/Issued 5:54 PM CDT, Friday, October 20, 2017/
12z European model from October 20, 2017 valid for Friday, October 27, 2017 — 500mb forecast
12z European Ensemble model from October 20, 2017 — Valid for Saturday, October 28, 2017
A few strong to severe thunderstorms could develop Saturday into Saturday night in parts of Minnesota and Wisconsin.
18z NAM Nest model — Simulated radar forecast starting at 7 AM Saturday, ending at 1 AM Sunday morning. A few rounds of scattered showers and a few thunderstorms on the way for Saturday with dry weather in between the waves of showers.
This current streak of warm temperatures peaked today with widespread 70s across northeast Minnesota and northwest Wisconsin — 850mb temperatures at 4 PM were around +18C while 925mb temperatures were at +20C. Southwesterly flow aloft covered the upper Midwest today in between a strong upper trough over the northern Rockies and an upper ridge over the southern/eastern U.S. Low level moisture has been increasing today due to the southerly flow, late afternoon dew points have climbed into the 40s to lower 50s over most of the Northland.
Tonight: Partly to mostly cloudy skies with very mild low temperatures in the 50s to lower 60s. Note: Normal lows for October 21 are around 30 degrees! A few showers or thunderstorms are possible late tonight as elevated instability increases while a warm/moist advection pattern persists through the night.
Saturday: Mild and quite humid for the time of year with dew points in the 50s to lower 60s while high temperatures make it into the 60s except for slightly cooler temperatures along the North Shore of Lake Superior. A strong area of low pressure ~988mb over southern Saskatchewan Province late this afternoon will track E-NE into central Manitoba Province by Saturday evening — A cold front attached to that low will move through the Northland Saturday night. Forcing along this front and also with the approaching upper level trough will result in scattered rain showers in northeast Minnesota and northwest Wisconsin for Saturday. Elevated instability will also be sufficient (300-1000 j/kg) for a few thunderstorms with heavy downpours and occasional lightning.
Sunday: Drier and cooler than recent days but still above average for late October. Will have a mix of sun/clouds as Saturday’s cold front moves into the eastern Great Lakes region. Highs will be in the 50s to lower 60s.
Note: 2nd warmest October 20 on record today at International Falls, Minnesota while Duluth tied for 2nd warmest — See lists below.
International Falls, Minnesota
1: 80 degrees set in 1953
2: 79 degrees set in 2017
1: 79 degrees set in 1953
2: 75 degrees set in 2017 and 1978
Forecast for Duluth and Superior
.Tonight… Partly to mostly cloudy. A few showers possible after midnight. Low 53 to 58. Wind south to southeast at 10 to 15 mph.
.Saturday… Mostly cloudy. Scattered showers. Isolated thunderstorms also possible. High 60 to 65. Wind south to southeast at 10 to 20 mph.
.Saturday night… Scattered showers mainly during the evening with isolated thunderstorms also possible. Mostly cloudy. Low around 50. Wind south at 10 to 15 mph becoming west at 15 to 25 mph late.
.Sunday… Breezy. Partly to mostly cloudy. High 55 to 60. Wind southwest at 15 to 25 mph.
Normal temperatures for Saturday
Sunrise Saturday: 7:35 AM CDT
Sunset Saturday: 6:10 PM CDT