Latest Duluth Area Text Forecast Discussion product from NWS:
044
FXUS63 KDLH 151207
AFDDLH
Area Forecast Discussion
National Weather Service Duluth MN
607 AM CST Mon Dec 15 2025
.KEY MESSAGES...
- A warming trend continues today, peaking Tuesday with highs
reaching the upper 30s and even the mid 40s across the
Northland.
- There is a 20% chance of a mix of freezing rain and snow
tonight and early Tuesday morning mainly north of US-2.
- A potent storm system targets the region Wednesday night into
Thursday, bringing strong winds and a messy mix of rain,
freezing rain, and snow.
- Two more clippers will make a run at the Northland and may
bring accumulating snow Friday night and Saturday and again
Monday.
&&
.DISCUSSION...
Issued at 430 AM CST Mon Dec 15 2025
An active weather pattern will persist through the week and
into early next week. A blocking upper-level high off the coast
of California will remain in place with a Rex Block over the
Aleutians and northern Pacific. These features will continue to
squeeze the subtropical jet across the Pacific Northwest.
Several atmospheric rivers will keep a flow of Pacific moisture
streaming across the Rockies and into the Northern Plains and
Canadian Prairies.
This morning a shortwave trough over Ontario and Lake Superior
will propagate farther east. That feature was responsible for
light snow over the eastern Arrowhead overnight and early this
morning. Snow will taper off quickly this morning as the upper-
level support departs. Northwest flow aloft will bring warm
Chinook air into the region. Temperatures continue the warming
trend which began yesterday. Look for daytime highs in the
middle teens to middle 20s. The warmest temperatures may be
recorded close to midnight tonight.
An upper-level ridge will propagate eastward across the region
and 850 mb winds will back southwesterly early Tuesday morning.
Temperatures will likely dip several degrees this evening before
the next surge of warm air advection takes over. Look for temps
to rise from late this evening through Tuesday morning.
Isentropic ascent associated with the warm air advection may be
sufficient for a light wintry mix tonight and Tuesday morning. A
considerable warm nose aloft supports the idea of snow melting
aloft and falling as freezing rain. Should the precipitation
develop, ice accumulation on roads will be a concern. Overall
think the chance of precipitation tonight is less than 20
percent.
Tuesday is on tap for the warmest day in quite a while. High
temperatures will climb into the upper 30s to middle 40s.
Hibbing and International Falls will have a chance at setting
new record high temperatures for the day (records - HIB: 44,
INL: 47). The warm air advection will be supported by a
relatively strong clipper moving eastward across the northern
Prairies and into northern Ontario. A tight pressure gradient
over the Northland will bring the potential for gusty winds
along with the warm temperatures. A strong cold front will
propagate southeastward across the Northland Tuesday afternoon
through early Wednesday morning. There is a slight chance of
light wintry mix changing to snow behind the front.
Attention then shifts to an unusually strong low pressure
system which will move quickly eastward across the region
Wednesday night and Thursday. That system will be accompanied by
a surge of Pacific moisture from a Pac NW atmospheric river.
Strong northward moisture advection Tuesday night and Wednesday
over the Plains and Mississippi River Valley will introduce the
possibility of Gulf moisture being drawn into the clipper as
well. Winds with that low pressure system will be quite strong.
As my colleague revealed yesterday the strong 70+ knot
southwesterly low-level jet ahead of the low pressure system has
an average return interval of 30 years (per NAEFS climatology).
The annual probability of a jet that strong this time of year
is only around 3%. Ample atmospheric moisture will bring a swath
of precipitation to the Northland. Precipitation may begin as a
mix of freezing rain and snow before changing to all snow. A
dusting up to several inches of snow are forecast from late
Wednesday evening through Thursday. Strong and gusty winds
Thursday may result in widespread blowing snow. Travel may
become challenging overnight and Thursday morning.
After Thursday, weather whiplash machine will continue with
several periods of warming and then cooling temperatures as
several additional clippers traverse the region. Another bout of
accumulating snow is possible Friday night and Saturday and
again Monday.
&&
.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
Issued at 606 AM CST Mon Dec 15 2025
The Northland will be between clippers for a time today. Look
for MVFR ceilings to scatter out for a time at most terminals
today before warm air advection aloft brings another round of
MVFR ceilings. There is a potential for IFR ceilings after 04Z
tonight. An unusually strong low-level jet will develop ahead of
the next clipper tonight. Wind speeds in the core of the
southwesterly LLJ will be between 60 and 65 knots. The
strongest wind shear will develop between 06Z and 15Z. LLWS will
diminish before a second strong jet develops in the wake of a
cold front Tuesday afternoon and evening. There is a 20% chance
of freezing rain mixed with snow at INL between 16.06Z and
16.12Z. There will likely be radar echoes though dry air between
the ceilings and the precipitation generating cloud layer may
evaporate/sublimate the precipitation before it reaches the
ground.
&&
.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 453 AM CST Mon Dec 15 2025
Wind and waves will quickly subside this morning. A strong and
fast-moving clipper will move eastward across the northern
Canadian Prairies and northern Ontario on Tuesday. A tight
pressure gradient will develop over the waters resulting in
strengthening southwest winds on Tuesday. Sustained winds of 15
to 30 knots are forecast with gusts of 30 to 40 knots. Gale
Watches were issued this morning for the areas most likely to
see gales of 35 to 40 knots Tuesday. A cold front will move
southeastward over the region Tuesday afternoon through
Wednesday morning. Winds will veer northwesterly and will
diminish Wednesday morning. Cold air pouring onto the lake from
the North Shore may result in a period of strong katabatic winds
along the North Shore. Therefore the Gale Watch for Taconite
Harbor to Grand Portage runs until 6 AM Wednesday. There will be
a brief reprieve from the gusty winds and dangerous waves on
Wednesday before the next clipper moves into the region
Wednesday night and Thursday. Winds will back southwesterly by
Wednesday afternoon and become hazardous again Wednesday
evening. Gales are possible overnight. As that clipper departs
on Thursday winds will veer northwesterly and strengthen
further. Sustained winds of 30 to 40 knots are forecast by noon
Thursday with storm-force gusts possible along the North Shore.
As of this morning the potential for 60 knot gusts near Grand
Marais Thursday is around 10%. Additional clippers are forecast
Friday night and Saturday then again on Monday. Each of those
systems will likely produce hazardous conditions.
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...Gale Watch from Tuesday morning through late Tuesday night for
LSZ140-141.
Small Craft Advisory until 10 AM CST this morning for LSZ141-
146-147-150.
Gale Watch from Tuesday morning through Tuesday evening for
LSZ146-147-150.
&&
$$
DISCUSSION...Huyck
AVIATION...Huyck
MARINE...Huyck
NWS DLH Office Area Forecast Discussion
