A later start time to the snow is becoming increasingly likely across the Northland — The images below are from the 12z European computer model (ECMWF)
7 AM Thursday – Snow will begin to push into far southern portions of the Northland. Should still be dry in Duluth at 7 AM Thursday.
1 PM Thursday – Snow lifts slowly north through Noon and should reach the Twin Ports of Duluth and Superior between 10 AM and 1 PM Thursday.
7 PM Thursday – The leading edge of snow should reach the Borderland and far Arrowhead of Minnesota Thursday evening, probably after 7 PM.
18z NAM-WRF model 4-10-19
Here’s the radar forecast showing the northward progression to the snow Thursday. Again, I can’t stress this enough, the snow is going to take some time before it reaches Duluth. If it’s not snowing by 9 or 10 AM Thursday that doesn’t mean the storm isn’t coming, it’s just taking a while to get here.
18z NAM-WRF model 4-10-19
Wind gust forecast valid through 1 PM Friday.
Strong northeast winds of 25 to 40 mph near Lake Superior with wind gusts 45 to around 60 mph. The strongest winds are expected Thursday afternoon into Thursday evening. Winds will diminish by mid or late Friday morning.
Precipitable water values show the dry air up in our area and the more humid air farther south. Eventually will see the deeper moisture currently in southern Minnesota get pulled north into our area, but this will take some time!
The combination of some elevated instability (MUCAPE) and steepening mid level lapse rates could be enough to produce a few thunderstorms across much of Minnesota and Wisconsin Thursday with a risk of severe thunderstorms in the darker green and yellow shaded areas on map. So yes there may be a few instances of Thundersnow or Thundersleet across the Northland on Thursday.
Lakeshore Flood Warning
•Lakeshore Flood Warning in effect from 1 AM Thursday to 1 AM Friday including southern Lake, southern St. Louis and Carlton Counties in northeast Minnesota, and Douglas, Bayfield, Ashland and Iron Counties in northwest Wisconsin — This includes the cities of Duluth, Superior, Two Harbors, Silver Bay, Port Wing, Bayfield and Ashland.
•Large waves may cause lakeshore erosion and tidal overflow into areas like Canal Park and Brighton Beach. The lakewalk may be damaged especially since the waves will contain large chunks of ice that will loft onto the shoreline.
•Lakeshore flooding is possible on along the shoreline of western Lake Superior.
•A lakeshore flood warning means that flooding is occurring or imminent along the lake. Residents on or near the shore in the warned area should be alert for rising water and take appropriate action to protect life and property.
Storm warning information
Storm warning in effect 11 AM Thursday to 10 PM Thursday. Sustained east gales 35 to 45 knots with waves 15 to 20 feet. Storm force gusts up to 55 knots.
Winter Storm Warning remains in effect from Thursday morning through early Friday afternoon for all of northeast Minnesota and northwest Wisconsin.
Road conditions will deteriorate quickly once the snow begins with roads becoming snow covered and slippery from south to north across the Northland Thursday. Expect poor visibilities due to snow and blowing snow. Times of whiteout conditions are possible in the most intense snow bands.
Here’s my updated snowfall forecast. Biggest changes were made in northwest Wisconsin to tighten up the snowfall gradients as more of a mix of precipitation is expected Thursday afternoon/night especially in southeast portions of northwest Wisconsin, this mix of precipitation should result in lower snowfall amounts.
Note: I still may need to adjust the snowfall gradients/amounts across northeast Minnesota as well, but will see how the models trend tonight and Thursday morning before making any additional changes.
A few things that could lead to lower snowfall totals not only in Duluth but in other parts of northeast Minnesota include:
-More in the way of mixed precipitation, mainly in the form of sleet.
-Snow taking longer to push into northeast Minnesota due to dry air coming off the Hudson Bay high.
-Dry slot approaching from the south Thursday night. At the moment it looks like this dry slot would remain south of northeast Minnesota, but a slight shift to the north would bring the dry slot into northeast Minnesota essentially ending most of the snow later Thursday night.
Should one or more of these things happen, then snow totals shown on the map below could probably be cut in half.
Goes-16 visible satellite loop from Wednesday, April 10, 2019. Powerful spring storm covering the Plains with low pressure of 986mb over west-central Kansas at 5 PM Wednesday.
Here’s how this powerful spring storm looks on Goes-16 water vapor satellite imagery from Wednesday, April 10, 2019.
Radar loop ending at 6:15 PM Wednesday, April 10, 2019.
It’s been snowing most of the day in southern Minnesota with up to a half-foot of accumulation reported in some locations.
An amazing but typical setup for such a powerful spring storm across the Plains today! Incredible temperature contrast late this Wednesday afternoon.
***Top 5 highest daily April Snowfall totals in Duluth, Minnesota***
Note: Snowfall records for Duluth date back to 1884
1: 12.7 inches April 15, 2018
2: 12.1 inches April 3, 2007
3: 11.6 inches April 14, 1983
4: 11.2 inches April 18, 2013
5: 8.8 inches April 11, 2008
Interesting to note 4 out of the top 5 highest daily April snowfall totals have occurred since 2007.
Top 5 highest snowfall totals for April 11 in Duluth, Minnesota
1: 8.8 inches in 2008
2: 7.0 inches in 2013
3: 3.2 inches in 1929
4: 2.5 inches in 1887
5: 2.0 inches in 1993
Note: Could see a new daily snowfall record for April 11 on Thursday, or at the very least I’d say a top 3 snowiest April 11.
Outlook for Duluth
Tonight: Windy but dry. East to northeast wind 20 to 30 mph with gusts to 40 mph.
Thursday: Very windy. Snow gradually developing between 10 AM and 1 PM. East to northeast wind 25 to 45 mph, gusts 50 to around 60 mph during the afternoon.
Thursday night: Windy. Snow which could mix with sleet. East to northeast wind 25 to 45 mph with gusts to 55 mph during the evening.
Friday: Some lingering snow which could mix with drizzle. Windy early. Northeast wind 20 to 35 mph, decreasing to 10 to 20 mph and becoming north. Total snowfall storm accumulations of 8 to 12 inches.
Note: Strong winds could bring down tree branches and power lines leading to some power outages through Friday morning.