Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 280038

Area Forecast Discussion
National Weather Service Duluth MN
738 PM CDT Sat May 27 2017

Issued at 725 PM CDT Sat May 27 2017

A quick update to account for the latest radar trends, and
aviation section below.


.SHORT TERM...(This evening through Sunday)
Issued at 352 PM CDT Sat May 27 2017

Scattered showers and isolated thunderstorms tonight then showers
and thunderstorms on Sunday. A few storms may be strong Sunday.

A closed upper-level low was centered over central Manitoba this
afternoon with three distinct vorticity maxima observed by water
vapor imagery. Self-destructive sunshine in north-central
Minnesota this morning and early this afternoon has supported the
development of scattered showers and isolated thunderstorms.
Expect the showers/ storms to increase in coverage through early
evening and gradually diminish tonight with the loss of daytime
heating. Sharp 850 mb height falls are expected overnight as the
vort max over southwest Manitoba rotates into northern Minnesota
tonight. The shower coverage should increase once again late
tonight as the trough moves across northern Minnesota.
Temperatures tonight will dip in to the upper 30s in portions of
northern Minnesota to near 50 degrees in the Brainerd Lakes and
locales from Spooner to Phillips, WI.

Temperatures will be a little cooler on Sunday with partly to
mostly cloudy skies expected. The shortwave trough and initial
vort max will push through northwest Wisconsin during the morning
with a few showers possible. Skies will clear behind the morning
precipitation yielding increased insolation and warming
temperatures. The combination of early morning precip and heating
should result in MLCAPE values of 750-1500 J/kg. Deep layer shear
is somewhat limited, between 25 and 30 knots in the 0-6 km layer.
However, with continued cool advection aloft and modest
instability, a few strong thunderstorms are possible in northwest
Wisconsin and northeast Minnesota. Frequent lightning, brief heavy
downpours, and hail up to penny size are possible with the
strongest storms. Anyone with outdoor plans is encouraged to keep
up with the forecast during the day and be aware of the nearest
shelter should storms threaten. Highs will reach the middle 60s in
north-central Minnesota to near 70 degrees in our southern zones.

.LONG TERM...(Sunday night through Saturday)
Issued at 352 PM CDT Sat May 27 2017

Much of the long term period will be dominated by a massive upper
level low that will establish itself over the Great Lakes region.
Scattered showers will be common across the Northland from Sunday
night into Tuesday. A few thunderstorms will also be possible,
especially Sunday evening and Monday afternoon, and due to the
cold air aloft, perhaps some small hail. The chance of showers
should diminish considerably by Tuesday night, although cannot
rule out a few showers on Wednesday. Have kept it out of the grids
for now, but may need to add some diurnally driven showers for
Wednesday afternoon in the Minnesota Arrowhead and northern
Wisconsin. High pressure will build in for the end of the work
week, but northwest flow will continue into Thursday or Thursday
night. Heights are then expected to build at the end of the work
week and into the first part of the weekend. The ECMWF and GFS do
show some dramatic differences at that range, so will carry small
POP`s but confidence is lower. Highs on Monday and Tuesday will be
limited to the 50`s due to showers and fairly abundant cloud
cover. By Wednesday, temperatures should return to the 60`s, with
70s for the last portion of the work week and into the weekend.
Temperatures will be cooler at times near Lake Superior, as is
typical this time of year.


.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 725 PM CDT Sat May 27 2017

Scattered showers and isolated thunderstorms to affect the
northern MN terminals this evening, before diminishing a little
around 03z. Then, the main shortwave moves through the area later
tonight, with more showers moving through the area after 07z
tonight, continuing through approximately 18z for the MN
terminals, and through 20z for KHYR. Lower clouds to linger after
the showers move through, with MVFR ceilings to affect KINL, KHIB
and possibly also KDLH after 15z.


DLH  48  66  46  57 /  30  50  30  40
INL  45  64  47  54 /  50  50  50  60
BRD  50  69  49  58 /  30  40  40  30
HYR  49  71  47  59 /  20  40  30  40
ASX  50  69  47  59 /  20  50  30  50




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