Area Forecast Discussion
Issued by NWS Bismarck, ND

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FXUS63 KBIS 181737

Area Forecast Discussion
National Weather Service Bismarck ND
1237 PM CDT Fri Aug 18 2017

Issued at 1236 PM CDT Fri Aug 18 2017

Scattered showers and perhaps isolated thunderstorms should be
moving out of the James River Valley early this afternoon. Otherwise
only changes were to lower expected high temps in the James Valley
due to lingering cloud cover in the early afternoon.

UPDATE Issued at 905 AM CDT Fri Aug 18 2017

Showers linger over the James River Valley with some
thunderstorms, which continue to push to the east/southeast as the
mid-level circulation continues on its way. For mid-morning update
have adjusted precipitation chances to match current conditions.

UPDATE Issued at 625 AM CDT Fri Aug 18 2017

Showers becoming numerous across east central North Dakota
associated with a mid level circulation. Will adjust POPs to
follow the trends for the next few hours. Otherwise the
precipitation chances will decrease with time east. Added widely
scattered showers across the southwest through the mid morning.


.SHORT TERM...(Today and tonight)
Issued at 244 AM CDT Fri Aug 18 2017

Forecast concerns for the short term include thunderstorms over
central and southeast sections of the forecast area this morning.
Thunderstorms formed Thursday evening along a surface trough with
an associated shortwave aloft. Shear and instability are somewhat
marginal for significant thunderstorms at this time of the night but
the storms definitely are sustaining themselves. Used the HRRR
time lag ensemble to provide short term guidance. The trends
suggest the convective activity will exit end/exit the region by
noon Friday.

This will leave Friday afternoon and night mainly clear. Highs
today will be in the 70s to middle 80s.

.LONG TERM...(Saturday through Thursday)
Issued at 244 AM CDT Fri Aug 18 2017

The extended period begins with very warm temperatures associated
with a short wave ridge moving through the region Saturday. GEFS
plumes of 2 meter temperatures support upper 80s to mid 90s
for highs on Saturday which is above Superblend guidance by 2 to
4 degrees. To warm the temperatures used the maximum of all
guidance temperatures with the current SB forecast to provide the
warmer forecast. This gave upper 80s northwest to mid 90s
central. Felt this was reasonable with the mixing associated with
an approaching cold front. As a result there are fire weather
concerns for Saturday afternoon west.

This will be followed by a Pacific cold frontal passage cooling
the region back into the 70s and lower 80s Sunday through Tuesday.
The next significant chance for showers and thunderstorms Sunday
and Sunday night. Broad ridging develops aloft by early to middle
of next week suppressing convection and returning warmer, but near
normal temperatures to the region.


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

VFR conditions will prevail at all TAF sites.


Issued at 244 AM CDT Fri Aug 18 2017

Have issued a Fire Weather Watch for Saturday for low humidity and
sustained west winds around 20 mph. Very warm temperatures in the
upper 80s to mid 90s across southwest and west central North
dakota Saturday will produce low humidity as low as 15 percent. An
approaching cold front saturday morning will pass through and
bring west winds by noon. Afternoon winds should increase to 20
mph behind the cold front.


Fire Weather Watch from Saturday afternoon through Saturday
evening for NDZ017-018-031>033-040-041-043-044.



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