Nighttime Tornadoes…Ugh

Bottom Line Up Front

• Much of Kansas re-added to the ENHANCED (3 of 5) risk area this morning. MODERATE (4 of 5) wouldn’t be a surprise in the mid-day or mid-afternoon updates.
• Most models have converged on an area along/near Highway 56 from southwest of Dodge City through Larned or Great Bend as where a few supercell storms may fire in the 8pm to 10pm time frame and move slowly northeast.
• Strong tornadoes are possible, especially early in the storms’ life. Very large to giant hail (2-3 inches or larger) is possible over a broad area as the storms eventually build into a line.

Risks by Location

SPC Update (745am)

Convective initiation should be delayed across much of KS… until around 00Z (7pm CDT) as a southerly low-level jet rapidly strengthens to 50-60 kt. Very large hail (around 2-3 inches in diameter) will be a threat with any supercells that can form along/near the warm front (KS/NE line and north), or southward along the length of the dryline into western KS. Low-level hodographs are forecast to become enlarged/curved in the 00-06Z time frame tonight, and the threat for tornadoes is likewise expected to increase with any supercells that can persist and remain at least semi-discrete.

Confidence has increased in a more concentrated corridor of tornado potential across parts of western/central KS into central NE, where supercells appear most likely in very favorable thermodynamic and kinematic parameter space. Given the forecast strength of the low-level shear, strong tornadoes appear possible this evening/tonight across this area.

SPC Day 1 outlook issued 0745 CDT 2024-04-15

Risk Categories

Only risks of “slight” or higher shown

Tornado Probability

Any tornado within 25 miles of any point in the shaded area

The silver area is a 10% probability of an EF-2 or stronger tornado within 25 miles of any point in the sliver shading.

Overall risk of a tornado happening in that same region is also 10%. If tornadoes happen, they could be strong, in other words.

Hail Probability

Any hail within 25 miles of any point in the shading

10% Probability of Significant (2″+ stones) Hail

Caveats

• There is still uncertainty about whether the cap will hold. As the later runs of the hourly-updating models come out, that is looking less and less likely. But it’s still possible.
• This could line out very quickly. If that happens, the tornado risk will lessen somewhat, and they would likely be more QLCS-type tornadoes, which tend to be EF-0 and EF-1, if they cause damage at all.

Our take

(Written by Scott, but due to internal requirements this has the entire team’s consensus.)

We believe storms will happen and lean toward the solutions which show a few supercells in the first 3-5 hours of the event. In that time frame, as long as a supercell can remain fairly isolated it has all the right stuff to work with. There is a narrow corridor for this risk, in our opinion, and it is where we will be chasing. As I mentioned above, US-56, give or take 30 miles north or south, from southwest of Dodge City into Pawnee county, is where we believe the conditions come together. By the time the front moves east into the highway 281 corridor (Pratt, Great Bend, Russell), we believe it will be a line, perhaps a broken line, or may still devolve into a broad area of showers and storms. That would ramp the tornado risk down, but the hail risk would remain. It may be in the wee hours of the morning before storms make it to the Hutchinson/Wichita area, Salina, and points east. It’s not beyond imagination to have severe warnings active somewhere in Kansas as the kids go to school tomorrow morning.

These values are on a 1- to 10-point scale.

Peak Risk Value takes into account the additional risk from a nighttime event, due to the complications of getting warnings to people who are asleep, not being able to see the storms coming (especially the hail or tornado within the storm), and that there are far fewer spotter reports on nighttime storms because of the personal risk of being out in the conditions.

This can generally be read as (to inject just a bit of levity into a potentially stressful situation) “we have the normal amount of confidence in saying it will be a bad night for someplace in the risk area.”

Actions You Should Take

Before All Else: ENABLE WIRELESS EMERGENCY ALERTS

See our article here
Put a pair of sturdy, closed-toe shoes by the bed and put them on if you go to shelter. No sandals or flip-flops.
Sleep in safe clothing like a t-shirt and sweats, leggings, pajama pants or shorts.