Area Forecast Discussion
Issued by NWS Bismarck, ND

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FXUS63 KBIS 232302

Area Forecast Discussion
National Weather Service Bismarck ND
602 PM CDT Sun Jul 23 2017

Issued at 544 PM CDT Sun Jul 23 2017

Current forecast keeps clear skies over the region tonight. A
developing lee side trough in eastern Montana along with an
elevated mixed layer (EML) should set the stage for warm
temperatures Monday. A developing low level jet of 45kts below
the EML should provide some low level convergence for elevated
non severe convection during the predawn hours Monday, which will
mix out during the day. Current forecast looks good in this
regard. No updates needed.


.SHORT TERM...(This evening through Monday)
Issued at 329 PM CDT Sun Jul 23 2017

Main concern in the short term are elevated non-severe thunderstorms
late tonight in the far southwest, then isolated chances of
thunderstorms Monday afternoon in parts of western and central
ND...possibly severe.

Currently, surface high pressure was over the eastern Dakotas with
the upper level ridge over the Front Range/western Plains of Canada
and the northern US. Regarding smoke aloft from Montana and Canadian
fires, sat pics and web cams not showing any tangible evidence of
smoke aloft (like we saw yesterday from satellite pics).

Tonight a shortwave in the flow aloft is forecast to move east
across Wyoming and southern Montana this evening, and across SD and
far southern ND late tonight and Monday. Expect isolated elevated
thunderstorms associated with this feature in ND.

More concerning is a cold front moving into western ND Monday
afternoon. This feature is associated with a stacked low pressure
system moving from central Alberta eastward into central
Saskatchewan. A low level jet is forecast to develop up the US
Plains well northward into central Canada. Most of the energy with
this system should reside in Canada, but enough instability with
projected CAPE values over 2000 J/Kg along the surface cold front
for SPC to continue a marginal risk for severe storms over ND. Thus
at this time isolated storms - possibly severe - over
western/central ND mid-afternoon and becoming a bit more numerous in
central/eastern ND Monday evening. Best chances of precipitation
over north central ND during the evening.

Along and ahead of the cold front we expect temperatures to climb
into the 90s across western and most of central ND, with upper 90s
in the southwest.

.LONG TERM...(Monday night through Sunday)
Issued at 329 PM CDT Sun Jul 23 2017

Monday night into early Tuesday morning thunderstorms may linger in
parts of south central ND into the eastern part of the state as an
upper level impulse moves across the ND/SD border Monday
night/Tuesday in the wake of the surface cold front.

The strong low pressure system continues moving east across
central/northern Manitoba into Ontario Tuesday/Tuesday night.
This will bring a dry day to western and central ND Tuesday with
westerly winds behind the cold front. Not confident regarding
strength of winds or how low relative humidity values will be
Tuesday...but this will need to be monitored for possible fire
weather concerns.

Upper level ridging builds again over the Rockies. Some shortwaves
move through the flow from time to time, bringing some slight
chances for showers/thunderstorms Thursday. Looking at seasonable
temperatures Tuesday through next weekend with highs mainly in the


.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 544 PM CDT Sun Jul 23 2017

With high pressure to the east and a warm trough of low pressure
across eastern Montana expect to see generally light winds this
evening increase from the south overnight. Wind shear has been
included at KMOT- KISN after 06z. Otherwise VFR at all TAF sites.




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