Area Forecast Discussion
Issued by NWS Bismarck, ND

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FXUS63 KBIS 172006

Area Forecast Discussion
National Weather Service Bismarck ND
306 PM CDT Mon Jul 17 2017

.SHORT TERM...(This evening through Tuesday)
Issued at 238 PM CDT Mon Jul 17 2017

An upper and surface low were located over the Hudson Bay over
Canada with a cold front extending south across western Ontario,
the northeast corner of Minnesota, eastern North Dakota, and into
central South Dakota. This cold front will be the focus of
scattered showers and thunderstorms later this afternoon. The
front has moved east faster than initially forecast, so any
thunderstorm development in our forecast area will likely be
limited to our far southeast counties, if that. The Storm
Prediction Center has maintained a marginal risk of severe weather
over McIntosh, Lamoure, and Dickey counties, but there is
considerable uncertainty regarding thunderstorm formation in these
areas. Still, with CAPE exceeding 2000-3000 J/kg and 35-40 knot
shear in place at the moment, if something does go it will have to
watched closely. One other thing to note is that there could be
some smokey issues due to some Canadian wildfires, especially in
the north.

Overnight, the upper level ridge continues to flatten with
embedded shortwaves propagating through the fast flow. Another
area of showers and thunderstorms will develop late over
southeastern Montana and move into southwestern North Dakota along
the South Dakota border. Some of the high resolution models
suggest this activity could strengthen overnight and sustain
itself as it moves across the southern part of the state through
the early morning hours. Confidence is low regarding this
solution, but some of the models do show these storms becoming rather
strong to marginally severe. Therefore, we will be monitoring.

Tuesday may see some lingering showers and storms early, with
relatively cooler temperatures during the afternoon. Highs will
mainly be in the low 80s, which should be a nice relief from the
recent hot weather.

.LONG TERM...(Tuesday night through Monday)
Issued at 238 PM CDT Mon Jul 17 2017

A weak, broad ridge briefly tries to build in on Tuesday night,
before another embedded shortwave trough travels through the flow
on Wednesday, bringing more shower and thunderstorm chances. The
progressive pattern will remain through the long term with brief
ridging and troughing alternating and near daily chances of hit
and miss thunderstorms. Conditions will likely be favorable for
strong to severe thunderstorm on a few of these days, but model
discrepancies on wave timing and strength preclude any confidence
in the potential at this time. Either way, it looks like and
active weather pattern will be in place for through the extended.


.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 1204 PM CDT Mon Jul 17 2017

Isolated thunderstorms possible this afternoon into this evening
over the James River Valley. Scattered thunderstorms possible
tonight into Tuesday morning over southern North Dakota. Over far
northern North Dakota, patchy smoke may lead to brief visibility




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