We may have just witnessed the biggest tornado outbreak in Minnesota history.
As of late Thursday night, NOAA's Storm Prediction Center lists 36 tornado reports in the state of Minnesota Thursday. Some of these may be multiple reports of the same tornado from different observers.
NWS offices around the region will dispatch survey teams to confirm final numbers, but it is possible that Thursday's final number of tornadoes may break or rival the record for most tornado touchdowns ever on record for a single day in Minnesota.
The standing record until Thursday was 27 tornadoes in one day on June 16th, 1992.
Here are the top 10 single day tornado outbreaks in Minnesota history. (NWS data)
1. June 16, 1992: 27 tornadoes
2. July 1, 1997: 18 tornadoes
3. June 11, 2001: 16 tornadoes
3. June 13, 2001: 16 tornadoes
5. June 28, 1979: 15 tornadoes
5. June 24, 2003: 15 tornadoes
7. July 21, 1995: 14 tornadoes
7. October 26, 1996: 14 tornadoes
7. March 29, 1998: 14 tornadoes
7. July 25, 2000: 14 tornadoes
There were 20 reports of tornadoes in North Dakota Thursday.
It appears we made (dubious?) weather history in Minnesota on Thursday.
NWS survey teams were in the field Friday to assess the number and severity of tornadoes from Thursday's tornado outbreak. But the work they did before and during Thursday's outbreak likely saved many lives.
I do not hesitate to point out when I think NWS can do better. Issuing tornado warnings early this week for small "rotating" thundershowers that produced no severe weather was a bit aggressive I thought. But in the events leading up to and during Thursday, regional NWS forecast offices shined.
It started with a good lead time for the possibility of severe weather for Thursday. Both SPC and local NWS offices gave the public plenty of advance notice that severe weather was likely Thursday with outlooks and graphics. Even though from a synoptic meteorological perspective this was a pretty clear cut severe weather situation, NWS did an excellent job of previewing the event to the public.
As events unfolded Thursday SPC and local NWS offices were on the money with timely tornado watches and warnings. At one point yesterday, I counted at least 12 tornado warnings in effect at the same time for Minnesota, with a total of at least 20 of Minnesota's 87 counties under tornado warnings at the same time. I can't recall an event even approaching that intensity and coverage, and that doesn't even take into account severe thunderstorm warnings that were in effect at the same time.
I was too busy to count the actual number of Minnesota counties under severe thunderstorm and tornado warnings at the peak of Thursday's event, but I think an educated guess would have put that number at around 40 of Minnesota's 87 counties. Incredible.
MPR's All Things Considered host Tom Crann and I were talking about how we've never seen the MPR weather alert service that keeps track of severe weather so choked with warnings Thursday. It was hard to even get through the tornado warnings in one broadcast, let alone the severe thunderstorm warnings.
The bottom line is, regional NWS offices deserve our thanks for the excellent work they did Thursday. Grand Forks (GFK) Twin Cities (MPX) Duluth (DLH) La Crosse (ARX) Sioux Falls (FSD) and even Des Moines (DSM) all dispatched warnings and other critical weather information at lightning speed for parts of the huge MPR regional listening area.
Trained and dedicated volunteer SKYWARN severe weather spotters also provided critical "ground truth" as events unfolded.
As a broadcast meteorologist, it is good to know that we are supported by such a dedicated team of weather professionals in the Upper Midwest.