692 
FXUS63 KBIS 190547
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
1247 AM CDT Tue Oct 19 2021

.UPDATE...
Issued at 1233 AM CDT Tue Oct 19 2021

Cold front continues to makes its way through the area, with the
low clouds still lingering behind over southern
Saskatchewan/Manitoba. Going forecast reflects this well, so only
minimal changes needed.

UPDATE Issued at 956 PM CDT Mon Oct 18 2021

The cold front continues to slowly sag into northwest North Dakota
late this evening. Some stronger gusts have been reported behind
the front, and model soundings do show mixing potential of 20-30
kts. Forecast winds and gusts were increased along and trailing 
the frontal passage through mid morning.

Patchy fog has also been added to the forecast for Tuesday morning
and early afternoon across higher terrain areas of southwest North
Dakota, as well as the rise in elevation due west of the southern
James River Valley. This potential is the result of cold air
advection intersecting a subtle theta-e ridge, and will
essentially be cloud ceilings lowering to the surface if it
materializes. Some drizzle cannot be ruled out, but remains
unlikely due to the shallower depth of low level saturation.

UPDATE Issued at 650 PM CDT Mon Oct 18 2021

The cold front is starting to move into far northwest North
Dakota, where stronger northerly winds and surface pressure rises
are being noted. Only minor adjustments were made for this 
update, mainly to temperatures tomorrow to account for the 
expected lack of solar insolation. Current observations and high-
resolution model trends were blended into the forecast.

&&

.SHORT TERM...(This evening through Tuesday)
Issued at 147 PM CDT Mon Oct 18 2021

High temperatures this afternoon look mostly on track, although a
few locations may fall a bit short of forecast highs this 
afternoon due to cloud cover stretching from south central through
north central North Dakota. Even so, most locations will top out 
in the upper 60s to mid 70s, which is still 10 to 15 degrees 
above average for this time of the year. Tonight, a cold frontal 
boundary presently draped over north central through western 
Montana will transition through the CWA. This will lead to cooler 
temperatures for the region Tuesday with highs failing to reach 50
degrees in most locations. Post frontal north to northeasterly 
winds will also become breezy tonight through the day Tuesday. 
Precipitation is not expected with the frontal passage tonight.

.LONG TERM...(Tuesday night through Monday)
Issued at 147 PM CDT Mon Oct 18 2021

To begin the period, cutoff low pressure will transition through
the Central Plains states with the center of the upper low over
the SD/NE border and the surface low generally scooting through 
Nebraska. With continued trends slightly further south,
precipitation totals continue to be gradually shaved off, 
especially for the southwestern forecast area. The best chance for
seeing at least a quarter inch or more of QPF remains in the
southern James River Valley.

Precipitation will gradually begin as light rain Tuesday evening 
before mixing with light snow later Tuesday night. A mix of rain 
and snow should occur through Wednesday morning before returning 
to rain Wednesday afternoon. Any snow accumulations, of which 
should be limited to south central North Dakota, are likely to 
remain as little more than a dusting. Isolated freezing rain is 
not completely out of the question. However, with surface 
temperatures barely dropping below freezing and ground 
temperatures still relatively warm, not expecting any 
accumulations nor widespread impacts from any freezing rain that 
may occur.

Once this system passes through, things dry out through Friday
night as chilly conditions take hold over the area. Low 
temperatures will reach the 20s for most locations Wednesday night
through Friday night, while highs generally stay in the 40s 
Thursday through Saturday. The main exception is the far 
southwestern part of the state, which may see highs hit the 50s 
Thursday and Friday. Beyond that, uncertainty in temperatures
remains higher, although NBM ensembles indicate a warming trend.

&&

.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1233 AM CDT Tue Oct 19 2021

Winds will become northerly and increase as a cold front makes its
way through the area overnight. Later this morning, MVFR ceilings
will develop in the wake of the front. Some clearing then expected
towards evening over northern parts of the area.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...JJS
SHORT TERM...Telken
LONG TERM...Telken
AVIATION...JJS