NOAA Duluth, MN
.SHORT TERM...(This evening through Tuesday)
Issued at 251 PM CST Mon Jan 28 2019
The focus remains on the extremely cold and historic air that will
soon be moving into the Northland. This latest forecast has even
colder wind chills than earlier forecast. Confidence is high for
widespread dangerous wind chills. Wind Chill Warnings and
Advisories have now been issued.
An Arctic cold front will continue moving east through the
Northland this afternoon through this evening, bringing an influx
of extremely cold air out of Canada into the Northland into
tomorrow. This will be a rare situation in which a deep upper
level polar low will dive south into the Minnesota and Wisconsin
region by tomorrow morning. This airmass will feature 850 hpa
temperatures at least as cold as -40 degrees Celsius, with the
coldest air across western into southern Minnesota. Gusty winds
late tonight and Tuesday will cause widespread dangerous wind
chills of 30 to 55 below zero across the Northland, with the
coldest wind chills across central and northern Minnesota. Expect
northwest winds of 10 to 20 mph gusting 20 to 30 mph. There will
be little improvement of the winds and wind chills for the
afternoon.
The worst conditions will come Tuesday night through Wednesday
morning. Air temperatures will plummet to 20 to 40 below zero.
Northwest winds of 5 to 15 mph, and up to 20 mph along the
Minnesota North Shore, will cause jaw dropping wind chills of 45
to 65 below zero which will continue well into Wednesday morning.
These wind chills are on the order of an event that the Northland
typically only sees at least once every 5 to 10 years. The latest
comparable situations occurred in January 2014 and February 1996.
Frostbite can occur within 5 minutes under these conditions!
This overall forecast was by no means on the extreme side of model
guidance. The temperature and wind forecasts were close to a
consensus of available model guidance, especially the
temperatures. That means there were other models that were
significantly colder. It is possible we may need to forecast even
colder temperatures with subsequent forecasts. If this were the
case, the wind chills could be substantially, and incredibly,
colder.
.LONG TERM...(Tuesday night through Monday)
Issued at 251 PM CST Mon Jan 28 2019
Near-record cold and dangerously cold wind chills are expected
mid- week, then a welcome warm-up this weekend.
On the synoptic scale a maturing low will be over the Upper Great
Lakes Tuesday night, weakening and exiting to the northeast on
Wednesday. This low will be responsible for bringing what will
almost certainly be the coldest air of the season to the Upper
Midwest as an arctic high then builds in from the west Wednesday
into Thursday, which is expected to allow skies to finally clear
out Wednesday night into Thursday and allow temperatures to
plummet to near record-breaking values. Late in the week a
mid/upper level longwave ridge builds from the Rockies into the
Great Plains and Midwest, ushering in a surge of warmer air across
the Great Plains and Midwest. The warm frontal zone on the
leading edge of this warmer air will move across the Upper Midwest
late Thursday which could result in a brief period of drizzle,
but the main impact to sensible weather will be increasing
temperatures. Temperatures will surge to the mid 20s to mid 30s on
Saturday before a cold front arrives Saturday night into Sunday
bringing in more seasonable temperatures into early next week. A
potent mid-level shortwave trough will eject out of the southwest
into the Great Plains Sunday into Monday, tracking towards the
Upper Great Lakes. This mid-level shortwave and associated surface
low could produce a broad area of precipitation Sunday night into
Monday, with the best chance across central Minnesota and
northern Wisconsin.
The coldest wind chills of the season are likely to occur
Wednesday with northwest winds 10-20 mph and temperatures 20 to 35
below zero resulting in wind chills around 40 to 60 below. At
these extreme wind chills, frostbite can develop on exposed skin
in as little as five minutes. Spending more than a few minutes
outside on Wednesday without proper attire *will* result in
frostbite. The "warmest" the wind chill will reach on Wednesday is
20 to 35 below zero, with the air temperature around 5 to 15
below zero. Cloudy skies in the morning will give way to sunshine
from west to east during the afternoon.
Wednesday night will be the coldest night of the season, with
record lows possible. High pressure will be centered over the
Midwest Wednesday night with mainly clear skies across northern
Minnesota and northwest Wisconsin. These clear skies will allow
for radiational cooling through the night, creating perfect
conditions for temperatures to fall to record-breaking levels.
Forecast lows have been lowered a few more degrees from the
previous forecast, but locally colder temperatures are possible.
With high pressure nearby, winds will be much less of an issue,
but since at these temperatures just a 5 mph wind can result in
much greater heat loss, wind chills of 30 to 50 below are expected
on Thursday morning.
In addition to the cold, lake effect snow will linger along the
south shore through Wednesday, but amounts will be light.
Enjoy the sunshine on Thursday morning because clouds return from
west to east late in the day as the warm front builds in. Lows
Thursday night 15 to 25 below zero, with little to no wind. Not as
cold Friday with highs in the single digits to low teens ABOVE
zero.
Warmer Saturday with highs in the mid 20s to mid 30s, warmest in
northwest Wisconsin. Southerly winds 5 to 10 mph. Cooler Sunday
with highs mid teens to low 30s. An increasing chance for snowfall
Sunday night into Monday, greatest along and south of Highway 2.