Increasing thunderstorm chances today; updated severe weather outlook

Periods of showers and thunderstorms are in the forecast today and tonight. Thunderstorms will favor portions of western Minnesota Thursday morning, then expand in coverage to include parts of eastern Minnesota and western Wisconsin Thursday afternoon.

The National Oceanic and Atmospheric Administration’s High-Resolution Rapid-Refresh forecast model shows the potential rain pattern Thursday morning through Thursday evening:

The National Weather Service Storm Prediction Center has parts of far southern Minnesota in an enhanced risk of severe weather (shaded orange in the left-hand panel below) Thursday and Thursday night:

Enhanced risk means that numerous severe thunderstorms are possible. The Twin Cities metro area is in a marginal risk (shaded dark green) of severe weather today and tonight, meaning an isolated severe thunderstorm is possible. Metro area thunderstorm chances increase this afternoon and continue into this evening.

The image in the right-hand panel above shows potential rain totals from Thursday through Saturday.

You can hear updated weather information for Minnesota and western Wisconsin on the Minnesota Public Radio network, and you can see updated weather info on the MPR News live weather blog.

Cooler

Thursday highs will be in the 60s north and in the 70s south:

Air quality alert

The Minnesota Pollution Control agency continues an air quality alert until 8 p.m. Friday for northeastern Minnesota and parts of north-central Minnesota:

Here are details of the alert, from the MPCA:

The Minnesota Pollution Control Agency (MPCA) has issued an air quality alert effective until 8 p.m. on Friday, Aug. 27, for St. Louis, Carlton, Itasca, Koochiching, Lake and Cook Counties. The affected area includes Duluth, Cloquet, Hibbing, International Falls, Grand Rapids, Ely, Virginia, Hoyt Lakes, Babbitt, Isabella, Two Harbors, Silver Bay, Grand Marais, and the tribal Nations of Grand Portage, Leech Lake, Red Lake, and Fond du Lac.

The Greenwood fire continues to burn in the Superior National Forest in northeast Minnesota. The fire is located near Greenwood Lake, or approximately 15 miles southwest of Isabella. The fire is estimated to be 22,000 acres with no containment. Further growth of the fire is expected through Friday. In addition to the Greenwood fire, fires just across the border in the Canadian Quetico Provincial Park continue to burn with no containment and will also contribute to smoke concentrations. Further expansion of the Greenwood Fire is expected Wednesday and smoke will impact all of northeastern Minnesota as winds turn from the northwest to the northeast and eventually east by Friday. Precipitation arriving Friday will temporarily reduce the fine particle concentration to below alert level.

Fine particle levels are expected to reach the Red AQI category, a level that is considered unhealthy for everyone. Red AQI conditions are expected today across much of the alert area, especially as winds pivot from the northwest to the east and push the smoke over all of northeastern MN.

Sensitive groups whose health is affected by unhealthy air quality

There are people who are more likely to be affected when fine particle pollution reaches an unhealthy level.

• People who have asthma or other breathing conditions like chronic obstructive pulmonary disease (COPD).

• People who have heart disease or high blood pressure.

• Children and older adults.

• People of all ages who are doing extended or heavy, physical activity like playing sports or working outdoors.

• People who don’t have air conditioning to reduce indoor air pollution.

Health effects

Air pollution can aggravate heart and cardiovascular disease as well as lung diseases like asthma and COPD. When the air quality is unhealthy, people with these conditions may experience symptoms like chest pain, shortness of breath, wheezing, coughing, or fatigue. If you are experiencing any of these symptoms, use your inhalers as directed and contact your health care provider.

In areas where air quality is in the Red (Unhealthy) AQI category, sensitive individuals may experience increased aggravation of heart or lung disease and respiratory conditions. The general population may also experience increased respiratory effects.

In areas where air quality is in the Orange (Unhealthy for Sensitive Groups) AQI category, sensitive individuals may experience aggravation of heart or lung disease and increasing likelihood of respiratory conditions.

Take precautions

• Take it easy and listen to your body.

• Limit, change, or postpone your physical activity.

• If possible, stay away from local sources of air pollution like busy roads and wood fires.

• Keep indoor air as clean as possible. Use indoor air filtration or air conditioning with the fresh-air intake closed/set on recirculate to reduce indoor air pollution.

• If you have asthma, or other breathing conditions like COPD, make sure you have your relief/rescue inhaler with you.

• People with asthma should review and follow guidance in their written asthma action plan. Make an appointment to see your health provider if you don’t have an asthma action plan.

In areas where air quality is in the Red (Unhealthy) AQI category, sensitive individuals should avoid prolonged exertion. Everyone else should limit prolonged exertion.

In areas where air quality is in the Orange (Unhealthy for Sensitive Groups) AQI category, sensitive individuals should limit prolonged exertion.

This Updraft blog will be updated by 10 a.m. with a look at the weekend forecast.

Programming note

You can hear my live weather updates on MPR News at 7:35 a.m., 9:35 a.m. and 4:39 p.m. each Saturday and Sunday.