Midwest Storm Hunters

SPC has made some adjustments with the slight risk for later today. They are now forecasting the greatest severe potential along the Interstate 80 corridor from eastern Illinois to central Nebraska. The main hazards will be damaging winds and large hail, some significant. The tornado threat is lower but definitely not zero.

I'm also still monitoring any boundaries or remanents of an MCV in the region by afternoon. It's not looking likely but there is still a low chance for some severe activity with these features if enough ingredients come together in time this afternoon. Expect updates as needed later today.

A large portion of the Country is experiencing some sort of abnormally dry to drought conditions. Some of these areas in the Midwest will see some relief with rainfall forecasted over the next several days.

AURORA ALERT: a strong solar storm could bring the northern lights to much of the U.S. tonight (Thursday, June 4). NOAA has issued a G3 ("strong") geomagnetic storm watch for June 4 into June 5. If it pans out, the aurora may be visible across the northern states and into the central U.S., with a small chance even farther south during brief bursts called substorms.

What's happening: an active sunspot region called AR 4455 fired off several CMEs (giant clouds of solar plasma) on June 3, including ones tied to an M9.5, M7.8, and an X1 flare. At least three are aimed our way and may arrive together. NOAA expects the first impact around midday Thursday (18 UT or about 2 PM Eastern, 1 PM Central, 11 AM Pacific), while NASA's model leans to the evening and another (HUXt) pushes it into the early hours of June 5. It's a wide window, so watch tonight into early Friday.

How strong: NOAA's official forecast is G3 (Kp 7), but a lot depends on whether we take a direct hit or a glancing blow, so it could land higher or lower. Don't put too much stock in pinpoint Kp numbers or app forecasts days out. Space weather is hard to predict and the storm will evolve on its own. Treat them as a sign activity may be enhanced, not a guarantee.

How to catch it: get away from city lights, find a clear view to the north, and look during the darkest part of the night. Watch for substorms when the sky can go from dark to full of color in just a few minutes. Two things working against us: clouds (even thin, high clouds can mute the show) and a bright ~80%-lit moon that rises around local midnight. Your best window is the dark gap after dusk and before the moon comes up.

The map shows roughly how far south the aurora might reach tonight. Forecasts like this don't always come true, so keep your hopes up but your expectations realistic.

A few free resources to help you chase:

Sign up for my aurora alerts + guides: https://theauroraguy.com/

Live aurora webcams (100+): https://theauroraguy.com/pages/webcams

What is a substorm? https://theauroraguy.com/blogs/blog/a-practical-substorm-guide

What resources you may look at but are actually NOT helpful for chasing in real-time: https://theauroraguy.com/blogs/blog/top-five-low-value-practices-to-avoid-aurora-chasing

How to read the HUXt model: https://theauroraguy.com/blogs/blog/aurora-chasers-guide-to-the-huxt-forecast

Support these free alerts on Patreon: https://patreon.com/TheAuroraGuy

Tomorrow a MCV looks to track across parts of S WI or N IL by mid day. I'm intrigued on how this pans out as it could get me out for a local chase if timing is right and enough instability is present. Right now its a low confidence forecast as the timing for this region is slightly too early for any robust storm development associated with the MCV and impeding trough.
Better chances will likely reside in the evening for a few severe storms for parts of the Midwest.

Severe storm potential Friday 6/5.

We'll see severe storm potential shift further south and east from what we have been seeing recently. There is a slight risk in place from eastern Nebraska to western Wisconsin.

Storm development is likely ahead of a frontal boundary from the upper Midwest into the central Plains. A mid level trough with a 40 to 50 knot jet streak, sufficient moisture return and instability will lead to several severe storms. All hazards appear possible, the tornado potential will be dependent on discrete storm mode longevity. Things will grow upscale into a south eastward moving MCS during the evening with an attendant wind threat.