563 FXUS63 KDLH 282338 AFDDLH Area Forecast Discussion National Weather Service Duluth MN 638 PM CDT Sun Jun 28 2026 .KEY MESSAGES... - Scattered thunderstorms are possible tonight and early Monday morning. While most storms are not expected to be severe, an isolated strong to severe storm or two capable of producing large hail can't be ruled out. - A conditional chance for strong to severe storms exists Monday and Tuesday. There will be additional chances of thunderstorms Wednesday through next Sunday. - Hot and humid weather is expected starting Monday and lasting through this week. Extreme Heat Warnings and Heat Advisories have been issued for east-central Minnesota into northwest Wisconsin Monday into Tuesday. && .DISCUSSION... Issued at 400 PM CDT Sun Jun 28 2026 This afternoon and tonight: We have a fair amount of cloud cover over the region this afternoon, and this has suppressed thunderstorm activity this afternoon. We do have some clearing down towards the Twin Cities with some building instability down there where a warm front is present. This warm front will slowly lift northward tonight, but the actual surface front will still remain pretty well south of our area. Elevated instability associated with strong warm air and moisture advection will gradually increase overnight, and we may see some scattered showers and thunderstorms develop. CAMs have been struggling to paint a reasonable picture of what might happen later tonight as they fail to capture current conditions well, placing rain showers where none is currently falling. The overall synoptic pattern tonight will be broad ridging aloft without much focused synoptic support for storms. Therefore, we essentially have some factors favoring storms (increasing instability) and negating factors (lack of broad synoptic support). Any showers and storms that develop are expected to be elevated. We will have potential for 2-3k J/kg of MUCAPE, but that's only if some of the capping can be eroded, which isn't a guarantee. So, the risk for severe weather tonight looks pretty isolated. Large hail is looking to be the primary hazard in addition to the usual thunder/lightning and heavy rain threat with general thunderstorms. Monday and Monday night: As has been the story of this weather pattern, whatever thunderstorm activity happens tonight will at least partially determine how storms and heat end up panning out for Monday and Monday night. In addition to that, guidance in the broader sense seems to have a bit of a Fujiwara effect between an upper low over Montana and a trough moving north across the Dakotas Monday. Convection over there may take more of a northerly trajectory that could bring the risk for severe weather further north into Canada. With all that said, we will be dealing with substantial instability and heat on Monday in our area with 3-4k J/kg of MUCAPE (most of which will probably be elevated and capped during the day Monday). Some CAMs bring nearly all convection north of the Canadian border while some develop a squall line that, if it happened, could bring a threat for large hail (to about golf ball size, perhaps larger), strong winds (to about 70 mph), and perhaps a tornado or two. This would be most likely in the afternoon through early overnight. This threat remains very conditional, so stay tuned for updates. We'll know more once we see how thunderstorms develop Monday morning across the Dakotas. As for the heat, it's still looking like it will be a hot day. The current forecast is largely in line with the NBM, which is on the upper end of guidance. This means there's at least some potential for temperatures to be a little cooler than forecast, but not likely to be warmer. Main concerns with that are lingering cloud cover and capping that could result in temperatures slightly less hot than forecast. But there's definitely high potential for 100 degree plus heat index values with very high dew points in the mid to upper 70s for much of east-central Minnesota into northwest Wisconsin. Because of this, a few Extreme Heat Warnings have been issued for Pine/Burnett/Washburn counties and a broader swath of Heat Advisories have been issued for east-central and all remaining northwest Wisconsin counties. We opted not to issue for the South St. Louis and Carlton county zone since we will have onshore flow from Lake Superior that should keep most of the county from reaching criteria. With that said, the far western and southern areas of that zone should see ~100 degree heat indices a ways away from the lake influence. Heat Advisories for Bayfield/Sawyer counties and east go through Tuesday early evening as lows are not likely to fall below 70 degrees Monday night, and we'll see another hot day there on Tuesday with highs in the 90s and heat indices approaching 100 degrees again. Moderate to major heat-related impacts are expected in the advised areas. Tuesday and Tuesday night: A cold front will slowly work east on Tuesday, and out ahead of it, instability will linger mainly across northwest Wisconsin but also perhaps a ways into east-central Minnesota. We may start to lose some capping, so that works in favor of there being some thunderstorms in general. A few storms capable of producing some large hail and strong winds may be possible, and timing of those could be morning, afternoon, or both. This remains a conditional threat much like Monday, but with increasing likelihood that there will be at least a few storms out there as the cap starts to erode ahead of the cold front. It is looking like another hot day, especially in northwest Wisconsin. On the Minnesota side, dew points and temperatures take a bit of a tumble, so it won't feel quite as hot as Monday. Wednesday through the Weekend: On Wednesday, we'll have to keep an eye on potential for some more convection with southwesterly flow and a shortwave passing by aloft. The storm threat could continue into Wednesday night. MUCAPE in the 1-2k J/kg range may be marginally favorable for some severe weather. Otherwise, more warm/hot weather is expected. General warm southwesterly flow will continue on into the weekend, so expect more of the same with warm to hot weather and plenty of chances for thunderstorms. Severe weather may be possible at times. && .AVIATION /00Z TAFS THROUGH 00Z MONDAY/... Issued at 619 PM CDT Sun Jun 28 2026 VFR/MVFR cloud cover continues to build as warm air is advected north this afternoon and is leading to some scattered light showers in central Minnesota headed north. CAMs showing a similar feature predict that these will continue to have a north to northeast trajectory, affecting all terminals except INL. MVFR visibilities are possible with heavier rainfall, but restricted conditions will mainly be due to lowering ceilings tonight. Cloud bases are expected to lift by late morning Monday, and winds will again increase out of the southeast with maximum gusts around 25 kts. && .MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/... Issued at 400 PM CDT Sun Jun 28 2026 Breezy northeast winds will continue into this evening, producing waves in the 3-4 ft range and winds gusting to around 25 kt, especially by the head of the lake. Winds will lessen briefly tonight, though they will increase again Monday with similar conditions as today expected. Small Craft Advisories will likely be needed. Winds will flip over to southwesterly following a cold frontal passage on Tuesday. Gusts to around 20 kt are expected. Downsloping winds around the head of the lake could briefly produce some 25 kt gusts on Tuesday which may be hazardous for small craft, especially near the shore. Expect some on and off chances for thunderstorms the next couple days. Scattered showers and storms tonight are possible. Isolated large hail to quarter size could happen. More storms are possible Monday late afternoon into the overnight and perhaps again on Tuesday. For the open water discussion, refer to the NWS Marquette Area Forecast Discussion at weather.gov/mqt. && .FIRE WEATHER... Issued at 400 PM CDT Sun Jun 28 2026 Hot but also moist air is expected through Monday night. There will be chances for showers and storms tonight and again Monday late afternoon and night. Rainfall amounts are expected to be highly variable with some places seeing little to none and others seeing perhaps an inch or more locally. A few storms could be strong to severe tonight with large hail being the main threat. The storm chances Monday late afternoon and evening are very conditional, but if they do happen, all hazards will be possible including large hail, strong winds, and perhaps a tornado or two. A cold front will lead to drier weather on the Minnesota side on Tuesday with min RH into the 35-45% range. Winds are also expected to gust up to around 20-25 mph from the southwest. Winds are expected to be a bit less the rest of the week. Overall, fire weather hazards look to be minimal given plenty of moisture through the rest of the week. See the Fire Weather Forecast product for a more thorough breakdown of fire weather conditions. && .DLH WATCHES/WARNINGS/ADVISORIES... MN...Heat Advisory from 9 AM to 8 PM CDT Monday for MNZ025-033>036. Beach Hazards Statement until 10 PM CDT this evening for MNZ037. Extreme Heat Warning from 9 AM Monday to midnight CDT Monday night for MNZ038. WI...Beach Hazards Statement until 10 PM CDT this evening for WIZ001. Extreme Heat Warning from 9 AM Monday to midnight CDT Monday night for WIZ006-007. Heat Advisory from 9 AM Monday to midnight CDT Monday night for WIZ001. Heat Advisory from 9 AM Monday to 7 PM CDT Tuesday for WIZ002>004-008-009. MARINE...Small Craft Advisory until 10 PM CDT this evening for LSZ140>145. && $$ DISCUSSION...JDS AVIATION...KML MARINE...JDS FIRE WEATHER...JDS