At least 4 tornadoes struck Thursday; nice September weekend ahead

What do you do when you work for the National Weather Service the day after a damaging storm?

You go into the field and survey the damage this nasty line of severe storms produced.

Radar replay of Thursday evening’s damaging squall line via Twin Cities NWS.

Survey teams from the Twin Cities National Weather Service Office fanned out across southern Minnesota Friday. The teams of meteorologists find evidence of at least 4 different tornadoes so far.

As of 230 PM, Friday, September 21, 2018, damage survey teams from the NWS were in the process of surveying areas of damage across the area impacted by the storms. Thus far, four tornadoes have been confirmed, near Granada, MN, near Morristown, MN, near Faribault, MN, and near Lake Elysian/Waterville, MN. Radar data and spotter reports indicated that additional tornadoes may have occurred with the storms, and survey teams will make the final determination as to if, when, and where they occurred. This page will be updated as new information is received.

Here’s an overview of the set-up for the severe weather event Thursday evening.

A line of severe thunderstorms moved through southern Minnesota and into west central Wisconsin during the late afternoon and early evening of Thursday, September 20, 2018. Prior to the development of severe storms, numerous showers and thunderstorms affected much of central and southern Minnesota during the morning and early- to mid-afternoon. This activity developed well north of a warm front, which was located over northern Iowa at the time. The warm front quickly surged north during the mid- to late-afternoon as a strengthening low pressure system moved northeast from Nebraska toward southern Minnesota. Scattered non-severe thunderstorms continued to develop north of the warm front as a broken line of strong to severe storms developed from the low pressure system southward ahead of the attendant cold front. These storms raced northeast at up to 70 mph, and moved across southern Minnesota and into west central Wisconsin from around 430 PM through 8 PM. Widespread severe weather occurred with these storms.

See updated reports from the NWS survey teams here.

Flooding rainfall 

A swath of 2 to 5 inches of rain blasted southern Minnesota Thursday. The heavy rain swath laid out right over the Twin Cities. It was like being in a car wash.

Nice weekend

We enjoy a nicer weekend across Minnesota. Frost is likely in northern Minnesota both Saturday and Sunday mornings.

NOAA

Highs will reach the 70s Sunday and Monday in the Twin Cities. Temperatures cool off again next week. Fall is in the air.

NOAA via Weather Bell.

Harvest Moon

The Harvest Moon is full Monday at 9:52 pm. So what is a Harvest Moon? Here’s a good explainer from EarthSky.

What is a Harvest Moon? On average, the moon rises about 50 minutes later each day. But when a full moon happens close to an autumn equinox, the moon rises closer to the time of sunset. For mid-temperate latitudes, it rises only about 30 to 35 minutes later daily for several days before and after the full Harvest moon.

For very high northern latitudes, there’s even less time between successive moonrises.

The difference between 50 minutes and 35 minutes might not seem like much. But it means that, in the nights after a full Harvest Moon, you’ll see the moon ascending in the east relatively soon after sunset. The moon will rise during or near twilight on these nights, making it seem as if there are several full moons – for a few nights in a row – around the time of the Harvest Moon.

Enjoy this brightly moonlit weekend.