/Issued 6:20 PM CDT, Wednesday, September 27, 2017/
12z NSSL WRF-ARW model
*82 days so far this year with a high temperature of at least 70 degrees at the Duluth Airport; The annual average is 86 days.
*20 days so far this year with a high temperature of at least 80 degrees at the Duluth Airport; The annual average is 26 days.
*5-day rainfall total (September 22-26) of 1.95 inches at the Duluth Airport — Average rainfall from the 22nd-26th is 0.67 inches. Rainfall surplus of 1.28 inches.
*8 days so far this year with at least 1.00 inch of precipitation — The annual average is 6 days.
High pressure covered the central Plains today but even with the high in control of our weather skies weren’t very sunny, in fact mostly cloudy skies continued today over most of the Northland with a few peeks of sun from time to time. Highs today ranged from the mid 50s to low 60s which is right around average for late September.
After several days of southwest flow aloft we’re now in a northwest flow today with cooler temperatures covering the upper Midwest. The 500mb flow will remain out of the northwest through Friday before shifting to the southwest once again this weekend.
Tonight — Partly to mostly cloudy skies with lows in the 40s but a few 30s are possible in the typical cold spots.
Thursday — Low pressure drops southeast out of northern Manitoba Province, passing just north of Lake Superior during the afternoon-evening hours. A cold front attached to this low will move through the Northland on Thursday. A mix of sun and clouds on the way for Thursday with a few widely scattered showers especially during the afternoon and early evening hours. The combination of colder temperatures aloft (H5 temps -20 to -25 C) combined with milder temperatures near the surface will make the atmosphere a little unstable Thursday which combined with a cold front moving through the area should be enough to pop a few showers. Highs will be in the upper 50s to upper 60s with west or northwest winds at 10 to 15 mph with gusts to 25 mph.
Friday — Looks dry as high pressure settles into the upper Midwest behind Thursday’s cold frontal passage. Cooler airmass moves overhead with highs Friday in the 50s. Could be some patchy frost in parts of the Northland (Away from Lake Superior) early Saturday morning.
Note: Dry weather should continue Saturday, but shower chances will be on the increase possibly as early as Saturday night but more likely Sunday into early Monday morning the way it looks now.
Forecast for Duluth and Superior
.Tonight… Partly to mostly cloudy. Low 45 to 50. Wind west to southwest at 10 to 15 mph.
.Thursday… Partly to mostly cloudy. A few showers possible. High 63 to 68. Wind west to northwest at 10 to 20 mph with gusts to 25 mph.
.Friday… Partly cloudy. Cooler. High 54 to 59. Wind north at 10 to 15 mph.
Normal temperatures for Thursday
Sunrise Thursday: 7:04 AM CDT
Sunset Thursday: 6:54 PM CDT