Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 181810
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
110 PM CDT Thu May 18 2017

.UPDATE...
Issued at 110 PM CDT Thu May 18 2017

Updated for the new 18Z Aviation Discussion below.

&&

.SHORT TERM...(Today through Friday)
Issued at 259 AM CDT Thu May 18 2017

The closed upper low was located in west central Wisconsin at 07Z
with the surface low center vertically stacked underneath the upper
low. Pieces of embedded energy will continue to rotate around the
low as it moves northeastward today. Last band of heavy rain was
affecting much of northwest Wisconsin at 0715Z. Models are in good
agreement with the handling of this system. The closed upper low
opens into a trof by 12Z as the surface low center becomes elongated
over Lake Michigan by mid morning. Some areas of rain will still
affect northwest Wisconsin through mid morning before diminishing.
Some light rain will also occur along the north shore of Lake
Superior through the early morning. The rain will completely end by
18Z over northwest Wisconsin as the upper trof, and whats left of
the surface low center, move off to the east. A very dry airmass
follows behind this system and covers the forecast area by late
afternoon. The sky will clear through the day from northwest to
southeast. Max temps should reach the upper 50s over the western
third of the region, with upper 40s in north central Wisconsin.

Flood potential has diminished as the highest rain fall rates,
occurring now over a portion of northwest Wisconsin, will end by
12Z. After coordination with neighbors and no reports of flooding
per law enforcement, except in the Glidden area, have ended the
flash flood watch.

Surface and upper level ridging covers the area tonight. With a
clear sky and lighter wind, low temperatures will be in the lower to
middle 30s. Have added frost to much of the forecast area. Will hold
off on headlines for now as there is some question on wind speed
which will affect minimum temps as well as frost potential.

The aforementioned ridging prevails Friday morning. By afternoon,
the upper ridging is pushed off to the northeast as the next closed
upper low, currently over northern Utah, reaches western Nebraska
late. Model differences begin to show with the handling of embedded
impulses lifting northward from the low into the region. Used a
blend which results in small pops over southern Crow Wing county in
the afternoon. Max temps will reach the lower 60s over the
Borderland, with 50s elsewhere.

.LONG TERM...(Friday night through Wednesday)
Issued at 259 AM CDT Thu May 18 2017

A longwave trough will extend from northern portions of
Alberta/Saskatchewan into the southwest CONUS Friday evening. This
trough will then move east over the weekend with a northern
shortwave moving south over the Northland keeping the upper level
trough over the Northland into early next week before it finally
shifts east midweek. More rain will occur Friday night through
Tuesday with chances highest Saturday and Saturday night.

Another surface low pressure system will move from the Southern
Plains Friday evening into Iowa by 18Z Saturday, then to far western
Lake Superior by 12Z Sunday before exiting the area later Sunday
night into Monday morning. Rain will develop from south to north
Friday night into Saturday with rain likely for most areas Saturday
into Saturday evening. Rainfall amounts of a 0.50 inches to 1.50
inches will be possible. It will be a cool day Saturday with highs
from the mid forties to lower fifties and winds will be off Lake
Superior and be gusty. The rain will diminish Saturday night into
Sunday and temperatures will be a bit warmer Sunday, mostly in the
fifties.

We have periodic chances for showers Sunday night into Tuesday with
the upper trough still over the area along with cyclonic flow to the
surface. High temperatures Monday and Tuesday will range from the
mid fifties to mid sixties.

As the upper trough exits Wednesday, dry surface low pressure will
develop over the Northland with high temperatures from the mid
fifties to mid sixties.

&&

.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
Issued at 110 PM CDT Thu May 18 2017

Lingering MVFR ceilings across northwest Wisconsin, and nearby
areas of northeast Minnesota, as of early this afternoon, will
continue to lift and scatter back to VFR this afternoon. Expect
overall clearing from the north and west through the rest of the
day. Clear skies and light winds will develop this evening. Fog is
possible late tonight because of the clear skies, light winds, and
saturated soils in some areas. The chances though look fairly low
after reviewing the latest model guidance. The overall atmosphere
moving in today and tonight may be just too dry. Plus, much of the
area will drop to the near the freezing mark tonight, so
saturation of the air may more likely result in ground frost than
fog. The KHYR area in northwest Wisconsin has the best chance of
getting fog considering the saturated soils from several days of
rains.

&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  52  33  52  35 /  50   0  10  30
INL  55  31  62  37 /   0   0   0  10
BRD  57  36  57  39 /  10   0  10  40
HYR  49  31  57  39 /  50   0  10  40
ASX  46  31  51  35 /  80   0   0  30

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
LS...Small Craft Advisory until 10 PM CDT this evening for LSZ121-
     140>148.

&&

$$

UPDATE...Grochocinski
SHORT TERM...GSF
LONG TERM...Melde
AVIATION...Grochocinski



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