Area Forecast Discussion
Issued by NWS Duluth, MN

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49
FXUS63 KDLH 122116

Area Forecast Discussion
National Weather Service Duluth MN
316 PM CST Thu Jan 12 2017

.SHORT TERM...(This evening through Friday)
Issued at 316 PM CST Thu Jan 12 2017

A potent Canadian Clipper, currently over Ontario north of Lake
Superior, brought a blast of Arctic air into the Northland this
afternoon with its strong cold front. There will be widespread
wind gusts of 25 to 35 mph through early this evening due to
efficient boundary layer mixing because of the strong pressure
rises in the wake of the cold front and strong cold air advection.
There will be blowing and drifting snow in more open areas because
of the fresh snowpack of fluffy snow, so travel may be difficult
in spots. Temperatures will plummet through tonight, resulting in
another round of frigid air temperatures and bitterly cold wind
chills. Much of the Northland can expect wind chills of 25 to 35
below at times through at least the wee hours of the morning, with
the coldest conditions across northern Minnesota. Wind chill
advisories have been issued for all of the Northland.

High pressure will move into the region tonight and Friday
morning. The resulting clear skies and weakening winds, combined
with the fresh snowpack, will contribute to strong radiational
cooling. Air temperatures will drop to 15 to 30 below zero across
the Northland, with the coldest conditions across northeast
Minnesota. Leaned a little on our coldest model guidance, like our
local wrf, for tonight`s low temperatures. Our typical cold spots
in northern Minnesota, like Embarrass and Brimson, will likely
approach 35 below zero.

The winds weaken overnight, becoming very light by dawn. However,
considering the very cold air temperatures tomorrow morning,
decided not get cute with the "wind" in the wind chill advisory,
and just extend the advisories through Friday morning. Subsequent
shifts might cancel parts of the advisories early depending on how
things look later this evening and overnight.

Light southerly return flow will develop Friday in the wake of the
passing high pressure. The morning looks sunny, but some clouds
should begin to move in from the south in the afternoon. Highs
should reach the single digits above zero, with this forecast
being a little higher than the previous forecast.

.LONG TERM...(Friday night through Thursday)
Issued at 316 PM CST Thu Jan 12 2017

The extended forecast period looks to be much more quiescent
compared to the past week. It does appear that Friday
night/Saturday morning may have a brief chance of snow showers as
a mid-level shortwave trough translates through the region,
especially the southern portions of the forecast area. The latest
GFS/NAM soundings indicate the isentropic lift will be very weak,
with little in the way of dendritic snow growth. Kept slight
chance PoPs in during this time period as the shortwave moves

Then, a short quiet stretch of weather begins late Saturday
morning through Sunday night as sfc high pressure builds into the
region. South to southwesterly winds will help keep temperatures
near seasonal normals, with highs in the upper teens and lower 20s
Saturday and Sunday. Chances of precipitation will ramp up Monday
across NW WI and adjacent MN counties as sfc low pressure develops
across the TX/OK Panhandle region. This system looks to have a
good push of 700 mb thermal and moisture advection, which will
support at least chances of precipitation. The 12.12z models are
showing some disagreement on the precipitation duration Monday
into Tuesday as the GFS brings only a brief period of precip
Monday morning before increasing chances Tuesday afternoon and
evening, while the CMC ramps up precipitation Monday morning,
keeping it through Wednesday morning. The 12.12z ECMWF is more
aligned with the CMC, and the consensus blends are more aligned
with the ECMWF/CMC, so will keep what the consensus blend has.
Precipitation type is still uncertain at this time as the models
are supporting more of a wintry mix across the extreme eastern
portions of NW WI in our forecast area. Much will depend of the
amount of warming through the atmospheric profile because a change
in temperatures a few degrees will change precip types. The period
in question will be from late Tuesday morning through the
afternoon. For those planning on traveling during this period in
northwest/north-central Wisconsin, be sure to keep up with the
latest forecasts. The precipitation should come to an end Tuesday
night/Wednesday morning as the system moves off to the east.

Conditions look dry through the rest of the forecast period as
sfc ridging develops. Tuesday through Thursday are showing the
possibility of temperatures reaching above freezing, at least for
NW WI, as the 700 mb warm air advection associated with the system
helps to bump up temperatures. The ECMWF is the most AGGRESSIVE
with the warm temperatures, as it is bringing above freezing
temperatures as far north as the Arrowhead. Not sold on the ECMWF
solution yet as the GFS/CMC models are going a bit colder.


.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
Issued at 1148 AM CST Thu Jan 12 2017

A strong Arctic front associated with an area of low pressure
over southwestern Ontario Canada will move across the region. A
tight pressure gradient along the backside of the front will bring
very gusty west to northwest winds. Gusts between 30 and 35 knots
were observed over eastern ND/western MN at time of TAF issuance,
so some gusts may be up to 35 knots this afternoon. Along with the
gusty winds will be some vsby reductions as blowing snow is a
concern this afternoon. Upstream obs are showing vsbys as low as
one-quarter of a mile from the blowing snow. Ceiling heights may
reduce to MVFR categories as well, but this is expected to be

As the low pressure and frontal boundary moves off to the east,
winds should decrease overnight and skies look to clear. The
weakening winds and clearing skies will increase radiational
cooling, which will lead to a very cold night ahead. Wind chill
values should fall to as low as -40 degrees in some locations.


DLH -21   5  -4  16 /   0   0  10   0
INL -31   2  -4  14 /   0   0  10   0
BRD -26   7  -4  19 /   0   0  10   0
HYR -25   6  -3  18 /   0   0  20   0
ASX -17  10   0  20 /   0   0  10   0


WI...Wind Chill Advisory until noon CST Friday for WIZ001.

     Wind Chill Advisory from 9 PM this evening to 10 AM CST Friday
     for WIZ002>004-006>009.

MN...Wind Chill Advisory until noon CST Friday for MNZ010>012-018>021-

LS...Small Craft Advisory until 4 AM CST Friday for LSZ121-144-145-

     Gale Warning until 10 PM CST this evening for LSZ140>143-146-147.

     Heavy Freezing Spray Warning until 10 PM CST this evening for



SHORT TERM...Grochocinski
AVIATION...JTS is the U.S. government's official web portal to all federal, state and local government web resources and services.