There is a marginal risk of severe thunderstorms Sunday night in much of the Northland (blue shaded area on map) Primary threat is hail.
A little bit of everything out there today with summer heat hanging on across the southern and eastern U.S.; while signs of winter are showing up across the northern Rockies.
A classic fall storm is on the way with cold, wind and snow on one side of the low with warm and humid air on the other side of the low with showers and thunderstorms.
Source: 18z Nam-Nest model; https://weather.cod.edu
Here’s the 18z HRRR model radar forecast valid from 7 PM Saturday to 1 AM Monday. Source: https://weather.cod.edu
A powerful trough over the western U.S. today per Goes-16 water vapor satellite imagery from Saturday, September 28, 2019.
The western trough will slide east and will eventually break down the massive ridge which is over the southern/eastern U.S.; this will allow cooler weather to push south/east out of the western U.S. from mid to late next week.
Source: 12z European ensemble model 9.28.19; https://www.tropicaltidbits.com
It’s been a warm and wet September in Duluth. The average temperature for the month (thru the 27th) 60.4 degrees, this is +4.2 degrees above normal. Note: September 2019 currently ranks as 6th warmest September on record in Duluth.
So far this September, 4.51 inches of rain (thru the 27th) in Duluth, this is +0.77 inches above normal.
Note: September 2019 currently ranks as 3rd warmest September on record in Brainerd. Average temperature thru the 27th: 62.9 degrees. Warmest September on record occurred in 1931 and 2009 with an average temperature of 63.6 degrees.
Low temperature reports from Saturday morning, September 28, 2019. Source: https://www.weather.gov/dlh/
- 2 W Iron Junction, MN: 25 F
- Chisholm-Hibbing Airport: 26 F
- Eveleth, MN: 26 F
- Cook, MN: 27 F
- Ely, MN: 27 F
- Aitkin, MN: 28 F
- Silver Bay, MN: 28 F
- Crane Lake, MN: 28 F
- Grand Marais, MN (Airport) 28 F
- Bigfork, MN: 28 F
- Orr, MN: 28 F
- Hill City, MN: 29 F
- International Falls, MN: 29 F
- Isabella, MN: 30 F
- Grand Rapids, MN: 30 F
- Pine River, MN: 30 F
- Longville, MN: 30 F
- Walker, MN: 31 F
- Hermantown, MN: 32 F
- Deer River, MN: 32 F
- Saginaw, MN: 32 F
- Grand Portage, MN: 32 F
- McGregor, MN: 32 F
- Moose Lake, MN: 32 F
- Superior, WI (Airport) 32 F
- South Range, WI: 33 F
- Esko, MN: 34 F
- Cloquet, MN: 34 F
- Solon Springs, WI: 34 F
- Brainerd, MN: 35 F
- Hayward, WI: 35 F
- Siren, WI: 35 F
- Hinckley, MN: 36 F
- Duluth, MN (Airport) 37 F
- Danbury, WI: 38 F
- Glidden, WI: 38 F
Note: Low of 37 degrees at the Duluth Airport Saturday morning, September 28th, this is the coldest temperature in Duluth since May 20th, low of 36 degrees.
Low temperature forecast for Sunday morning, September 29. Source: https://graphical.weather.gov
High temperature forecast for Sunday, September 29
A cool late September day but nothing really out of the ordinary with highs today in the 50s which is slightly below normal. Patchy stratocumulus clouds were found in northern Minnesota today while more extensive clouds (mid and high level variety) spread E-NE out of western Minnesota per Goes-16 satellite imagery.
September will end on a wet note thanks to a large upper level trough over the western U.S. Southerly winds ahead of this trough will pull warm and humid air northward into the upper Midwest through Monday.
As low pressure approaches from the SW along with its warm front will see showers break out over the Northland later tonight and during the day Sunday.
Lows tonight will range from the middle 30s to middle 40s, not quite as cold as it was Saturday morning, and with clouds increasing during the night there is little chance for frost formation. Sunday will be a cool day with highs in the upper 40s to middle 50s with easterly winds gusting 10 to 20 mph.
Initially there is very little instability so will likely just have some showers in our area later tonight and Sunday, but a push of higher instability is forecast to lift NE into our area Sunday night with CAPE of 500 to around 1500 J/kg, this along with the warm front nosing into southern Minnesota combined with a strong low level jet of up to 55 knots will likely produce some thunderstorms for Sunday night. Heavy rain and lightning will be the main threats from these storms, but hail is also possible in the strongest storms Sunday night. Note: Precipitable water increasing to >1.50″ Sunday night does raise a concern for possible flooding if thunderstorms begin to move over the same location, this potential also extends into Monday.
Low pressure is forecast to move E/NE out of eastern South Dakota on Monday while a warm front remains near or over the Northland while a cold front moves east out of western Minnesota. An unstable air mass is expected to linger over eastern Minnesota and northern Wisconsin Monday with more showers and thunderstorms forecast to develop. A few of the storms could become strong to severe on Monday from east-central Minnesota into northern Wisconsin, but warm temperatures aloft may keep the atmosphere capped from producing surface-based storms, if this is the case, then the main threat from the stronger storms on Monday would continue to be from hail and perhaps gusty winds, but if surface-based thunderstorms are able to develop, then we could have a short window where a few tornadoes could develop. Stay tuned.
Much cooler temperatures will push SE into the Northland the middle of next week with lingering chances for some light rain Tuesday through Thursday.
Forecast for Duluth and Superior
.Tonight… Mostly cloudy. Showers possible mainly after Midnight. Low 45 to 49. Wind east 10 to 20 mph.
.Sunday… Breezy. Occasional showers. Thunderstorms possible Sunday night. Mostly cloudy. Some fog and drizzle possible. High 49 to 53. Wind east 15 to 25 mph.
.Monday… Occasional showers and thunderstorms. Areas of fog and drizzle. High 57 to 62. Wind east 10 to 15 mph.
Normal temperatures for Sunday
- High 59
- Low 41
- Sunrise Sunday 7:05 AM CDT
- Sunset Sunday 6:53 PM CDT
Thanks for reading!