/Issued 4:58 PM CDT, Friday, August 31, 2018/
Source: http://weather.cod.edu
Large scale forcing appears to be increasing in the Northland late this afternoon but there are still some negatives in place for thunderstorm development, so will just have to wait and see how things shake out during the next few hours, if thunderstorms do develop, they could become severe with favorable amounts of instability and wind shear over the area.
Note: Yellow outlined area on map is where I’m watching for the potential of strong to severe thunderstorms this evening.
…Flash Flood Watch remains in effect from this evening through early Saturday morning for parts of northeast Minnesota and all of northwest Wisconsin, including the Twin Ports, North Shore and South Shore…
September Climate Normals for Duluth, Minnesota
Temperature: 55.6 degrees
Precipitation: 4.1″
Snowfall: 0.1″
Warmest September on record: 62.6 degrees set in 1897
Coldest September on record: 47.8 degrees set in 1974
Normal high on the 1st: 71 degrees
Normal high on the 30th: 59 degrees
Normal low on the 1st: 52 degrees
Normal low on the 30th: 40 degrees
Wettest September on record: 11.52″ set in 1881
Driest September on record: 0.19″ set in 1952
Snowiest September on record: 2.4″ set in 1991
Average number of days with a high temp of at least 80 F: 2; Record is 10 days set in September 1908.
Average number of days with a low temp of 32 F or lower: 1; Record is 7 days set in 1974.
Astronomical Data
Sunrise on September 1: 6:28 AM CDT
Sunrise on September 30: 7:05 AM CDT
Sunset on September 1: 7:48 PM CDT
Sunset on September 30: 6:49 PM CDT
Note: The first official day of fall is September 22, but Meteorological fall begins on September 1, or the 3-month period from September 1 to November 30.
Meteorological fall Climate Normals for Duluth, Minnesota
Period: Sep 1 to Nov 30
Temperature: 42.5 degrees
Precipitation: 9.05″
Snowfall: 16.1″
Normal High on September 1: 71 degrees
Normal High on November 30: 28 degrees
Normal Low on September 1: 52 degrees
Normal Low on November 30: 14 degrees
Sunrise on September 1: 6:28 AM CDT
Sunrise on November 30: 7:31 AM CST
Sunset on September 1: 7:48 PM CDT
Sunset on November 30: 4:22 PM CST
Note: Daylight Saving Time ends on November 4 at 2 AM. We fall back an hour on the 4th.
Meteorological fall 2017 climate stats for Duluth, Minnesota
Average temperature: 43.3 degrees
Departure: +0.8 degrees above normal
Precipitation: 8.26″
Departure: -0.79″ below normal
Snowfall: 21.6″
Departure: +5.5″ above normal
Local Storm Reports for August 31, 2018
Source: https://www.weather.gov/dlh/
•3:40 PM CDT: Hail — 0.25 inch. 1 NW Loman, MN (Koochiching County)
•3:56 AM CDT: Hail — 1.00 inch. 2 NE Mercer, WI (Iron County) Quarter sized hail.
Weather Synopsis
A mild, muggy but rather gloomy day as we end the month of August. The Northland saw plenty of clouds today with warm southerly winds, highs were mainly in the 70s with dew points in the mid to upper 60s! An area of thunderstorms affected a small part of far northern Minnesota this afternoon, otherwise it’s been mainly dry with just a few areas of drizzle or showers.
Late afternoon RAP model analysis showed SW flow aloft covering the upper Midwest with an elevated mixed layer resulting in very steep mid level rates from 8.0 to 9.0 c/km! The air is capped, however, over most of the Northland late this afternoon with CIN to 100 J/kg except in western/far northern portions of the area where the cap is much weaker.
Tonight:
Still have some doubts on how things will play out tonight, but with a cold front and trough approaching from the west combined with the already unstable airmass over the area, the potential remains for scattered strong to severe thunderstorms over northeast Minnesota and northwest Wisconsin — Large scale forcing tied with the cold front and trough will need to be strong enough to erode the cap, if that doesn’t happen, then we probably won’t see much in the way of thunderstorm activity tonight.
Saturday:
Cold front exits to the east by daybreak as high pressure builds into the upper Midwest for Saturday. Mostly cloudy skies during the morning should give way to some sunshine by the afternoon with highs in the 70s.
Sunday:
Another cold front moves through the Northland during the afternoon-evening time frame. If we can build up enough instability and keep enough moisture around, then isolated to scattered showers and thunderstorms will be possible Sunday into Sunday evening. Highs Sunday will be in the 70s.
Duluth, Minnesota Climate Normals for September 1
High: 71
Low: 52
Sunrise Saturday: 6:28 AM CDT
Sunset Saturday: 7:48 PM CDT
Tim