732
FXUS63 KDLH 132147 CCA
AFDDLH

Area Forecast Discussion...CORRECTED
National Weather Service Duluth MN
447 PM CDT Tue May 13 2025

.KEY MESSAGES...

- Critical fire weather conditions with a Red Flag Warning in
  effect for all of northeast Minnesota and much of northwest
  Wisconsin.

- Widespread rain chances return Thursday through Saturday.

- Strong to severe thunderstorms are possible Thursday
  afternoon and evening in northwest Wisconsin and portions of
  northeast Minnesota.

&&

.DISCUSSION...
Issued at 225 PM CDT Tue May 13 2025

Critical fire weather conditions will continue across all of
northeast Minnesota and most of northwest Wisconsin into this
evening, and a Red Flag Warning remains in effect until 900 pm
CDT. Late tonight into Wednesday morning low level moisture will
finally be on a slow increase across northwest Wisconsin and
into the I-35 corridor and over much of western Lake Superior.
This is expected be associated with a deck of low level
stratus. Will be monitoring for fog develop on and near Lake
Superior late tonight into Wednesday morning with increasing
moisture over the cold lake.

With a rather similar surface pattern on Wednesday as has been
seen the last couple of days, another warm day is expected with
widespread temperatures in the upper 70s to the mid 80s on
Wednesday. A few readings near 90 are possible in Koochiching
county where drier air will be in place. In regards to Fire
Weather, Near Critical Fire Weather Conditions are expected on
Wednesday across northeast Minnesota given the warm temperatures
and very dry fuels. The main limiting factor to reaching
critical levels is primarily higher afternoon relative humidity
in the 30 to 40 percent range for most areas, with higher values
near Lake Superior. Higher relative humidity in the 40 to 50
percent range and weaker winds across northwest Wisconsin
further reduce the overall fire weather threat across northwest
Wisconsin on Wednesday. Still fuels are very dry across the
area, and vigilance is still a necessity. Scattered diurnally
driven rain showers and thunderstorms are forecast across
northwest Wisconsin into the I-35 corridor of northeast
Minnesota on Wednesday with a few weak impulses aloft and
increasing moisture. Severe weather is not expected, however
lightning and possible fire starts will be the primary concern.

On Thursday, a potent negatively tilted mid level shortwave is
forecast to propagate into the Upper Midwest, supporting deepening
of surface low pressure across northwest Minnesota and eastern North
Dakota through the day. This low placement has moved from
yesterday across the major ensemble families, which had a low
placement further to the south and east across central
Minnesota. With a central pressure in the 980s mb range, this
low is near the bottom of the climatology. An occluded front is
forecast to lift northeast through day as the low deepens,
crossing through northwest Wisconsin and northeast Minnesota
between 18Z and 24Z. Buoyancy on the order of 1000-1500 j/kg is
expected to establish itself across northwest Wisconsin and into
the I-35 corridor Thursday afternoon and into the early
evening. Given the strong forcing, upscale growth into a linear
mode is likely along the occluded front. Given a likely linear
mode, damaging winds will be the primary threat, followed by a
QLCS tornado threat with a highly sheared low level environment.
Further into northeast Minnesota, buoyancy is expected to be
less with a lower potential for severe thunderstorms. However,
with precipitable water values climbing to 1.25 to 1.40 inches,
a broad area of precipitation with embedded thunderstorms will
spread across northeast Minnesota with the passage of the
occluded front.

A dry slot associated with the deep low is likely to overtake most
of the Northland Thursday night, with a lull in precipitation before
wrap around moisture and precipitation expands across the area
through the day on Friday. With afternoon heating a few embedded
thunderstorms are possible on Friday. Rain showers in wrap
around moisture will decrease through the day on Saturday as the
low exits to the east.

In regards to precipitation totals, widespread amounts of one-half
to three-qaurters of an inch are expected across most of the
Northland Thursday through Saturday. Given the further northwest low
location Thursday into Friday, the heavy deformation zone
precipitation will also be displaced into North Dakota, resulting in
a reduction in the rainfall forecast from yesterday for the Brainerd
Lakes through Lake of the Woods areas.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 225 PM CDT Tue May 13 2025

VFR conditions across northeast Minnesota and northwest
Wisconsin this afternoon and evening. Southerly wind gusts of
20-25kts will continue across northeast Minnesota through
sunset, with gusts around 15 kts across northwest Wisconsin. Low
level moisture will increase tonight across northwest
Wisconsin, Lake Superior and into Duluth. MVFR/IFR conditions in
fog and stratus are possible (50-70 percent chance).

&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 225 PM CDT Tue May 13 2025

Northeast winds around 10 kts this afternoon and into the early
evening. As moisture increases over Lake Superior late tonight
into Wednesday, areas of fog may develop (40-60 percent
chance). Northeast winds will increase to 10 to 15kts with gusts
to 20 kts on Wednesday, and further increase to sustained at 15 to
20kts with gusts of 25 to 30kts on Thursday as strong low
pressure approaches the area. Waves heights will increase to 3-6
feet on Thursday. A Small Craft Advisory will likely be needed on
Thursday. Thunderstorms, some with wind gusts over 34kts, are
likely Thursday afternoon and evening.

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

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...Red Flag Warning until 9 PM CDT this evening for MNZ010>012-
     018-019-025-026-033>038.
WI...Red Flag Warning until 9 PM CDT this evening for WIZ001-002-
     006>008.
MARINE...None.

&&

$$

DISCUSSION...PA
AVIATION...PA
MARINE...PA