textproduct: Duluth

KEY MESSAGES

- Slight chance for a few stray showers or storms this afternoon/evening.

- Areas of smoke are expected this afternoon into tonight.

- Another hot summer day on Thursday with highs in the 80s.

- Widely scattered showers/storms Thursday morning and early afternoon, then widespread rain and storms Thursday night into Friday morning.

- Quiet and closer to average temperatures over the weekend, then more occasional rain chances next week.

DISCUSSION

Issued at 1216 PM CDT Wed Jul 29 2026

We have mainly quiet weather out there early this afternoon with some patchy diurnal cumulus clouds (notably some cloud streets up in the Arrowhead) as well as a single storm that has popped up around Lake of the Woods. In addition to that, there is a general haze in the sky from wildfire smoke, especially in north-central Minnesota. This is expected to spread east, giving the sky a hazy appearance likely into tonight.

For this afternoon, expect mainly quiet and hot weather. A heat advisory remains in effect through the afternoon with highs in the upper 80s to low 90s expected. The main trick for this afternoon will be monitoring for isolated pop-up showers and storms. The environment out there is already and will continue to be quite unstable with SBCAPE in the 1-2+ kJ/kg range. Bulk shear isn't very strong, but there is up to ~30 kt and most of that in the lower atmosphere with southeast winds at the surface and northwest winds aloft. DCAPE is also quite high with just over 1 kJ/kg in north-central Minnesota. But, synoptic lift is going to be pretty weak with just a few ripples within the broader ridging aloft. The entire model sounding profiles for this afternoon generally look too dry for much thunderstorm development, but if we could get any to pop, then there is a small chance we could see some strong winds or maybe a little hail. That risk will persist into this evening along the Canadian Border, where eventually warm air advection and some more pronounced cyclonic vorticity advection aloft should promote more synoptic development of showers/storms in general. We'll likely go from this small/isolated severe chance through early evening into a more widespread chance of rain up that way but with decreasing severe chances gradually into tonight as we lose both instability and shear.

Thursday morning, a little more of the same for a while with some showers/storms roughly along the Canadian Border while most other places may be dry. Exact placement could vary though, so even as far south as the Iron Range has at least a chance of morning rain. Everywhere else, clouds will be on the increase. Ahead of the clouds, we'll have plenty of warm air advection and partial sunshine for a while, so another hot and muggy summer day is expected. Widespread highs in the 80s are expected. The current forecast is close to criteria that would justify another heat advisory, but we will hold off for now since it should be a touch cooler tomorrow compared to today and the increasing clouds and rain chances support that we may not need one.

Thursday afternoon and evening, we will have more robust synoptic forcing aloft with a broad trough passing through. Surface low pressure will pass by to our south and a cold front will swing through on the backside Thursday night. As a result, expect some widespread rain and embedded thunderstorms. We should have plenty of instability in place in the afternoon and evening, but almost nothing for shear. One concern is that we could end up with a line of storms out ahead of the cold front, which would introduce a marginal damaging wind threat. Some large hail can't be ruled out as well.

We've been watching for a low-end potential for flooding as well with widespread synoptic rain and embedded storms close to the low pressure center. Models continue to favor southern Minnesota into Wisconsin for the heaviest rain overall, where some widespread 1"+ amounts may fall. Up here, we will be dealing with more of the scattered thunderstorm variety. Some places could definitely see an inch or two of rain from thunderstorms, but widespread amounts will likely be less than an inch and many places may only see ~0.1-0.3".

Lingering rain should see its way out on Friday with some non- severe storms lingering in Wisconsin Friday afternoon and early evening. Temperatures will fall closer to normal Friday and into the weekend. We'll find ourselves on the far eastern side of a broad ridge to the west, so quiet weather is looking likely through the weekend. We'll have some onshore flow Saturday, then a return to more southerly flow Sunday.

Next week, more southerly flow and warm air advection, so temperatures will trend a bit upwards again. It's looking like we may have another cold front swinging through going into Tuesday, so perhaps some more shower/storm chances followed by a brief cool down. Then rinse and repeat with more warmer air to end the week and then perhaps another low pressure system sometime late-week into the weekend to bring some more rain chances.

AVIATION /12Z TAFS THROUGH 12Z THURSDAY/

Issued at 1216 PM CDT Wed Jul 29 2026

Mainly VFR conditions expected through the period. Some diurnal cumulus clouds this afternoon may create some 3-4 kft broken ceilings briefly, but not expecting much impact from that. There is a ~20% chance for a stray shower or storm to affect INL/HIB this afternoon and early evening. Hazy skies due to wildfire smoke are expected, and while a little bit of that smoke could make it to the ground, observations to the west where it is worse still remain VFR, so it should be the same here. Some showers and storms could persist around INL into Thursday morning, but with low confidence on timing or persistence. Handled that with a PROB30 group for the best estimate on timing for now.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 1216 PM CDT Wed Jul 29 2026

No major concerns in the near term. Light southeast winds today will become light and variable tonight with a land breeze circulation possible, briefly reversing wind direction but with light speeds. A similar trend is expected Thursday and into Thursday night. A cold front will pass through Thursday night into Friday, bringing widespread rain and a few thunderstorms. Thunderstorms are not expected to be severe, but some gusty and erratic winds and lightning will be possible.

For the open water discussion, refer to the NWS Marquette Area Forecast Discussion at weather.gov/mqt.

FIRE WEATHER

Issued at 1216 PM CDT Wed Jul 29 2026

Warm weather will persist into the afternoon, but with light winds and RH expected to remain in the 40-50% range, fire weather is not much of a concern. More hot weather is expected Thursday with increasing humidity, clouds, and rain chances increasing through the day. Scattered thunderstorms are expected to develop across the far north during the morning with chances increasing elsewhere into the afternoon. Widespread rain is expected overnight into Friday morning with lingering rain and a few storms in northwest Wisconsin into Friday afternoon. Widespread rainfall amounts may hover around a quarter of an inch with some places seeing a little less and some more. There will probably be quite a few locations that do see 0.5"-1" of rain and perhaps even a few locally higher amounts where thunderstorms develop. Overall, the highest chances for rainfall in excess of 0.5" will be in east-central Minnesota.

Quiet weather over the weekend with temperatures closer to normal. Not much wind or low RH in sight over the weekend. We may see some breezier conditions Sunday evening into Monday.

See the Fire Weather Forecast product for a more thorough breakdown of fire weather conditions.

DLH WATCHES/WARNINGS/ADVISORIES

MN...Heat Advisory until 7 PM CDT this evening for MNZ010>012-018- 019-025-026-033>038. WI...Heat Advisory until 7 PM CDT this evening for WIZ001>003- 006>008. MARINE...None.