Area Forecast Discussion
Issued by NWS Duluth, MN

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000
FXUS63 KDLH 221755 AAA
AFDDLH

Area Forecast Discussion...UPDATED
National Weather Service Duluth MN
1255 PM CDT WED JUN 22 2016

.SHORT TERM...(Today through Thursday)
Issued at 351 AM CDT Wed Jun 22 2016

Weak high pressure was aiding in keeping the region precipitation free
as of 08z. However, a low near the Nebraska/South Dakota border,
a shortwave in southern Saskatchewan, and low level warm
air/moisture advection were all contributing to showers and storms
across portions of the Dakotas into southern Minnesota and Iowa.
Drier and stable air was located over the Northland so we expect
a diminishing trend to the precipitation early as it approaches.
Most of the guidance agrees with this trend early this morning.
There may be some light showers that make it into portions of our
western CWA, roughly from the Bigfork area south through Aitkin
but will then decrease for a time. As the day progresses, the
shortwave and surface low will move east and south bringing a
better chance for showers and a few thunderstorms this afternoon
and continuing into tonight.

Northwest flow aloft and weak high pressure will affect much of
the Northland on Thursday. We kept the forecast dry, but there are
some indications isolated to perhaps some scattered showers or
storms could develop in the afternoon over the southern half of
the Northland and perhaps along the lake breeze along the North
Shore. If more of the guidance shows this we will introduce a
chance with later updates.

Highs today will be in the lower to mid seventies for most areas
and mid to upper seventies on Thursday. Both days will feature
winds off of Lake Superior, with the wind strongest today keeping
lakeside areas cooler.

.LONG TERM...(Thursday night through Tuesday)
Issued at 351 AM CDT Wed Jun 22 2016

Warmer and more humid towards the weekend ahead of a strong low that
will deepen across the northern Plains and southern Manitoba this
weekend, resulting in the possibility of strong to severe storms
across the Northland. As the low exits to the east late in the
weekend into early next week more seasonable conditions will return.

On the synoptic scale there remains some uncertainty with the
progression of the pattern, but strong to severe storms and heavy
rainfall remain possible late Friday into Saturday. Confidence in
the heat and humidity from this pattern is a bit higher as dew
points approach the low 70s Saturday with highs in the low 80s
Friday and mid 80s in some locations Saturday - perhaps even
approaching 90 in some locations such as the Interstate 35 corridor
and east towards the WI/MN border.

The long-term period begins Thursday night with a broad mid-level
longwave ridge over the northern Plains  becoming amplified and
moving east towards the upper Midwest Friday, with the ridge axis
over north-central Minnesota by Friday evening. To the west, a
strong upper low moving into the Pacific northwest Thursday night
crosses the Great Basin and northern Rockies Friday into Friday
night. Two areas of low pressure develop in response to this upper
low Friday - the first a northern low central Saskatchewan and a
second low in eastern Montana/western North Dakota. A warm front
will lift northeast across the central/northern Plains Friday into
Friday night, with the lead edge of a 30-40+ knot low level jet
across the Red River Valley into northwest/north-central Minnesota.
The GFS, ECMWF, and GEM have depicted elevated convection firing
along this frontal boundary late Friday night at least for most of
the past few runs, though how that convection evolves through
Saturday morning is uncertain because the various timing/location
differences across the guidance. Strong to severe storms are
possible as well as the possibility for heavy rain rates leading to
flash flooding, fed by the strong warm air advection along the nose
of the low level jet.

During the day Saturday a cold/occluded front is expected to move
east across northeast Minnesota and northwest Wisconsin. With warm
and moist conditions in place combined with moderate instability and
strong flow aloft, strong to severe organized storms will be
possible. How the day evolves will be directly dependent on the
coverage of storms the night/morning prior, but most of the
ingredients will be in place for strong storms. Deep-layer shear
could be limited if the progression of the low is a bit slower such
as the 00z ECMWF depicts because of weaker mid/upper level winds.
However, the model-to-model and run-to-run differences at this point
are great enough that strong to severe organized storms remain
possible Saturday into Saturday night.

As the low matures across southern Manitoba Saturday night into
Sunday morning it will gradually weaken and move east/northeast into
northern Ontario. GEM remains the slowest with this progression with
GFS and ECMWF are in fairly good agreement with regards to timing
and placement after Sunday morning. In the wake of the low cooler
temperatures and perhaps some light rain showers are expected Sunday
into Monday within the northwest flow aloft. High pressure builds in
across the upper Mississippi by Tuesday morning leading to mostly
sunny skies and seasonable conditions. A weak clipper-like
disturbance may result in increasing clouds and a chance for light
showers late Tuesday into Wednesday, but otherwise seasonable
conditions will prevail through mid-week.

&&

.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
Issued at 1248 PM CDT Wed Jun 22 2016

VFR conditions will prevail through much of the period with MVFR
conditions possible late this afternoon and this evening as
showers and isolated thunderstorms result lower ceilings and
visibility. once low presure passes to the south of the forecast
area, winds will become light and variable for the rest of the
forecast period as high pressure builds into the area.

&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  69  48  74  53 /  40  60  10   0
INL  71  47  78  52 /  50  30   0   0
BRD  74  53  75  57 /  60  60  10   0
HYR  76  52  76  52 /  40  70  10  10
ASX  69  48  75  52 /  40  60  10  10

&&

.DLH Watches/Warnings/Advisories...
WI...Beach Hazards Statement until 8 PM CDT this evening for WIZ001.

MN...Beach Hazards Statement until 8 PM CDT this evening for MNZ037.

LS...Small Craft Advisory until 10 PM CDT this evening for LSZ144-145.

&&

$$

SHORT TERM...LE
LONG TERM...JJM
AVIATION...clc



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