This blog was written and released at 7:30 AM CDT on March 25, 2021. Just like with any weather extreme, it is imperative that you are working with fresh information. If you are working with information that is 10-12 hours old, you are working with bad information.
If you are in the the Deep South, be very weather aware today! A tornado outbreak is expected this afternoon and evening across parts of the Deep South today into the Tennessee Valley. Several intense, long-track tornadoes, very large hail, and destructive winds are all possible. Everyone needs to pay special attention to any watch and warning that is issued today.
SPC CATEGORIES - A strong upper level trough will generate a stronger upper low over the Miss-Ark-Ten corner, which will interact with a buoyant, volatile airmass to bring a major severe weather threat. The Storm Prediction Center (SPC) has issued a very rare High Risk (level 5/5) of severe weather for parts of central, eastern, and northern Mississippi into Northwestern Alabama and Southern Tennessee. A Moderate Risk (level 4/5) exists for the central 2/3rds of Mississippi, Alabama, into most of central and western Tennessee, expanding into extreme southern Kentucky. An Enhanced Risk (3/5) surrounds those two risks from about 25-50-75 miles.
Before I proceed further. I encourage everyone to not get hung up on the exact placement or name of these risks. Storms do not follow these colorful guidelines and have no idea where they are. Many tornadoes that occurred with last Wednesday's tornado outbreak did not occur in the high risk zone. Some red letter severe weather days happened on moderate risk days. The point is that everyone that is in the Enhanced Risk (3/5) and higher need to pay special attention to the weather over the next 24 hours, and finalize tornado preparations this morning.
SYNOPSIS - Just like last Wednesday, a negatively tilting trough with a high wind gradient will spin up an upper low over the triple point located on the Mississippi River Valley. Warm, moist, unstable air will already be covering most of the Deep South. The mid-level jet will become coupled with the low-level jet by the afternoon and evening hours tomorrow, creating a favorable combination of lift, shear, and helicity for potentially intense tornadoes and very large hail, and damaging winds. The greatest probabilities for a regional outbreak of tornadoes is forecast in the moderate risk and high risk areas. In addition to the tornado risk, very large to giant sized (golf ball sized or larger) hail and wind damage will like be likely across a large part of Mississippi and Tennessee into parts of Alabama, Arkansas, and extreme northeast Lousisana. The threat for damaging winds is expected to increase as a mesoscale convective system (MCS). The wind damage threat is forecast to become more widespread as a squall line organizes along a cold front in the Mississippi Valley. This line of severe storms is forecast to move quickly eastward across the Ohio and Tennessee Valleys this evening, producing widespread wind damage.
TIMING - Non-severe thunderstorms are ongoing across the northern part of the region this morning. Some of the storms could be strong to marginally severe. The severe weather threat associated with morning batches are very low. However, on days like today, we will have to continue to closely monitor.
Afternoon storms will begin to develop to the west by noon, where they will be scattered in nature. Any storm that develops in the afternoon could quickly turn severe. The peak of discrete supercell thunderstorms for Mississippi, Alabama into parts of Tennessee will come from around 1PM - 11PM tonight.
THREATS - ALL modes of severe weather will be possible this afternoon and evening, including the threat for VERY large hail, widespread wind damage and several tornadoes. A few intense, long-track tornadoes are forecast, including the potential for a violent tornado or two in the mix.
UNCERTAINTY - With any severe weather event, comes with the air of uncertainty that could either make for a worse-case scenario or for storms to not be as intense, which is ultimately what we want. Elevated convection within the warm sector is expected during the morning hours, which could dampen the overall severe potential, or produce enough outflow to introduce a higher-end tornado potential. In addition, the extent of the convective inhabitation has not been realized yet. The abundance of rain, storms, and other non-severe storms precluded violent long track tornadoes from occurring last week. This week, we are in the same situation again, which may limit the overall tornado potential. Regardless of the extent of moisture abundance in the most affected zones, several intense tornadoes are expected across the Deep South today, and a High Risk was issued this morning to address that threat.
WiLl tHiS bE LiKE aPRiL 27tH, 2011?: I really do not like this question at all. 216 tornadoes were confirmed that day, with a third of them being strong to violent. Those are generational events. Meaning, they tend to happen once every 40 years or more. However, bear in mind that if there is only one tornado in your state, and that happens to come down your street, that is YOUR April 27th, 2011.
PREPARE, PREPARE, PREPARE: You know the drill. People across the Deep South did a REMARKABLE job in preparing for a red letter severe weather outbreak, as over 40 tornadoes were confirmed, and not a single casualty resulted from that, despite major damage in many places. We need you to have the same level of preparedness today.
Just like March 17, this is not a day to play around with. Treat every tornado warning as if there is a tornado on the ground, doing significant damage. That is more than likely what we are going to be seeing across the Deep South today.
Today is day where you and your family need to keep ready for severe thunderstorms. Be sure you have multiple ways of receiving warnings. NEVER RELY ON A TORNADO SIREN. First, make sure you have a NOAA Weather Radio. Every home in the Deep South needs one as they work off of their own network, making them very reliable.
On your phone, make sure you have WEA (Wireless Emergency Alerts) enabled on your phone. To make sure of this go to Settings > Notifications > scroll all the way down to the bottom to ensure that "Emergency Alerts" are enabled.
Find the safest place in your home. It is typically in a small room, on the lowest floor, near the center of your house, away from windows. In that safe place, have helmets for everyone, airhorns (in case you are injured and need to alert first responders on site), and hard-sole shoes (if you must walk over tornado debris).
If you live in a mobile home, you can not stay put during a tornado warning. Identify the nearest location of a shelter or safe place, and know how to get there at a moments notice.
More severe weather prep tools can be found here.
MAP LITERACY - Just about anytime we forecast extreme weather, we get dozens of messages that consist of "what about *insert town or city here*". Most of these messages come on posts with references to counties or major highways.
In my five years of doing this, I have learned that several people struggle with geography, and more specifically have a tough time trying to read maps. I understand. I struggle with many things to. If you were to give me analytic geometry questions, I would look at you like you just shot a man before my eyes. But there is no way we can name hundreds of municipalities on every post.
I encourage you to take a few minutes to learn the major highways and counties relative to your location. I promise it will help you understand the blog entries and the posts I make here addressing any time of weather extreme.
YOU ARE GOING TO BE FINE - I am well aware that we are in a time in our society that most people in the South, and nationwide, are suffering from high anxiety from a global pandemic and civil tensions. The last thing we want as trusted forecasters is to add to that anxiety. However, at the same time, we must present the weather situation the way it currently stands. I understand we have many people across the south who have a literal phobia of thunderstorms and tornadoes. If you are located anywhere in the Deep South, just know that there is no reason to panic about today. Even during a severe weather outbreak, the chances of a tornado hitting your house are low, as tornadoes are tiny compared to counties, or the entire state. Unfortunately, lots of amateur weather weenies are on the social media outlets today using a myriad of scare tactics, which is ridiculous and irresponsible. They do not have any prior knowledge behind the different models and maps, what they mean, or how to interpret it. Yet, people will share them without second guessing. Please stay away from these pages, as nobody needs more anxiety. Only get weather information from trusted sources (like this blog and our social media outlets).
Owner - ApexStorm