000
FXUS63 KDLH 170557
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
1257 AM CDT Tue Apr 17 2018

.UPDATE...
Issued at 1247 AM CDT Tue Apr 17 2018

Updated below for 06Z aviation discussion.

UPDATE Issued at 1000 PM CDT Mon Apr 16 2018

Latest short term hires models indicate accumulating snow is
still a factor until 4 am for Iron County, WI. Have extended the
Winter Weather Advisory as a result. Made some other minor
changes.

UPDATE Issued at 642 PM CDT Mon Apr 16 2018

Snow has increased in coverage over the tip of the Arrowhead as an
elongated area of vorticity moves through. Light snow continues
along the south shore of Lake Superior, occasionally making it
well inland to the Hayward Lakes and east to near Mercer. Made
some adjustments to pops/weather to account for these trends.

&&

.SHORT TERM...(This evening through Tuesday)
Issued at 312 PM CDT Mon Apr 16 2018

Lake effect snow showers and scattered flurries are expected
tonight and Tuesday as high pressure builds into the Northland.

The remnants of the weekend storm remain over the Great Lakes
this afternoon. Cool cyclonic flow over the Northland has kept
clouds over much of the Northland. The stratus has thinned over
western zones and surface features are visible on GOES-16
satellite imagery. The northerly winds over western Lake Superior
will keep lake effect snow showers in play over Bayfield, Ashland,
and Iron Counties. The highest snow totals through Tuesday
morning are expected over northern Iron County where a Winter
Weather Advisory remains in effect. Additional snow amounts from 1
to 4 inches are expected along the Penokee Range in Iron and
Ashland Counties. Scattered flurries will continue in the cyclonic
flow aloft over much of the rest of the Northland tonight.

A mid-level ridge to our west this afternoon will amplify as an
Omega Block pattern evolves tonight and Tuesday. Surface high
pressure will build into the Northern Plains in response to rising
heights working to scatter out the stratus over western and
central Minnesota. Cyclonic flow and upstream ice-covered lakes
over the Canadian Shield will keep stratus in the picture over our
eastern zones on Tuesday. Temperatures will trend warmer with
highs in north-central Minnesota in the low 40s to the middle 30s
in north-central Wisconsin.

.LONG TERM...(Tuesday night through Monday)
Issued at 312 PM CDT Mon Apr 16 2018

Summer is on its way, well maybe spring, but it may feel like
summer by the weekend when highs break into the mid to upper 50s
and maybe even up into the 60s. Now that the good news is out of
the way, we still have to endure another wintry system before that
happens. Luckily this one should be a quick hitter with most of
its energy going to the south of our CWA.

There is quite good model agreement on another wintry system that
should impact mainly Iowa into south-central Minnesota on
Wednesday. There is a chance some light wintry precipitation could
make it up into the southern parts of our CWA. This system is
quite different in dynamics than last weekends system. It`s more
of a tight pinwheel 500 vort max quickly passing in zonal flow.
There should not be a great deal of impact to the area with the
exception of some light icing/snow on roads. Accumulations should
be <1" for snow and only a couple hundredths for ice if it even
occurs. After this system passes, weather is quiet as high
pressure builds and eventually much warmer air. Melting the
snowpack will steal some of the heat, so not very confident on max
daily temps.

&&

.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1247 AM CDT Tue Apr 17 2018

High pressure will build in from the west overnight. VFR
conditions have already moved in to KINL, KHIB and KBRD. MVFR CIGS
at KDLH should scatter out within the next few hours as clearing
line passes by. Light lake effect snow at KHYR is leading to MVFR
VSBYS, but this is expected to taper off within the next hour or
so. All sites then expected to see VFR for much of the remainder
of the TAF period. However, winds will turn easterly Tuesday
evening bringing MVFR CIGS to KDLH. Clouds ahead of the next
system will move in to KHIB and KBRD Tuesday evening bringing MVFR
CIGS as well.

&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  19  39  25  35 /   0  10  10  30
INL  19  44  27  42 /   0   0  10  20
BRD  19  43  27  39 /   0   0  10  40
HYR  20  39  23  38 /  50   0  10  40
ASX  24  37  24  37 /  90  10  10  30

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
WI...Winter Weather Advisory until 4 AM CDT early this morning for
     WIZ004.

MN...None.
LS...Small Craft Advisory until 10 AM CDT this morning for LSZ121-
     140>148.

&&

$$

UPDATE...BJH/GSF
SHORT TERM...Huyck
LONG TERM...Wolfe
AVIATION...BJH