Area Forecast Discussion
Issued by NWS Duluth, MN
FXUS63 KDLH 261732
Area Forecast Discussion
National Weather Service Duluth MN
1132 AM CST Sun Feb 26 2017
Issued at 1031 AM CST Sun Feb 26 2017
A cold front boundary, as evidenced by a wind shift from
southwest to northwest and a radar fine line, continues to
advance southeast through northeast Minnesota this morning. Light
to moderate snow continues to fall along this frontal boundary,
which may produce slick spots on roadways and reduced
visibilities. Another one-half inch up to one inch of new snow
accumulation is expected along this boundary. Current radar shows
the back-end of the snow band reaching from the Brainerd Lakes
area northeast to Shermans Corner, so snow should come to an end
soon along these areas.
Northwest Wisconsin will be in line to receive accumulating snow this
afternoon as the band of snow progresses southeast. This band
should exit northwest Wisconsin later this afternoon and early
evening as indicated by the latest mesoscale model guidance.
UPDATE Issued at 641 AM CST Sun Feb 26 2017
Updated POPs, QPF, and snow amounts through today to reflect the
faster arrival of this next disturbance. Snowfall is farther north
and south than earlier forecast, so raised POPs across our
western zones and pull the band east across the Northland through
late this afternoon. Additional QPF yields a swath of 1 to 3
inches, which is a bit more than earlier expectations. Highest
accumulation should stretch from the Pine River vicinity in Cass
County along and north of MN Highway 210 into the Twin Ports, and
then across far northern Wisconsin.
.SHORT TERM...(Today through Monday)
Issued at 413 AM CST Sun Feb 26 2017
At 4 AM light to locally heavy snow was falling from the Twin
Ports east including Two Harbors, Silver Bay, and the northern
tier of northwest Wisconsin Counties. Visibility of three-quarters
of a mile have been reported, but there may be pockets with
visibility less than one-quarter mile. Snow reports have ranged
from a dusting to a little more than three inches during the
evening and overnight. A quasi-stationary front stretched from
northwest Ontario through northern Minnesota and across southern
South Dakota. A shortwave trough was located over northern
Minnesota with an area of frontogenesis oriented mainly east-west
from Lake Superior across the Twin Ports and into central
Minnesota. The area of snow seems to be supported by falling
heights from the approaching trough and enhanced forcing for
ascent with the FGEN band. Have issued an SPS for reduced
visibility and slippery driving conditions. MNDoT reported most
roads from Grand Rapids to near Brainerd and east to the Twin
Ports are snow covered.
Expect the first area of snow to scoot eastward across the
remainder of northwest Wisconsin by 9 AM. The Hi-Res Window ARW
core has been handling this band exceptionally well, along with
the next round of snow over the Red River Valley. Leaned heavily
on a blend of the ECAM and HiResW-ARW for POPs this today. ECAM
QPF seemed reasonable, too, so mixed a bit of that blend into the
grids. This yields a swath of up to 3 inches of snow from midnight
through noon today. A more organized area of snow will move
across our southern zones later this morning through the
afternoon. That band seems to be associated with the main
shortwave trough with robust FGEN and DCVA. Think the bulk of that
snow will fall generally south of MN Highway 200 and US Highway 2
in Minnesota and generally south of US Highway 2 in Wisconsin.
Rising heights behind the departing shortwave this afternoon
should bring precipitation to an end and may work to clear skies
over the northern half of the CWA. The break will be short-lived
as another shortwave trough and double-barreled surface reflection
will move into the Northland tonight. Cloud cover will increase
once again and light snow should spread eastward across northern
Minnesota overnight. Areas north of a Walker to Grand Rapids to
Grand Portage line will have the best chance of snow with
accumulation of up to 2 inches by Monday afternoon.
.LONG TERM...(Monday night through Saturday)
Issued at 413 AM CST Sun Feb 26 2017
An upper trough over the western third of the CONUS will move
over the central CONUS by midweek, then continue east late week. A
stronger shortwave and surface low will affect the Northland
Monday night through Tuesday night.
An inverted trough will extend north into Minnesota Monday night
from low pressure centered in the Central Plains. Although the
guidance handles the trough similarly, there are differences in
how much precipitation is generated with the ECMWF keeping much of
the area dry with most of the other models generating some light
snow. As the upper trough continues east, surface low pressure
will lift northeast toward southern Wisconsin or northern Illinois
on Tuesday continuing into Michigan Tuesday night/Wednesday.
There are significant differences in the track and timing of the
low leading to uncertainty in how much precipitation will occur.
At this time, we have the highest chance for precipitation on
Tuesday into Tuesday evening. Temperatures do warm enough over the
southern half of the Northland for a wintry mix, mainly on
Tuesday and all rain may occur over portions of northwest
Wisconsin. Several inches of snow will be possible from late
Monday night into Tuesday night. High temperatures Tuesday will
range from 25 to 30 along the International Border, to 35 to 40
over northwest Wisconsin. Light snow may linger into Wednesday as
colder air moves in as the low/upper trough continue to pull away
from the region.
A relatively dry period will occur Wednesday night into Friday
with northwest flow aloft. There will be some chances for lake
effect snow along the south shore of Lake Superior, especially
Wednesday through Thursday. Some additional snowfall will be
likely. Highs Wednesday through Friday will range from 20 to 25
along the International Border, to 25 to 30 from the Brainerd
Lakes into northwest Wisconsin.
Warmer temperatures will move in Saturday bringing a chance for a
light mix over portions of the area. Highs will warm into the
lower thirties to around 40.
.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 1132 AM CST Sun Feb 26 2017
A cold front was moving through northwest Wisconsin at the start
of the forecast. MVFR conditions will accompany the front along
with some light snow. The front should move past HYR by 21Z.
Elsewhere and behind the front, VFR is expected. An upper level
disturbance may bring some light snow near the terminals after
08Z. Added a predominate light snow mention at HIB from 12Z to
17Z with MVFR vsbys.
.PRELIMINARY POINT TEMPS/POPS...
DLH 25 12 36 23 / 90 20 20 40
INL 17 5 28 10 / 80 20 30 20
BRD 28 16 40 23 / 90 10 10 30
HYR 31 14 40 29 / 100 0 10 40
ASX 30 15 40 27 / 100 10 10 40