Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 200826
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
326 AM CDT Mon Mar 20 2017

.SHORT TERM...(Today through Tuesday)
Issued at 320 AM CDT Mon Mar 20 2017

The remnants of a weak frontal boundary will exit northwest
Wisconsin early this morning, which will shift the winds to a west
to northwesterly direction. As of 08z, there were some returns on
radar early this morning across southern North Dakota, which are
expected to advance to the east into northern Minnesota. These
returns are associated with a mid-level shortwave. While this
shortwave is expected to translate over our forecast area, there is
some uncertainty as to whether or not the precipitation associated
with these returns will actually reach the surface. Analysis of the
latest RAP/NAM/HRRR soundings all indicate a robust layer of dry air
near the sfc this morning, and especially this afternoon, which
should prohibit precipitation from reaching the surface. Additional
analysis of the high-res mesoscale model guidance indicates no
progged QPF associated with this shortwave across our southern
forecast area, save for the 20.06z NAM model. Considering the dry
air from the soundings, and only one of the six high-res model
guidance analyzed had any QPF, decided not to introduce
noteworthy POPs to the forecast.

The latest synoptic guidance is indicating a more robust mid-level
shortwave with a lobe of PVA and isentropic lift ahead of it to glance
our northern fringe of counties this evening after 00z. A sfc
cold front looks to accompany this shortwave as well. The high-res
model guidance was progging some higher QPF associated with this
system, so introduced some chance/slight chance POPs across
Koochiching, northern St. Louis, and northern Lake and Cook
counties through 06z Tuesday. RAP/NAM model soundings were showing
better low-level moisture associated with this shortwave, which
support this increase in POPs, with the 20.00z NAM soundings
indicating more saturated air up to 700 mb. P-types could briefly
start out as a rain/snow mix before becoming all snow as the cold
front translates to the southeast. This cold front boundary looks
to bring colder air than what we have seen the last few days, with
925 mb temperatures dropping as low as 14 degrees C below zero
across Koochiching county. Guidance for the low temperature
Tuesday morning was a bit too warm, given the magnitude of cold
air expected to move into the region, so leaned the lows towards
MOS guidance. Low temperatures Tuesday look to drop into the
lower teens north to near 20 south. There could also be a small
chance for some lake enhanced snow showers Tuesday over the
snowbelt region of Ashland and Iron counties as more favorable 850
mb temperatures move in behind the cold front.

.LONG TERM...(Tuesday night through Sunday)
Issued at 320 AM CDT Mon Mar 20 2017

Cool Canadian high pressure will build into the Northland Tuesday
night and Wednesday, as it slides into the Great Lakes region. A
strong upper level ridge will build to the west of our area on
Wednesday, and will bring warmer but wet weather to the region from
Wednesday night into Friday night. While there are still some model
differences regarding the upper level trough and low pressure system
to affect the area during the latter part of the week, there is much
better synoptic scale agreement than the previous model runs. The
most active period should be Thursday night and Friday, as rain, or
a wintry mix, moves across the Upper Midwest. The low will then park
itself across the mid section of the country, eventually migrating
to the central Great Lakes by the end of the weekend. Another system
will then move into the region early in the next work week, but
there are a good deal of model differences during that time. High
temperatures throughout the long term period should generally range
from the mid 30s to the mid 40s. Tuesday night should be the coldest
night of the long term period, with lows ranging from zero in the
tip of the Arrowhead, to around 10 above in southern portions of the
CWA.

&&

.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1252 AM CDT Mon Mar 20 2017

VFR conditions expected through the upcoming TAF period.  Weak
front/trough axis moving through the area at this time has turned
southwest winds to a more westerly direction.  A cold front is due
to move through the terminals beginning around 03z, and should turn
winds more northerly.  This front may be accompanied by showers and
some MVFR ceilings, but confidence in timing and ceiling heights is
poor and have put in some lower VFR cloud bases into INL and HIB for
now.


&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  45  17  29  10 /  10   0   0   0
INL  45  12  25   3 /  10  20   0   0
BRD  50  21  33  12 /  10   0   0   0
HYR  49  19  35  10 /  10   0   0   0
ASX  49  21  33  12 /  10   0  10  10

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
LS...None.
&&

$$

SHORT TERM...JTS
LONG TERM...DAP
AVIATION...DAP



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