Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 270853
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
353 AM CDT SAT AUG 27 2016

.SHORT TERM...(Today through Sunday)
Issued at 353 AM CDT Sat Aug 27 2016

An upper level trof was moving into the western Dakotas at 08Z with
embedded pieces of energy cruising through the western Great Lakes.
The southwest flow aloft is helping to raise the amount of
moisture/cloud cover into the forecast area. This is resulting in
some high based showers/sprinkles attempting to dot the landscape
this morning. Meanwhile, surface high pressure was centered over
northeast Wisconsin with a ridge axis over the area.

The upper trof will reach western Minnesota by 00Z/7pm with those
pieces of energy lifting northeastward through the area on the
southwest flow aloft. Meanwhile, the surface high remains nearby.
Will see the opportunity for showers increase this morning, with
some thunderstorms possible in the afternoon. The bulk of the rain
will fall over northeast Minnesota where the best source of moisture
is located, as well as better forcing. Northwest Wisconsin will be
dry for most of the day after the early morning showers.

The upper trof moves through northern Minnesota this evening and
lifts into Ontario later tonight. Have the highest pops over the
northern third of the forecast area this evening as the trof crosses
overhead. Lower pops farther south and into northwest Wisconsin. As
the upper trof reaches Ontario, the forcing remains ahead of the
trof and in the immediate vicinity. The moisture diminishes through
the evening with the surface high still nearby. Have some small pops
right along the Canadian border for any lingering showers.

On Sunday, upper level ridging begins to build across the region
with the surface high in the vicinity. However, the models are
allowing for a small vorticity maximum to scoot through the area as
the upper flow becomes westerly. There is just enough instability to
warrant a mention of thunderstorms in the afternoon over the
southern half of the forecast area.

.LONG TERM...(Sunday night through Friday)
Issued at 353 AM CDT Sat Aug 27 2016

Seasonable to slightly warmer than usual temperatures as August
comes to an end with a chance for showers and storms early in the
week...dry mid-week...then chances for precipitation returning late-
week into the weekend.

Sunday night into Monday a warm front lifting into the Northland
will result in a chance for showers and storms, with chances coming
to an end as a cold front moves through from west to east Monday
night. With an upper high to the southeast and a mid-level shortwave
trough approaching from the west, moderate warm air advection Sunday
into Sunday night will aid in the large-scale forcing for Sunday
afternoon/evening convection, but the real driver for widespread
precipitation will likely be a strong low level jet that ramps up
overnight aiding in sustained convection. Elevated instability will
be on the order of 1500-3000 j/kg, and while deep layer shear could
be only 20-30 knots due to weaker mid and upper level winds, the low
level jet combined with the moderate to potentially extreme
instability through a deep column could produce some strong storms.
This is evident especially in the GFS which has an odd donut of
omega around a convective complex it develops Monday night. Last few
runs of the NAM are not as aggressive with the convective
development, but it seems if the steep mid level lapse
rates/elevated instability can advect this far north combined with
the warm front, any storms that develop could be strong to severe.

Ahead of the cold front Monday highs will reach the low 80s, likely
the warmest day of the forecast period, with dew point values
approaching 70. Cold front moves through Monday night leading to
clearing skies. Sunny skies Tuesday/Wednesday then mostly sunny
Thursday as a broad area of high pressure builds across the upper
Midwest in response to a mid-level longwave ridge across Canadian
Prairie building eastward. Highs in the 70s through the mid-week.


This ridge axis crosses the Northland Friday morning with clouds
increasing due to increasing low/mid level moisture and warmer air
moving in from the southwest at low/mid levels. Chance for showers
and storms increases Friday, with the better chance for precipitation
on Saturday as a warm front builds into the region from the west.

&&

.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
Issued at 1238 AM CDT Sat Aug 27 2016

A trough of low pressure over the Northern Plains will continue east
tonight moving into Minnesota on Saturday. There may be some showers
that develop overnight, mainly over western and northern areas of
the Northland, but a better chance will occur on Saturday. The most
widespread showers and thunderstorms will occur over northern
Minnesota. Mostly VFR conditions are expected through the period
with brief MVFR conditions in the stronger showers/storms. There was
plenty of mid to high clouds over the region late this evening, but
if some thin spots develop, fog may form. At this time, we limited
the mention to KHYR.

&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  71  55  75  61 /  20  20  20  50
INL  70  53  77  61 /  80  60  10  60
BRD  73  57  80  66 /  50  40  20  30
HYR  74  57  79  63 /  10  10  20  40
ASX  74  58  77  63 /  10  10  20  30

&&

.DLH Watches/Warnings/Advisories...
WI...None.
MN...None.
LS...None.
&&

$$

SHORT TERM...GSF
LONG TERM...JJM
AVIATION...Melde



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