941
FXUS63 KDLH 172357
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
657 PM CDT Sun May 17 2026

.KEY MESSAGES...

- Strong to severe storms return tonight. Primary hazards are
  damaging winds and large hail.

- Another round of strong to severe storms Monday with timing
  most likely being overnight once again. Threats are hail,
  winds, and tornadoes. Heavy rainfall leading to localized
  flooding will also be possible.

- Colder air returns Tuesday and Wednesday, a Freeze Warning
  may be needed for Tuesday night.

&&

.DISCUSSION...
Issued at 224 PM CDT Sun May 17 2026

Current Conditions/Today:

Strong easterly flow envelops the region today with cloud cover
increasing. Radar shows areas of weak echoes across western MN and
NW WI. Reports thus far have not yielded much in way of rainfall yet
and will likely still take some time for this rain to make it to the
surface. Especially with how dry the morning sounding was for INL.
We are seeing some noticeable areas of isentropic ascent ahead of
the approaching warm front though. These surges are over both
the Red River Valley and into NW WI which will likely be our
best chances for this initial batch of rain before the main
system ramps up later tonight. That being said rain chances
through the afternoon are 20-30%.

Tonight:

The main show is expected to arrive later tonight. An inverted
trough moving across the Northern Plains will transition into the
primary low pressure system with a strong cold front trailing into
the Central Plains. Severe storms are expected to develop in
SW SD this afternoon. Through the evening hours the low pressure
will advance NE towards NW WI. A strong low level jet will help
to sustain the ongoing convection and drive the activity into
the Northland. Storm mode as it moves into our region will be
linear with damaging winds being the primary hazard. Large hail
can`t be ruled out as well but the more favorable lapse rates
don`t line up well with the current progression of the storms.
Tornado threat also looks low as surface based convection tied
to the cold front looks to stay south of the region. Overall
timing for the worst conditions look to move in after 9PM and
exit to the east after 4AM. Primary impact areas align with
where SPC has their severe weather outlook. Clipping the
Brainerd Lakes area with NW WI mostly likely seeing the lion`s
share of the activity. Rain totals with the main band of storms
could range from 0.50-1.00" with PWATs over 1.25" some storms
could produce totals over 1.50"

Monday:

Monday`s set up will heavily depend on the progression of the
previous nights frontal boundary. The 12Z suite of
deterministic guidance is in decent agreement with stalling out
the frontal boundary over NW WI. SPC severe outlook has the
marginal risk draped across NW WI and sliding southwest into
southern MN. This outline essentially highlights the most likely
warm sector in which we have potential for the atmosphere to
reload on instability for strong to severe storms once again.
Areas west of this could still see some rain development as a
mid level trough pivots across the Northern Plains, but
thunderstorm potential is not as great. High res guidance is
once again suggesting a late night threat with linear storm
mode. With the cold front being much closer to the region some
storms may become tied to the surface allowing for some surface
vorticity ingestion. All modes of severe will be in play with
QLCS tornadoes not out of the question. Activity may ramp up as
early as 7PM with some discrete cells forming in the warm sector
initially. The linear storm is currently projected to move in
after 9PM and out of the region by 3AM with some lingering
showers. Additionally, localized flooding may become a concern.
Heavy rainfall rates may impact areas already inundated from the
previous round of storms.

Tuesday/Wednesday:

High pressure will start to move in from the west on Tuesday with
highs in the 40s and 50s. Remnant moisture from the departing
system with cyclonic flow aloft could still lead to some scattered
showers. Tuesday night will sport some very chilly temperatures with
a Freezing Warning likely being needed for most of the
Northland. Temperatures rebound a bit on Wednesday as surface
high pressure saunters off to the east. Highs will climb back
into the 50s and 60s.

End of the Work Week:

With the departure of high pressure Thursday will see southerly
flow returning to the Northland. Highs continue to trend back up
with widespread afternoon temps expected to reach the 60s. Cluster
analysis shows an upper level trough moving out of the Rockies once
again which will prompt increased chances for precipitation. At
this time we are carrying 20-30% chance of rain to end the week.

&&

.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 651 PM CDT Sun May 17 2026

VFR for now with east winds decreasing and eventually turning
light north. A complex of storms will move through this evening
and overnight. Thinking KHYR will be the most impacted though
believe there will be the typical spring return flow that brings
LIFR conditions into KDLH in the post-complex air mass with
onshore easterly flow. Thinking this will last into tomorrow
morning with moderate confidence on its occurrence. Another
round of storms is expected tomorrow evening.

&&

.MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 224 PM CDT Sun May 17 2026

Strong easterly winds are impacting the Lake this afternoon with
gales being observed across the head of the Lake and up the North
Shore. Wave heights of 7 to 10 ft are also being observed as well.
Gales will subside this evening but we will still need a Small Craft
Advisory for a bit. Monday afternoon northeast winds ramp up again
with gales possible in the overnight hours.

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

&&

.FIRE WEATHER...
Issued at 224 PM CDT Sun May 17 2026

Gusty east winds today but Min RHs are much higher than the past few
days. Isolated rain showers are possible this afternoon. More
widespread rain and storms will enter from the southwest tonight,
some storms may be strong to severe. This first round of storms
exits early tomorrow morning with another round possible tomorrow
evening and overnight. Tomorrow`s set up will also be primarily
during the overnight hours with severe storms possible. Rain totals
haven`t shifted too much from the previous forecast package. NW WI
still stands the best chance of seeing 1.5-2.0" of rain with lesser
amounts as you progress northwest.

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

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
MARINE...Small Craft Advisory until 10 PM CDT this evening for LSZ121-
     148.
     Small Craft Advisory until 10 AM CDT Monday for LSZ140.
     Gale Warning until 10 PM CDT this evening for LSZ141>145-150.
     Small Craft Advisory until 1 AM CDT Monday for LSZ146-147.

&&

$$

DISCUSSION...Britt
AVIATION...Wolfe
MARINE...Britt
FIRE WEATHER...Britt