Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 221727 AAA

Area Forecast Discussion...UPDATED
National Weather Service Duluth MN
1227 PM CDT Sun Apr 22 2018

Issued at 1227 PM CDT Sun Apr 22 2018

Please see the 18Z Aviation Discussion below.

UPDATE Issued at 613 AM CDT Sun Apr 22 2018

In coordination with FGF and MIFC, have upgraded the Fire Weather
Watch to a Red Flag Warning for Koochiching and northern portions
of Itasca Counties. No other changes with this update.


.SHORT TERM...(Today through Monday)
Issued at 253 AM CDT Sun Apr 22 2018

Critical fire weather conditions are possible for portions of
north-central Minnesota this afternoon. Otherwise, abundant
sunshine is expected with above to much above normal temperatures.

A flattened ridge aloft was located over the Northern Plains,
Canadian Prairies, and Upper Midwest this morning with surface
high pressure over the western Great Lakes into the Dakotas. A
weak thread of vorticity marked a shortwave trough over North
Dakota and southern Manitoba, which was also indicated by GOES-16
water vapor channels. An area of cirrus also accompanied the

Look for mainly sunny skies once again today across the Northland
as high pressure slides slowly eastward, away from the area, and
the shortwave trough advances eastward into western and northern
Minnesota. Using the location of the trough earlier this evening,
the surface observations and 00Z sounding from Bismarck, ND seem
to be representative of the forecast conditions over north-central
Minnesota this afternoon. Continued to lean on persistence for
relative humidity this afternoon, which results in a wide area of
sub-25% minimum values. Winds aloft will gradually increase from
the southwest ahead of the approaching trough. Deep boundary layer
mixing should boost sustained winds into the 10 to 15 mph range
over our western zones, with frequent wind gusts between 15 and 25
mph. A few occasional gusts of 25 to 30 mph are possible over
Koochiching and northern portions of Itasca County. The
combination of very dry RH values and gusty winds will create
critical to near-critical fire weather conditions this afternoon.
Will hold onto Fire Weather Watch pending coordination with FGF
and MIFC. Highs today will be above to much above normal with
readings in generally in the low to upper 60s. A few spots near
the Lake Superior shore and where snowpack lingers may only reach
the middle to upper 50s.

Dry conditions are expected to continue Monday with temperatures
slightly warmer. Cirrus may linger over the area, but otherwise
mostly sunny skies are expected. Look for afternoon highs in the
low to upper 60s, except where deep snow pack remains in place and
areas along the North Shore of Lake Superior where middle to
upper 50s are expected.

.LONG TERM...(Monday night through Saturday)
Issued at 253 AM CDT Sun Apr 22 2018

Monday night and Tuesday finds the GFS as the only model
generating any precipitation with some upper level energy moving
through Minnesota. The ECMWF and GEM are stronger with the upper
trof, but have a drier column, and thus no precipitation. With a
nod toward the GFS and persistence from prior forecast, will have
some low POPs Monday night and Tuesday. The precipitation
diminishes from west to east Tuesday as high pressure builds in
and the upper trof departs. Upper level and surface ridging cover
the region Tuesday night and Wednesday. Humidities will be low
during the day and tough to recover at night with such a dry
atmosphere. Models have had a tough time handling this dry air and
adjusted as needed. A long wave trof will move into the
Dakotas/Minnesota border area Wednesday night. The GEM and GFS
increase the moisture in the column versus the ECMWF. There is
some question as to where the models are getting this moisture
from as its not from the Gulf of Mexico. An area of low pressure
will move along the international border ahead of this trof. Its
associated cold front will move into Minnesota late. Only the
ECMWF has a dry forecast. Used a blend for POPs. The ECMWF
catches up with the GEM/GFS on Thursday with precipitation along
the advancing cold front. The GEM/GFS have a closed upper low
associated with the surface low Thursday night while the ECMWF
maintains an long wave trof. This results in the ECMWF quickly
moving the precip out of the area versus the slower ending
according to the GEM/GFS. Leaned toward the slower consensus. Much
colder air follows behind the front. Will see a rain/snow mix
during the morning and night transitions, with rain during the day
and snow at night with this system. Not expecting any snow
accumulations. Back to a rain/snow mix Friday morning before
ending as the cold front and upper features depart. High pressure
settles over the region Friday afternoon through Saturday. Temps
will be near to slightly above normal through the long term.


.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 1227 PM CDT Sun Apr 22 2018

VFR through the forecast with gusty winds this afternoon becoming
light this evening as the mixed layer decouples. Expect gusty
winds at INL/HIB and BRD through the afternoon as the pressure
gradient tightens across northwest and north-central Minnesota due
to an approaching cold front. Elsewhere winds will remain at or
below 10 knots.

The mixed layer will decouple this evening and gusty winds will
subside per NAM/RAP/GFS guidance. Did introduce low level wind
shear for a few hours as the low level jet sets up. Winds will
remain light through the rest of the forecast as the cold front
weakens as it moves into the region on Monday.


DLH  61  37  65  39 /   0   0   0  10
INL  64  41  63  34 /   0  10   0  10
BRD  61  37  66  42 /   0   0   0  10
HYR  61  32  63  38 /   0   0   0  10
ASX  62  36  65  38 /   0   0   0  10


MN...Red Flag Warning until 7 PM CDT this evening for MNZ010-018.



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