Scattered showers/t-storms possible tonight and Monday; turning cooler mid to late week

A marginal risk of severe thunderstorms covers much of north-central into far northeast Minnesota tonight (darker green shaded area on map)

Primary threats in the marginal risk area include

  • Damaging wind gusts
  • Large hail

There is a risk of non-severe thunderstorms over the rest of the Northland including Duluth and Superior for tonight (lighter green shaded area on map)

Note: All thunderstorms will produce heavy downpours and lightning.

Radar forecast valid from 8 PM Sunday to 8 PM Monday per 18z NAM-WRF model.

Source: https://weathermodels.com

  • 35 days so far this summer (since June 1) with a high temperature of at least 80 degrees in Duluth; average for the summer (June 1 to August 31) is 23 days with a high temp of at least 80 degrees. Note: Last summer thru August 4 had 27 days with a high temp of at least 80 degrees in Duluth, and the summer of 2018 finished with 39 days with a high temp of at least 80 degrees.

Storm Reports from Saturday, Aug 3, 2019.

Source: https://www.weather.gov/dlh/

5:50 PM: HAIL — 0.25 inch. 2 SSE La Prairie, MN (Itasca County)

4:58 PM: HAIL — 0.25 inch. 1 NNW Duquette, MN (Pine County)

4:55 PM: HAIL — 0.25 inch. 3 SW Nemadji, MN (Carlton County) Note: 10 to 15 minutes of pea size hail.

4:47 PM: HAIL — 0.70 inch. 3 SSW Bruno, MN (Pine County)

4:27 PM: HAIL — 0.50 inch. 3 S Mahtowa, MN (Carlton County)

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Temperature departure map for the week of July 28, 2019. Most of the Northland had near to below average temperatures last week, while other parts of the Northland had above average temps (yellow and orange colors on map)

Source: https://hprcc.unl.edu

Precipitation departure map for the week of July 28, 2019.

Temperature and Precipitation report for Duluth, Minn

July 28 through August 3, 2019

High Temperatures/Departure from Normal

7/28: 80F/+3 degrees above normal

7/29: 73F/+3 degrees above normal

7/30: 76F/-1 degree below normal

7/31: 78F/+1 degree above normal

8/1: 85F/+9 degrees above normal

8/2: 87F/+11 degrees above normal

8/3: 80F/+4 degrees above normal

Low Temperatures/Departure from Normal

7/28: 60F/+4 degrees above normal

7/29: 59F/+3 degrees above normal

7/30: 49F/-7 degrees below normal

7/31: 50F/-6 degrees below normal

8/1: 58F/+2 degrees above normal

8/2: 65F/+9 degrees above normal

8/3: 62F/+6 degrees above normal

Note: Average temperature for the week of July 28: 68.7 degrees (+2.5 degrees above normal) Source: https://www.dnr.state.mn.us

Total Precipitation: 1.84″

Normal: 0.78″

Departure: +1.06″ above normal

State Average for Minnesota for the week of July 28, 2019

  • Temperature: 68.3 degrees
  • Departure: -1.4 degrees below normal
  • Precipitation: 0.66 inches
  • Departure: -0.17″ below normal

Low temperature forecast for Monday morning, August 5, 2019.

Source: https://graphical.weather.gov

High temperature forecast for Monday, August 5, 2019.

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

…Weather Summary…

Warm weather sticks around through Tuesday followed by somewhat cooler temperatures mid to late week. Humid tonight and most of Monday, then turning less humid mid to late week.

A warm front has been moving through the Northland today with a few showers and thunderstorms developing near this front across portions of northern Wisconsin and in far northern Minnesota. Storms today haven’t been very strong due to a lack of deep layer wind shear. Brief downpours and occasional lightning have been the biggest threats from today’s spotty storms.

A shift in wind direction led to a very warm Sunday afternoon near Lake Superior as east winds Saturday shifted to the southwest this afternoon. Temps on Saturday were in the low to mid 70s by the lake with mid to even upper 80s occurring this afternoon thanks to that southwesterly wind.

Focus for tonight and Monday will be on a cold front which moves southeast out of the Dakotas. Winds aloft will strengthen during the night which helps to generate stronger deep layer wind shear which could help to sustain thunderstorms that do form later tonight.

The environment along and ahead of the cold front will feature CAPE of 500 to around 2000 J/kg which is enough for convection. Mid level lapse rates don’t look very impressive though (6.0-6.5 c/km)

Computer models show a few showers and thunderstorms continuing this evening mainly in far northern Minnesota. More widespread shower and thunderstorm development will be possible late tonight into Monday morning as we get some better lift to move in as a cold front moves into the Northland.

It will be a warm and muggy night as lows remain in the 60s. Highs Monday will range from the middle 70s to lower 80s with dew points remaining in the muggy 60s, but drier air (lower dew points) will push southeast out of northern Minnesota later Monday afternoon.

Spotty showers or thunderstorms are possible Tuesday afternoon/evening as another cold front passes through the area. Still warm Tuesday with highs mainly in the 80s.

Will cool off a little bit mid to late week with mainly dry weather expected Wednesday and Thursday. Highs on both of those days ranging from the upper 60s to middle 70s while overnight lows fall into the 40s and 50s. Note: Doesn’t look cold enough for frost this week anywhere in the Northland.

Normal temperatures at Duluth for the week of Aug 4.

  • Normal high on the 4th: 76F
  • Normal low on the 4th: 56F
  • Normal high on the 10th: 76F
  • Normal low on the 10th: 55F

Astronomical data at Duluth for the week of Aug 4.

  • Sunrise on the 4th: 5:53 AM
  • Sunset on the 4th: 8:35 PM
  • Sunrise on the 10th: 5:59 AM
  • Sunset on the 10th: 8:27 PM

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