Thursday, March 28, 2024

Early look at potential weather trends for the eclipse


If you are a longtime follower of this site/blog and our content in general, you know I'm not real keen on looking beyond a week out in our forecast, especially when details unresolvable several days out could end up producing wild swings in the resulting weather. For instance: pinpoint temperatures that could mean the difference between rain, snow, or ice. Or temperatures, dewpoints, magnitude of the wind, and cloud cover that could mean the difference between severe storms and rain showers. All of these details can make a big difference in forecasts beyond 3-4 days, let alone a week.

However, trends in the overall meteorological pattern are a little different. While specific timing or forecast details may not be discernible, a colder/warmer or wetter/drier pattern CAN be discerned out to a week or more. So I may not be able to say WHEN on day 6 or 7 an upper level trough will drive a cold front through the Mid-South. But I could say if there is some overall model agreement on the pattern and can probably tell you that we'll see a cool-down, or a wetter than average pattern, a week or more out.

All that said, we have a MAJOR astronomical event occurring about 10 days from now that I know you are all aware of, and many of you (like me) are greatly anticipating! A total eclipse, like that which that will cross the state of Arkansas and block out 97% of the sun here in Memphis for a couple of minutes on April 8, will not occur again for another 21 years. And far be it from me to withhold information for such an event once we start to creep into the "forecast-able period" of said event.  


Information presented here, on March 28, is provided as a very early look at the possibilities, or trends, and includes NO guarantees. Do not change any plans you have based upon information presented. Do not tell me on April 9 how good/bad my "forecast" was on March 28 (believe me, I will be well aware!). Do not sue me. Do not TP my house. And do not call me or my family bad names. This is NOT a forecast - it is general "trend" information. It is presented vaguely on purpose, because anyone who will tell you on March 28 exactly what will happen at 2pm on April 8 is lying. I present the trends, because there is agreement amongst our various computer model sources on those trends - but certainly not the details. Moving on...


To get to April 8, we start with the general trends leading up to it. 

The next several days will be influenced by building high pressure aloft and surface high pressure sliding to our east. That means dry weather and warming temperatures with increasing southerly breezes. That trend continues through the weekend. By early next week, models are in concurrence that low pressure will form in the Plains and move by to our north on Monday/Tuesday with an upper level trough advancing from the southwest U.S. This will lead to a generally wet and possibly stormy pattern to start next week. (Without diving into too many details, because we're 4-5 days out, the most likely severe weather threat appears to be to our west and north Monday and then to our southeast Tuesday.) 

Behind that system, high pressure builds back in for the latter half of next week and into the weekend. Then (are you sensing a pattern?), by the weekend of April 6-7, long-range models generally concur on upper level troughing (low pressure) forming  in the Plains again. With surface high pressure to our east, southerly flow sets up over the Mid-South by the 8th. This pattern typically results in building cloud cover and increasing rain chances. BOOOOO!!!!! 👎

Comparisons of the mid and surface level pattern on April 8 from the European and GFS (American) ensembles show fairly remarkable agreement on the overall pattern for an 11-day forecast. (WeatherBell)

Below, I have placed graphs from three of the major global model ensembles - the European, American (GFS), and Canadian. Ensembles basically are iterations of the model, run many times with slightly different parameters and schemes, to provide a range of potential outcomes. They are the BEST way to look at long-range trends. The models themselves can change multiple times a day. An ensemble effectively averages out all of those different possibilities. The averages, or oftentimes probabilities, of a particular scenario give us a much better idea of the range of possible outcomes than a single model does.

I've chosen to show precipitation in 6-hour increments, since if the model shows rain falling, that would also mean some amount of cloud cover - which ultimately is the forecast element we most care about for an eclipse! Each of the three model ensembles are shown below. Each ensemble is run four times a day, and those "runs" are stacked horizontally (oldest on top, most recent at the bottom) with time going out into the future from left to right and precipitation amounts shown in dark grey to green boxes for each 6-hour time increment. 

On each graph, I have boxed April 8 in red. There is one thing that stands out to me immediately when looking inside those red boxes (and either side of the box to see what might happen before and after the 8th). Each model ensemble, and each of the previous several times that ensemble has run (going back at least a few days), shows precipitation occurring on April 8 in Memphis. Essentially, what is shown is the culmination of hundreds of runs of the three models over the past 3-5 days. And each of those averages has rain falling in Memphis on April 8.


Now, before we break all the guidelines and disclaimers mentioned above and cancel all our plans, it is still many days before the eclipse happens. A "pattern" is NOT a "forecast!" There is not enough detail in this outlook to make any rash decisions. All we really need is partly cloudy skies for a few minutes on April 8 (preferably around 2pm) to see a pretty amazing astronomical spectacle. I'll continue to watch the trends, and as we get within a week, our daily forecast found on our website or app will reflect the latest information.

A final p.s.: For those that spent a bunch of money on a place to stay in Arkansas to see totality... I looked at this same data for Little Rock and there was almost no difference. They are in the same pattern we are according to the data. It is also too far out to define the details that could make a difference between here and there. Keep those reservations (I am!) and go chase the eclipse! If the sun doesn't shine, hopefully you still have had a nice day or two away from the daily grind.

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
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

Saturday, March 9, 2024

2024 Total Solar Eclipse Details

Many of you recall the total solar eclipse of August 21, 2017 that passed directly over Nashville and provided the Memphis area with a view of 93% obscuration of the sun. In fact, some of you might still have your eclipse glasses from that event, hanging on to them in anticipation of the next total eclipse 7 years later! Well, that time is drawing closer, as we're under a month from the 2024 Total Eclipse!

We've assembled some resources and put them here to guide you through observing the 2024 eclipse safely and enjoyably! Like its 2017 counterpart, the "total" portion of the 2024 eclipse will just miss Memphis once again, but we'll still be close enough to it to see 97% of the sun blacked out during the early afternoon hours. A short drive to the north or west an hour or two will put you squarely in the path of totality... and it will be worth it!

Memphis-area viewing details

If you are staying local, here are the stats you need to know about this year's eclipse.

Beginning of the partial eclipse: 12:37pm
Maximum obscuration / time: 97.4% at 1:57pm
End of the partial eclipse: 3:17pm
Weather forecast: Too early - check back around April 1!

Here is a simulation of how the eclipse will look from Memphis:


Regional viewing opportunities

If you are looking to take a road trip, here are some regional locations that will experience a total eclipse. Totality occurs around 2:00pm (plus or minus 15 minutes) at all locations:

Jonesboro, AR: 1 hour drive; 2 min 23 sec totality
Little Rock, AR: 2 hour drive; 2 min 27 sec totality
Conway, AR: 2 hour and 20 minute drive; 3 min 52 sec totality
Hot Springs, AR: 2 hour and 45 minute drive; 3 min 36 sec totality (1 of 2 national parks to experience totality)
Cape Girardeau, MO: 2 and a half hour drive; 4 min 5 sec totality
Cairo, IL: 2 and a half hour drive; 3 min 7 sec totality

Viewing tips

The most important advice for viewing of an eclipse is to NEVER look directly at the sun without specialized glasses or a specially designed lens for solar viewing. Looking directly at the sun for any length of time can cause permanent eye damage. There is only one short period of time when it is safe to remove the glasses for viewing, and that is during the period of totality - the couple minutes when the sun is completely obscured by the moon's shadow. You will know the eclipse is total because you will not be able to see ANY portion of the sun through eclipse glasses. And as soon as a sliver of the sun re-appears, it is time to put the glasses back on. 

Always use glasses or solar viewers that comply with the ISO 12312-2 international standard, which are thousands of times darker than standard sunglasses. Be sure to closely monitor children for proper use of glasses as well. In addition, do not use eclipse glasses or viewers with cameras, binoculars, or telescopes, which require different types of solar filters. And of course, do not use those devices without any supplemental eye protection either! Here is a good source for more information.

Fun fact! Did you know that the largest manufacturer of 3D and eclipse glasses in the world is based in Bartlett, TN? Tens of millions of pairs of eclipse glasses, in a wide variety of designs, are created and manufactured at American Paper Optics. There is a good chance that your eclipse glasses were made right here in the Memphis metro! You can even buy directly from them here (this is not an affiliate link; we make nothing on purchases made).

Driving tips

Pack your patience and fill your gas tank! Thousands of sightseers will be flocking to the path of totality, likely clogging road networks in and out of the path. This is especially true on the morning of the eclipse (Monday, April 8) and especially right after totality is complete, as everyone returns home. 

My suggestion? Make a long weekend out of it! (But book your accommodations now. Many hotels in the path are already full.) Travel to (or near) the spot where you want to be on Saturday or Sunday, and delay returning home until Monday night or, even better, Tuesday morning. This is a rare event and the difference between totality and "almost" is literally like night and day, so many people will be taking advantage of a short drive to be in a spot where full obscuration occurs. Expect drive times to be MUCH longer than typical for Monday travelers, even on interstates.

The All-Important Weather Forecast!

While we can't provide an actual forecast this far in advance, the scientists at NOAA’s National Centers for Environmental Information (NCEI) have created an interactive map that uses historical weather data to determine the "viewability" for spots across the United States. For Memphis, the following are the historical sky conditions for April 8th at 2pm:

Clear/Mostly Clear - 31.9%
Partly Cloudy - 14.2%
Mostly Cloudy/Overcast - 53.9%

So it looks like there s a slightly less than 50% chance that conditions will allow for decent viewing. It doesn't take a perfectly clear sky to get a good view of the eclipse - just not a poorly-placed cloud! And as noted above, the eclipse covers a 2 hour and 40 minute time period, so hopefully we'll get to observe at least part of it, and maybe we'll get a perfectly sunny day! (For those traveling west to view totality, the historical chance of mostly cloudy to cloudy skies is very similar to Memphis.) 

When is the next total solar eclipse?

You'll have to go to Alaska to see the next total eclipse in the U.S., and that is in 2033. After that, the next one will be in 2044, but again, you'll have to head north - to North Dakota or Montana! The next total eclipse visible to a large population will be August 2045 (21 years from now!) as the path of totality crosses the southern U.S. from Florida to California. So don't miss this one!

Additional Resources

Great American Eclipse - comprehensive resource - another excellent website

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
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, March 8, 2024

February 2024 Climate Report for Memphis, TN

February Climate Recap

The month of February was warmer than normal by over six degrees, ranking it the sixth warmest February on record. High temperatures ranged from the 50's to the upper 70's, while lows ranged from near 30 to the mid 60's. Overall, only six days during the month saw an average temperature below normal.

Departure from normal temperatures for February for the Lower 48 states

Precipitation was slightly below normal for the month, with our wettest day coming on the 10th at 1.64", followed closely by 1.27" on the 4th. In total, both the airport and MWN headquarters in Bartlett saw 3.82". A trace of snow fell on the 12th at both stations as well.

As far as lingering drought goes, there was continued improvement across the area. Much of the portion of the Memphis metro in west Tennessee is now out of drought status (or nearly so), while northwest Mississippi continues in a moderate to severe drought, but has also improved in the past month.

Drought conditions as of March 5, 2024

Change in drought conditions over 4 weeks as of March 5, 2024

Memphis International Airport, Memphis, TN

Average temperature: 52.4 degrees (6.3 degrees above average) 
Average high temperature: 62.8 degrees (7.3 degrees above average) 
Average low temperature: 42.0 degrees (5.3 degrees above average) 
Warmest temperature: 78 degrees (27th) 
Coolest temperature: 25 degrees (18th) 
Heating Degrees Days: 363 (169 below average)
Cooling Degree Days: 7 (5 above average) 
Records set or tied: Record high minimum of 65 on the 27th, breaking the old record of 62 from 1955.
Comments: This month was the 6th warmest February on record. 

Monthly total: 3.82" (0.73" below average) 
Days with measurable precipitation: 9 (0.9 days below average) 
Wettest 24-hour period: 1.64" (10th) 
Snowfall: Trace (1.0" below average)
Records set or tied: None
Comments: None

Peak wind: South/48 mph (27th) 
Average wind: 9.6 mph 
Average relative humidity: 64%
Average sky cover: 54%

 Click here for a daily statistical recap for Memphis International Airport. Headquarters, Bartlett, TN

Average temperature: 51.4 degrees 
Average high temperature: 63.5 degrees 
Average low temperature:  39.6 degrees 
Warmest temperature: 78.9 degrees (27th) 
Coolest temperature: 19.7 degrees (18th) 
Comments: None

Monthly total: 3.82" (automated rain gauge), 3.90" (CoCoRaHS rain gauge) 
Days with measurable precipitation: 9
Wettest date: 1.46" (4th) (via automated gauge) 
Snowfall: Trace
Comments: None

Peak wind: South/30 mph (27th)
Average relative humidity: 69% 
Average barometric pressure: 30.02 in.
Comments: None

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

MWN Forecast Accuracy

Average temperature error: 2.16 degrees 
Forecast temperatures within 2 degrees of actual: 70% 
Average dewpoint error: 2.80 degrees 
Forecast dewpoints within 2 degrees of actual: 56% 

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

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
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, March 3, 2024

A spring-like week ahead with some unsettled weather

It's only the beginning of March and we already have a rainy week ahead of us!

The end of February brought along a well-pronounced taste of spring, and that will persist into the upcoming work week. Mild to warm temperatures and chances of rain will mostly be the memo for this week as low-pressure systems and fronts advance over the coming days. While severe threats will overall be limited for most of us, we're still likely to see a few t'storms this week. 

A somewhat unstable Monday night and Tuesday

After this past warming weekend, we'll be greeted with an active beginning to the work week. Increasing cloud cover with the presence of an unstable airmass on Monday might lead to a few daytime showers with warm highs in the mid to upper 70s. Instability, or what storms use as fuel, looks to increase in the overnight hours on Monday ahead of a cold front, though the environment will be fairly limited in severe weather ingredients in the metro compared to Arkansas, as seen in the NWS graphic below. 

Per the NWS, the low severe threat for Monday night will be mostly confined to areas west of the river, but the metro could still see sub-severe t'storms.

The limited severe threats will be hail and strong winds for those in AR. For most of us in the metro, we likely will not be seeing those threats on Monday night. Early Tuesday may be a little different, as the distribution of warmer temperatures and moisture could be conducive to some hail during the morning hours. Note that, at this time, hail remains only a small possibility for early Tuesday -- we'll have more info on the threat environment closer to then. For now, expect showers and t'storms on Monday night to persist into at least the morning hours on Tuesday as the cold front passes. 

Slight rain chances for the midweek

With the passing cold front on Tuesday, temps will slightly drop into the 60s during the midweek on Wednesday and Thursday. Partly sunny skies with a few light showers appear to be the case for Wednesday and Thursday, as moisture levels will be just high enough to support the development of a few showers on both days.
This weather map valid at 6am on Thursday depicts the chance for a few showers that morning (NWS/WPC). 

A few showers will likely be during the afternoon hours on Wednesday, while Thursday's showers will mainly be in the morning, though timing will likely be adjusted as the week progresses. Unfortunately, rain chances will not be dropping even after the early-week system; during the mid-week, a mid-level disturbance will be building across the central U.S. and advance towards our area between Thursday and Friday, which will lead to an unsettled, possibly stormy end to the week. 

Similar to early in the week, the end of the week could be stormy

The mid-level disturbance will likely destabilize the environment enough on Friday to produce showers and a few t'storms, though it seems weak wind profiles and a lack of severe weather ingredients will lower the potency of any storms that form on Friday. Most storm activity should be confined to areas south of us, but we'll likely see showers and a few storms at the very least. 

Another weather map (valid at 6am Friday) shows increased rain chances for Friday (NWS/WPC). 

Besides that, temperatures will steadily decrease at the end of the week, with forecasted highs in the mid-60s for Friday and lower 60s for Saturday. Another cold front passes through on Saturday, too, leading to a few early showers and cooler temperatures arriving. 

Per the European model, a cold front passes through late afternoon on Saturday (temp. change gif valid from 1pm to 6pm on Saturday). Temps will be quickly dropping after the front passes (WeatherBell).

Beyond this upcoming week, next week likely will see some more rainy activity for much of the U.S. based on long-range outlooks (shown below). Outlooks also show a seasonably average week for temperatures in the metro, with varying probabilities elsewhere. You may need an umbrella if you have spring break plans around the country!

The precipitation probability outlook shows a likelihood for above-normal rain amounts across much of the U.S. next week, while the temperature outlook shows near average temps for the southeast. (NWS/CPC) 

Lei Naidoo   
MWN Intern

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
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