FXUS63 KDLH 201754

Area Forecast Discussion
National Weather Service Duluth MN
1154 AM CST Tue Nov 20 2018

Issued at 1154 AM CST Tue Nov 20 2018

Updated for the latest 18Z Aviation Discussion below.

UPDATE Issued at 619 AM CST Tue Nov 20 2018

Snow has reached International Falls and expect it to spread
southeastward. This is a bit ahead of schedule and have updated
pops accordingly. Rest of the forecast on track.


.SHORT TERM...(Today through Wednesday)
Issued at 303 AM CST Tue Nov 20 2018

A ridge of high pressure covered the forecast area at 0830Z. A
weakening northerly flow over Lake Superior had brought and end to
the light snow/flurries. Clouds were also beginning to break up over
northwest Wisconsin. Warm air advection was underway ahead of the
next system due to affect the area today. A mix of mid and high
clouds were pushing their way into northeast Minnesota as a result.

An Alberta clipper is still expected to march across far northern
Minnesota today with some snow showers. There is still a relatively
small window for some patchy freezing drizzle late this morning and
this afternoon from east central Minnesota into northwest Wisconsin.
The models have backed off on this potential from 24 hours ago and
no longer expect any ice accumulation. Adjusted the forecast
accordingly. The precipitation will end in northeast Minnesota by
sunset, but linger in northwest Wisconsin through the early evening.
Up to one inch of snow is possible from near International Falls, to
Cook and Orr, as well as the western Iron Range. There is a small
window of opportunity for some lake effect snow showers along the
higher terrain of Iron County with a northerly flow. However, dry air
will be advecting across the lake late in the evening as high
pressure builds across the region. Up to one inch may fall over this
area before ending with the dry air. A clearing sky elsewhere
tonight, with light and variable winds, the coldest min temps will
be along the international border region with temps from 5 to 12
below zero. Warmer farther south.

Mid level and surface ridging cover the forecast area on Wednesday.
However, some lake effect snow showers will again be possible along
the south shore with a northerly flow. Max temps will be in the
teens to lower 20s.

.LONG TERM...(Wednesday night through Monday)
Issued at 303 AM CST Tue Nov 20 2018

High pressure will extend south through Ontario over Lake Superior
and Lake Michigan Wednesday night. The high move east Wednesday
night and the low level flow will start out easterly then become
southerly on Thanksgiving Day. The airmass will remain cold enough
for lake effect snow which will be possible along the North Shore
Wednesday night. Lack of large scale lift and a dry airmass will
keep any snow showers light.

Warm air advection will develop Wednesday night and continue
Thursday as an upper ridge moves overhead. We kept Thursday dry for
now but there remains some indication some light drizzle could
develop. However, forecast soundings show the moisture is rather
shallow. We did increase cloud cover though and expect highs from
the upper twenties in the Arrowhead to the lower thirties in the
Brainerd Lakes, Aitkin, Pine City areas.

An upper trough arrives on Friday and will remain in some form
through the weekend into early next week. An initial trough Friday
will be replaced by a longwave trough late in the weekend. There
will be a chance for mainly light rain on Friday but there could be
a light mix in spots. A wintry mix will be possible Friday night as
well. Although heavy snow or mixed precipitation looks unlikely,
there could be enough to make for some slick travel in spots Friday
night into Saturday depending on surface temperatures. The ECMWF is
more bullish on QPF versus a faster GFS solution. The
shortwave/trough moves off to the east late Saturday with another
longwave trough arriving Sunday. Both the GFS and ECMWF show a
strong surface low centered in the Missouri/southern Illinois area
at 00Z Monday. There will be a chance for snow well north into the
eastern half of the Northland Sunday, but amounts look light at this

The models show significant differences early next week with the GFS
stronger and slower moving the low east. The GFS has precipitation
from the low continuing to affect eastern parts of the Northland
while the ECMWF develops a ridge and is mostly dry. We have a chance
for light snow for now.

Temperatures will warm from Thursday into Friday with highs Friday
in the upper thirties to lower forties. Temperatures will cool from
there with mid twenties to lower thirties by Sunday and cool a few
more degrees Monday.


.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 1154 AM CST Tue Nov 20 2018

Snow will continue spreading east through northwest Wisconsin and
parts of northeast Minnesota this afternoon, exiting the region by
late this afternoon. There could be brief light freezing drizzle
in the wake of the snow today. Overall, expect widespread MVFR
conditions with periods of IFR conditions this afternoon, and then
MVFR this evening. Drier air will filter into the Northland
tonight, leading to a return to VFR conditions overnight.


DLH 18 5 18 13 / 90 0 10 10
INL 17 -1 12 7 / 100 0 0 0
BRD 25 9 22 15 / 50 0 0 0
HYR 21 11 21 13 / 80 10 0 0
ASX 21 13 19 12 / 90 10 20 10


LS...Small Craft Advisory until 10 AM CST Wednesday for LSZ140-

Small Craft Advisory until 10 PM CST this evening for LSZ121-

Small Craft Advisory until 4 AM CST Wednesday for LSZ141-145.



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