257
FXUS63 KDLH 160900
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
400 AM CDT Fri May 16 2025

.KEY MESSAGES...

- Light rain showers throughout today and lingering into Saturday.

- Much cooler temperatures with highs dropping into the 40s and 50s
  for the weekend. For context that is 10-20F below normal.

- Widespread frost potential Sunday night into Monday morning.

&&

.DISCUSSION...
Issued at 355 AM CDT Fri May 16 2025

Current Conditions/Today:

A 981mb low was located over the ND and MN border this morning
slowly moving east. The dry slot associated with this vertically
stacked low is slicing through NW WI and curving back across
northern MN. Wrap around moisture associated with this low is
bringing clouds back in from the west with radar showing weak
echoes of rain returning across the Brainerd Lakes region. As
the day progresses this low will continue its path east through
the Northland as it begins to fill. PWATs have dropped to
around 0.75 inches and buoyancy is largely unavailable which
will result in intermittent light showers through the day.
Additionally, pressure gradient winds out ahead of the low will
lead to some gusty winds out of the southwest for portions of
the Northland today.

Weekend:

The aforementioned low pressure system continues to weaken and move
out into the Great Lakes Region on Saturday morning. Remnant
moisture over the region within the northwest flow aloft will lead
to some isolated rain showers through the day. Not nearly as
expansive as what will be observed today. Dry air aloft and
subsidence moves in for Sunday shutting off our precipitation
chances. The overall precipitation totals from Friday and Saturday
are expected to be between 0.10-0.25 inches. With the cooler air
mass filtering in for the weekend we will see a bit of whiplash in
our temperatures. Highs will now be about 10 to 20F below normal
with highs in the 40s and 50s. Our overnight lows will also drop in
to the 30s leading to concerns of frost. The latest probabilistic
guidance suggests a 60-80% of widespread frost early Monday morning.

Early Next Week:

Another system looks to develop over SD and slide east early next
week. Confidence on how much this will actually impact the Northland
is still on the low side. The NBM seems to be a bit aggressive with
bringing in PoPs as early as Monday and carrying 20-40% chance PoPs
through Tuesday. The LREF is a little more pessimistic and aligns
better with cluster analysis. A strong high pressure emanating from
the Hudson Bay combined with an upper level ridge over the Northland
may force this system further to the south.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1212 AM CDT Fri May 16 2025

A deep surface low is moving into western MN this morning. A dry
slot slices through NW WI and wraps back into northern MN but
additional rainfall will fill in as the low moves east through the
day. Cloud cover is largely VFR right now but will also see ceilings
drop to MVFR and IFR through the period. Additionally, there is a
small corridor of strong winds in the low levels leading to some
shear. Surface winds will increase in the morning and remain
enhanced through most of the day. Expect direction to gradually be
changing through the day as the low moves west to east.

&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 355 AM CDT Fri May 16 2025

Satellite this morning shows a fog bank along the North Shore. This
fog bank is expected to dissipate around 10AM. A vertically stacked
low will be entering in from the west today leading to different
wind directions across the Lake. The strongest winds will be out of
the south along the South Shore where a Small Craft Advisory is in
effect through 3PM.

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

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
MARINE...Small Craft Advisory until 3 PM CDT this afternoon for LSZ121-
     144>148-150.
     Dense Fog Advisory until 10 AM CDT this morning for LSZ140>143.

&&

$$

DISCUSSION...Britt
AVIATION...Britt
MARINE...Britt