Area Forecast Discussion
Issued by NWS Bismarck, ND

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FXUS63 KBIS 170853

Area Forecast Discussion
National Weather Service Bismarck ND
353 AM CDT Thu Aug 17 2017

.SHORT TERM...(Today and tonight)
Issued at 313 AM CDT Thu Aug 17 2017

A surface low pressure across eastern Montana is forecast to move
to central North Dakota tonight then into eastern North Dakota by
Friday morning. Aloft, a significant shortwave over Minnesota
will lift northeast into the Great Lakes region by tonight
leaving broad cyclonic flow aloft over the Northern Plains in its
wake. The combination of surface trough and weak cyclonic flow
aloft will combine to support widely scattered thunderstorms today
and tonight across west and central North Dakota.

Ahead of the surface trough today a thermal ridge associated with
a weak EML will move to western North Dakota supporting warm
temperatures close to 90 southwest. The HRRR RH values fall close
to 15 percent across much of the west central and southwest this
afternoon. Clouds could be the one limiting factor for high
temperatures today but don`t believe there will be enough cloud
cover to hold back temperatures too much.

Tonight, the model consensus supports 20 to 30 POPs across
central North Dakota, in the form of showers and widely scattered
thunderstorms. Severe weather is not expected.

.LONG TERM...(Friday through Wednesday)
Issued at 313 AM CDT Thu Aug 17 2017

The extended forecast begins Friday with a shortwave ridge
bringing warmer temperatures Friday and especially Saturday.
Highs should be in the 80s Friday with more widespread lower 90s
by Saturday. This will be followed by a Pacific cold frontal
passage cooling the region back into the 70s and lower 80s Sunday
through Tuesday. This will also bring a chance for scattered
showers and thunderstorms Sunday and Sunday night. Broad ridging
develops aloft by early to middle of next week suppressing
convection and returning warmer temperatures to the region.


.AVIATION...(For the 06Z TAFS through 06Z Friday evening) Issued
at 1235 aM CDT THU Aug 17 2017

Hazards to aviation include patchy MVFR/IFR conditions in fog at
KJMS between 09-13Z. Otherwise surface low pressure in eastern
Montana at 06Z will move east to western North Dakota by noon
Thursday. The low will be the focus for widely scattered -TSRA
KMOT-KDIK-KBIS after 22Z. Too much uncertainty to include this in
TAFs instead used VCTS.


Issued at 313 AM CDT Thu Aug 17 2017

While there are some fire weather concerns today critical fire
weather conditions are not expected.

A warm thermal ridge will support high temperatures today around
90 southwest into west central North Dakota. While consensus
models show Minimum RH values around 20 percent opted to use the
dryer HRRR model which supports Minimum RH`s as low as 15 percent.
A wind shift to the Northwest is forecast with the surface trough
passage this afternoon. Again, raised winds a tad over consensus
to around 15 mph with gusts 20 to 25. Based in this there should
not be sufficient winds to create critical fire weather
conditions today.

However another warm day is forecast Saturday with a more
significant frontal passage late Saturday afternoon and night.
This period will be monitored for possible critical fire weather.




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