Area Forecast Discussion
Issued by NWS Bismarck, ND

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FXUS63 KBIS 202349

Area Forecast Discussion
National Weather Service Bismarck ND
549 PM CST Mon Nov 20 2017

Issued at 536 PM CST Mon Nov 20 2017

Dry cold front has moved through western and central ND.
Currently, strongest winds are within the fall/rise pressure
bubble and tightest gradient from Minot to Rolla and south into
the James River Valley. Winds here are gusting in the 40 to 50 mph
range. Farther west, winds are not as strong but many locales are
gusting in the 30 to 40 mph range. Current Wind advisory remains
in effect until 9 pm CST. No need to make any changes at this
time. Will revisit with the evening update.

Strong cold advection will keep winds breezy through the night.
Temperatures are already in the lower to mid 20s far northwest,
and will continue to fall through the night across the forecast
area. Made some adjustments to sky cover to account for increased
mid clouds over the west. May see a few flurries/sprinkles this
evening as this area moves across the southwest during the
evening. Not expecting any accums.


.SHORT TERM...(This evening through Tuesday)
Issued at 254 PM CST Mon Nov 20 2017

Strong winds this afternoon into tonight, near critical fire
weather conditions south this afternoon, and a much colder
Tuesday highlight the short term forecast.

The strong cold front extending from the clipper across southeast
Manitoba has cleared all of western and central North Dakota as of
21 UTC. Strong post-frontal winds continue to develop across the
area. The strongest winds with gusts of 40-45kts are expected
along and north of North Dakota Highway 200 where isallobaric
forcing will be maximized into the early evening. However, winds
have already peaked across the far northwest, and a slow decrease
in winds are expected through the evening and overnight as
isallobaric forcing focuses into Minnesota. A Wind Advisory
remains in effect until 03 UTC for generally west of US Highway
83, and through 06 UTC to the east. This may be allowed to be
cancelled a bit early.

See the fire weather discussion below regarding a brief period of
near critical fire weather conditions south this afternoon.

A much colder Tuesday is expected area wide as cold high pressure
builds across western and central North Dakota in the wake of the
cold front today. Highs will likely be 20 to 30 degrees colder on
Tuesday for most areas based on the 12 UTC global consensus.

.LONG TERM...(Tuesday night through Monday)
Issued at 221 PM CST Mon Nov 20 2017

A wintry mix Wednesday, possible record highs southwest on
Thanksgiving, and a windy Friday highlight the extended forecast.

The 12 UTC global suite is in agreement on a warm front
propagating into western and south central North Dakota on
Wednesday, and stalling out. A clipper will propagate along this
baroclinic zone and support the potential for a wintry mix of
freezing rain, sleet and snow with an warm layer aloft above sub-
freezing air and road temperatures across northwest and central
North Dakota. Overall QPF amounts are expected to be light,
however, even a small amount of freezing rain will impact
travel on Wednesday. The areas of most concern for light ice
accumulations are across northwest and north central North
Dakota, into the James River Valley.

For Thanksgiving, the baroclinic zone remains, bisecting North
Dakota from northwest to southeast. The 00 UTC NAEFS 850 mb mean
temperatures climb to their 99th percentiles across the west,
supporting the top of the forecast envelope for highs for November
23. The record High for Dickinson is 63 set in 1984, with a
forecast of 65. The record high for Williston is 56, with a
forecast high of 57. With the aforementioned baroclinic zone in
place, a large temperature gradient is favored from southwest to
northeast with highs only in the 20s across the Turtle Mountains.

On Friday, another windy day is possible behind a cold front
extending from a southern Canada clipper system.


.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 536 PM CST Mon Nov 20 2017

Strong northwest winds will persist through the night and into
Tuesday morning. Winds will diminish from west to east during the
day Tuesday. VFR conditions west and south central through the
forecast period. Moisture wrapping around exiting surface low may
pull some MVFR ceilings into central and eastern ND late tonight
into Tuesday morning with a possible MVFR ceiling at KMOT and
KJMS. For now will mention a scattered MVFR layer at each site
and continue to monitor.


Issued at 254 PM CST Mon Nov 20 2017

A period of near critical fire weather conditions is ongoing this
afternoon across southern North Dakota where relative humidity
has fallen to near 20 percent with mixing, coincident with strong
post-frontal winds. However, with sunset around 5 pm CST, and
cooler air with higher dewpoints advecting in from the north, the
overall threat should be rather limited in time.


Wind Advisory until 9 PM CST /8 PM MST/ this evening for NDZ001-

Wind Advisory until midnight CST tonight for NDZ003>005-011>013-



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