Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 280817
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
317 AM CDT SUN AUG 28 2016

.SHORT TERM...(Today through Monday)
Issued at 317 AM CDT Sun Aug 28 2016

The vigorous upper level trof was moving through the Arrowhead at
07Z/2am. Meanwhile, at the surface, high pressure covered the
forecast area with plenty of stratus and patchy fog. A thunderstorm
complex has developed in northeast South Dakota which is on the nose
of a low level jet moving through eastern South Dakota and into west
central Minnesota. This complex is also on the leading edge of an
area of positive vorticity advection as the next short wave is
moving through the central Dakotas. At this time, the track of the
storms takes it into the Brainerd lakes area by 10Z/5am. Have
adjusted pops accordingly to account for this complex. The latest
short term hires model guidance, particularly the HRRR, has this
complex lingering/expanding around the Brainerd lakes until early
afternoon, expanding toward the I35 corridor. The NAM does not pick
up on this at all, while the GFS and ECMWF do. These models have the
complex staying in west central Minnesota through the morning before
decaying. Leaned more toward the HRRR, but will mention to the next
shift about the GFS/ECMWF solution. Elsewhere, with upper ridging
building across the region, no rain is expected.

Model solutions vary widely with the evolution of the next round of
storms to affect the area tonight. The NAM has an MCS plowing
through northern Minnesota, the GFS has storms over the northern
third of the area, the GEM hints at something developing in central
Minnesota, the ECMWF has a complex of storms from eastern North
Dakota to the Twin Ports before 06Z/1am. Leaned away from the NAM
and GEM and used a blend of the GFS/ECMWF for pops. These storms
will form on the nose of the level jet moving into Minnesota as a
potent vorticity max moves quickly into Minnesota on the fast
westerly flow aloft. There is a potential for some of the storms to
be strong to severe overnight as shear increases, as does lapse
rates, and MUCAPE ranges from 1500 to 3000 J/kg. This is in response
to the low level jet/vorticity max moving eastward over the area,
and an approaching cold front.

Thunderstorms will continue on Monday as the cold front moves into
the region by Monday afternoon. Will have the highest pops along and
on either side of the cold front. Severe is possible again on
Monday, but due to ongoing storms from Sunday night, this may limit
the amount of instability available for severe to form.

.LONG TERM...(Monday night through Saturday)
Issued at 317 AM CDT Sun Aug 28 2016

A stormy and warm start to the work week Monday will be followed by
sunny and seasonable days through the rest of the work week. Chances
for storms return late Friday into Saturday. Highs in the low to mid
70s each day, except for across the tip of the MN Arrowhead where
highs will be a bit cooler in the upper 60s. Overnight lows likely
coolest Tuesday night with lows in the 40s to low 50s, otherwise in
the 50s most nights.

On the synoptic scale the extended period will be dominated by a mid-
level longwave ridge across the Plains/Canadian Prairie mid-week
resulting in broad area of high pressure building mid to late week.
This area of high pressure builds to the east towards the lower
Great Lakes by Friday with a zonal to west-southwest flow developing
aloft, setting the stage for a number of embedded mid-level
disturbances to move across the northern Plains into the upper
Midwest for the weekend.

&&

.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
Issued at 1236 AM CDT Sun Aug 28 2016

A trough of low pressure will move off tonight and brief ridging
will build in its wake. Showers or storms will end overnight as
well. The latest satellite imagery showed plenty of IFR and MVFR
ceilings over northwest Wisconsin and across portions of northern
Minnesota. The clouds were expanding toward the west. Fog will
become more widespread overnight, but the clouds may limit how dense
the fog becomes. However, where clouds remain thin or absent, the
fog may become dense. KHIB has been down to a quarter mile already.
The fog and low ceilings will rise Sunday morning. There may be a
cumulus field that develops and some broken MVFR ceilings may occur
at the onset, but then mainly VFR conditions will occur through the
afternoon.

A few showers or thunderstorms will be possible Sunday, mainly in
the afternoon with chances increasing during the evening and
overnight period. More fog will be possible Sunday night.

&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  77  62  83  57 /  20  60  60  40
INL  79  63  81  51 /  30  60  40  10
BRD  80  66  82  57 /  40  50  40  20
HYR  78  63  81  59 /  10  60  40  60
ASX  79  62  84  61 /  10  60  40  60

&&

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

$$

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


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