Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 201146

Area Forecast Discussion
National Weather Service Duluth MN
646 AM CDT Tue Mar 20 2018

.SHORT TERM...(Today through Wednesday)
Issued at 258 AM CDT Tue Mar 20 2018

Some light snow is expected for this morning through mid afternoon
today near the Brainerd Lakes region, with dry conditions expected
through the day Wednesday. Current regional radar imagery indicates
a large swath of precipitation extending from far eastern Nebraska
up towards north-central Minnesota as an inverted trough and upper-
level wave makes its way eastward. Despite light radar returns on-
going over our western tier of counties, very little precipitation
is reaching the ground, per current observations and webcams. The
models have seemed to trend precipitation a bit lower than from 24
hours ago, as seen in both the GEFS and SREF ensemble snowfall
plumes. There`s still some weak lift across a good chunk of the
region today per the Thaler QG omega values, with the strongest lift
over our region from Brainerd southeast towards Hinckley. Surface
high pressure continues to linger over central Ontario Canada, which
is keeping easterly winds over the Northland, with some stronger
winds over adjacent areas of Lake Superior. The pressure gradient
that kept winds breezy yesterday has diminished, so not expecting
the winds today to be quite as strong. Due to the persistent east
flow, some lake effect snow flurries are possible from the Twin
Ports and along the North Shore through the afternoon. However, not
expecting any accumulation from these flurries due to drier air over
Lake Superior. The bulk of the snowfall will occur around the
Brainerd Lakes area since the best lift will be collocated there. We
have also decreased snowfall amounts in this area, with total new
snowfall up to one inch for areas in southern Cass county, with
around a half-inch over the town of Brainerd.

Chances of light snow will come to an end this evening as the
inverted trough dives southward. Then, the dry air over Lake
Superior will begin to take control late tonight, and especially
during the day Wednesday. The surface high over Ontario will linger
over James Bay, keeping conditions mostly dry. Some of the synoptic
model guidance is wanting to keep some lingering moisture/QPF over
northwest Minnesota during the day Wednesday, but some of the high
resolution mesoscale models appear to have hardly any precipitation
over these areas. Due to the uncertainty, decided to lean on the
consensus blends for QPF Wednesday, which keeps things dry
Wednesday. High temperatures Wednesday will be near seasonal normal,
with highs ranging from the lower 30s along Lake Superior into the
middle to upper 30s further inland. Skies look to range from mostly
sunny over the east to partly to mostly cloudy over the west.

.LONG TERM...(Wednesday night through Monday)
Issued at 258 AM CDT Tue Mar 20 2018

The extended period will start out dry for most areas with a chance
for accumulating snow over portions of the Northland Friday night
into Saturday.

A shortwave will exit the Northland Wednesday night and an upper
level ridge will extend from the Four Corners region through the
Rockies into western Canada. This upper level ridge will amplify
some as it moves into the Northern Plains by Thursday night. An
upper low off the Pacific Northwest Coast will send several
shortwaves east and cause the upper ridge to flatten with time as it
continues east over the Northland Friday/Friday night. High pressure
will be at the surface Wednesday night and it will move slowly east
through Friday with a dry east/northeast flow out of the high
keeping much of the region dry Wednesday night into much of Friday.
There could be some lake effect very light snow or flurries around
Lake Superior at times but conditions do not look favorable for much

The models are in decent agreement with the pattern through Saturday
as they develop a broad area of surface low pressure from the
Southern Plains northwest into Alberta Friday. A baroclinic zone
will be over/near the Northland Friday into Saturday. The
combination of a shortwave, broad isentropic lift, and FGEN will
cause precipitation to develop Friday night over portions of the
Northland and continue into Saturday. How far east and north the
precipitation gets will be a challenge as there will be a
continual feed of drier air out of the high over northern Ontario
and the strongest forcing looks to remain west and south of the
area. The 00Z/20th ECMWF is further north and east and higher with
its QPF compared to the 00Z/20th GFS but both are higher and
farther north/east than they were 24 hours ago. It`s starting to
look more favorable for some accumulating snow over parts of the
Northland Friday night into Saturday and at this time the
southwest third, including the Brainerd Lakes region, has the
highest chance. The center of the southern surface low will track
well south of the Northland and the northern low will move well
north on Saturday so the precipitation is expected to diminish
through the day. There still remains considerable uncertainty with
this system so stay tuned through the week for updates.

As the upper trough moves further east into the western CONUS the
upper flow will turn southwesterly for a time Sunday into Monday.
There will be additional chances for rain or snow Sunday into Monday
but differences between the models increase during this time.

Temperatures Thursday and Friday will start out several degrees
above normal then cool toward normals over the weekend.


.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
Issued at 646 AM CDT Tue Mar 20 2018

An inverted trough and shortwave has lead to areas of light snow
over mainly western portions of the Northland, affecting KBRD to
KXVG and points west. Light snow will make some eastward progress
today but it will encounter drier air as an easterly flow
continues out of dry high pressure. A mix of MVFR and VFR
ceilings can be expected with the MVFR ceilings most likely over
western areas including KBRD. Some MVFR ceilings will also be
possible around Lake Superior as a long fetch across the lake
occurs and occasional reduced ceilings can be expected as seen at
KBFW at 1135Z. Some flurries/very light snow could also occur.

As the inverted trough weakens tonight, the chance for snow will
end for most areas. Lake induced clouds and perhaps some light
snow/flurries will continue to be possible around Lake Superior,
possibly affecting KDLH.


DLH  28  14  33  17 /  10  10   0   0
INL  34  13  37  15 /  10  10   0  10
BRD  32  16  37  19 /  70  20   0   0
HYR  32  14  38  12 /  10  10   0   0
ASX  30  14  33  13 /  10  10   0  10




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