Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 171721

Area Forecast Discussion
National Weather Service Duluth MN
1221 PM CDT Sat Mar 17 2018

Issued at 1221 PM CDT Sat Mar 17 2018

Please see the 18Z Aviation Discussion below.

UPDATE Issued at 1003 AM CDT Sat Mar 17 2018

Decreased relative humidities across the Northland, as there is
little difference in air mass between yesterday and today.
Increased cloud cover across the Minnesota Arrowhead and eastern
portions of northwest Wisconsin. Utilized the 700 hPa RAP RH as a
proxy as it has a best handle on the cloud cover sliding in from


.SHORT TERM...(Today through Sunday)
Issued at 207 AM CDT Sat Mar 17 2018

Dry conditions continue across the Northland today and tonight.
Another day of abundant sunshine is anticipated today as surface
high pressure currently situated over northeast North Dakota at 07z
this morning is progged to translate southeastward through the day.
Didn`t deviate much from the previous forecast package in regard to
the high temperatures today, with highs still expected to rise into
the middle 40s to lower 50s across the area. For these highs, leaned
heavily towards the bias-corrected raw model blends, which seems to
have had a good handle on the high temperatures lately. Also,
decreased the minimum relative humidity values up to 5 percent due
to the abundant sunshine and warm, dry return flow around the
surface high.

Clouds will slowly increase, especially across north-central
Minnesota and over the tip of the Minnesota Arrowhead early Sunday
morning as a surface low pressure system passes by to our northeast
this evening, bringing better moisture with it. No precipitation is
expected from the passage of this low as NAM/GFS soundings indicate
too much dry air near the surface for anything to materialize, but
cloud cover should increase through the day Sunday as colder air
seeps into the region once the low passes through. 925 mb
temperatures could drop to between 5 to 10 degrees C below zero over
adjacent areas of Lake Superior, with nearly 0 degrees C elsewhere.
Temperatures Sunday should still be above seasonal normals, but will
be cooler compared to today`s temperatures, with highs in the upper
30s to lower 40s.

.LONG TERM...(Sunday night through Friday)
Issued at 207 AM CDT Sat Mar 17 2018

The extended period remains relatively quiet with few significant
weather makers moving through/near the Northland. Temperatures will
be a couple degrees either side of normal, starting off cooler then
moderating slightly Thursday and Friday.

A surface low pressure system will be centered along the
Colorado/Kansas border Sunday evening with an inverted trough
extending well north into the Northern Plains. An area of high
pressure will extend from northern Manitoba to Lake Superior at the
same time. The low and inverted trough will move east Sunday night
into Tuesday with the inverted trough weakening over that time. A
northern stream shortwave will also move into the region Tuesday
into Wednesday. The low level winds will become easterly Sunday
night and continue through much of the week. Most of the Northland
will remain dry Sunday night into Monday but some light lake effect
snow showers or flurries will be possible over western Lake Superior
through at least mid week. Plenty of dry air will be in place over
eastern Lake Superior which should keep significant lake effect snow
in check despite the long fetch and upstream 850MB temperatures
supportive for lake effect snow. Light snow will be possible over
other portions of the area Monday night through Tuesday night but
little accumulation is expected at this time.

Little or no precipitation is expected outside of lake effect snow
showers around Lake Superior from mid through late week as an upper
ridge builds and then moves over the region through that time.


.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
Issued at 1221 PM CDT Sat Mar 17 2018

VFR through the forecast with winds less than 10 knots. High
pressure will remain in place over the Upper Mississippi River
Valley today through Sunday, but will gradually shift eastward as
the ridge slides east. This will bring winds less than 10 knots at
all terminals with a westerly wind direction shifting to a
north/northeasterly direction through the forecast period.


DLH  50  24  39  18 /   0   0  10  10
INL  50  17  40  15 /   0   0  10  10
BRD  47  19  43  21 /   0   0  10  10
HYR  49  18  44  20 /   0   0   0  10
ASX  48  24  39  17 /   0   0  10  10




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