Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 241739

Area Forecast Discussion
National Weather Service Duluth MN
1239 PM CDT Mon Apr 24 2017

Issued at 1130 AM CDT Mon Apr 24 2017

Update to reflect big temperature difference between Lake Superior
areas and inland areas due to strong off-lake winds. About 40 near
the lake and in the 60 to 65 degree range well inland.

UPDATE Issued at 847 AM CDT Mon Apr 24 2017

Added precipitation chance for far northern MN this morning to
reflect radar trends.


.SHORT TERM...(Today through Tuesday)
Issued at 456 AM CDT Mon Apr 24 2017

Light snow showers continued across far northern Minnesota early
this morning, associated with a weakening area of frontogenetic
forcing which was retreating northward. Strong northeast winds
were found over western Lake Superior due in part to tightening
pressure gradient between a surface ridge over northern Ontario
and approaching low pressure over the Plains. Those strong winds
extended inland to Two Harbors airport, the Twin Ports, and even
to Cloquet and Moose Lake. During the last hour at DLH winds were
sustained at 19 knots gusting to 33 knots and at Superior
sustained at 17 knots gusting to 23 knots. Sustained winds at DYT
were stronger, 27 knots gusting to 30.

Snow showers will continue to slide east-northeast and weaken by
noon today as FGEN continues to push northward well ahead of the
surface warm front. Isentropic upglide will also weaken later
today. Southerly winds aloft should be able to erode some of the
cloud cover over northwest Wisconsin into the Arrowhead later this
morning, but the amount of clearing remains in question. Dry
relative humidities of less than 30% are expected over portions of
northwest Wisconsin this afternoon. Fires may start easily due to
lingering dry grasses and leaf litter combined with limited
botanic activity. Winds will generally be southerly from the
Brainerd Lakes east across northwest Wisconsin south of the
Pattison, Bayfield, and Gogebic ranges. Wind speeds will increase
by this afternoon to 10 to 20 miles per hour, which could support
efficient fire spread. The easterly to northeasterly winds over
western Lake Superior and in the lower elevation locales inland
from the lake will gradually weaken this evening as the surface
pressure gradient eases.

Cloudy skies will linger over the remainder of the forecast area
today as the surface low fills to an inverted trough and lifts
toward the Northland. Precipitation will continue to expand over
the Dakotas today, advancing northeast into our western zones this
afternoon. Temperatures are trending warmer than expected this
time yesterday, so think rain will be the dominant precip type
through tonight. There is a slight chance some of the higher
elevation areas of far northeast Minnesota may see a mix of rain,
freezing rain, or snow tonight. The inverted trough will advance
eastward across northern Minnesota tonight, with a cool front
moving across central and southern Minnesota into Wisconsin by
sunrise Tuesday. Rain chances shift eastward on either side of the
trough and generally along and ahead of the cool front. As the
trough lifts out of the Northland, precipitation will end from
southwest to northeast. However, by Tuesday afternoon the leading
elements of the next system will be in the vicinity of our
southern zones. Rain chances expand northward once again by late
afternoon. There is a small chance of a thunderstorm late Tuesday
over portions of northwest Wisconsin, but think the threat is too
low to include in the weather grids at this time.

.LONG TERM...(Tuesday night through Sunday)
Issued at 456 AM CDT Mon Apr 24 2017

A major low pressure system will impact the Northland from
Tuesday night into the end of the work week. The models are in
pretty good agreement concerning the evolution of a low pressure
system, that will lift northeast across the plains states on
Tuesday night and Wednesday. While the models agree early on,
there are substantial differences between the ECMWF and GFS after
Wednesday. Have gone closer to the ECMWF solution based on the
fact that the models and ensembles have generally shifted west and
slower than previous runs. Will continue with categorical POP`s
for Tuesday night, with likely POP`s into Wednesday. The main
question at this point is the potential for snow and/or ice
accumulation. Definitely think there is potential for snow
accumulation, especially across northeast Minnesota. The best
chance for ice accumulation would be in the Lake Superior area,
and across northwest Wisconsin. Relatively high POP`s will
continue to be needed from Wednesday night as well, especially
across the eastern half of the CWA. Precipitation should gradually
decrease across the area from Thursday into Thursday night, with
a mix of precipitation types again possible. There is actually
quite a bit of model discrepancy from Friday into Saturday. The
national blend generally favors the ECMWF in this scenario as
well. The next major low pressure system is expected to move into
the western Great Lakes region on Sunday and Monday. Again, the
models are in major disagreement concerning the track of this
system. Will feature the highest POP`s at this point in the
southeast half to two thirds of the CWA. Overnight lows will
generally range from the 20s to 30s, with highs in the 30s and 40s
throughout the period.


.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 1239 PM CDT Mon Apr 24 2017

VFR conditions this afternoon will deteriorate to MVFR/IFR
ceilings tonight as rain showers move across the region from west
to east. Rain will end towards dawn Tuesday but patchy fog and low
ceilings will persist into the mid morning hours at least. Gusty
east winds this afternoon will subside this evening, with winds
out of the north-northwest towards Tuesday morning.


DLH  42  37  54  30 /  40  50  70  70
INL  44  33  40  24 /  90  90  20  30
BRD  62  39  52  32 /  50  50  60  70
HYR  64  47  63  35 /  30  40  80  80
ASX  60  44  61  32 /  30  40  70  80


LS...Small Craft Advisory until 10 PM CDT this evening for LSZ121-

     Small Craft Advisory until 4 AM CDT Tuesday for LSZ144-145.

     Small Craft Advisory until 9 AM CDT Tuesday for LSZ140>143.



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