Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 120526

Area Forecast Discussion
National Weather Service Duluth MN
1226 AM CDT Mon Mar 12 2018

Issued at 1226 AM CDT Mon Mar 12 2018

Please see the 06Z Aviation Discussion below.


.SHORT TERM...(This evening through Monday)
Issued at 251 PM CDT Sun Mar 11 2018

The upper level trof that was affecting the forecast area today was
moving out of northwest Wisconsin as of 19Z/2pm. One more piece of
vorticity was already beginning to affect northeast Minnesota as a
longer wave trof in Ontario was nearby. At the surface, a couple of
weak surface trofs were affecting the region. They were working in
concert with the upper level trof to generate some flurries over the
Arrowhead. Even though the aforementioned vorticity will flow over
the Arrowhead tonight, good moisture is lacking for a mention of
pops. However, some flurries may occur early in the evening, then
again late tonight. Low level flow turns northerly tonight, combine
with cold air advection, especially over Lake Superior, and generate
some lake effect snow showers. Need some significant improvement in
delta T`s for any noteworthy snow showers, which finally occurs late
tonight. Cannot rule out some very light snow amounts over the
higher terrain over Iron county and have a mention.

The aforementioned vorticity becomes elongated and remains over the
Arrowhead into northwest Wisconsin Monday. The cold air advection
from tonight becomes neutral on Monday. Since delta T`s will not
change much, will carry chance pops along the south shore, as well
as just inland. There is some question on the amount of moisture
available for accumulating snow. The better opportunity for
accumulating snow appears to be Monday afternoon, but only expect
less than one half inch. There is a chance that some of the
precipitation in northwest Wisconsin may mix with rain early in the
afternoon. This would also affect snow totals. Some light snow
showers or flurries will occur in the afternoon over the Arrowhead
and along the Borderland in response to the elongated vorticity
with no accumulation. Dry elsewhere.

.LONG TERM...(Monday night through Sunday)
Issued at 251 PM CDT Sun Mar 11 2018

An upper level shortwave will drop southward across western Lake
Superior on Monday night. This shortwave will reinforce the
potential for lake effect snow showers along the south shore of Lake
Superior on Monday night and Tuesday. At present it looks like there
is potential for a couple inches of snow along the Gogebic Range
from Monday night into Tuesday. Surface high pressure and upper
level ridging will then move slowly into the western Great Lakes
region for the remainder of the work week. Dry weather is expected
to prevail from Tuesday night into Thursday night. The models
actually show a good deal of uncertainty starting on Friday, and
continuing into the weekend. The GFS brings some QPF into the CWA on
Friday, while the ECMWF indicates surface high pressure and dry
weather over our area on Friday and Friday night. In fact, by 12Z
Saturday, the GFS has an upper level trough over our CWA, while the
ECMWF has a ridge over the area. The models have changed a fair
amount since the 00Z runs, so confidence in any particular solution
is on the lower side. On Sunday night, the GFS indicates the
potential for precipitation across the southern half of the CWA,
while the ECMWF has little to no precipitation. Temperatures will be
above normal for much of the long term period, with highs warming
from the 30s on Tuesday to the upper 30s and lower 40s on Wednesday.
Those temperatures in the 40s should then persist throughout the
extended period. Lows will rise from the teens at the beginning of
the period to the 20s at the end of the period.


.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1226 AM CDT Mon Mar 12 2018

VFR through the upcoming TAF period with gusty winds developing
mid to late Monday morning as the mixed layer develops. High
pressure will build into the Northern Plains, while an upper level
disturbance slides southward into eastern Minnesota late on
Monday. The lift from the trough combined with daytime heating
may bring a few snow showers to portions of northeast Minnesota
during the afternoon. Ceilings will straddle MVFR per the RAP/NAM
guidance, but have opted to keep things VFR at this point. Gusty
winds will subside during the evening as the mixed layer


DLH  17  33  13  31 /   0  10  10   0
INL  17  33   9  34 /   0  10  10   0
BRD  16  35  13  35 /   0   0   0   0
HYR  20  35  15  31 /   0  10  20  10
ASX  25  35  17  30 /  10  30  30  20




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