Rain and much cooler temperatures on the way for Tuesday; Dry pattern returns after Tuesday with milder temps late this week

Published by

Timothy Burr

on

July 5, 2021

A big drop in temperatures is coming on Tuesday – Check out the temperature forecast from the 18z NAM 3km model valid from Midnight tonight to 7 PM Tuesday. Overnight temps in the 60s to lower 70s tonight, and then will see falling temperatures during the day Tuesday, in fact by Tuesday afternoon we could have temperatures only in the upper 40s to upper 50s in much of eastern Minnesota and northwest Wisconsin, and there will also be a gusty NE wind near Lake Superior with wind gusts to 25 mph. Note: It’s possible we could see temps low enough where we are able to calculate a wind chill (feels like temp) near Lake Superior come Tuesday afternoon, how’s that for some weather whiplash?

A rather organized low pressure system over the Northern Rockies today will move east and will affect the upper Midwest’s weather on Tuesday – This system should bring a decent amount of lift with it resulting in a widespread light to moderate rainfall event for much of northeast Minnesota and northwest Wisconsin on Tuesday.

Rainfall totals with Tuesday’s system look to range from a half inch to an inch across southern portions of the Northland, while areas farther north see a lot less rain, with totals ranging from a trace to less than a quarter inch for International Falls, Crane Lake, Ely and Grand Marais.

Note: So far in 2021, Duluth is running -4.14″ below normal in precipitation, but if you go all the way back to 2020 and include the precipitation deficit from then through July 4th, 2021 reveals that Duluth is ~14″ below normal in precipitation, we’re certainly seeing a longer term dryness/drought event locally, and it’s going to take time to erase the longer term deficit. The problem we’ve been having is that we’ve been getting into long stretches, 2 weeks or more between significant rain events (0.50″+) That type of pattern has to stop, because it really isn’t doing any good if we get a good soaking rain (0.50-1″) if we just go right back into a dry spell that lasts 14 days or longer until our next significant rain event.

Goes-16 water vapor loop from Monday, July 5, 2021 showing our system for Tuesday currently moving across the Rockies and Northern Plains today.

There is some disagreement in computer models on the start and end times to the rain in Duluth and Superior, but at the moment it looks like the rain will begin in the Twin Ports between 4-7 AM Tuesday, and will end between 4-7 PM Tuesday.

Tuesday’s system looks very similar to a system which impacted our area back on June 20th, that one produced an all day rain with over an inch of rain in Duluth.

Here’s a look at the 18z NAM 3km model simulated radar forecast valid from 1 AM tonight to 7 PM Tuesday.

Note: A few thunderstorms are possible Tuesday across northwest Wisconsin and eastern Minnesota where some elevated instability will be present, but severe weather is not expected in our area on Tuesday.