Storms Friday night punctuate the hot pattern

The humidity plummets Saturday, elevating Minnesota's fire risk

Storms Friday night are not expected to bring enough rain to dent Minnesota’s drought, and the hot, mostly dry weather continues into next week.

Friday’s forecast

The weather Friday morning already gives a hint of what much of the day will be like. The state started much warmer than average, with many areas in the 70s, and muggy thanks to dew points in the 60s. 

Plenty of sunshine and winds from the south are expected to put almost the entire state back into the 90s Friday. 

weather graphic
Friday high temperatures
National Weather Service

Dew points also stay elevated, in the upper 60s and low 70s, making for oppressive humidity at times. This raises the heat index into the upper 90s for portions of central and southern Minnesota by Friday afternoon, causing a heat advisory to be in effect for areas including the Twin Cities.

weather graphic
Heat advisory Friday
National Weather Service

There will be enough instability for a couple very isolated showers and storms in northern Minnesota during the day Friday.

weather graphic
Severe weather risk Friday evening/overnight
National Weather Service

Then, by Friday evening, a cold front starts pushing in from the north and moves showers and storms across the state through the evening and overnight. 

This brings an isolated (“marginal” in dark green) severe weather risk to much of southern Minnesota, and a more scattered (“slight” in yellow) risk to northern Minnesota.  Wind and hail are the primary threat. 

Unfortunately, rainfall is forecast to average under a quarter inch in most places as the storms move through, with slightly higher amounts in northeastern Minnesota, especially under downpours with thunderstorms.

Extended forecast

The rain clears quickly early Saturday, and skies will be mostly sunny by the afternoon. However, with the wind shift behind the cold front, haze from the fires in Canada could make it back into Minnesota, although it is not expected to be as smoky as it was earlier in the week.

There is little temperature change behind the front, except a couple more 80s in northern Minnesota Saturday, but most of the state will still be in the 90s. 

The most noticeable change is likely to be the drier air the front ushers in, dropping dew points for much of Minnesota into the 40s by Saturday afternoon. That puts the relative humidity Saturday afternoon in the 20 percent range or lower for most of Minnesota.

weather graphic
Forecast relative humidity Saturday afternoon
National Weather Service

This makes the air feel much more comfortable and lowers the heat index significantly.  Unfortunately, the dry air elevates the fire risk even higher than it currently is.

Sunday’s forecast is looking very similar with 80s north, 90s south, sunny skies, and lower humidity.

Temperatures Monday will be much the same, but a little more humidity starts creeping back in, and there will be enough instability for spotty showers and storms to develop again.

Here is that forecast for the Twin Cities:

weather graphic
Twin Cities forecast through Monday
National Weather Service

That pattern looks like it will linger much of next week, with a few showers and storms here and there, but overall rainfall remains below average. 

Temperatures also remain hot, with a couple 80s north, but most of the states sees highs in the 90s all week. There could even be a few 100s midweek, especially in southwestern Minnesota.

Programming note

You can hear my live weather updates on Minnesota Public Radio at 7:48 a.m. Monday through Friday morning.

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