Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 231735

Area Forecast Discussion
National Weather Service Duluth MN
1235 PM CDT Fri Jun 23 2017

Issued at 1030 AM CDT Fri Jun 23 2017

Increased POPs over portions of northwest Wisconsin for this
afternoon as well as mentions of thunder. With the upper-level low
continuing to churn overhead and the Northland in a cyclonic flow
regime, high-res meso models like the HRRR are progging a more
expansive area of showers across the area. Scattered showers have
already developed over northeast Minnesota, and it`s expected to
only expand southeast through the day. Latest MUCAPE values from
the 12z guidance has dropped a bit, but may still reach up to 700
J/kg later this afternoon, so increased the mention of thunder as

UPDATE Issued at 752 AM CDT Fri Jun 23 2017

Updated for new 12Z Aviation Discussion below.


.SHORT TERM...(Today through Saturday)
Issued at 435 AM CDT Fri Jun 23 2017

The next 24 hours are going to be dominated by the large upper
low over the James Bay area, producing cyclonic flow over the
region. Shortwaves rotating through this northwest cyclonic flow
is going to bring periodic chances for showers and thunderstorms
today through Saturday. Today, the first and weakest of these
waves is going to move through the area with diurnal effects to
help generate scattered showers mainly for areas along and north
of the Iron Range, with lower chances farther south. Thunder is
possible, but we just do not develop much CAPE today and have kept
the chances for that relatively low. Clouds to also follow this
trend, with mostly cloudy conditions north and a bit more sunshine
to the south. This extra cloud cover is going to keep conditions
cooler today than yesterday, with highs mainly in the 60s for
northern Minnesota, with lower 70s mainly for northwest Wisconsin.
Tonight chances for showers continue with a weak surface trough
in the vicinity, also mainly for areas to the north. Lows to be
warmer than this morning as well, staying in the 40s for most
locations. Saturday a stronger shortwave moves through the upper
level flow, but mainly to our southwest, which is going to
increase pops overall compared to today, but will increase the
most across the southern CWA. We will also have more instability
around, and expect a number of garden variety thunderstorms
Saturday afternoon and early evening. Highs Saturday to remain
cool in the northwest flow, with highs only in the upper 50s far
north to mid 60s south.

.LONG TERM...(Saturday night through Thursday)
Issued at 435 AM CDT Fri Jun 23 2017

Summary: A broad and slow-moving longwave trough will keep the
Northland in a northwest flow pattern through Monday. The main
upper trough will push eastward Tuesday and Wednesday as a ridge
to our west flattens into a quasi-zonal flow for mid-week. A
number of shortwave troughs will rotate through the region during
the period with several chances of showers and thunderstorms.

A broad longwave trough will remain over the area Saturday
evening with a departing shortwave over central and southern
Wisconsin. Showers and thunderstorms should be ongoing over the
Northland and will gradually diminish in coverage and intensity
overnight. Far northern Minnesota has the best chance of keeping
scattered showers overnight thanks to falling heights ahead of
another shortwave trough. The next trough will continue to rotate
southeastward across the Northland during the day Sunday.
Continued cool air advection aloft and a few breaks in the cloud
cover should yield weak instability with MUCAPE values between 250
and 500 J/kg by mid- afternoon. Thunderstorms will be possible
once again, but severe weather is not anticipated.

A surface ridge will slide southeastward across the Dakotas and
much of Minnesota on Monday. Increasing sunshine is expected along
with a break in rain chances. Temperatures will trend warmer but
are expected to remain below seasonal averages. The warming trend
continues into Tuesday as southerly flow develops behind the
departing surface ridge. The increasing northward moisture
transport will set the stage for showers and thunderstorms Tuesday
night and Wednesday. A progressive shortwave trough will move
across the Dakotas Tuesday night and into Minnesota and Wisconsin
on Wednesday. A surface low and cool front will accompany the
passing trough. Deterministic models point to a potential for
strong to severe storms, but confidence is low given the myriad of
mesoscale details which will contribute to any severe weather
threat. A few more thunderstorms will be possible on Thursday as
another fast-moving shortwave races through the region.


.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 1235 PM CDT Fri Jun 23 2017

Scattered showers and a few thunderstorms will occur this
afternoon into the evening but will decrease in coverage
overnight. Mostly VFR ceilings will occur this afternoon but there
will be occasional MVFR. A better chance for MVFR ceilings will
develop tonight into Saturday morning. Another shortwave will
affect the Northland later tonight into Saturday and bring another
chance for showers and a few thunderstorms. Ceilings should
increase to VFR for most areas Saturday afternoon.

The gusty northwest winds today will diminish this evening.


DLH  67  49  62  48 /  30  10  30  30
INL  64  48  58  47 /  30  30  50  50
BRD  66  48  62  48 /  20  10  30  30
HYR  70  50  64  48 /  30  10  40  20
ASX  71  51  64  49 /  10  20  40  20




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