If you are outside today, it is almost unimaginable that we are expecting a dangerous severe weather threat across the Deep South in 24 hours. We are enjoying blue sky, sunshine, and low humidity. But, the atmosphere will undergo a remarkable transformation tomorrow, and by the evening hours a very unstable airmass will be in place, with dewpoints up in the 67-70 degree range (dewpoints this afternoon are in the 30!).
SPC OUTLOOK: The Storm Prediction Center, in their updated “Day 2” severe weather outlook, pulled the “moderate risk” (level 4/5) a little deeper into East Alabama, but overall there weren’t that many changes.
The bottom line is that ALL of Alabama has a significant threat of severe storms late tomorrow and into tomorrow night. Don’t get too focused on map colors, lines, and verbiage.
THE SETUP: While the risk of all severe hazards will be quite high if supercells develop, uncertainty remains regarding how convection will evolve from the morning into the afternoon. Severe weather events here in Dixie Alley are often “messy”, with multiple waves of storms. And, how each wave unfolds (placement, timing, intensity, etc) will often determine the severity of the next wave. Rain is likely tomorrow morning north of a warm front, that represents the leading edge of very unstable air moving up from the south. As the unstable air settles in, dynamic forcing comes into play and severe storms are likely by late afternoon into tomorrow night.
TIMING: While rain and thunderstorms are possible tomorrow morning, the core severe weather threat will likely come from 3 p.m. until midnight. The threat will linger after midnight for Southeast Alabama.
THREATS: Storms will be capable of producing large hail, damaging winds, and tornadoes. Based on the forecast dynamic/thermodynamic fields, a few strong/violent, long track tornadoes will be possible.
FLOODING: Rain amounts could exceed three inches over the northern quarter of the state, generally north of U.S. 278 (Hamilton to Cullman to Gadsden). Flooding is possible there … to the south amounts of 1-2 inches are likely for the I-20/50 corridor, and major flooding issues are not expected there.
UNCERTAINTY: Thunderstorms events in “Dixie Alley” are often complex, and often the magnitude of a severe weather event is determined by small scale boundaries and interactions that are hard to define in advance. But confidence is high in the large, synoptic scale event tomorrow.
WILL THIS BE LIKE APRIL 27, 2011? No. Alabama experienced 62 tornadoes that day, many were strong/violent. Those type events happen once every 40 years on average. But that doesn’t mean you don’t need to prepare for the event tomorrow. If there is only one tornado in the entire state tomorrow, and if that one comes through your neighborhood, then that is YOUR April 27. And, there is a good chance we see more than one tornado tomorrow evening.
PREPARE TONIGHT: Now is the time to get ready for severe weather. Be sure you get the warnings; NEVER rely on an outdoor siren. The baseline for getting the warning is a NOAA Weather Radio. Every Alabama home needs one; they work independently of cell networks, and are very reliable. If you need help programming your radio, see this video from ABC 33/40 Meteorologist Taylor Sarallo.
On your phone, be sure WEA alerts are active. Go to settings, notifications, and be sure “emergency alerts” are enabled. Download the free ABC 33/40 Weather app as well; it is an excellent way of getting severe weather watches and warnings pushed to your phone.
Determine your safe place. In a site built home, it is a small room (closet, bathroom, closet) on the lowest floor, near the center of the house, and away from windows. You do not have to be underground. In that safe place, have helmets for everyone, along with portable airhorns (if you are injured and need to alert first responders), and hard sole shoes (if you have to walk over a tornado debris field).
If you live in a mobile home, you cannot stay there during a tornado warning polygon. Know the location of the nearest shelter or safe place, and know how to get there quickly. Check with your local county EMA (Emergency Management Agency) concerning shelter locations if you need help.
ANXIETY: I am well aware that many suffer from storm anxiety. And, this is amplified with the current COVID-19 situation. The last thing we want to do is create another “wall of worry”, but at the same time we have to let you know of the danger potential tomorrow. Simply be prepared, and we will get through the day together fine. Even on a “moderate risk” day, odds of any one place being hit by a tornado are low. Stay away from the social media pages run by amateurs that are built on hype and fear; they just want your to like and share their content, even if it means scaring you. Find a reliable source from professional meteorologists.
COVID 19: From the National Weather Services offices in Alabama, and the Alabama Department of Public Health:
“The decision to seek shelter in a community storm shelter is certainly made more difficult by the consideration for COVID-19, and each individual will need to make an educated decision on where and when to shelter from a tornado.
At this time, the Alabama Department of Public Health (ADPH) is recommending that your first priority should be to protect yourself from a potential tornado. If a warning is issued for your area, you are more likely to be affected by the tornado than the virus.
However, the decisions to open any community shelters are done at the local or county level. Before you make a decision to go to a community shelter, you should check with your community shelter managers to ensure they are open, and if there are any local COVID-19 considerations. Certainly, wherever you choose to shelter from a tornado, you should use as many precautions as possible to inhibit the spread of COVID-19 as best as you can. If you rely on public community shelters, now may be the time to explore other options that might keep you safer from severe weather and possibly limit your exposure to COVID-19.”
I will have another update tonight… stay tuned!
For more weather news and information from James Spann and his weather team, visit AlabamaWx.com.