textproduct: Twin Cities

KEY MESSAGES

- Dense wildfire smoke is creating hazardous air quality and reduced visibility for much of the coverage area, lasting into Friday morning.

- Dangerous heat expected to persist into Friday, despite a small respite for all areas outside of the Twin Cities metro for today. This is a long duration and cumulative threat due to highs in the low-mid 90s and heat indices from the mid 90s to near 100 degrees.

- Only main likelihood for rain comes Sunday night into Monday morning, otherwise mainly dry conditions through late next week.

DISCUSSION

Issued at 131 AM CDT Thu Jul 16 2026

Fairly widespread visibility reductions and significant increases in airborne particulates (per MPCA) have been observed from last evening into the early morning hours as a wide swath of wildfire smoke has been dragged south with a frontal boundary over central-southern MN through southern WI. At a minimum, AQI values into the Moderate category have been observed as far south as the IA/MN border, while Hazardous values (the worst of the AQI categories) have been observed throughout the Twin Cities metro and as far west as Kandiyohi County, and also includes the Alexandria, Brainerd and Duluth areas up through the MN Arrowhead region and over much of western WI. The smoke will reach as far south as the front sags, which looks to reach as far south as a line roughly Morris-Hutchinson-Rochester. Though the front will have very little upper level support as the upper heat ridge remains over the region, a few isolated showers are possible in eastern MN into western WI, similar to what developed late Wednesday afternoon. Nothing heavy or enough to appreciably clear out the hazardous wildfire smoke from the air, but still a small chance of precip nonetheless. MPCA has opted to place the majority of our coverage area in the Maroon category, the worst of the 6 categories for air quality, with the air quality listed as being Hazardous. To the south of the Maroon area is a line of counties in Red category, Unhealthy (4th out of 6 categories), from roughly Montevideo-Mankato- Rochester. The Air Quality Alert remains in place through late Friday morning.

The next issue is the prolonged dangerous heat. Per observations of temperatures, heat indices and WBGT levels, the smoke and frontal boundary are having appreciable impacts by diminishing the temperature and dewpoints and limiting the combination needed to produce Advisory or Warning-level heat index and WBGT values. With the front and smoke expected to have their peak daytime impacts on Thursday, highs will only range from the upper 80s to lower 90s. In turn, heat index values will be limited to no higher than the mid- 90s. In addition, low temperatures this morning and again early Friday morning will range from the mid 60s to lower 70s. Therefore, we have opted to cancel all Heat Advisories for today and only maintain the Extreme Heat Warning for the TC metro counties due to the more prolonged urban heat island effects, the likelihood of lows remaining in the lower 70s and the lower threshold of heat index values in the mid 90s. Otherwise, heat index values are expected to run no higher than the mid 90s in all other counties for today.

Once past today, the smoke will retreat northward in tandem with the surface front sliding back north in response to an area of low pressure developing over the western Dakotas. The upper ridge will also flatten out and have its axis retreat westward in response to a large upper low developing over Hudson Bay which will shift slightly south. This will allow for weak shortwaves to drop southeast from central Canada towards the Great Lakes, helping drag the aforementioned low pressure center eastward. As it progresses, the WFO MPX coverage area will become warm-sectored on Friday, leading to a return of high temperatures into the mid 90s and heat index values to the 95-100 degree range for much of the area. A final day of broad heat headlines is looking more likely for Friday, but confidence is not there to issue at this time, plus more time to evaluate the impacts and location of the smoke swath is desired.

The upper ridge will break down more completely over the weekend into early next week, allowing for a more organized frontal system to push through the region late Sunday into early Monday. This will be the best chance for fairly widespread precipitation across our coverage area through the end of next week. Chances have been upped to the Likely category with QPF potentially nearing 0.25". Yes, that isn't much, but given the lack of rain and prolonged heat, we shall take what we can get. Once past that system, precipitation will be decidedly lacking but the tradeoff is noticeably lower temperatures. Highs drop to the upper 80s to lower 90s Saturday-Monday, then fall to the lower 80s Tuesday-Thursday. In addition, overnight lows will drop to the upper 50s to mid 60s Monday night through Thursday night.

AVIATION /12Z TAFS THROUGH 18Z FRIDAY/

Issued at 638 AM CDT Thu Jul 16 2026

Smoke/haze has been a tad bit slower to move back to the north and east this morning. Therefore have delayed flight category improvements for all sites by an hour or two. MN sites can anticipate P6SM vsby by this afternoon. WI sites should expect to hang on to lingering smoke for much of the period. Fog this morning has developed across our western sites which is expected to mix out over the next two hours as surface some heating occurs. Light and variable winds this morning become southerly by this afternoon below 10kts. Did not include in this TAF but fog potential will be something to watch once again for tomorrow morning.

KMSP...Hazy/Smoke conditions expect to improve by 14z this morning back into MVFR category. By mid morning, VFR vsby should return although some lingering smoke can be expected until around 22z. At that time, smoke should retreat east.

/OUTLOOK FOR KMSP/ FRI PM...VFR. Wind SW 10-15kts. SAT...VFR. Wind N 10-15kts. SUN...VFR. Chc -TSRA. Wind S 5-10kts.

MPX WATCHES/WARNINGS/ADVISORIES

MN...Extreme Heat Warning until 9 PM CDT Friday for Anoka-Carver- Dakota-Hennepin-Ramsey-Scott-Washington. WI...None.