Tuesday, May 24, 2016

May 24, 2016: Gusty east winds, cool, foggy and some drizzle in the Twin Ports through Wednesday; Rain moves in Wednesday afternoon/evening. Storm reports and rainfall reports included in this post

/Issued 5:42 PM CDT, Tuesday, May 24, 2016/

Severe weather outlook for Wednesday, May 25, 2016.  Source, WSI; Storm Prediction Center.

*Slight risk for severe thunderstorms in yellow.
*Marginal risk for severe thunderstorms in light green.
*Risk for non-severe thunderstorms in dark green.

Note:  5 point scale with 1 being the lowest risk and 5 being the highest risk for severe thunderstorms.

Filtered Storm Reports map for May 23, 2016.  Source, Storm Prediction Center.

Red dots=Tornado reports
Blue dots=Damaging wind reports (58 mph or stronger)
Green dots=Large hail reports (1.00" or greater in diameter)

24-hour rainfall total map ending the morning of May 24, 2016.  Source, Midwest Regional Climate Center.

7-day rainfall forecast valid through May 31, 2016.  Source, Weather Prediction Center.

Low temperature forecast for tonight.  Source, National Weather Service Duluth, MN.

High temperature forecast for Wednesday.  Source, National Weather Service Duluth, MN.

24-hour rainfall totals ending at around 6 AM on May 24, 2016
Source:  National Weather Service Duluth, MN; MesoWest

Bayfield, WI:  1.65"
2 SW of Moose Lake, MN:  1.57"
Washburn, WI:  1.50"
Ashland, WI:  1.12"
Grand Rapids, MN:  1.08"
Walker, MN:  1.03"

Two Harbors, MN:  0.98"
1 WSW of Maple, WI:  0.96"
Solon Springs, WI:  0.92"
5 S of Ely, MN:  0.89"
Saginaw, MN:  0.78"
Brookston, MN:  0.75"

Barnes, WI:  0.71"
Glidden, WI:  0.63"
3 ENE of South Range, WI:  0.56"
Superior, WI:  0.50"
Silver Bay, MN:  0.44"
Grand Portage, MN:  0.44"

Littlefork, MN:  0.39"
2 NE of Duluth, MN:  0.37"
1 ESE of Esko, MN:  0.25"

*Local Storm Reports*
Source, National Weather Service Duluth, Minnesota

*5/24/16 (4:55 PM CDT)  HAIL.  0.50".  2 ENE of Mercer, WI (Iron County)  Pea sized hail with largest hail of 0.5".

*5/23/16 (5:36 PM CDT)  THUNDERSTORM WIND DAMAGE.  3 SSW of Iron River, WI (Bayfield County)  A couple of 6" diameter softwood pine trees broken at ground level and some at 20 feet above ground level.

*5/23/16 (5:40 PM CDT)  THUNDERSTORM WIND DAMAGE.  Iron River, WI (Bayfield County)  Report of several trees down in Iron River.  A few fell on US-2.

Weather Summary for NE Minnesota & NW Wisconsin
Date:  May 24, 2016

A messy surface pattern remains in place today with a frontal boundary more or less over central Minnesota while another front pushes south/west off Lake Superior.  

Scattered showers and thunderstorms with heavy downpours affected parts of the Northland early this morning which was followed by partly to mostly sunny skies this afternoon.

Lingering moisture and instability combined with a decent amount of convergence associated with the westward moving boundary off Lake Superior helped to trigger a few showers and thunderstorms this afternoon in far northern Wisconsin with other spotty activity occurring most of the day across far northern Minnesota.  The majority of these storms have remained below severe levels today although one storm has reached severe criteria this afternoon over parts of Ashland and Iron County in northern Wisconsin.

Highs today were in the 70s to lower 80s but it has turned cooler this afternoon near Lake Superior thanks to a stronger push of onshore winds late this afternoon.

Forecast Discussion for NE Minnesota & NW Wisconsin

Confidence:  Medium.

Tonight:  A few showers and thunderstorms especially during the evening hours.  There is sufficient amounts of moisture, instability and enough wind shear in place to support an isolated strong to severe thunderstorm risk in parts of the Northland this evening.  Otherwise expect a partly to mostly cloudy sky through the night with areas of fog developing mainly near Lake Superior.  Low temperatures will mainly be in the 50s with 40s near Lake Superior.  Winds will be out of the east or southeast at 5 to 15 mph,  higher gusts near Lake Superior.

Wednesday:  An area of low pressure is forecast to move northeast into the northern Plains tomorrow while a warm front lifts slowly north out of southern Minnesota -- Occasional showers and a few thunderstorms are expected in the Northland especially during the afternoon and evening hours.  A stronger flow off Lake Superior will likely keep the amount of instability on the low side in most of our area tomorrow so severe weather isn't a real big concern.  Heavy rain and occasional lightning should be the primary hazards in any thunderstorm that manages to develop on Wednesday.  High temperatures will be in the 60s and 70s with 40s near Lake Superior, fog and drizzle is also possible near Lake Superior tomorrow.  Winds will be out of the east or southeast at 10 to 15 mph with stronger gusts near Lake Superior.

...Looking ahead...

Confidence:  Medium.

The overall weather pattern will change little through the holiday weekend - A southwest flow aloft will be in place with moist and unstable air pushing north at times into the Upper Midwest.  Low pressure disturbances lifting northeast out of the Plains combined with the moist/unstable air will likely produce occasional rounds of showers and thunderstorms across the Northland from Thursday through Memorial Day (May 26-30)  Note:  Even though there are rain chances every day through Memorial Day the pattern that is setting up favors dry hours as well, so I wouldn't cancel any outdoor plans but just have a plan B ready just in case.  

As for temperatures, expect daytime highs to be in the 70s, possibly up near 80 degrees from Thursday through Monday but it will remain cooler near Lake Superior.

Heads up!  Could be dealing with a patchy frost threat sometime during the June 3-6 time frame in northeast Minnesota and northwest Wisconsin...That'll be something to watch for late next week/weekend.

Normal temperatures for May 25th at Duluth, Minnesota

High:  65
Low:   43

Sunrise Wednesday:  5:23 AM CDT
Sunset Wednesday:   8:49 PM CDT