(update, 4:15 pm. Doppler radar is hinting at ¼” hail just east of St. Cloud [small green triangle shows the location]. Remember that hail isn’t considered severe unless it reaches 1″ diameter, roughly quarter-size. The heaviest storms extend from Foley and St. Cloud southwest to Litchfield and Redwood Falls – the entire line is pushing east at 25-30 mph and should be exiting the St. Cloud area by 5 pm at the latest. In the Twin Cities the best chance of getting wet (or hailed on) is between 5 and 6:30 pm. A few isolated storms may still turn severe, but moisture is limited (dew points a bit too low) and most towns will only pick up thunder, lightning, pea-size hail and 60-90 minutes of rain, maybe some .50 to .75″ amounts. Good news: no need to water the lawn, garden or fields this weekend!
(update: 2:30 pm) Doppler shows fairly strong rotation just north of Redwood Falls, Minnesota. Although no tornado watch is in effect, there is always a slight risk of an isolated tornado in this kind of pattern. Conditions are very marginal for tornadoes (dew points in the low to mid 50s) but there is sufficient wind “shear” (changing wind speed/direction as you rise up through the atmosphere) to spin up a brief, isolated tornado in parts of Minnesota. It’s worth repeating that most towns will only see a downpour, possibly small hail, thunder and lightning. But you’ll want to stay alert and be ready to move to a safe area if threatening conditions approach. The safest spot: in the basement, under the stairs. If you don’t have a basement a small, ground-floor room on the lowest level is safest, a closet or bathroom. Avoid outer walls and windows. More updates as warranted….
(update 2:00 pm) Doppler shows strong T-storms approaching from the west. There are indications that some of these cells are producing 1/2″ diameter hail. If the hail size reaches 1″ diameter warnings will be issued for specific counties. Time to move the kids indoors (get the car in the garage if possible, to avoid potential hail-dings!) The greatest risk comes from 3:30 to 6:00 pm, west metro obviously the first to feel the effects of these storms, which may drop a quick .50″ of rain. A few isolated storms may go severe, with large hail, 58 mph+ winds, even an isolated tornado. Stay alert and stay tuned for possible warnings.
(update 1:05 pm) SPC (Storm Prediction Center) has placed much of Minnesota in a “slight risk” of severe thunderstorms. We’re getting enough sunshine and surface heating, coupled with an increasingly ripe wind profile aloft. Dew points are rising through the 50s, ample moisture to fuel storms capable of 1″ hail and wind gusts > 60 mph later today. The greatest risk of a few isolated severe storms will come around the dinner hour, between 4 and 7 pm. Stay alert, check into this site for updates, and stay tuned for possible watches and warnings later this afternoon.