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000
FXUS63 KDLH 222335
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
635 PM CDT Sat Jul 22 2017

.SHORT TERM...(This evening through Sunday)
Issued at 241 PM CDT Sat Jul 22 2017

This afternoon we are watching the cumulus field over northern
Minnesota very carefully, as the airmass is increasingly unstable
with deep layer shear values approaching 40 knots. We have had
some echoes over Koochiching and Itasca county as some updrafts
have tried to get going, but these have not lasted long and it
seems we may need to wait until the colder temperatures associated
with the potent upper low over southern Manitoba moves a little
closer in the next few hours. Am expecting an active evening over
the forecast area once storms can initiate though, with CAPE
values now approaching 1500j/kg, and only forecast to continue to
increase into the evening hours. Expect initiation sometime in the
next 1-3 hours and our main threat to be large hail and damaging
winds. After the storms move through this evening a cooler and
drier airmass will move in, and expect temperatures to fall into
the 50s nearly everywhere. This cooler airmass will keep us cooler
for Sunday with some lingering showers during the afternoon hours.
Highs on Sunday will only get into the low to mid 70s, with cooler
conditions near Lake Superior.

.LONG TERM...(Sunday night through Saturday)
Issued at 241 PM CDT Sat Jul 22 2017

The early part of the extended period will be affected by another
round of strong to possibly severe thunderstorms. A cold front
will move through the region as a shortwave moves through southern
canada Tuesday morning through early Wednesday morning. Ahead of
the front as indicated by the previous shift, a strong push into
the forecast area of high theta-e values along with an increase in
PWATs. Showers and strong thunderstorms will spread west to east
Tuesday with possible severe storms Tuesday afternoon and evening.
SPC has all of the forecast area in a 15% chance for severe
weather on Tuesday.

After the front passes, high pressure will build into the region
on Wednesday and keep the area rain free through the weekend. The
only chance for any precipitation will be late Sunday as a
shortwave moves through the region. High temperatures will be
near their normals levels in the upper 70s to the lower 80s with
60s along Lake Superior.

&&

.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 635 PM CDT Sat Jul 22 2017

A strong upper level shortwave was located along the common border
of Minnesota, Manitoba, and northwest Ontario this evening. This
feature will continue to move east-southeast tonight toward the
Upper Peninsula by 12Z. A low level trough was located ahead of
this shortwave and these features will produce stronger
thunderstorms through the evening hours as they move through the
Northland. Additional showers and a few thunderstorms were
occurring under and just ahead of the upper wave over northwest
Minnesota. The showers/storms will continue for a few more hours
but will then end overnight for most areas. There is a chance for
MVFR or even IFR ceilings as the colder air moves south over the
region and we do have a mention in some of the TAFS for that...and
may have to expand. Patchy fog will be possible as well later
tonight. Conditions will improve to VFR during the day Sunday.

&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  56  69  51  75 /  40  20   0   0
INL  55  76  53  80 /  40  10   0   0
BRD  59  75  54  78 /  10  10   0   0
HYR  57  70  51  77 /  40  10   0   0
ASX  55  67  50  76 /  30  20   0   0

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
LS...None.
&&

$$

SHORT TERM...LE
LONG TERM...Stewart
AVIATION...Melde