Sun and patchy clouds for our Fourth of July

We've enjoyed very pleasant weather this July 4 holiday weekend.

There has been plenty of sunshine, with seasonal temperatures and low humidity.

You can expect some minor changes in the weather today. Temperatures will be a few degrees warmer, reaching the upper 80s in parts of western Minnesota:

Dew point temperatures will creep into the 60s in many areas, so it will feel a bit muggier.

The northwestern half of Minnesota has the best chance of scattered showers and thunderstorms during the late afternoon and evening hours into tonight.

The National Oceanic and Atmospheric Administration’s North American Mesoscale Forecast System shows the development of several waves of thunderstorms from later today through Tuesday night:

The main wave of thunderstorms for southeastern Minnesota and the Twin Cities is expected to occur from Tuesday afternoon into Tuesday evening.

Severe weather risk

The Storm Prediction Center of the National Weather Service shows a slight risk of severe weather later this July 4th afternoon and into tonight for northwestern Minnesota, with a marginal risk extending into central and northeastern Minnesota:

Here are the risk categories that are use by the Storm Prediction Center:

For Tuesday and Tuesday night, there is an enhanced risk of severe weather over much of Minnesota, including the Twin Cities:

Tuesday will also be steamy, with dew points  around 70 and highs in the upper 80s before the thunderstorms arrive.

Anniversary of 1999 derecho

On July 4, 1999 a historic derecho moved through northern Minnesota, toppling millions of trees and injuring 60 people in the Boundary Waters Canoe Area.

A derecho is defined by the Storm Prediction Center (SPC) of the National Weather Service as:

A derecho (pronounced similar to "deh-REY-cho" in English) is a widespread, long-lived wind storm. Derechos are associated with bands of rapidly moving showers or thunderstorms variously known as bow echoes, squall lines, or quasi-linear convective systems.

There is an excellent discussion of the event here .

Here are some excerpts:

Much more information about derechos can be found here .

I hope that you have a great Fourth of July!