Blizzard and Extreme Cold in Minnesota, February 12 to 13, 2020

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
616 AM CST Wed Feb 12 2020

.SHORT TERM...(Today through Thursday)
Issued at 510 AM CST Wed Feb 12 2020

The forecast remains on track for today's strong Arctic front and
blizzard conditions across western Minnesota, with upstream
observations from eastern North Dakota already showing widespread
Blizzard conditions along and west of the Red River Valley. Wind
gusts up to 50 mph have been measured in the Grand Forks area, and
while we expect these winds to diminish somewhat by the time they
reach west-central Minnesota, gusts around 40 mph are still expected
across open areas of west-central and southwest Minnesota as the
front moves through the morning and afternoon. This should result in
a few hours of blizzard conditions during a few hours of light snow
falling during the strongest winds, and relatively fresh snow still
on the ground from this weekend's storm still able to blow around.
Conditions have not been as bad on the Minnesota side of the Red
River Valley this morning with wind gusts typically in the 30-35 mph
range, so decided to keep the current Blizzard warning as is and
issue a Winter Weather Advisory to the east of the warning into east-
central and southeastern Minnesota. Areas of blowing snow and
possibly periods of near-blizzard conditions across open areas are
possible later this morning and afternoon with with light snow along
the front and blowing antecedent snow as winds gust to 30-35 mph
behind the front. While snowfall amounts look to remain light and
generally an inch or less, another concern later this afternoon and
evening will the the potential for light snow to flash freeze on
roadways and surfaces as temperatures rapidly plummet behind the
front. While the light snow is expected to be over with by late
afternoon, flash freezing could lead to impacts to the evening
commute so kept the advisory going into late evening.

The other hazard with this Arctic front will be the plummeting
temperatures in its wake along with strong northwest winds, which
will lead to dangerous wind chills this evening through tomorrow
morning. Air temperatures are expected to already drop below zero by
mid-afternoon across western Minnesota, with lows bottoming out near
-20 tomorrow morning across western Minnesota and near -10 across
 eastern Minnesota and west-central Wisconsin. The strong gusty
 winds will diminish a few hours after the front passes, but will
 still remain around 10-20 mph through tomorrow morning. A Wind
 Chill Warning has been issued for this evening across west-
 central, southwestern, and south-central Minnesota where wind
 chills are forecast to drop below -35, wit minimum wind chills as
 low as -45 possible across far-western Minnesota. Farther east, a
 Wind Chill Advisory has been issued for the rest of Minnesota and
 west-central Wisconsin where wind chills are expected to drop to
 -25 to -35 degrees. These Dangerous wind chills could begin as
  early as late afternoon across far-western Minnesota, but
  generally will begin to reach Wind Chill Warning/Advisory
  criteria this evening and tonight. Winds become lighter tomorrow
  morning and temperatures will begin to rebound with the rising
  sun so think the wind chill headlines can be dropped by mid-
  morning, although wind chills near advisory criteria may persist
  for a good portion of the day across western Minnesota.
  Temperatures will remain frigid Thursday afternoon with the
  Arctic high pressure overhead, highs are expected to remain
  below zero across western and south-central Minnesota, and
  struggle to reach a degree or two above zero across eastern
  Minnesota and west-central Wisconsin.

.LONG TERM...(Thursday night through Tuesday)
Issued at 510 AM CST Wed Feb 12 2020

Broad high pressure settles in across the Upper Midwest on Thursday
evening. Temperatures in the low to mid teens below zero look to be
common overnight into Friday morning. Surface winds declining to
around or below 5 knots will temper wind chill values to some
extent, but still look likely to necessitate a Wind Chill Advisory
generally west of the I35 corridor. With high pressure sliding to
the southeast of the area on Friday, southerly flow will develop by
daybreak in the west. Therefore expect temperatures to rise slightly
in the west overnight into Friday morning.

Southerly winds become brisk on Friday as the surface pressure
gradient tightens ahead of a developing Plains trough. This feature
and associated mid-level wave pass across the area on Friday night
and Saturday. Have maintained chance POPs for snow during that time
frame, with the potential appearing the highest on Saturday from
east central MN into west central WI where moisture and forcing come
into sync.

For the weekend, weak ridging looks to foster mild temps and dry
weather.

Model agreement diverges for next week, with the ECMWF continuing to
show a notable trough and accumulating snow in the Tuesday-Wednesday
time frame. The GFS is also trending toward the potential for snow,
but generated from a weak, fast-moving clipper and not from an
amplified trough as the ECMWF suggests. Will include slight chance
POPs for now until model agreement improves.

&&

.AVIATION...(For the 12Z TAFS through 12Z Thursday morning)
Issued at 616 AM CST Wed Feb 12 2020

Conditions will deteriorate through the morning and early
afternoon as light snow and strong northwesterly winds associated
with an Arctic front lead to periods of IFR visibility and
blowing snow. Accumulations are expected to be an inch or less,
but plummeting temperatures behind the front may lead to flash
freezing on untreated surfaces. Ceilings will drop to MVFR as the
front moves through and are expected to remain MVFR into the
evening at most terminals, with skies scattering out overnight.
Winds will be southwesterly this morning ahead of the front, with
gusts up to 20-25 kts at times. Winds will quickly become
northwesterly as the front passes from west to east through the
morning and early afternoon, with sustained winds becoming 20-25
kts and gusts as high as 30-35 kts. Visibilities will improve once
the light snow ends, but blowing snow will likely continue into
the evening. Winds will remain northwesterly but begin to
diminish overnight, with speeds around 10 kts by the end of the
period.

KMSP...VFR conditions with southwest winds around 10-20 kt are
expected through the morning. We expect the front to come through
around noon, with winds quickly becoming northwesterly and
increasing to 20-30 kts. IFR visibilities look likely for a few
hours during the afternoon, as falling light snow along with
blowing snow from this weekend's system drop visibility as low as
1SM. New snow accumulation is expected to remain under an inch,
but could flash freeze on untreated surfaces as temperatures drop
below zero tonight. VFR conditions are expected to return as
skies scatter out after midnight, with winds diminishing to around
10 kts early tomorrow morning.

/OUTLOOK FOR KMSP/
Thu PM...VFR. Wind W 5-10 kt.
Fri...VFR. Wind S 10-20kt.
Sat...MVFR/IFR possible. Chance -SN. Wind SW 10-20 kts becoming NW
&&

.MPX WATCHES/WARNINGS/ADVISORIES...
WI...Wind Chill Advisory from 3 AM to 10 AM CST Thursday for
     WIZ014>016-023>028.

MN...Winter Weather Advisory from noon today to 9 PM CST this evening
     for MNZ051-059>063-068>070-076.

     Wind Chill Advisory from midnight tonight to 10 AM CST Thursday
     for MNZ043>045-050>053-059>063-068>070-076>078-084-085-093.

     Winter Weather Advisory until 3 PM CST this afternoon for MNZ041-
     048.

     Wind Chill Warning from 6 PM this evening to 10 AM CST Thursday
     for MNZ041-047-048-054>056-064-073-074-082-091.

     Winter Weather Advisory until 6 PM CST this evening for MNZ049-
     057-058-066-067-075-083-091-092.

     Wind Chill Warning from midnight tonight to 10 AM CST Thursday
     for MNZ042-049-057-058-065>067-075-083-092.

     Blizzard Warning until 6 PM CST this evening for MNZ047.

     Blizzard Warning until 6 PM CST this evening for MNZ054>056-064-
     065-073-074-082.

     Winter Weather Advisory from 3 PM this afternoon to 9 PM CST
     this evening for MNZ077-078-084-085-093.

&&

SHORT TERM...ETA
LONG TERM...LS
AVIATION...ETA

Hazardous Weather Outlook
National Weather Service Twin Cities/Chanhassen MN
600 AM CST Wed Feb 12 2020

MNZ047-054>056-064-065-073-074-082-131200-
Stevens-Lac Qui Parle-Swift-Chippewa-Yellow Medicine-Renville-
Redwood-Brown-Watonwan-
600 AM CST Wed Feb 12 2020

This Hazardous Weather Outlook is for portions of central
Minnesota...south central Minnesota...southwest Minnesota and
west central Minnesota.

.DAY ONE...Today and Tonight

Widespread blowing and drifting light snow will lead to a few
hours of blizzard conditions this morning and afternoon.
Temperatures will plummet today behind an Arctic front, and may
result in flash freezing on roadways and surfaces.

Dangerous wind chills below -35 will develop as late afternoon,
and continue into Thursday morning. Wind chills could drop as low
as -40 to -45 overnight.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday

Dangerous wind chills below -35 will continue into mid-morning,
with hazardous wind chills near -25 still possible during the
afternoon. Wind chills will drop back to -25 to -35 Thursday
evening through Friday morning.

.SPOTTER INFORMATION STATEMENT...

SKYWARN spotter activation will not be needed.

MNZ041-042-048-049-057-058-066-067-075-083-091-092-131200-
Douglas-Todd-Pope-Stearns-Kandiyohi-Meeker-McLeod-Sibley-Nicollet-
Blue Earth-Martin-Faribault-
600 AM CST Wed Feb 12 2020

This Hazardous Weather Outlook is for portions of central
Minnesota...south central Minnesota and west central Minnesota.

.DAY ONE...Today and Tonight

Areas of blowing and drifting light snow will lead to periods of
reduced visibility, and potentially near-blizzard conditions
later this morning and afternoon. Temperatures will plummet this
afternoon behind an Arctic front, and may result in flash freezing
on roadways and surfaces.

Dangerous wind chills of -35 to -40 will develop late this
evening and tonight through mid-morning tomorrow.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday

Dangerous wind chills below -35 will continue into mid-morning.
Hazardous wind chills of -25 to -35 will redevelop Thursday
evening through Friday morning.

.SPOTTER INFORMATION STATEMENT...

SKYWARN spotter activation will not be needed.

MNZ043>045-050>053-059>063-068>070-076>078-084-085-093-WIZ014>016-
023>028-131200-
Morrison-Mille Lacs-Kanabec-Benton-Sherburne-Isanti-Chisago-
Wright-Hennepin-Anoka-Ramsey-Washington-Carver-Scott-Dakota-
Le Sueur-Rice-Goodhue-Waseca-Steele-Freeborn-Polk-Barron-Rusk-
St. Croix-Pierce-Dunn-Pepin-Chippewa-Eau Claire-
600 AM CST Wed Feb 12 2020

This Hazardous Weather Outlook is for portions of central
Minnesota...east central Minnesota...south central Minnesota...
southeast Minnesota...northwest Wisconsin and west central
Wisconsin.

.DAY ONE...Today and Tonight

Areas of blowing and drifting light snow will lead to periods of
reduced visibility later this morning and afternoon. Temperatures
will plummet this afternoon and evening behind an Arctic front,
and may result in flash freezing on roadways and surfaces.

Hazardous wind chills of -25 to -35 will develop tonight through
mid-morning tomorrow.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday

Hazardous wind chills of -25 to -35 will continue into mid-
morning. Hazardous wind chills below -25 are also possible
Thursday night into Friday morning.

.SPOTTER INFORMATION STATEMENT...

SKYWARN spotter activation will not be needed.