Weather Blog: Significant severe weather likely Tuesday

Posted: Apr 4, 2023 / 09:55 AM CDT

Updated: Apr 5, 2023 / 02:06 PM CDT

**The Latest Day 1 Convective Outlook From The Storm Prediction Center (SPC)**

FAYETTEVILLE, Ark. (KNWA/KFTA) — 10AM UPDATE (4/4/23): A significant severe weather event is possible across Northwest Arkansas and the River Valley, starting Tuesday during the late afternoon and continuing into the early morning hours Wednesday. All modes of severe weather will be possible, including the risk for strong to violent long-track tornadoes.

Current Severe Weather Risk

The most likely area for significant severe weather potential is located in the Moderate Risk (Level 4 of 5), which is currently positioned just to the east of Fayetteville and Fort Smith, along the I-40 corridor. Strong to violent tornadoes are most likely in these areas, where confidence continues to increase in the severe weather potential being realized. From there, a very thin Enhanced Risk (Level 3 of 5) covers the Fayetteville area, as well as the I-49 corridor north of the Bobby Hopper Tunnel. Significant tornado potential also resides in these areas, though some uncertainty still remains. The rest of NE Oklahoma, far NW Arkansas and SW Missouri are under a Slight Risk (Level 2 of 5) of severe weather, which includes far western portions of Benton and Washington counties. The potential for significant severe weather also exists in these areas, but overall confidence is low at this time. There is still the chance that these risks are upgraded as more data becomes available, so stay tuned to the latest information.

Severe Weather Hazards

All modes of severe weather will be possible with this storm system, including large hail up the size of baseballs, damaging wind gusts up to 70 mph and strong to violent tornadoes (EF2-EF5). The tornado potential will exist for an extended period of time with any storms that form in both the evening and overnight hours. Large hail will be more likely during the late afternoon and evening with any initial supercells that develop. Damaging winds will become more likely as we go throughout the overnight hours, with an intense squall line along the cold front.

Timing

One of the uncertainties that surrounds this particular storm system is the timing and evolution of thunderstorms throughout the event. Thunderstorms could begin to fire right around sunset, and any storms that do will have the potential to produce very large hail and strong tornadoes. The confidence in this happening, however, is low. Confidence begins to increase in storm development between 9 P.M. – 2 A.M., where a broken line of supercells could develop to our west, and these storms will have the greatest chance to produce strong to violent tornadoes. This is because the parameters for significant tornadoes will be at it’s highest. After 2 A.M., the cold front will quickly push through the area, transitioning the severe weather threat to favor damaging winds. The storm potential should end by the morning hours Wednesday around 7 A.M. at the latest.

The Role Of The “Cap”

**Capped (Left) Vs. Uncapped (Right) Environment**

The greatest uncertainty with this system has to do with the “cap”, which acts like a lid on the atmosphere to prevent thunderstorm development. The cap refers to a layer of warm air aloft (typically between 3,000 to 7,000 feet) that can keep storm updrafts from reaching the colder, drier air in the upper levels, which allows bubbling cumulus clouds to erupt with convection. During the daytime hours, the cap will likely hold over Northwest Arkansas and the River Valley, which will keep storms from forming. Once the energy pushes into the area, the cap will rapidly erode, allowing for storms to develop, and thus crank up the severe weather potential. The models are struggling with this particular aspect of the system, which makes this forecast very complicated. Regardless, remain weather aware as we go throughout the next 12-24 hours, and follow the latest information closely.

Prepare For Severe Weather

This is highly complex forecast, with many different factors at play. It is crucial to stay up to date on the newest details over the next several hours, so follow the Weather Authority Team below for up-to-the-minute updates. You can also download the Weather Authority App below by scanning the QR code or searching it up on the Google Play and Apple App Store. Have an emergency plan in place in case of severe weather, and remember to D.U.C.K. if a tornado warning is issued for your area! Stay weather aware, and stay safe!!