/Issued 5:53 PM CDT, Wednesday, August 29, 2018/
12z European model 8-29-2018
18z 3km NAM
Radar Forecast valid from 7 PM Thursday to 7 AM Friday — Scattered showers and thunderstorms develop over west central Minnesota Thursday evening, then spread E-NE late Thursday night-early Friday morning. Heavy downpours and lightning will occur with these storms with hail possible in the strongest storms.
Note: I think will stay dry in Duluth Thursday evening followed by increasing chances for showers and thunderstorms early Friday morning the way it looks now.
12z GEFS model 8-29-2018
Precipitation Anomaly Forecast valid through September 14, 2018 — Little change in the overall weather pattern through possibly mid September. More frequent rainfalls expected in northeast Minnesota and northwest Wisconsin resulting in above average rainfall totals over the next 2 weeks or so.
Note: Green colors on map represent above average rainfall totals.
…Climate Data for August 29, 2018…
International Falls, Minnesota
4th coldest low temperature on record for August 29 with a low Wednesday morning of 37 degrees. The record low for August 29 is 33 degrees set in 1911 and tied in 1917.
…Climate Data for August 28, 2018…
Record cold high temperature set for August 28 with a high on Tuesday of 55 degrees, this breaks the previous record cold high of 58 degrees which was set on August 28, 1946.
International Falls, Minnesota
Tied for coldest high temperature on record for August 28 with a high on Tuesday of 58 degrees, this ties with August 28, 1976 and August 28, 1988 for coldest high temperature on record for August 28.
Tied for 3rd coldest high temperature on record for August 28 with a high on Tuesday of 62 degrees. Record cold high for August 28 is 60 degrees set in 1946.
Tied for 5th coldest high temperature on record for August 28 with a high on Tuesday of 62 degrees. Record cold high for August 28 is 57 degrees set in 1935.
Tied for 5th coldest high temperature on record for August 28 with a high on Tuesday of 59 degrees. Record cold high for August 28 is 54 degrees set in 1885 and tied in 1931.
Weather Tidbits for Duluth, Minnesota
•High temperature of 59 degrees on Tuesday, August 28 was the coldest high temperature since June 24, high of 58 degrees.
•Summer of 2018 should go into the books as a warmer than average summer.
The average temperature from June 1 to August 28 was 66.3 degrees (+2.8 degrees above normal) There are only 3 days left of Meteorological summer (the period from June 1 to August 31) and its unlikely that our average temperature would drop below average with just a few days left to go before the end of meteorological summer.
•As for rainfall — 11.08 inches of rain has fallen so far this summer (thru Aug 29) which is -0.45 inches below normal. Rainfall for the summer could tilt above average depending on how much rain we get Thursday night/Friday.
A much more pleasant day compared to Tuesday’s weather around here. We saw a mix of sun and clouds across the Northland today with highs in the mid 60s to around 70 degrees, about 5 degrees cooler than normal for late August.
Surface map late this afternoon had an area of high pressure over southwest Minnesota/northern Iowa.
Upper level analysis per RAP model showed W-NW flow covering the upper Midwest this afternoon while the next dip in the jet stream heads into the Pacific northwest, and this will be the next system that will affect the upper Midwest by Friday.
A plume of steep mid level lapse rates over 9.0 c/km associated with the elevated mixed layer covered the Rockies and western High Plains this afternoon, and as the energy now over the northwest U.S. moves farther east it will help turn mid/upper level winds more to the southwest which will advect higher lapse rates and instability into the upper Midwest Thursday night into Friday.
Clear to partly cloudy skies with pleasantly cool conditions, lows will be in the 40s to lower 50s, but a few of the typical cold spots could drop into the 30s once again.
Southerly winds increase to 10 to 25 mph with mostly sunny to partly cloudy skies expected during the day, highs will mainly be in the 70s except cooler along the North Shore of Lake Superior. Elevated instability, steeper mid level lapse rates and moisture advecting NE into our area Thursday night will probably lead to the development of a few to scattered coverage showers and thunderstorms later Thursday night or early Friday morning.
Scattered showers and thunderstorms are possible as a low pressure system with its warm front and cold front move into the upper Midwest. There is some uncertainty on how things setup Friday, but the potential is there for a rather unstable airmass to develop over some parts of the Northland, this combined with stronger winds aloft and favorable wind shear could cause a few strong to severe thunderstorms in parts of the Northland Friday afternoon or Friday evening.
Saturday, mainly dry with highs in the 70s the way it looks now. Sunday and Labor Day could see a few showers and thunderstorms returning to the Northland, but it doesn’t look like either day would be a complete washout.
Duluth, Minnesota Climate Normals for August 30
Sunrise Thursday: 6:26 AM CDT
Sunset Thursday: 7:52 PM CDT