Sunday, November 27, 2022

Early details on the severe weather threat for Tuesday (Nov. 29)

The Thanksgiving holiday has been somewhat dreary and damp, and definitely cloudy, thanks to a slowly-lumbering upper level low that passed nearby. As that 800-lb gorilla moseys away, a much more dynamic atmospheric setup will move through the Mississippi Valley early this week - one that poses a level of severe weather risk that we have not seen in some time. These late-season severe patterns can be tricky, but also quite potent when they do come into form. (Some may remember or have heard of the Thanksgiving weekend Germantown EF-3 tornado that occurred nearly 30 years ago. Tornadoes in the cool season are definitely possible in the Mid-South.) This one will definitely bear watching, and require your attention and preparation.

Tuesday is the day of concern. While this event is still 48+ hours out, some atmospheric parameters are coming into place and others are still unknown, and as usual there are also a few potential flies in the ointment. Currently, the Memphis metro is in an "Enhanced Risk" of severe weather, or level 3 out of 5, according to the severe weather experts at the National Weather Service. Let's run through the scenario.

What we know: an upper level jet stream blowing at over 150 mph will be screaming overhead from the west-southwest, ahead of a strong upper level trough (lower pressures) moving east across the Plains. Also, very strong wind at the low and mid levels also appears to be a given (50+ mph at about 2000 feet and gusts to 30 mph at the surface, blowing from the south). That means that we have one key ingredient: wind shear.  There also will be a lifting mechanism to get air rising - producing the convective process to initiate thunderstorms: an approaching cold front, and perhaps a pre-frontal surface trough. In addition, moisture will be abundant is well-above-average surface dewpoints in the lower, to possibly mid, 60s are expected. 

The jet stream will be strong (150 mph wind), and basically directly overhead, by 6pm Tuesday.  (GFS model, Sunday 12Z)

A low level jet stream will also be quite strong and overhead early Tuesday evening, topping out above 50 mph. (GFS model, 12Z Sunday)

Atmospheric moisture, as measured by precipitable water (PW) at 9pm Tuesday is forecast to be well above average, or nearly 1.5" (GFS model, 12Z Sunday)

What is not quite as certain: the amount of "storm food," or fuel, that is needed to keep air rising once it is lifted, and thus tap into the abundance wind shear.  In the cool season, it doesn't take nearly as much instability to generate severe weather as it is often compensated for by an abundance of wind shear, which will be the case this time. It does take SOME instability though, and how much we will have is a big question mark. Models are all over the place, and tend to under-forecast this parameter a few days out. I'm betting we'll have enough to generate strong storms, and if they can become strong, they will certainly have the potential to be severe.

Instability, or storm fuel, as measured by CAPE is one of the big question marks, though we should have sufficient fuel for storms. This Euro model representation at 9pm Tuesday is one of the higher solutions we have seen, with values near 1000. Other models only show a couple hundred CAPE. (WeatherBell)

How it might play out: I expect that we'll see some daytime "elevated" thunderstorms, mainly in the afternoon hours, as an initial push of moisture and mid-level instability arrives on gusty south wind, as dewpoints climb into the 60s. These could have the potential to produce some gusty wind and large hail, as well as localized downpours. 

By late afternoon, and more likely during the evening, the more potent atmosphere appears to move in as surface-based instability rises (again, we don't know how much). While it is possible that there will be fewer echoes on radar after sunset than during the afternoon, the potential for them to be strong to severe will be heightened. Rotating storms are entirely possible, and thus we have a potential for large hail, damaging wind gusts, and even a few tornadoes, which could be strong. Late in the night, the cold front itself arrives, so the storm threat continues overnight. It's a bit more uncertain how those could behave. We may have to wait and see how the day unfolds to know for sure.

Bottom line: all Mid-Southerners need to be preparing now for the potential for severe storms, capable of large hail, damaging wind, and tornadoes, from Tuesday afternoon into Tuesday night. Secure items outdoors that you want to keep, plan to garage vehicles as able on Tuesday, and stay tuned to additional details that will help you plan your activities for the day. As of right now, Tuesday evening is my greatest concern. If you have flexible plans, go ahead and adjust now. By all means, STAY IN TOUCH with your trusted weather sources as details are likely to change in the next 48 hours, and have multiple methods of receiving severe weather alerts prepared in case they are needed Tuesday.

Erik Proseus
MWN Meteorologist

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Tuesday, November 22, 2022

Consider the forecast before making those Thanksgiving holiday plans!

After two weeks of cold weather, a little bit of a warmup is in store for the southeast this week! The past couple of days have shown this cold trend. Temperatures on Saturday only reached the low 40s with lows in the upper 20s. Sunshine was abundant on Sunday as temperatures were once again in the low 40s with an even colder night than Saturday. Yesterday was the first day of our warmup with temperatures climbing into the low 50s as a warm front is beginning to make its way through. Despite the chilly weather, skies have been mostly clear the past few days as a high pressure was over our region. This week, a low-pressure system is going to be moving into the area from the southern plains which will bring some warmer temperatures but also a good bit of rain Thursday and into Friday.

Tuesday Night into Wednesday

Today temperatures are continuing to be on the rise with highs near 60 degrees with mostly sunny skies. While this is average for this time of the year, it is going to be great relief from the chilly weather we have been experiencing. Tuesday night will be chilly with temperatures in the upper 30s, but temperatures will warm up to the low to mid 60s for the day Wednesday thanks to the warm front and high pressure that is continuing to push through the area. Skies are going to be partly sunny with clouds increasing through the day but no rain is expected. Wednesday is looking to be a beautiful day for anyone traveling for Thanksgiving!

Thanksgiving and Black Friday

Surface weather map for Thursday morning showing the rain for the area caused by the low-pressure system over Oklahoma. (Weather Prediction Center) 

As the high pressure moves out of the area, a low-pressure system will begin to take its place, which is going to make for a soggy Turkey Day. Rain showers are looking to begin early Thursday morning and will continue to be scattered throughout the area through late morning. Widespread rain will be moving in from the southwest during the afternoon due to the low-pressure system and cold front that is going to park itself over Oklahoma and Texas. Despite this, temperatures will rise to the low 60s. With winds from the east/southeast, plenty of moisture will be available for this system to use from the Gulf. We could see anywhere from one-half to over two inches of rainfall in the region through midnight Thursday with amounts being greater to the south.

Total rainfall forecasted through Friday at noon. (Weather Prediction Center) 

On Friday, we see a large upper-level trough continuing to move east into the southeast region of the country. Thursday’s rainfall will decrease and end into the Friday morning hours, leaving mostly cloudy skies for Black Friday shopping. Temperatures will be a bit cooler, in the mid-50s, after the Thanksgiving rain, but still warmer than last week! Going into the nighttime hours, temperatures will drop into the mid-40s so a jacket will be needed for any evening shopping or playoff football! We will likely see rain showers from the low-pressure system to the south, especially as we head later into Friday night.

500mb (18,000') pressure and wind pattern from the GFS model showing the large upper level low pressure system, which will be responsible for our Friday and Saturday rain chances, centered over Oklahoma/Texas on Friday. (Pivotal Weather)

Saturday and Sunday

Scattered showers will continue into Saturday morning. By Saturday night the low pressure system will have moved north/northeast and the rain will have moved out of the area. High temperatures will rise to the mid-50s and the low will be in the lower 40s. Going into Sunday, a high-pressure system trailing behind the low pressure that just moved out is going to fill into the area. This ridge is going to dry us out once again for the end of the weekend and into early next week. Temperatures will warm up to around 60 and the low will drop to the mid-40s. After a wet holiday week and beginning of the weekend, Sunday is going to be pleasant and dry with partly cloudy skies.

As low-pressure moves out of the area late Saturday, high pressure will move into the area Sunday, as shown by the GFS model. (Pivotal Weather)
Kailah Gordon
MWN Intern

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

Thursday, November 10, 2022

Big changes coming: Temperatures tumble, plus the tropics aren’t done

If you’ve found yourself wishing away the unseasonably warm temperatures we’ve had this fall, you’re going to enjoy the changes headed our way! We have a pretty active weekend ahead of us.

First: The Tropics

Nicole made landfall just south of Vero Beach, Florida early Thursday morning as a category one hurricane with estimated wind speeds of 75 miles per hour. The current National Hurricane Center Track takes Nicole through central Georgia on Friday and to the northeast towards New England by Saturday. While most of the tropical system’s impacts will remain well to our east, north MS and west TN might see some clouds filter in and winds pick up a bit on Friday as the low makes its northern turn through Georgia.

Nicole stays well to our east as it moves up the east coast and a strong cold front approaches from the plains. (Pivotal Weather)

Big temperature swing coming...

More rural areas have already seen sub-freezing temperatures, but this weekend will likely bring our first sub-freezing temperatures in the city itself. Our main story starting Friday is a strong cold front brought about by an upper-level trough swinging through the eastern U.S. As of lunchtime on Thursday, the cold front was draped from Wisconsin down through Oklahoma and continues to push eastward.  The front will be approaching the metro Friday evening, ushering in borderline-winter-like temperatures, and the cold is here to stay this time. A strong northerly wind will pick up in the wake of the front, and temperatures will drop to the mid-30s Friday night with showers likely, but probably not until after high school football playoff games end for the evening! Precipitation from the front itself will dissipate as it approaches the metro, but a weak upper level disturbance following just after will bring rainfall in from the southwest.

Nicole stays well to our east as it moves up the east coast and a strong cold front approaches from the plains. (Pivotal Weather)

Here’s a still shot from the HRRR of surface temperatures at 6pm on Friday as the front approaches the metro. (Pivotal Weather)

Now, I tread carefully with this one, but areas northwest of us in NE Arkansas have the potential to see some sleet/wintry mix in the pre-dawn hours Saturday morning as cold air rushes in. Rest assured, surface temperatures will still be above freezing so there will be little to no impact. I’m not expecting too much in the way of precipitation amounts - maybe a tenth to a quarter of an inch with slightly higher amounts well to the south of the metro. Saturday night, lows to drop to around 30, so remember to cover your plants and bring your four-legged friends inside. Don’t be caught without a coat this weekend as temperatures won’t make it out of the 40s during the daytime despite sunshine. Thankfully these overnight temperatures aren’t quite cold enough to warrant more extreme precautionary measures, such as dripping faucets or covering outdoor pipes.

Early next week

Temperatures start to creep back up into the 50s on Monday, which is actually when our next chance for rain presents itself. A strong upper level trough pushes its way across the U.S. early next week, bringing about a storm system across the southern Plains into the Mid-South. Our chances for rain extend from Monday night into early Tuesday morning. Right now I’m looking for somewhere between a quarter and a half of an inch of precipitation with areas south of Memphis (again) receiving higher amounts. Rain gives way to a drier pattern in the middle of the week, but cooler temperatures stick around with highs in the upper 40s/low 50s through the end of the week.

The upper level disturbance responsible for our rain chances on Monday night can be seen over northern TX on this forecast map of the atmosphere at about 18,000 feet up. (Pivotal Weather)

Caroline Sleeper
MWN Meteorologist

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

Monday, November 7, 2022

October 2022 Climate Report for Memphis, TN

October Climate Recap

Temperatures for the month of October in Memphis averaged just below normal, though the number of above and below average days were fairly equal. Most of the above average days were in the last third of the month, while a cold spell mid-month (highs in the 50s) helped to skew the monthly average down. Despite the swings in temperatures, there were no days that reached 90 degrees.

The temperature anomaly map for the month of October shows slightly below average temperatures across the Mid-South. (PRISM temperature data via WeatherModels)

Drought conditions continued early in the month with no precipitation until mid-month, when a couple of wet systems moved through dropping a couple of inches of rain as well as producing thunderstorms. After another dry spell, rainfall returned again in the past week of the month, including the wettest day in over 18 months at the airport on the 29th with 2.37" of rain. The thunderstorms on the 12th resulted in a couple of reports of hail in northwest MS. Severe Thunderstorm Warnings were issued on the 15th for storms moving through Tipton County though there were no reports of severe weather. 

Memphis International Airport, Memphis, TN

Average temperature: 63.2 degrees (1.4 degrees below average) 
Average high temperature: 74.5 degrees (0.6 degrees below average) 
Average low temperature: 51.9 degrees (2.1 degrees below average) 
Warmest temperature: 85 degrees (6th, 12th) 
Coolest temperature: 35 degrees (19th) 
Heating Degrees Days: 102 (14 below average)
Cooling Degree Days: 54 (48 below  average) 
Records set or tied: None
Comments: No days reached 90 degrees this month, which is 0.9 below the average October. 

Monthly total: 4.82" (0.84" above average) 
Days with measurable precipitation: 6 (1.5 days below average) 
Wettest 24-hour period: 2.37" (29th) 
Snowfall: 0.0"
Records set or tiedDaily maximum rainfall set on the 29th (2.37")
Comments: None 

Peak wind: Northwest/46 mph (12th) 
Average wind: 7.9 mph 
Average relative humidity: 58%
Average sky cover: 31%

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

Cirrus Weather Solutions /, Bartlett, TN

Average temperature: 60.6 degrees 
Average high temperature: 75.0 degrees 
Average low temperature: 48.4 degrees 
Warmest temperature: 87.9  degrees (12th) 
Coolest temperature: 29.3 degrees (19th) 
Comments: None 

Monthly total: 2.77" (automated rain gauge), 2.90" (manual CoCoRaHS rain gauge) 
Days with measurable precipitation: 5
Wettest date: 1.60" (29th) (via automated gauge) 
Snowfall: 0.0"
Comments: None

Peak wind: Southeast/29 mph (29th)
Average relative humidity: 66% 
Average barometric pressure: 30.07 in. Hg
Comments: None

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

MWN Forecast Accuracy

MWN average temperature error: 1.78 degrees 
MWN forecast temperatures within 2 degrees of actual: 78% 
MWN average dewpoint error: 1.98 degrees 
MWN forecast dewpoints within 2 degrees of actual: 81% 

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

Sunday, November 6, 2022

Mild weather for Election and Veterans Days, then the bottom falls out...

A strong frontal system that produced tornado damage in the Southern Plains Friday night brought a couple of thunderstorms, but mostly much needed (and well-timed) overnight rainfall Friday night to the Mid-South. With clearing by the afternoon, Saturday turned out decent with temps in the 60s, leading to a chillier (but not abnormal) morning with lows today in the 40s. Today has been gorgeous with highs in the 70s and sunshine. The motto for the coming week's weather is going to be "enjoy it while you got it!" A major early winter cold front promises to bring MUCH colder air next weekend!

Sunday night-Monday

As a warm front lifts north, remnants of what was leftover from yesterday's front, and another cold front approaches in the coming 24 hours, clouds increase this evening with showers not far behind. We're expecting scattered showers after midnight with rain likely over the area for the morning rush hour. Showers should diminish as we head toward the lunch hour, and be mostly gone before we hit that unwelcome 5pm sunset! Temperatures will generally remain mild with 60s throughout the night tonight and lower 70s for highs on Monday.

A loop of the surface weather map from Sunday evening through Tuesday evening shows a front in the vicinity with some showers tonight and Monday. The western U.S. will be where the wild weather resides! (Weather Prediction Center)

Election Day through Thursday

With no major fronts in the area and winds starting to switch back toward the south, more mild weather is expected for elections on Tuesday and right through the mid-week. Clouds should break apart Tuesday as well with a light northeast breeze, so expect highs back in the mid 70s after another mild morning low. These conditions continue Wednesday and Thursday with highs generally in the mid 70s and lows near 60 Wednesday morning and mid 50s Thursday morning. 

Veteran's Day and beyond

The next major cold front arrives on Friday. But with not a lot of moisture to work with, rain chances are fairly low (and we may remain dry altogether), though clouds will accompany the front. Temperatures remain mild in the morning - mid 50s for lows - but only recover to the mid 60s by early as northwest wind becomes gustier, signaling the front's arrival. 

A strong cold front will be poised to move through the Memphis area by Friday morning, bringing the coldest air of the season next weekend. Note also the red "L" over northern FL where a tropical system is forecast. (Weather Prediction Center)

For next weekend, the sunshine will be great, but the temperatures not so much! More winter-like temperatures will encompass a large portion of the country. For Memphis, we're thinking lows will be near freezing with highs barely reaching 50 degrees, if that, both Saturday and Sunday! Below normal temperatures also look to continue right into the following week.

Forecast high and low temperatures from the NWS Blend of Models shows a tale of two seasons in the coming ten days! (

The temperature outlook for mid-November shows most of the country in the grips of below-average temperatures. For Memphis, "normal" during this period is lower 60s for highs and lower 40s for lows. (Climate Prediction Center) 

An eye on the tropics

One other interesting weather note this week - it appears that Florida will be dealing with a tropical system, perhaps a hurricane, by the middle of the week! The National Hurricane Center expects this development to occur as a low approaches the Bahamas from the east on Tuesday, then likely moves over the Florida peninsula Wednesday/Thursday before recurving up the east coast. Tropical weather season doesn't end until November 30, so while late for a tropical system in Florida, it's not unheard of!

Tropical development appears likely in the northern Caribbean early this week with models taking a tropical storm or possibly a hurricane into Florida around mid-week. A "fish storm" in the central Atlantic will pose no threat to land. (National Hurricane Center)

Erik Proseus
MWN Meteorologist

Follow MWN on Facebook and Twitter for routine updates and the latest info!
Complete MWN Forecast: 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