Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 191736 AAA

Area Forecast Discussion...UPDATED
National Weather Service Duluth MN
1236 PM CDT Wed Jul 19 2017

.SHORT TERM...(Today through Thursday)
Issued at 323 AM CDT Wed Jul 19 2017

As of early this morning, an area of high pressure was centered
over central Minnesota. Much of the region had clear skies and
calm wind. There was some fog in parts of the Northland,
especially in parts of northwest Wisconsin.

The high pressure will shift south and east into the Great Lakes
region today. Morning sunshine should quickly dissipate this
morning`s fog. Warm, southerly flow will develop by this
afternoon, with temperatures reaching the upper 70s and low 80s.

A shortwave trough is expected to lift out of the Rocky Mountains
today into the Northern High Plains early this morning, then
track through the Dakotas later this morning and this afternoon,
before passing through Minnesota and Wisconsin late today.
Meanwhile, a warm front will push into the Dakotas as a low near
the lee of the Rocky Mountains moves into South Dakota. A plume of
instability likely extend into southern North Dakota, and it is
here at the pinnacle of the plume that a complex of thunderstorms
will likely develop, in part thanks to the shortwave(s) crossing
through the region. The models indicate the CAPE gradient will
extend east-southeast from the Dakotas to southern Minnesota into
southern Wisconsin. This complex, which will likely become an MCS,
will likely track down the CAPE gradient. This should keep the
MCS just south of the forecast area, where SPC has placed a slight
and enhanced risk for severe weather. Prefer models that keep
most of the precipitation south of the Northland, such as the GFS.
Some models, such as the NAM and HRRR, are indicating a more
northern solution that could affect more of the Northland than
this forecast. However, think these latter models` precipitation
are more a reflection of the large precipitation shield that
should develop with the MCS, but are indicating much more
precipitation than would likely occur with this precipitation
shield. While the precipitation shield would mainly bring rain,
have some thunder in the forecast considering the passing
shortwave could help trigger some isolated thunder. The MCS will
bring a threat of damaging winds, and this threat is primarily
south of the forecast area. It`s possible southern fringes of the
forecast area could get strong winds, too.

High pressure will build into the Northland tonight in the wake
of the passing shortwave and region`s MCS. Clear skies and calm
winds will develop by later in the night. Fog is possible for some
areas, especially across southern portions of the forecast that
get any significant rain today. That soil moisture would help
develop fog. Lows should range from the lower and middle 50s
across northern Minnesota, to the upper 50s and lower 60s from
central Minnesota into northwest Wisconsin. Thursday looks warm
and sunny. Highs should be in the lower to middle 80s.

.LONG TERM...(Thursday night through Tuesday)
Issued at 323 AM CDT Wed Jul 19 2017

Dry weather will continue into Thursday evening but then yet
another couple shortwaves will affect portions of the Northland
late and into Friday. Higher precipitable water values and CAPE
will exist just south of the Northland but will be drawn north as
high pressure slides off to the east. We have some small chances
for showers/storms just into our far northwest and southwest areas
late Thursday night with chances increasing on Friday, especially
south which will be affected by the stronger of the two waves and
closer to the higher moisture/instability. Highs will be in the
upper seventies to lower eighties for most areas.

Increasing southerly flow Friday night will increase moisture and
instability across the Northland. A stronger upper trough will be
moving across southern Canada toward the Northern Plains and be
centered over the northwest Ontario/northern Minnesota border by
00z Sunday. A surface low/front will move in as well and these
features will linger over at least eastern portions of the
Northland into Sunday night. There will be a chance for more
showers and storms Friday night into Sunday over much of the area
gradually shifting to mainly far northern and eastern areas Sunday
night. There will be at least low chances for severe storms
Friday afternoon into Saturday evening across parts of the area.
Highs Saturday will be in the lower seventies in the Arrowhead to
the lower eighties in the Brainerd Lakes area east through
Hinckley to Siren. Cooler air will move in Saturday night into
Sunday as northerly flow develops as the low moves east of the
area. Highs are expected in the lower to middle seventies.

High pressure will keep much of the region dry Monday with
chances for showers/storms returning to western areas Tuesday.


.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
Issued at 1230 PM CDT Wed Jul 19 2017

Showers will be widely scattered over the forecast area this
afternoon and early this evening, but expect conditions to remain
VFR. However, there could be some lower ceilings and visibilities
as a storm or two could pass over KBRD. High pressure will build
into the region tonight and the resulting calm winds could help in
forming fog. Any fog will lift by 12z-13z timeframe leaving clear
skies and light winds the remainder of Thursdasy.


DLH  80  58  83  61 /  20  40   0   0
INL  79  54  81  57 /  10  10   0  10
BRD  79  60  85  63 /  30  40   0  10
HYR  82  60  84  59 /  10  50  10  10
ASX  84  58  84  58 /  10  40  10  10




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