Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 181146

Area Forecast Discussion
National Weather Service Duluth MN
646 AM CDT Sat Mar 18 2017

.SHORT TERM...(Today through Sunday)
Issued at 330 AM CDT Sat Mar 18 2017

Chances of precipitation will continue to shrink this morning as a
sfc low pressure system and associated mid-level shortwave moves off
to the east. Best precip chances will remain along the snowbelt
region of Ashland and Iron counties as some lake enhancement is
possible as 850 mb temperatures cool to around 6 to 7 degrees C
below zero. New snow accumulations in this region may be around an
inch in spots, but nothing significant expected. 00.18z model
soundings are progging chances of freezing drizzle to accompany
chances of snow, as deep moisture seems to be lacking from the 800
mb level upwards, but could be just enough moisture in the low-
levels to support the drizzle. 1000-850 mb mean layer winds will
veer from the northwest to the northeast, along with increasing 850
mb temperatures, which will bring the lake enhanced precip chances
to an end by this afternoon.

Saturday afternoon through Sunday morning looks dry across the
Northland as sfc high pressure and mid-level negative vorticity
advection moves through the region during this time. However, by
Sunday afternoon, a subtle mid-level wave and a weak cool frontal
boundary will advance through the region. 290 K isothermal sfc
isentropic upglide looks to provide enough lift to introduce POPs to
portions of the area Sunday afternoon, but only have slight chances
for POPs at this time as there is some uncertainty regarding QPF.
The GFS/ECMWF models are progging some fairly light QPF for portions
of the forecast area, while the NAM is going with very light
amounts, and the CMC model is going dry. With the slight chance
POPs, didn`t put in much for QPF in the grids for the afternoon
period. Any precipitation that falls looks to be rain at this point,
thanks to a warm thermal profile supported by breezy southerly
winds. 850 mb level winds look to intensify ahead of the sfc cool
front boundary, so Sunday afternoon looks to be fairly breezy, with
gusts between 20 and 30 kts expected. Thanks to these southerly
winds, low-level warm air advection should be enhanced, which will
support high temperatures Sunday to return to the 50s as 925 mb
temps increase into the single digits above zero, with the ECMWF
model actually breaking double digits above zero from the Brainerd
Lakes area east towards Hinckley. Uncertainty does exist, however,
as increasing cloud cover may suppress diabatic heating, so went
with consensus blend maxTs for Sunday.

.LONG TERM...(Sunday night through Friday)
Issued at 330 AM CDT Sat Mar 18 2017

A cold front will move across the Northland Sunday night, allowing
high pressure to build into the region from Canada. Relatively flat
westerly flow will gradually transition to northwest flow by
midweek, as an upper level trough carves itself out across the Great
Lakes region. The shift in winds to the north and northwest by
Tuesday will bring a chance of lake effect snow showers along the
south shore, especially in the Gogebic Range area. There could be
some accumulation in that area. The upper level trough will
gradually move off to the east on Wednesday, as strong upper level
ridging moves from the Rockies into the western Great Lakes. Return
flow will then develop for the remainder of the work week, and into
the upcoming weekend. Quite a bit of disagreement amongst the models
during that time, but the general consensus is that there will be a
reasonably high chance of precipitation. A mix of rain and snow will
be possible at night, with mainly rain during the day and some
locations could see all snow on Thursday night and Friday night.
Highs on Monday will generally be in the 40s, but temperatures will
cool into the 20s and 30s on Tuesday and Wednesday. By Friday and
Saturday, warmer air will bring temperatures back into the 30s and
40s for daytime highs. The coldest night of the long term period
will be Tuesday night, with lows ranging from near zero north to
around 10 above south.


.AVIATION...(For the 12Z TAFS through 12Z Sunday morning)
Issued at 643 AM CDT Sat Mar 18 2017

Widespread IFR CIG`s will gradually give way to VFR conditions as
the morning wears on, as high pressure builds in from the
northwest. The result will be gradually clearing skies today.


DLH  38  23  48  29 /   0   0  10  20
INL  34  23  49  27 /   0   0  10  10
BRD  42  29  56  30 /   0   0   0  20
HYR  41  23  51  30 /  10   0  10  10
ASX  40  22  52  31 /  10   0  20  20




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