Area Forecast Discussion
Issued by NWS Bismarck, ND

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FXUS63 KBIS 201723

Area Forecast Discussion
National Weather Service Bismarck ND
1223 PM CDT Thu Oct 20 2016

Issued at 1216 PM CDT Thu Oct 20 2016

Minor update to temperatures and cloud cover. Persistent low
clouds across central North Dakota are keeping temperatures a
little cooler. Therefore lowered the high temperatures for today
and delayed the departure of clouds across central North Dakota.

UPDATE Issued at 923 AM CDT Thu Oct 20 2016

No major changes required for this update. Low clouds and fog
across southwest North Dakota will dissipate by the late morning

UPDATE Issued at 627 AM CDT Thu Oct 20 2016

No changes to the early morning update other than populating the
latest sensible weather elements and interpolating through mid
morning. Locally dense fog reported at Hettinger and possibly some
fog noted on Painted Canyon webcam. Otherwise no significant
reductions in visibility in the southwest this morning. Did extend
patchy fog up to 15z in the southwest to cover any areas that may
be slow to burn off with light winds this morning.


.SHORT TERM...(Today and tonight)
Issued at 240 AM CDT Thu Oct 20 2016

Clouds and temperatures are the main concern in the short term

Latest WV imagery shows an upper low near 150W 50N with a good
fetch of moisture spreading across the northern Pacific into the
northwest U.S. to the east a shortwave trough was located over
southern saskatchewan. Ahead of this shortwave, skies were mostly
cloudy across western and central ND. This shortwave will drop
southeast through north central into eastern ND this morning, with
upper level ridging building into the west this afternoon and
spreading east tonight.

A concern early this morning is areas of fog where skies have
started to clear in the far west. Will keep a mention of patchy
fog through mid morning but will continue to monitor.

Mesoscale models continue to indicate showers from north central
into the James River Valley this morning into early afternoon
ahead of the aforementioned shortwave. Nothing showing up at this
time on area radars but as we warm up today would not be surprised
to see a few sprinkles in this area. For now will keep the
forecast dry as would expect mainly trace amounts with a limited
amount of moisture between 4-8kft. This wave will likely keep
clouds across eastern portions of central ND into the afternoon,
while skies clear west with upper ridging building into the area.
Expect temperatures to range from the low to mid 40s over the
Turtle Mountains, to the mid and upper 50s west and south central.
Went a few degrees warmer than guidance over the western half of
the CWA today, closer to the numerical guidance.

Another shortwave and associated trough will move into western ND
late tonight, flattening the upper ridge and bringing a slight
chance of showers into the northwest toward morning.

.LONG TERM...(Friday through Wednesday)
Issued at 240 AM CDT Thu Oct 20 2016

A shortwave tracking along the International Border Friday with
an associated trough extending south through the state will bring
a chance of showers to the northern tier counties Friday morning,
with clearing following from west to east. Although the surface
gradient is weak, it does look like a breezy afternoon, especially
in the southwest as we mix out. We bumped up winds above guidance
in the southwest and south central Friday afternoon as guidance is
usually too weak with these situations. We also bumped up high
temperatures just a bit, again closer to a blend of MOS Guidance.

Upper level ridging then builds over the area Saturday with
daytime highs expected to be in the mid 50s north to mid 60s
southwest. A shortwave traveling through the mean ridge tracks
from Montana into Saskatchewan and could bring a chance of showers
to the far northern tier counties during the day Saturday.

Upper level ridging builds again over the area Sunday into early
next week as the northern Pacific low mentioned earlier finally
approaches the west coast. This will continue to bring mild and
mainly dry conditions to the forecast area Monday and Tuesday.

Deterministic models begin to diverge as we head into the middle
of next week in how this low evolves as though next weekend. It
does look like the potential for more active weather will increase
but the specifics are varying with differences in deterministic
models and a large envelope of solutions suggested by the GFS


.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
Issued at 1216 PM CDT Thu Oct 20 2016

Edge of lower ceilings run from a line from near Glen Ullin,
northwest to Williston, and southeast to near Selfridge. This
stratus deck extends east and north of this line with only
scattered high clouds to the west and south. Through the
afternoon, ceilings should continue to lift as the stratus deck
slowly moves east and eventually erodes. A brief period of MVFR
ceilings may remain over KBIS early this afternoon, but all other
sites should remain in VFR categories through the 18z forecast
period. Winds should remain generally light and variable,
alternating from the south to the southwest.




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