Wednesday, November 16, 2016

Major winter storm on the way for Friday (High winds, heavy snow, mixed precipitation, and rain changing to snow across the Northland)

/Issued 5:36 PM CST, Wednesday, November 16, 2016/

Here's my preliminary snowfall forecast for Friday -- Adjustments to this snowfall map are possible during the next 24 hours.











Source:  http://wx.aerisweather.com/

Winter storm watch in blue -- More information at this link http://forecast.weather.gov/wwamap/wwatxtget.php?cwa=dlh&wwa=winter%20storm%20watch

Blizzard watch in green -- More information at this link http://forecast.weather.gov/wwamap/wwatxtget.php?cwa=dlh&wwa=blizzard%20watch















Source:  http://mp1.met.psu.edu/
















This really isn't that unusual for an early season winter storm to be an elevation type event near Lake Superior, and this year with Lake Superior running abnormally warm late this fall the risk for an elevation event is even higher.  What this means is that most of Friday's precipitation should remain in the form of rain below the hill in Duluth, and also closer to Lake Superior along both the North Shore and South Shore of the lake -- An east/northeast wind blowing down the ~45 degree F lake will likely keep the surface temperature warm enough for rain...But as the low pulls away, a wind shift to the N/NW will occur, and that's when there should be a changeover from rain to snow even closer to Lake Superior, including in Downtown Duluth...Best guess right now is that the changeover to snow would occur between 1 PM-5 PM Friday (Earlier on top of the hill)  Some snow should be falling near Lake Superior Friday evening with a minor accumulation possible the way it looks now.

Note:  Could things change for Friday? Cold air move in quicker near Lake Superior? Low pressure shift slightly to the SE? Yes, those are all possibilities, but right now I'm not seeing much evidence of that happening per model guidance.















Source:  http://www.wpc.ncep.noaa.gov/















Source:  http://www.wpc.ncep.noaa.gov/

Forecast surface maps for Thursday evening through Friday evening.








































Tonight's low temperature forecast.  Source:  http://graphical.weather.gov/



















Thursday's high temperature forecast.  Source:  http://graphical.weather.gov/



















November 1-15, 2016 temperature departure map.  Source:  http://mrcc.isws.illinois.edu/



















November 1-15, 2016 precipitation departure map.  Source:  http://mrcc.isws.illinois.edu/




















The first half of November was a blowtorch across the Upper Midwest, and was also very dry/snowless.

Check out the stats for November 1-15, 2016 for select cities across the Upper Midwest.

Duluth, Minnesota

Average temperature:  47.7 degrees
Departure:  +14.8 degrees above normal

Total precipitation:  0.10"
Departure:  -1.02" below normal

Total snowfall:  0.0"
Departure:  -5.3" below normal

Note:  Warmest November on record through the 15th.

International Falls, Minnesota

Average temperature:  44.5 degrees
Departure:  +14.3 degrees above normal

Total precipitation:  0.19"
Departure:  -0.59" below normal

Total snowfall:  0.0"
Departure:  -5.6" below normal

Twin Cities, Minnesota

Average temperature:  51.1 degrees
Departure:  +13.1 degrees above normal

Total precipitation:  0.00"
Departure:  -0.91" below normal

Total snowfall:  0.0"
Departure:  -3.4" below normal

St. Cloud, Minnesota

Average temperature:  46.7 degrees
Departure:  +11.9 degrees above normal

Total precipitation:  Trace
Departure:  -0.74" below normal

Total snowfall:  0.0"
Departure:  -3.1" below normal

Eau Claire, Wisconsin

Average temperature:  47.5 degrees
Departure:  +10.4 degrees above normal

Total precipitation:  0.00"
Departure:  -0.97" below normal

Total snowfall:  0.0"
Departure:  -2.0" below normal

Marquette, Michigan

Average temperature:  45.7 degrees
Departure:  +11.9 degrees above normal

Total precipitation:  0.33"
Departure:  -1.24" below normal

Total snowfall:  Trace
Departure:  -9.0" below normal

Weather Summary for northeast Minnesota and northwest Wisconsin

The mild November continued today with highs in the 40s and 50s.  Partly to mostly cloudy skies were common throughout the area and there have been a few showers passing through extreme northern Minnesota today.  Surface map at 3 PM had low pressure of 1000mb over eastern Manitoba Province with a boundary (wind shift) along the Dakotas-Minnesota border.  Low pressure of 996mb was over Colorado with widespread 12-hour 500mb height falls of 90-150 meters covering much of the western U.S. today.

Forecast Discussion for northeast Minnesota and northwest Wisconsin

.Short Term Forecast...

Tonight (November 16)

Partly to mostly cloudy skies with patchy fog possible.  Low temperatures will be in the 30s and 40s with a south, east or north wind at 5 to 15 mph.  A weak frontal boundary and area of low pressure will be moving across the Upper Midwest tonight but no precipitation will occur as this system moves through.

Thursday (November 17)

Low pressure organizes as it moves out of Colorado and into Kansas on Thursday, this low heads northeast into western-north central portions of Iowa by daybreak Friday.

Mostly cloudy skies with areas of drizzle and perhaps some fog can be expected on Thursday with rain chances increasing later in the day or at night.  The rain will likely mix with and change to snow early Friday morning northwest of a line from Walker to Crane Lake.

Highs on Thursday will mainly be in the 40s with low 50s possible over far southern areas.  Lows Thursday night will be in the 30s to around 40 degrees.

Winds will be out of the north or east at 10 to 20 mph with higher gusts developing later in the day and during Thursday night.

.Extended Forecast...

Friday (November 18)

A powerful winter storm will be affecting the Northland on Friday as low pressure heads northeast out of northern Iowa -- This low is forecast to reach the east shores of Lake Superior by late Friday night the way it looks now.

Snow, heavy at times for western-northern areas in Minnesota with rain for eastern Minnesota, northwest Wisconsin and for locations close to Lake Superior.  Note:  The rain-snow line will advance east and should reach eastern Minnesota, northwest Wisconsin between 10 AM-2 PM (Might take a little longer though for the rain to turn to snow closer to Lake Superior)

-Snowfall rates of 1-2" per hour are possible on Friday across north central and northeast Minnesota.

-Strong north winds at 15-30 mph combined with falling snow will create near whiteout conditions.

-Rapidly deteriorating road conditions on Friday.

High temperatures on Friday will be in the 20s and 30s with 40s in far southern portions of northwest Wisconsin.  Lows Friday night mainly in the 20s.

Saturday (November 19)

Much colder compared to the record warmth so far this month -- Highs in the 20s to lower 30s with a brisk N/NW wind making it feel even colder.  Lake effect snow showers along the South Shore of Lake Superior in northwest Wisconsin.

Forecast for Duluth and Superior

.Tonight...  Partly to mostly cloudy.  Low 37 to 42.  Wind east at 10 to 20 mph.

.Thursday...  Mostly cloudy.  Patchy drizzle possible.  High 45 to 49.  Wind northeast at 10 to 20 mph.

.Thursday night...  Becoming windy.  Light rain and drizzle.  Areas of fog.  Low 37 to 41.  Wind east to northeast at 15 to 30 mph.

.Friday...  Windy.  Rain mixing with and changing to snow between 10 AM and Noon on top of the hill with some snow accumulation expected by late afternoon.  Rain below the hill mixing with snow and changing to snow between 1 PM-4 PM.  Northeast wind shifting to the north at 15 to 30 mph.

Normal temperatures for Thursday

High:  35
Low:   21

Sunrise Thursday:  7:15 AM CST
Sunset Thursday:   4:32 PM CST

Tim