Area Forecast Discussion
Issued by NWS Bismarck, ND

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FXUS63 KBIS 190237

Area Forecast Discussion
National Weather Service Bismarck ND
937 PM CDT Wed Oct 18 2017

Issued at 935 PM CDT Wed Oct 18 2017

Clear skies and light winds allowing temperatures to fall rapidly
across the northwest. How far the temperatures will fall may be
limited buy the strong h850 warm advection forecast by global
models already starting this evening. Lowered Mins about 3 to 5
degrees north.

UPDATE Issued at 705 PM CDT Wed Oct 18 2017

Winds will continue to diminish tonight. This update will expire
the Red Flag Warning as well as the wind advisory. Otherwise
current forecast looks ok.


.SHORT TERM...(This evening through Thursday)
Issued at 231 PM CDT Wed Oct 18 2017

Strong winds and critical fire weather conditions through early
this evening, and above normal temperatures Thursday highlight the
short term forecast.

No change to ongoing fire weather and wind headlines for this
afternoon into the early evening. The Wind Advisory for portions
of northwest North Dakota will expire at 21 UTC. Based on observed
trends through 19 UTC, this should work out as gusts are only
marginally in advisory criteria at best. Further east across north
central North Dakota, the Turtle Mountains and the upper James
River Valley, the wind field is stronger and is favored by the 18
UTC HRRR/RAP to remain at or above advisory levels through 00 UTC
with around 37-47kts at the top of the mixed layer around 800 mb
to transfer to the surface.

See the Fire Weather Discussion below regarding ongoing critical
fire weather conditions.

For Thursday, well above normal temperatures will return with 850
mb mean temperatures on the 00 UTC NAEFS around their 97.5th
percentiles. Thus, trended above the 12 UTC consensus for highs on
Thursday, with highs in the mid 70s to the lower 80s.

.LONG TERM...(Thursday night through Wednesday)
Issued at 231 PM CDT Wed Oct 18 2017

Another day of above normal temperatures Friday with the potential
for strong winds Friday night highlight the extended forecast.

The 00 UTC NAEFS continues to depict an anomalous warm signal for
Friday with 850 mb mean temperatures near the 99th percentile.
Friday may be a couple of degrees warmer than Thursday with
greater mixing. Widespread highs in the upper 70s and lower 80s
are expected, above the 12 UTC guidance consensus. A strong cold
front is forecast by the 12 UTC global suite to arrive across
western North Dakota Friday evening and move east through the
night. The strong wind potential will have to be monitored across
southwest North Dakota with significant isallobaric forcing via a
11-14mb/3hr pressure rise bubble as depicted on the 12 UTC GFS.


.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 707 PM CDT Wed Oct 18 2017

VFR conditions expected through the 00Z TAF period.


Issued at 231 PM CDT Wed Oct 18 2017

Strong west to northwest winds sustained between 25
to 30 mph were observed this afternoon coinciding with minimum
relative humidity values around 20 percent. Wind gusts up to 50
mph are possible, especially in the Turtle Mountains. The
combination of strong winds and low relative humidities have
created critical fire weather conditions for northern and most of
central North Dakota this afternoon and into the early evening. A
Red Flag Warning remains in effect.

Warmer temperatures with highs in the 70s to lower 80s can be
expected Thursday and Friday with minimum relative humidities
between 15 and 25 percent. However, southerly winds will range
from 10 to 15 mph both days, so not anticipating any fire weather

Cooler Saturday through early next week expected with highs
returning to the 50s. This period also looks to be windy, however,
minimum relative humidity values look to be above critical levels.




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