Twin Cities Severe Threat - May 18-19, 2022
Today - May 18th
The Twin Cities is again in the bullseye for severe weather, with a threat today (May 18th) and tomorrow (May 19th). The Storm Prediction Center (SPC) has a Marginal risk (1 out of 5) for severe weather across the region for this afternoon and into the late evening hours. I could see the SPC increasing these chances to a Slight risk (2 out of 5) in later updates today which could include parts of the north Metro, but I think that the more significant threat will stay north at this time.
The latest model guidance has that threat beginning around 5 PM across the far west-northwest Metro and continuing through about 10 PM as these showers and storms exit the east Metro. The greatest threat from these strong to severe storms will be along I-94 and points north, but there is a chance that some of this isolated activity could make it into the Twin Cities metro. The greatest risk from these storms will be isolated damaging wind gusts and large hail. As you work your way north, an isolated tornado can’t be ruled out in any longer lived supercells that may develop.
Tomorrow - May 19th
Our risk for severe weather across the Metro increases tomorrow with a Slight risk (2 out of 5) across the entire Twin Cities metro. A few rounds of showers and storms will be possible on Thursday, though models are struggling to handle how everything evolves. One of the reasons the models are struggling with resolving the threat on Thursday is because there is some uncertainty about how much moisture will be able. Less moisture is one factor that goes into how much instability could be available for strong to severe storms. This will be something we will have to continue to monitor. Another thing is the timing of when all the ingredients will come together. The severe threat today could play a role in the timing of this next system and how much instability will be available for tomorrow.
In regards to the timing, our first round of severe weather on Thursday could come around early afternoon noon to 3 PM as a warm front tracks northward across the region. This again will depend on when this warm front advances across the region. So if it arrives a little quicker, we could see some elevated strong to severe storms by late morning, or if it is a little slower to advance northward we could see these storms a little later in the afternoon. The main threat from these elevated strong to severe storms will again be isolated damaging winds and large hail.
The second couple rounds of strong to severe storms will come during the late afternoon into the late evening hours. Some isolated showers and storms could develop ahead of a cold front that will work across the region from the northwest off to the southeast. If these do, they could become supercellular with the threat of all modes of severe weather including tornadoes. The greatest threat though will be damaging winds and large hail. As the cold front advances southeast, additional convection is forecast to develop along that front and develop into a squall line. The main threat from these will again be damaging winds and hail, but an isolated tornado can’t be ruled out.
The threat time for these will be around the 8-9 PM timeframe to about 1-2 AM, May 19th. Again, the timing and overall severe threat will depend greatly on what happens today and on the timing tomorrow of when the ingredients will all come together. So we will be sure to post further updates on that threat. As always, please have multiple ways of receiving severe weather alerts today and tomorrow.
Severe Weather Safety - Driving
During the last severe weather setup, as I was out covering the severe weather, I saw several people seeking shelter by stopping under highway overpasses with some people completely blocking the road so that it was impassable and traffic became backed up. NEVER SEEK SHELTER UNDER A HIGHWAY OVERPASS! EVER! I get that people are trying to protect their vehicles, but please, for YOUR safety and the other people on the roads around you do not do that. If someone is driving and did not see that you stopped, they can hit you. Especially when there is low visibility from heavy rain. Take the nearest exit and take shelter off of the highway if you must stop.
There was actually a wreck during the last severe setup that killed one man and severely hurt another two people when they stopped for powerlines on the highway and were hit by a semi. The semi-driver reportedly did not see them or the powerlines down in the middle of the highway. That same thing can happen under highway overpasses as well. So please, be careful.
