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fxus63 kdlh 110534 
afddlh

Area forecast discussion
National Weather Service Duluth Minnesota
1134 PM CST Tue Dec 10 2019

Update...
issued at 1011 PM CST Tue Dec 10 2019

Upped pops for Thursday morning as 00z href came in lending more
confidence to the snow occurring.

&&

Short term...(this evening through Wednesday night)
issued at 221 PM CST Tue Dec 10 2019

Not much change to the going forecast, with bitterly cold wind
chills expected to begin this evening, continuing through Wednesday
morning. Our next round of light accumulating snow will move into
the region Wednesday night.

The synoptic pattern changes very little for tonight through
Wednesday afternoon, as the Northland remains under an upper-level
longwave trough, which will maintain an Arctic air mass over the
region, with northwest flow aloft. At the surface, a couple areas of
high pressure will swing by to our south, with the first one moving
through the central Great Plains states this afternoon, and another
one to move in late tonight through Wednesday afternoon. The result
will be generally westerly flow, with mostly dry conditions. The
only exception will be along the South Shore of Lake Superior as the
frigid temperatures will support some lake effect snow over the
relatively warmer Lake Superior waters. The 1000-850 mean flow will
be oriented from west to east, which will mainly bring chances of
lake effect to the u.P. Of Michigan, but this snow could graze the
Bayfield peninsula and far northern Ashland and Iron counties. Any
snow accumulations that occur will be very light in nature.

Tonight will be bitterly cold across the region, with minimum wind
chill values between 25 to 35 degrees f below zero. This will cause
frostbite in as little as 30 minutes to exposed skin. Use extra
caution if going outside! Highs on Wednesday will warm up into the
single digits above and below zero. The synoptic pattern will begin
to change Wednesday evening as a compact mid-level shortwave trough
sweeps into the region, which will spark off some snow
accumulations. The bulk of the large-scale forcing will remain to
our south, but the wave should graze our southern areas where some
stronger isentropic ascent is expected. The bulk of the snow
accumulations are expected over northwest Wisconsin and adjacent
areas of northeast Minnesota.

Long term...(thursday through tuesday)
issued at 221 PM CST Tue Dec 10 2019

Briefly warmer late-week, then a round of cold air this weekend
followed by another brief period of warmer (but still below normal)
temps early next week. After snow ends Thursday, a clipper
approaches the region Friday bringing up to 1-2 inches of snow to
parts of northern Minnesota with a chance for light snow lingering
into Saturday, then dry early next week.

On the synoptic scale a mid-level shortwave trough will be tracking
east across the upper Midwest towards the Great Lakes on Thursday
bringing a round of snowfall to most of the Northland, with the
strongest broad-scale lift over northern Wisconsin where as much as
3 to 5 inches of snowfall is possible, lesser amounts in northeast
Minnesota. Temperatures rise towards the end of the week as a
clipper approaches from the west, this second wave with a more
northerly track resulting in weaker broad-scale lift more focused on
northern Minnesota, perhaps up to 1-2 inches for areas along and
north of the Iron Range from Friday into Saturday. Highs in the mid
teens Thursday to as warm as the 20s on Friday.

A round of colder air moves in late weekend as high pressure builds
in from the west, with at least partially clearing skies possible on
Sunday as the area of high pressure builds across the upper
Mississippi River valley. Colder, with single digit highs above zero
on Sunday and lows Sat/Sun night in the single digits below zero.

Temperatures moderate a bit early next week with highs in the teens
and lows near zero under mainly cloudy skies. While these
temperatures are still below normal, the climate prediction center's
longer term forecasts for late December is trending towards above
normal temps!

&&

Aviation...(for the 06z tafs through 06z Wednesday night)
issued at 1132 PM CST Tue Dec 10 2019

VFR conditions expected with gusty northwest winds. No big
concerns except for some anthropogenic MVFR cigs/vsbys near khib
and a system moving into the kbrd area late in the taf period
which will bring snow.

&&

Marine...
issued at 1011 PM CST Tue Dec 10 2019

West-northwest winds 15 to 25 knots combined with Arctic air moving
in will result in a threat for heavy freezing spray tonight into
Wednesday, then winds weaken into Wednesday night, become light
around 5 knots and generally out of the south through the rest of
the week.

&&

Preliminary point temps/pops...
dlh -14 -3 -9 14 / 0 0 80 60
inl -13 -2 -9 9 / 0 0 30 30
brd -15 -4 -6 13 / 0 0 80 30
hyr -16 2 -8 18 / 0 0 80 70
asx -9 2 -5 18 / 10 10 80 70

&&

Dlh watches/warnings/advisories...
WI...Wind Chill Advisory until noon CST Wednesday for wiz001>004-
006>009.

Minnesota...Wind Chill Advisory until noon CST Wednesday for mnz010>012-
018>021-025-026-033>038.

Ls...heavy freezing spray warning until 10 am CST Wednesday for
lsz146-147.

Small Craft Advisory until 10 am CST Wednesday for lsz146-147.

Heavy freezing spray warning until 4 am CST Wednesday for lsz145-
148.

Small Craft Advisory until 4 am CST Wednesday for lsz145-148.

&&

$$

Update...Wolfe

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