Area Forecast Discussion
Issued by NWS Bismarck, ND

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FXUS63 KBIS 212003

Area Forecast Discussion
National Weather Service Bismarck ND
303 PM CDT Fri Jul 21 2017

.SHORT TERM...(This evening through Saturday)
Issued at 301 PM CDT Fri Jul 21 2017

Severe potential this afternoon and evening central ND, and
critical fire weather conditions southwest and south
central on Saturday highlight the short term forecast.

See the fire weather discussion below for details regarding
critical conditions southwest and south central Saturday
afternoon and evening.

Currently, ongoing thunderstorm activity that developed across
northwest and north central ND continued from the Devils Lake Basin
westward into Mercer and McLean counties. This is believed to be
associated with an upper level impulse moving east across the state
today. At the surface, low pressure was near Watford City/Stanley
area of western Lake Sakakawea...with drier northwest winds to its
west and humid southerly to easterly winds to its east. A surface
trough extending from the low into central SD is forecast to move
eastward slowly tonight. Thunderstorms are expected to develop along
this boundary, with the high res CAMs indicating south central ND
and into the James Valley as the most likely area for increasing
thunderstorm coverage as the CAP erodes with temperatures rising
into the 90s.

MU Cape values of around 3000 J/kg in current mesoscale analysis
with generally 40 knots of 0-6km bulk shear.

A a severe thunderstorm watch will be in effect through much of this
evening south central to the James Valley.

.LONG TERM...(Saturday night through Friday)
Issued at 301 PM CDT Fri Jul 21 2017

A progressive pattern dominates the long term with occasional upper
level shortwaves in the westerlies moving across North Dakota. One
such wave on Monday afternoon/night will bring a chance of
thunderstorms to our area. Another wave will bring a chance
Wednesday/Thursday as well.

Highs in the 85 to 95 range Monday, and in the 80s for the rest of
next week is expected.


.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 1236 PM CDT Fri Jul 21 2017

An upper level impulse moving east across northern ND late this
morning is expected to continue moving east this afternoon. Latest
convective cells have organized into a line near Bottineau/KMOT/New
Town. This elevated activity should continue moving east.

Otherwise, at noon CDT, a surface low had entered northwestern ND
and was located near KISN/Tioga/Stanley area. This low is forecast
to reach central ND near KBIS/KMOT by 21z-00z, and near KJMS by
around 03z. Dry air and westerly winds west of the front with
east/southeast winds and humid air ahead of it is forecast.
Thunderstorm initiation along this boundary is expected this
afternoon, with best chances near KBIS by around 21z-00z according
to the latest high res models.

Thunderstorms should increase in coverage late this afternoon into
the evening near KMOT/KBIS and into KJMS around 00z-04z. Severe
thunderstorms are expected with large hail and damaging winds.
Uncertainty regarding exactly where/when convection will initiate,
will continue to mention VCTS at KMOT/KBIS/KJMS through 03z, and
through 06z at KJMS.


Issued at 301 PM CDT Fri Jul 21 2017

For Saturday, afternoon humidity between 15 and 20 percent,
northwest winds sustained at 20 to 25 mph with higher gusts, and
temperatures in the 80s are forecast across southwest and south
central North Dakota Saturday afternoon. When combined with dry
fuels, critical fire weather conditions are possible. A Fire Weather
Watch remains in effect for Saturday afternoon and early evening.


Fire Weather Watch from Saturday afternoon through Saturday
evening for NDZ020-031>035-040>046.



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