Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 220555

Area Forecast Discussion
National Weather Service Duluth MN
1255 AM CDT Tue May 22 2018

Issued at 1255 AM CDT Tue May 22 2018

Updated below for 06Z Aviation Discussion.

UPDATE Issued at 1045 PM CDT Mon May 21 2018

The rain has ended and have removed. Latest short term hires
models point to some fog developing around northwest Wisconsin, as
well as near the Twin Ports and the Brainerd Lakes. Added a patchy
fog mention late tonight.


.SHORT TERM...(This evening through Tuesday)
Issued at 303 PM CDT Mon May 21 2018

Generally warm and dry with light winds though moisture is on the
increase as a system moves through Illinois. This system is
spawning some light showers this afternoon mainly south of a line
extending from Duluth to Red Lake under a short wave. None of
these storms should be severe - more of just nuisance showers.
This system will increase cloud cover over the southern half of
the forecast area.

High pressure builds for Tuesday for another quiet, dry, and warm
day. Even the winds will be light.

.LONG TERM...(Tuesday night through Monday)
Issued at 303 PM CDT Mon May 21 2018

The beginning of the extended period looks to start out quite
tranquil with short wave ridging overhead Tuesday night/Wednesday.
The result for sensible weather should be more of the same, with
rather chilly overnight temps (especially in the interior Minnesota
Arrowhead) Wednesday morning, but with temps rapidly rebounding
Wednesday to at or above seasonal norms for the late part of May.

An upper level disturbance will approach the region from the
southwest Wednesday night/Thursday time frame, and should be
accompanied by the first push of decent-quality low level moisture
for the season.  Surface dewpoints are expected to rise into the
lower/mid 60s during the late Thursday-Saturday time frame, and this
should be sufficient for the development of several rounds of
showers and thunderstorms late this week and into the first part of
the Memorial Day Holiday weekend.  Mean boundary layer mixing ratios
between 11-13 g/kg should support CAPE values between 1000-2000
j/kg, which could be sufficient for a few stronger thunderstorms.
However, at this time, the medium range models are not forecasting
deep layer shear to be particularly strong (generally around or less
than 30 knots) - and this will be a limiting factor for severe
storms unless shear eventually verifies as stronger.

While the strongest deep-layer forcing for ascent with this system
should be across far northern Minnesota and northward into Canada,
there should be sufficient forcing to allow for rather decent
coverage of showers/storms and some much-needed rainfall across the
region during the Thursday through Saturday time frame.

At present, the latter part of the upcoming Holiday weekend looks to
be a return to pleasant weather, with near or slightly above normal
temps, and minimal chances for precipitation Sunday and Memorial Day.


.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1255 AM CDT Tue May 22 2018

A mix of VFR and MVFR conditions are seen at the start of the
period. CIGS are expected to lower across most terminals through
the early morning hours. INL and HIB will be the exceptions as
they will remain north of the lower clouds through the period.
HYR will see further reductions around daybreak to IFR and perhaps
even LIFR CIGS before starting to improve to MVFR by mid-morning.
CIGS will then be slow to improve through the day before breaking
out by early evening. VFR conditions will then be seen across all
terminals. Otherwise, very light winds are expected with high
pressure in place overhead.


DLH  50  74  52  79 /  70   0   0  10
INL  47  77  48  83 /   0   0   0   0
BRD  52  74  53  81 /  10   0   0  10
HYR  51  74  51  82 /  10   0   0  10
ASX  49  75  50  79 /  10   0   0  10




LONG TERM...Miller
AVIATION...BJH is the U.S. government's official web portal to all federal, state and local government web resources and services.