/Issued 4:33 PM CDT, Friday, September 14, 2018/
12z HREF model 9-14-2018
Potential for half inch to around 2 inches of rain by 7 AM Saturday over portions of northeast Minnesota and far northwest Wisconsin.
21z HRRR model
Simulated Radar Forecast valid from 8 PM this evening to 10 AM Saturday — HRRR model has been consistently showing most of the storms staying north of Duluth tonight.
Still waiting for shower and thunderstorm development near a frontal boundary which was centered over central Minnesota this afternoon. There was very little CINH over most of our area, but warmer mid level temps remain in place which is likely playing a role in why there hasn’t been much thunderstorm development over the Northland today despite an unstable airmass and a front nearby.
Haven’t had to deal with any wildfire smoke the past few weeks across the Northland, but with new wildfires burning in northern Utah and northern Colorado combined with southwest winds aloft, some of that wildfire smoke will find its way into the northern Plains and upper Midwest through the weekend.
12z European Ensemble model (EPS)
Wetter times ahead? More frequent rainfalls are possible over the next few weeks across the northern Plains, upper Midwest and western Great Lakes.
12z GEFS model 9-14-2018
Temperature Anomaly forecast valid through September 30, 2018.
Definately seeing signs of a pattern change per long range model data — Watch how the above average temperatures represented by orange and red colors disappear and are replaced by below average temperatures represented by the blue colors on the map. Perhaps our first frost of the season in Duluth by the end of the month?
…Climate Data for September 13, 2018…
Tied for warmest low temperature on record for September 13 with a low on Thursday of 63 degrees. This ties with September 13, 1877 for warmest low temperature on record for September 13.
Tied for 3rd warmest high temperature on record for September 13 with a high on Thursday of 81 degrees. The record high temperature for September 13 is 84 degrees set in 1990.
2nd warmest low temperature on record for September 13 with a low on Thursday of 64 degrees. The warmest low temperature on record for September 13 is 65 degrees set in 1939.
3rd warmest low temperature on record for September 13 with a low on Thursday of 59 degrees. The warmest low temperature on record for September 13 is 61 degrees set in 1994.
International Falls, Minnesota
3rd warmest low temperature on record for September 13 with a low on Thursday of 58 degrees. The warmest low temperature on record for September 13 is 61 degrees set in 1952, tied in 2004.
Tied for 5th warmest high temperature on record for September 13 with a high on Thursday of 83 degrees. The record high for September 13 is 91 degrees set in 1939.
5th warmest low temperature on record for September 13 with a low on Thursday of 57 degrees. The warmest low temperature on record for September 13 is 64 degrees set in 1992, tied in 1994.
Weather Tidbits for Duluth, Minnesota
3 nights in a row so far with a low temperature of 60 F or warmer (September 11-13) This is quite unusual for mid September when our average lows are in the mid 40s! Our longest stretch of 60F or warmer lows this past summer (June-August) was 5 nights in a row, July 11-15.
Check out these stats!
Low Temperature/Departure from normal (Sept 11-14)
9/11: 61 degrees; +13 degrees above normal (6th warmest low on record for Sept 11)
9/12: 66 degrees; +18 degrees above normal (Tied for warmest low on record for Sept 12)
9/13: 63 degrees; +16 degrees above normal (Tied for warmest low on record for Sept 13)
9/14: 69 degrees (Thru 5 PM) +22 degrees above normal
Tropical! Feeling more like July than mid-September out there today with dew points in the mid 60s to low 70s near Lake Superior, northwest Wisconsin back to east-central Minnesota, drier air farther north with dew points in the 50s today.
A frontal boundary extended from central Lake Superior to central Minnesota late this afternoon, and there have been a few attempts for shower development north of this front this afternoon, but so far nothing very significant.
Computer models remain consistent in showing the development of showers and thunderstorms tonight north of a frontal boundary which will remain over central Minnesota and northern Wisconsin. Heavy rain will be the main hazard out of these storms with abundant moisture in place consisting of dew points in the 60s to around 70 degrees with PWATS increasing to 1.50 to around 1.90 inches. If storms start to move over the same location for a few hours tonight, then the threat for flash flooding could increase over some parts of the area — At the moment it looks like the greatest potential for excessive rainfall would be along or north of the Highway 2 corridor in northeast Minnesota, but it’s possible things could setup just a little more south, but with the warm mid level temps or CAP in place, a more northern trend seems the most likely scenario. Storms tonight will also contain cloud to ground lightning, and possibly some hail in the strongest storms. Lows tonight will range from the mid 50s to around 70 degrees.
Changes take place Saturday as will get a stronger lake wind to develop which should keep temperatures closer to average for this time of year with highs in the 60s near Lake Superior and most of northern Minnesota, warmer farther south with highs in the mid 70s to low 80s which is above average for mid-September.
The humid easterly flow off Lake Superior could lead to areas of fog and drizzle Saturday into Sunday morning.
A warm front will still be over central Minnesota and northern Wisconsin most of Saturday before it lifts off to the north by Sunday morning. Scattered showers and thunderstorms remain possible near and north of that front with heavy downpours possible along with some hail in the strongest storms.
Sunday still looks warm and quite breezy with southerly winds gusting to 20-25 mph. Highs mainly in the 80s, but cooler near Lake Superior as an easterly wind continues during the morning before winds gradually shift to the south later in the day. It will also be rather humid on Sunday with dew points in the 60s.
A cold front is forecast to pass through the area Sunday night/Monday with showers and thunderstorms possible as that boundary moves through.
Duluth, Minnesota Climate Normals for September 15
Sunrise Saturday: 6:46 AM CDT
Sunset Saturday: 7:20 PM CDT