Fantastic Friday; Severe Storms Likely Sunday

TODAY/TOMORROW: An approaching front will cause clouds to increase across the state today, but the day should be generally dry. Highs today will be around 80°. Tonight, the front will push through the state, some rain seems likely, but this will happen after midnight with rainfall amounts less than one-quarter of an inch. No storms and no severe weather, so most of you will sleep through it. The rain should end early Saturday, and the day will be partly sunny and nice with highs in the upper 70s.

MORE SEVERE STORMS LIKELY SUNDAY: The SPC has the entire southern half of Alabama outlined in an “Enhanced Risk” (level 3/5) for severe storms on Sunday, as it looks to be another very active day of strong and severe storms for the Deep South.

The front which comes through tonight, will being to lift back north as a warm front later Saturday night, as the high pressure to the east of the state, along with a weak upper level shortwave, will help lift this frontal boundary back northward. The southerly flow brings in warm/moist air into our area, increasing instability to 1000-1500 J/kg range across roughly the southern two-thirds of Alabama on Sunday. The northward extent of the instability, and therefore severe potential, remains uncertain given the track of the developing low pressure system. However, the low will act to enhance our low level shear profiles by both increasing and backing the surface winds. Aloft, the main upper level trough is expected to become more neutrally tilted, providing quite a bit of upper level diffluence. All of this together will provide enough dynamics and forcing to support strong to severe storms Sunday, morning, afternoon, and night across Alabama.

Again, how far north the warm front makes it determines the northward extent of the threat, but for now, it looks like areas along and south of Interstate 20 will have the highest potential for strong and severe storms on Sunday. This includes the River Region and all of South/Central Alabama. It looks again to be a day with multiple rounds of storms for the state, with round one likely early Sunday as the warm front lifts north. This round of storms will have the potential to produce large hail and damaging winds.

We should get a lull in the action by late morning and into the afternoon. This will allow for instability to build and could allow for the development of strong storms during the afternoon and evening hours, and these storms could be those individual supercells, which will be rotating, increasing our tornado threat, but also still being capable of producing damaging winds and large hail. This window for severe storms should come by mid-afternoon, around 3:00PM lasting through the evening and into the overnight hours and winding down shortly after midnight, with the severe weather threat expected to be over by 3:00AM Monday morning. All modes of severe weather will be possible including the threat for tornadoes, hail, and damaging winds up to 70mph. Rain amounts of 1-2 inches are possible, so we will have to monitor the threat of flash flooding as well.

Like the system last weekend, a lot will be determined by the small scale features which set-up the day of the event, and we still have a couple of days to prepare and plan for this event. This is April in Alabama, the heart of our severe weather season, so this is not unusual. No two events are the same, so don’t think this event will happen just like last weekend. It only takes one storm to makes this a very bad day for the state.

CALL TO ACTION: Now is the time to make sure you have all aspects of your severe weather plan ready for action again. Be sure you have multiple ways of receiving and hearing warnings. NEVER rely on an outdoor siren. Every home in Alabama should have a NOAA Weather Radio…be sure you have one in your home, properly programmed, and with fresh batteries. On your phone be sure WEA (Wireless Emergency Alerts) are enabled in your settings (under notifications). And, get the free Alabama News Network Weather app, ” ANN Weather” in your App Store, which does an excellent job of pushing warnings to you if you are in the polygon. Know your safe place, and have helmets for everyone ready. Also, we suggest portable airhorns and hard sole shoes. If you live in a mobile home, know where you are going, and a quick way to get there.

COVID 19: 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.

INTO NEXT WEEK: Rain should end by early Monday with a mainly dry weather continuing into Tuesday. Highs will be in the 70s, with lows in the 50s. Both long range global models continue to indicate, a dynamic weather system impacting Alabama during the late Wednesday/Thursday time frame, and yes it does look to have a significant potential to produce another round of strong, possibly severe storms. Way too early to be specific; just something to watch over as we roll into next week, but let’s get through Sunday before we start worrying about the system next week. Again, nothing too unusual as we are in the heart of our spring severe weather season in Alabama.

Keep social distancing and stay weather aware this weekend, both could save your life!
Ryan