.2 degrees 
Average high temperature: 92.1 degrees 
Average low temperature: 72.3 degrees 
Warmest temperature: 99.9 degrees (1st) 
Coolest temperature: 63.9 degrees (11th) 
Comments: None 

Precipitation 
Monthly total: 8.40" (automated rain gauge), 8.38" (CoCoRaHS rain gauge) 
Days with measurable precipitation: 14
Wettest date: 2.65" (21st) (via automated gauge) 
Snowfall: None
Comments: None

Miscellaneous 
Peak wind: West/35 mph (21st)
Average relative humidity: 78% 
Average barometric pressure: 29.97 in. Hg
Comments: None

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

MWN Forecast Accuracy

MWN average temperature error: 1.93 degrees 
MWN forecast temperatures within 2 degrees of actual: 71% 
MWN average dewpoint error: 1.79 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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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

Friday, July 28, 2023

Late summer heat builds, offset only by a few thunderstorm chances

After a stint of temperatures near or below average, we've turned a corner as we near the end of July with a stretch of highs in the mid to upper 90s is on its way to the Mid-South this weekend and next week. Grab your favorite frozen treat and let’s dive into the forecast!

Friday evening-Saturday

We’ll wrap up the work week hot and dry and continue that pattern to start the weekend. Saturday, highs will reach 97 under mostly sunny skies. Combined with humidity, heat index values will be near 105. A heat advisory will be continued into Saturday due to this potentially-dangerous heat.

Forecasted highs on Saturday will range in the mid to upper 90s. (NWS Memphis)

Sunday

The clockwise flow around a high pressure aloft over the Four Corners region will usher in a northwest wind on Sunday. A disturbance along this flow will be funneled into our area to provide the chance for afternoon storms. Given how hot and humid it’ll be, these storms could be gullywashers and have the chance to be strong to severe. At this time, all of us are under a level 1/5 “marginal” risk for severe weather.

The ECMWF (European) model shows a ridge of high pressure over the Four Corners region Sunday afternoon. Since Memphis is on the east side of the high, clockwise rotation will bring us a northwest wind. (WeatherBell)


A Marginal Risk of severe weather is currently forecast for the metro on Sunday. (NOAA/SPC)

Monday - Tuesday

A "cold" front will pass late Sunday into early Monday. So, we lose the chance for rain to start the week, but otherwise, it’ll be a carbon copy of Sunday. Highs won’t take a noticeable dive behind this front and will return to the mid 90s again. Behind the cold front’s passage, northwest flow will be reestablished on Tuesday. With that comes the chance for storms once again. Highs will be in the mid 90s.

Wednesday - Friday

A chance of storms remains for Wednesday, but the ridge of high pressure will push east into the lower Mississippi Valley for the end of next week. When that happens, we’ll drop the chance for rain and be left with brutal heat! Highs for Thursday and Friday will jump into the upper 90s. Let’s all cross our fingers and hope we don’t reach the century mark! 



Owen Basselman
MWN Intern

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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

Tuesday, July 4, 2023

June 2023 Climate Report for Memphis, TN

June Climate Recap

Following a slightly warmer than average month of May, June turned relatively cooler versus normal after the first week of the month, which started with high temperatures in the 90s. After the 6th, all but three days were at or below average from a temperature perspective, and two of those were the last two days of the month.


Contributing to the slightly below normal temperatures was above average rainfall, which eliminated the low-end drought conditions that existed at the start of the month. Rain fell on eleven days during the month (two more than average) and rainfall totaled almost five and a half inches for the month. Multiple rounds of severe weather occurred as well. The biggest of those events occurred on the evening of the 25th as a complex of severe storms brought 80-90 mph wind to northern Shelby County, downing trees and power lines and knocking out power to over 120,000 utility customers in Shelby County, as well as many in Fayette County. It would take well over a week to restore all power. 

One of hundreds of uprooted trees across the metro after severe storms swept through on the evening of June 25, 2023. (Photo: Erik Proseus, MWN)


Additional severe storms occurred on the 18th, as wind peaked at 57 mph at Memphis International Airport, as well as the 5th, 11th, and 16th, which produced wind damage and hail in various areas of the metro.

Memphis International Airport, Memphis, TN

Temperature 
Average temperature: 79.4 degrees (0.5 degrees below average) 
Average high temperature: 88.8 degrees (0.6 degrees below average) 
Average low temperature: 70.0 degrees (0.4 degrees below average) 
Warmest temperature: 97 degrees (30th) 
Coolest temperature: 64 degrees (7th and 13th) 
Heating Degrees Days: 0
Cooling Degree Days: 439 (8 below average) 
Records set or tied: Record high minimum tied (81 degrees on the 29th)
Comments: Fifteen days reached 90 degrees, which is 0.5 days below average for the month of June

Precipitation 
Monthly total: 5.40" (1.41" above average) 
Days with measurable precipitation: 11 (2.1 days above average) 
Wettest 24-hour period: 2.15" (18th) 
Snowfall: None
Records set or tied: Record daily rainfall (1.75" on the 16th)
Comments: None

Miscellaneous 
Peak wind: West/57 mph (18th) 
Average wind: 6.3 mph 
Average relative humidity: 67%
Average sky cover: 42%

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

MemphisWeather.net Headquarters, Bartlett, TN

Temperature 
Average temperature: 76.4 degrees 
Average high temperature: 89.8 degrees 
Average low temperature: 67.2 degrees 
Warmest temperature: 99.7 degrees (30th) 
Coolest temperature: 60.1 degrees (13th) 
Comments: None 

Precipitation 
Monthly total: 4.86" (automated rain gauge), 4.54" (CoCoRaHS rain gauge) 
Days with measurable precipitation: 9
Wettest date: 1.28" (18th) (via automated gauge) 
Snowfall: None
Comments: None

Miscellaneous 
Peak wind: Northwest/47mph (2nd)
Average relative humidity: 74% 
Average barometric pressure: 29.85in. Hg
Comments: None

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

MWN Forecast Accuracy

MWN average temperature error: 1.84 degrees 
MWN forecast temperatures within 2 degrees of actual: 68% 
MWN average dewpoint error: 2.17 degrees 
MWN forecast dewpoints within 2 degrees of actual: 65% 

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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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

Friday, June 9, 2023

May 2023 Climate Report for Memphis, TN

May Climate Recap

After a cool start to the month, May warmed quickly and featured above average daily temperature readings for about two weeks. A bit of cooling resulted in near to slightly below normal temperatures for the remainder of the month however. Overall, the month was slightly warmer than a typical May, as seen in the cooling degree day numbers, which ended above average. The Mississippi River served as a proxy "border" between cool temperatures in the eastern U.S. and warmer temperatures to the west, particularly over the northern half of the western U.S. where warmth was particularly pronounced.


Rainfall was somewhat regular, though not exceedingly heavy, during the first half of the month. However after the 20th, rainfall was nearly non-existent, as evidenced by no measurable precipitation at the airport and only 0.02" in Bartlett. The airport recorded less than 40% of typical rainfall for the month as low end drought conditions (D0 - abnormally dry) started to appear in the western half of the greater metro area. May was also a fairly quiet month for severe weather with just a few reports of tree damage and hail on the 10th and 11th, when a few Severe Thunderstorm Warnings were also issued. The peak wind gust at the airport of 55 mph was recorded in one of those storms on the 11th.

Memphis International Airport, Memphis, TN

Temperature 
Average temperature: 72.6 degrees (0.5 degrees above average) 
Average high temperature: 82.2 degrees (0.5 degrees above average) 
Average low temperature: 63.1 degrees (0.7 degrees above average) 
Warmest temperature: 91 degrees (15th) 
Coolest temperature: 46 degrees (2nd) 
Heating Degrees Days: 18 (3 below average)
Cooling Degree Days: 260 (20 above average) 
Records set or tied: None
Comments: Three days reached 90 degrees, which is average for the month of May

Precipitation 
Monthly total: 2.05" (3.22" below average) 
Days with measurable precipitation: 7 (3.6 days below average) 
Wettest 24-hour period: 1.02" (11th-12th) 
Snowfall: None
Records set or tied: None
Comments: None

Miscellaneous 
Peak wind: South/55 mph (11th) 
Average wind: 7.4 mph 
Average relative humidity: 65%
Average sky cover: 53%

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

MemphisWeather.net Headquarters, Bartlett, TN

Temperature 
Average temperature: 71.1 degrees 
Average high temperature: 83.0 degrees 
Average low temperature: 60.5 degrees 
Warmest temperature: 93.3 degrees (15th) 
Coolest temperature: 42.9 degrees (3rd) 
Comments: None 

Precipitation 
Monthly total: 3.05" (automated rain gauge), 3.03" (manual CoCoRaHS rain gauge) 
Days with measurable precipitation: 8
Wettest date: 0.95" (11th) (via automated gauge) 
Snowfall: None
Comments: 62% of the month's precipitation fell on just two days

Miscellaneous 
Peak wind: Northeast/26 mph (2nd)
Average relative humidity: 71% 
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: 67% 
MWN average dewpoint error: 2.29 degrees 
MWN forecast dewpoints within 2 degrees of actual: 67% 

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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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

Sunday, June 4, 2023

Cold fronts coming in the back door provide some relief

The early June weather pattern over the United Stated is a bit unusual - an "omega block" has set up in the upper levels of the atmosphere. This happens when the pattern becomes stagnant as a large ridge of high pressure sets up between two low pressure areas on either side of it. You can see this pattern in the image of the upper level pattern for Monday morning (below). Low pressure is positioned off the coast of California and over New England with high pressure situated over the central U.S. and Canada.


Under the ridge, well above normal temperatures occur, while cooler air sits under the lower pressure areas. As the relative positions of the low pressure areas shift, the edge of cooler and drier air also oscillates, while the overall pattern changes little. How does this affect the Mid-South? Glad you asked!

"Back door cold fronts" are the result of this shifting of the cooler/drier airmasses. If the normal movement of frontal systems is west-to-east, or northwest-to-southeast, those that come in the "back door" arrive from the northeast and move southwest. It's like a familiar neighbor or friend - they don't feel the need to knock, but usually their arrival is welcome anyway.


We've experienced a couple of those in the past week, and though the cooler air generally stays to our north, the recent drops in humidity on northeast wind have been a result of these welcome back door fronts! We'll have a couple more to watch in the coming week.

Early week

This weekend has been hot but not too humid as dewpoints (the best measure of absolute humidity in the atmosphere) have dropped into the 50s during the day - relatively comfortable when the weather is hot. Dewpoints will rise a bit into the low to mid 60s early this week ahead of the next cold front approaching from the northeast on Tuesday. That will mean a slight increase in afternoon thunderstorm chances (20-30%) and a bit stickier air as temperatures still manage to reach the lower 90s in the afternoon and stay near 70 in the early mornings. 

The HRRR model radar simulation for 4pm Monday shows a better chance of scattered showers and thunderstorms across the area. Note the northern edge of the scattered activity near the TN/KY line - where the back door cold front lies. (WeatherBell)

This first front stalls out Tuesday over the metro, resulting in highest rain chances in north MS and AR with drier air over west TN and Memphis near the dividing line between the two airmasses. By Wednesday, the front will basically wash out and we'll see continued low 90s for highs and dewpoints starting to creep back up again.

Late week

A more significant "back door" front will push through on Thursday, bringing with it increased thunderstorm chances (in the scattered range), but also a stronger push of dry air heading into Friday and Saturday. If everything stays on track, that front should bring a decent north wind and much drier air once again as we head to the end of the week. In fact, temperatures will drop a bit behind it as well - upper 80s for highs and mid 60s for lows Friday and Saturday - making for a pleasant few days. 



A massive wedge of dry air will back its way into our area by Friday morning according to the European model, and supported by other global models. This drier airmass will result in low humidity, slightly cooler temps, and dry conditions to start the weekend. (WeatherBell)

Return to wetter conditions?

By Sunday, it appears moisture starts to return and we could head into a bit more active pattern after that, which would be welcome news for those needing some relief from recent dry weather. It's been two weeks since the last good rainfall area-wide (though localized areas have benefited from spotty thunderstorms). With no more than a 20-40% chance of rain on any day this week, some of us could go nearly 3 weeks without beneficial rainfall, as we start inching our way into low-end drought conditions.

MWN staff transition

Finally, I would like to end with an update on who all is bringing you the daily weather information on our social media feeds. With the end of the spring semester in May, a few interns have moved on, while others have joined #TeamMWN! 


Those who have moved on to greener pastures: Kris Pitchford graduated from Mississippi State and is now working at ABC 33/40 in Birmingham as a News Producer (weather nerds may recognize that station as the home of the legend, James Spann!). Dorien Minor graduated with a master's degree from Georgia Tech and is now on-air with LIVE-5 News in Charleston, SC. Kailah Gordon received her bachelor's degree from #HailState and will pursue a master's degree while working full-time for EarthCast Technologies in the private sector. Finally, Carter Bentley also received his bachelor's from MSU and has a couple of weeks left with the team. We're grateful beyond measure for the contributions of these amazing young people and thank them for their service!

Arriving recently are Mississippi State University undergrads Lei Naidoo, Theo Cook and Kevin Conant. All are, or will soon be, appending their initials to social media posts from MWN and are excited to begin applying their classroom knowledge to the real world! And we're excited to have them on board! Follow our social channels listed below for routine updates each and every day.

Erik Proseus
MWN Meteorologist

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