/Issued 6:09 PM CDT, Thursday, September 27, 2018/
Frost advisory in effect for western portions of the Northland from 1 AM to 9 AM Friday (Blue shaded area on map) Low temps in the mid 30s with widespread frost expected early Friday morning.
Goes-16 visible satellite loop from Thursday, September 27, 2018.
Loop time: 11:37 AM to 4:32 PM CDT
A cold upper level trough is digging S/SE into the Northland this afternoon with scattered showers along with a few thunderstorms capable of producing small hail popping up over parts of the area.
18z NAM-Nest model 9-27-2018
Simulated Radar forecast valid from 7 AM Friday to 10 PM Friday.
Blue is snow; Green is rain — Another day with scattered shower coverage on the way for Friday, and some of the precipitation will likely fall as snow in northern Minnesota.
500mb height anomaly forecast valid through October 13, 2018.
Upper air pattern isn’t forecast to change a whole lot during the next 2 weeks with generally west or northwest flow covering the upper Midwest leading to cooler than normal temperatures at least into early October.
12z European computer model (ECMWF) 9-27-2018
Rainfall reports for September 26-27, 2018
Note: Totals listed below are for the 24-hour period ending at 4 PM, Sept 27.
Crane Lake, MN: 0.49 in
Littlefork, MN: 0.38 in
Chisholm-Hibbing Airport: 0.34 in
International Falls, MN: 0.27 in
Isabella, MN: 0.26 in
Orr, MN: 0.26 in
Ely, MN: 0.23 in
Effie, MN: 0.21 in
Grand Portage, MN: 0.19 in
Grand Marais Airport: 0.18 in
Hill City, MN: 0.17 in
Duluth Airport: 0.17 in
Clam Lake, WI: 0.15 in
Cass Lake, MN: 0.13 in
McGregor, MN: 0.12 in
Minong, WI: 0.12 in
Barnes, WI: 0.10 in
Glidden, WI: 0.09 in
Cook, MN: 0.08 in
Washburn, WI: 0.08 in
Hayward, WI: 0.07 in
Walker, MN: 0.06 in
Superior, WI: 0.06 in
Hinckley, MN: 0.06 in
Ashland, WI: 0.06 in
Two Harbors, MN: 0.05 in
Brainerd, MN: 0.04 in
Siren, WI: 0.04 in
Note: Today, September 27 marks the 10th consecutive day with at least a trace of rainfall at the Duluth Airport (September 18-27)
Local Storm Reports for September 27, 2018
5:05 PM: Hail — 0.25 inch. 1 ENE Duluth, MN (St. Louis County)
5:03 PM: Hail — 0.25 inch. Lester Park, MN (St. Louis County)
5:00 PM: Hail — 0.25 inch. 3 NNE Duluth, MN (St. Louis County)
4:59 PM: Hail — 0.25 inch. 2 WSW Lester Park, MN (St. Louis County)
4:36 PM: Hail — 0.70 inch. 3 SE Fredenberg, MN (St. Louis County)
2:15 PM: Hail — 0.25 inch. 7 SE Grand Rapids, MN (Itasca County)
1:47 PM: Hail — 0.25 inch. 3 ESE Inger, MN (Itasca County)
1:45 PM: Hail — 0.25 inch. 1 S La Prairie, MN (Itasca County)
1:10 PM: Hail — 0.25 inch. Linden Grove, MN (St. Louis County)
It’s been a gray and somewhat rainy day as an upper level trough digs south into the Northland. Some light rain earlier in the day transitioned to scattered popcorn type shower activity this afternoon as colder temps aloft combined with some modest heating near the surface, mid level lapse rates to around 7.0 c/km along with around 250 J/kg of CAPE helped to spawn a few thunderstorms this afternoon, and with the lowering freezing levels, small hail occurred with a few of these storms. Highs today ranged from the mid 40s to mid 50s.
Scattered showers will continue to move NW-SE across the Northland, but these showers should dissipate later tonight. Partly to mostly cloudy skies are forecast with lows in the mid 30s to low 40s.
Snow flurries on the way mainly for northern Minnesota! Aloft, temperatures at 850mb and 925mb will become cold enough for snow on Friday with H85 temps dropping to around -6C and 925mb temps falling to around -2C, also thickness values will be sitting at around 1300, all this is favorable for frozen precipitation, it will just come down to what the surface temperature will be when precipitation occurs, and right now it looks like surface temps will be sitting in the mid 30s to low 40s over much of northern Minnesota, and this should be cold enough for snow showers or a mix of snow, sleet and rain. Farther south, including east-central Minnesota, near Lake Superior and in northwest Wisconsin, it looks a bit warmer near the surface, although temps aloft and thickness values would support frozen precipitation, but again it looks warm enough near the surface for mostly rain showers or perhaps some sleet on Friday with highs in the 40s to around 50 degrees.
Note: A widespread frost and killing freeze is still expected over northeast Minnesota and northwest Wisconsin for Saturday morning.
Saturday looks mainly dry but it will be on the cool side with highs in the 40s to around 50 degrees. The period from Sunday through Wednesday could feature some rain at times as a frontal boundary sets up to our south, but it remains to be seen how far north the rain will spread. Stay tuned.
Duluth, Minnesota Climate Normals for September 28
Sunrise Friday: 7:04 AM CDT
Sunset Friday: 6:54 PM CDT