Wednesday, April 14, 2021

Cool pattern for spring appears persistent; #TeamMWN intern update

We've experienced a beautiful run of spring weather over the past week or so with mild temperatures in the 70s and even a few low 80s, lows generally in the 50s, and fairly dry - with a couple of exceptions. The pattern has shifted though and cooler weather has settled in, perhaps for a while! Let's dig into a few details.

Why the cooler air?

The cause for the upcoming string of below average temperatures can be seen if we look up a little ways - specifically about 18,000 feet up! At that level (what meteorologists refer to as 500 mb), a pair of low pressure centers dominate the eastern and western U.S. this evening. Over the coming week, the eastern U.S. low shifts east and strengthens (or "deepens") while the western U.S. low expands and shifts east as well. By this weekend, the western low becomes a very strong low over the Mississippi Valley. On its heels as it continues east early next week, more low pressure spills south from Canada into the eastern U.S. 

The loop below shows that progression, with blue shades representing below average pressure at that level of the atmosphere. Below average pressure aloft tends to result in below average temperatures at the surface and that is what much of the eastern and central U.S. will experience for at least the next week or so. In this case, it will also spell below average precipitation for our region over the coming week, but not necessarily perfectly dry as smaller upper level disturbances rotate around their parent low pressure centers.

This loop shows the 500mb (18,000') pressure levels over the coming week according to the European model. Blue to green shading is anomalously low pressure and yellows to reds are above normal. Note that the blues tend to stick around for much of the nation east of the Rockies for this time period. (WeatherBell)


Clouds depart late tonight and we start Thursday with sunny skies, but the next system (much like this morning's) moves in late in the day tomorrow, bringing clouds and eventually a slight chance of rain Thursday night. Even with sun, look for highs in the mid 60s Thursday.  

There won't be much time between a weak system Thursday night and a stronger one Friday night, which brings perhaps our best chance of rain overnight. Some showers are possible by late afternoon Friday with the highest chances after dark. Fortunately, thunderstorms are not predicted with this round of rainfall. Friday's high will be in the low 60s with lows in the upper 40s as you wake up to drying conditions Saturday morning. 

The Memphis Tigers spring football game #FridayNightStripes may look a lot like a regular game in late October!

With the main upper low to our north Saturday and Sunday, we expect more clouds than sun this weekend, though primarily dry weather - 10-20% rain chances is about it. Highs remain in the mid 60s with lows in the mid to upper 40s into Monday morning.

Next week looks primarily dry through mid-week with varying degrees of cloud cover, highs in the mid to upper 60s and lows in the 40s. Average for mid-April is low 70s and low 50s.

Intern update

As the spring semester comes to a close, a couple of transitions are occurring on #TeamMWN. Two excellent nowcaster/interns will be moving on. Justin Bowles will be graduating with a Master's Degree in Meteorology from Mississippi State in a couple weeks after serving MWN very well this past school year. And Gracie Anello will be shifting her focus to broadcast this summer as she finishes her junior year and begins an internship at WKRN-TV in Nashville. She has likewise done an exemplary job on our social media feeds for the past 12 months. We wish them both well on their next adventures!

Taking their places are another Gracie (Gracie Dencausse), who will start her senior year at Mississippi State this fall in broadcast meteorology, and Christian Bridges, who has one more semester left at MSU (this fall) as he completes his undergrad degree in professional meteorology with a minor in Broadcast. Both have made their first posts on our social channels and are excited for what will likely be a few hundred more over the coming months! 

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, April 10, 2021

March 2021 Climate Report for Memphis, TN

March Climate Recap

The month of February was very cold and one of the snowiest on record, but the script flipped heading into March with temperatures for the month averaging more than four degrees above normal at 58.3 degrees. The first week of the month featured near to slight below normal, but the middle half of the month recorded highs in the 70s to just above 80 degrees, well above average. Temperatures dropped back to near average to end the month.

Precipitation was near normal until the last week of the month when a total of 6.74" fell starting on the 25th, which would have been above normal for the entire month if the first 24 days of the month were thrown out. In sum, precipitation totaled more than 4 inches above average. Nearly 4" of rain fell on the 27th, when severe weather also occurred, a daily record. Severe weather occurred on the 27th. On the 27th, scattered wind damage occurred across the area and a total of five weak (EF-0, EF-1) tornadoes touched down in the region, including four in Mississippi County and one in Tate County. Additional reports of localized flooding were received on the 1st, 17th, and 27th.

Memphis International Airport, Memphis, TN

Average temperature: 58.3 degrees (4.3 degrees above average) 
Average high temperature: 68.8 degrees (4.9 degrees above average) 
Average low temperature: 47.9 degrees (3.8 degrees above average) 
Warmest temperature: 81 degrees (16th, 27th) 
Coolest temperature: 31 degree (3rd) 
Heating Degrees Days: 219 (139 below average)
Cooling Degree Days: 20 (3 above average) 
Records set or tied: None
Comments: Only one day recorded a low temperature at or below freezing, two days below average for March.

Monthly total: 9.37" (4.21" above average) 
Days with measurable precipitation: 10 (0.5 days above average) 
Wettest 24-hour period: 3.77" (27th) 
Snowfall: 0.0" (0.4" below average)
Records set or tied: Record daily maximum rainfall - 3.77" (27th)
Comments: Four days recorded precipitation of more than an inch, 2.4 days above average for March.

Peak wind: Southwest/47 mph (27th) 
Average wind: 8.7 mph 
Average relative humidity: 62% 
Average sky cover: 56% 

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

Cirrus Weather Solutions /, Bartlett, TN

Average temperature: 57.2 degrees 
Average high temperature: 69.2 degrees 
Average low temperature: 45.9 degrees 
Warmest temperature: 75.6 degrees (28th) 
Coolest temperature: -0.3 degrees (16th) 
Comments: None 

Monthly total: 8.04" (automated rain gauge), 8.85"(manual CoCoRaHS rain gauge) 
Days with measurable precipitation: 10
Wettest date: 2.41" (27th) (via automated gauge) 
Snowfall: 0.0"
Comments: None

Peak wind: West/31 mph (17th)
Average relative humidity: 69% 
Average barometric pressure: 30.08 in. Hg
Comments: None

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

MWN Forecast Accuracy

MWN average temperature error: 2.60 degrees 
MWN forecast temperatures within 2 degrees of actual: 58% 
MWN average dewpoint error: 3.80 degrees 
MWN forecast dewpoints within 2 degrees of actual: 45% 

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

Climate Outlook - April 2021

The April climate outlook for the United States from the Climate Prediction Center is shown below. Above average temperatures are forecast for a large section of the United States with highest probabilities from the western Great Lakes through the Plains. Below average temperatures are forecast in the Pacific Northwest. Odds favor above average temperatures for Memphis (49%) versus only 18% chance of below average temperatures. The average temperature for April is 62.9 degrees.

Precipitation is expected to be below normal from the central Rockies into the southern Plains and across much of the Deep South in April. Above average precipitation is forecast for a small section of the Upper Midwest. For Memphis, odds favor near average rainfall. Precipitation historically averages 5.50 inches.

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