Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 292042

Area Forecast Discussion
National Weather Service Duluth MN
342 PM CDT MON AUG 29 2016

.SHORT TERM...(This evening through Tuesday)
Issued at 342 PM CDT Mon Aug 29 2016

Surface cold front is making slow but steady progress eastward
this afternoon, currently located from near International Falls to
far northeast South Dakota. The airmass along and ahead of the
front continues to destabilize, with MLCAPE values from 2000-3500
j/kg across much of the Duluth CWA, although there is still a fair
amount of inhibition that will need to be overcome before new
TStorms can initiate and sustain.

The overall thinking has not changed much since late this
morning. Thunderstorms are expected to develop between 5 and 7 PM
along a general axis from the Brainerd Lakes region, northeastward
through the Duluth area and the MN Arrowhead. Deep layer wind
shear is quite weak across most of the primary instability axis,
so the severe threat will likely be tied quite strongly to the
strong instability in place with pulse-type storms. The
combination of weak flow, and rather slow moving storms should
result in some potential for heavy rainfall rates/amounts
underneath the most persistent storms, and there will be at least
some risk of damaging wind gusts with wet microbursts, some of
which could be accompanied by hail with the largest/strongest

The front should continue to act as the primary forcing mechanism
through the evening, with the main axis of TStorms shifting
eastward into NW Wisconsin by late evening, and then exiting the
area out of Price County sometime after midnight.

Areas of fog will be possible overnight and Tuesday morning with a
decoupled and moist boundary layer, but should quickly mix out
during the morning as diurnal mixing commences. Otherwise, Tuesday
should be a fairly typical post frontal day with scattered cumulus
clouds and temps primarily in the mid 70s.

.LONG TERM...(Tuesday night through Monday)
Issued at 342 PM CDT Mon Aug 29 2016

An upper level ridge will extend from the western portion of the
Northern Plains well north into Alberta and Saskatchewan. This ridge
will slowly move east over the central plains into Manitoba and
northwest Ontario on Friday. A ridge of high pressure will be over
or just east of the Northland through this period and this
combination will provide dry conditions and seasonable temperatures.

A deep upper trough will move onto the Pacific Northwest Coast
Friday and a surface low pressure system will move into the Northern
Plains into Friday night and continue east into next weekend. There
are differences in how the GFS and ECMWF handle this low, but there
are also similarities considering how far out we are in time. There
will be a chance of showers/storms that occur with this low over the
weekend into Monday.


.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 1223 PM CDT Mon Aug 29 2016

A cold front stretched from far northwest Ontario to near KINL
into South Dakota this afternoon. Scattered to broken clouds from
5KT to 25KFT were occurring this afternoon but we do expect some
cumulus development through the afternoon. As heating continues,
we do expect showers and thunderstorms to form along the front as
it moves through the Northland. Much of the guidance is in
agreement that it may take a couple more hours for initiation,
most likely after 21Z. Some strong to severe storms will be
possible, most likely at KBRD/KDLH/KHYR.

The wind will switch to the northwest behind the front tonight. If
winds are able to decouple overnight, some fog will form and we
have added to KHYR.


DLH  57  76  51  74 /  60   0   0   0
INL  51  75  48  74 /  10   0   0   0
BRD  56  77  52  76 /  20   0   0   0
HYR  59  77  49  75 /  60  10   0   0
ASX  61  76  52  73 /  60  10   0   0


.DLH Watches/Warnings/Advisories...

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