Area Forecast Discussion

KEY MESSAGES

- The Air Quality Index (AQI) is expected to be in the Orange or Unhealthy for Sensitive Groups category this afternoon and Sunday afternoon for southeast Minnesota. Due to this, the Minnesota Pollution Control Agency has issued an Air Quality Alert for ozone pollution.

- Showers and storms will move into areas along and south of Interstate 94 on Sunday, and across the entire area on Sunday night and then continue into Monday night.

- Excessive heat continues to look possible on Wednesday. Heat indices may range from the mid-90s to around 100.

DISCUSSION

Issued at 130 PM CDT Sat Jun 6 2026

This Afternoon

The Minnesota Pollution Control Agency has issued an Air Quality Alert for ozone pollution. The Air Quality Index (AQI) is expected to reach the Orange or Unhealthy for Sensitive Groups category. Mostly sunny skies, warm temperatures, and low humidity will provide a favorable environment for two types of pollutants (volatile organic compounds and nitrogen oxides) to react with sunlight in the air to produce ground-level ozone. As a result, ground-level ozone is expected to be high this afternoon across much of southern, central, and western Minnesota.

Sunday into Monday Night

A shortwave trough in the southern shortwave trough will move northeast out of the Southern Plains and Lower Mississippi River Valley on Sunday and through the Upper Mississippi River Valley from Sunday night into Monday night. 850 mb moisture transport ahead of this wave will be around 20 knots. This will result in showers and storms moving north into areas south of Interstate 90 on Sunday morning, up to the Interstate 94 corridor on Sunday afternoon, and across the entire from Sunday night into Monday night.

The 06.12z HREF has a 48-hour ensemble mean rainfall up to a tenth of an inch along and north of the Interstate 94 corridor, and ranging from a tenth to 1.5 inches across the remainder of the area. The heaviest rainfall will be south of Interstate 90. The 48-hour ensemble probability-matched mean has some rainfall totals up to 2 inches.

With both the 0-3 km and 0-6 km shear remaining weak, not Minnesota Pollution Control Agency has issued an Air Quality Alert for ozone pollution.anticipating any organized severe weather through this period.

The Minnesota Pollution Control Agency continued the Air Quality Alert for ozone pollution on Sunday afternoon. The Air Quality Index (AQI) is expected to reach the Orange or Unhealthy for Sensitive Groups category. While there will be rainfall in southeast Minnesota, ozone is not always washed out of the atmosphere under these conditions. However, this rain and higher relative humidities do add some uncertainty. They will continue to monitor these levels and may cancel this alert early.

Tuesday through Wednesday night

In the wake of the southern stream shortwave, high pressure will build northward across the area. The warmest temperatures will be likely on Wednesday as 850 mb temperatures climb into the 21 to 24C range. If there is not too many clouds, surface temperatures could potentially climb into the lower and mid-90s. With dew points ranging from the mid-60s to lower Minnesota Pollution Control Agency has issued an Air Quality Alert for ozone pollution.70s, heat indices could range from the mid-90s to around 100.

On Wednesday night, a cold front will move east through the area. 0- 1 km mixed-layer CAPES vary from 500 to 3000 J/kg ahead of this front. The amount instability will be highly dependent upon when this front moves through the region. If this front moves through during the early evening, the instability will be far greater than if the front moves through the area during the overnight. Another uncertainty is the shear, the GFS has a more favorable 0-3 km and 0- 6 km shear than ECMWF. With the AI guidance showing favorable instability and shear, SPC has a slight risk of severe weather for this day.

Thursday into Friday

A broad upper level trough in the northern stream will gradually move east into the Upper Mississippi River Valley. This will result in periodic showers and storms. In addition, temperatures will gradually cool and be much closer to normal.

AVIATION /18Z TAFS THROUGH 18Z SUNDAY/

Issued at 1250 PM CDT Sat Jun 6 2026

VFR expected through most of the 06.18Z TAF period. Similar FG/BR impacts possible early Sunday morning although confidence remains below threshold to include at either TAF site at current issuance.

ARX WATCHES / WARNINGS / ADVISORIES

WI...None. MN...None. IA...None.