580
FXUS63 KBIS 201731
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
1231 PM CDT Thu Mar 20 2025

.KEY MESSAGES...

- Southwest winds around 20 mph and minimum relative humidity
  values around 20 percent will result in critical fire weather
  conditions this afternoon and early evening over much of south
  central North Dakota into the James River Valley. A Red Flag
  Warning has been issued.

- Low to medium chances (around 20 to 50 percent) for light
  rain or snow over western and central North Dakota tonight,
  departing Thursday morning.

- Greater chances for rain or snow (40 to 60 percent) come
  Saturday into Sunday, with the highest chances Saturday night.
  Light snow accumulations possible.

&&

.UPDATE...
Issued at 1225 PM CDT Thu Mar 20 2025

No major changes were needed for this update. Just blended in
the latest observations to the going forecast and updated the
aviation discussion below.

UPDATE
Issued at 900 AM CDT Thu Mar 20 2025

Weak reflectivities are developing across northern and central
North Dakota this morning, associated with a surface trough
lifting across the forecast area. With dry near surface
conditions, however, little to no precipitation is anticipated
to reach the ground. Otherwise, generally quiet weather
prevails over western and central North Dakota, with no major
changes to the forecast performed for this update.


UPDATE
Issued at 625 AM CDT Thu Mar 20 2025

Quiet weather continues over the area, thus no changes needed
for early morning update.

&&

.DISCUSSION...
Issued at 354 AM CDT Thu Mar 20 2025

Current surface analysis places trough over central/southern
Alberta into southwest Saskatchewan nudging through eastern
Montana, with ridge stretching from the Texas Panhandle
north/northeastward towards northwest Minnesota. Upper level
analysis places ridge stretching northward from the central
Rockies towards the Alberta/Saskatchewan border. Over our area,
quiet conditions continue with south to southwest winds.

The main focus for today is fire weather conditions, mainly over
southern parts of the area. A rather dry airmass will be in
place allowing humidity values to drop to around 20 percent over
the southern half of our area as temperatures climb into the
50s, which is around 15 to 20 degrees above average. The highest
wind speeds of around 20 mph are expected over much of south
central North Dakota into the James River Valley, thus resulting
in critical fire weather conditions. Therefore, a Red Flag
warning has been issued for this area. Winds should be a bit
less elsewhere, but still resulting in near critical fire
weather concerns, mainly for southwest North Dakota into areas
surrounding the Red Flag Warning.

As we go into tonight, a weak clipper system will approach the
area, resulting in low to medium chances for rain, possibly a
little snow later on as cooler air pushes into the area. System
will depart Friday morning, with some chances possibly lingering
into the morning hours mainly over southern portions of the
area. Thereafter, quiet and cooler conditions expected for
Friday in the wake of the clipper.

Next clipper pushes through the area Saturday into Saturday
night, bringing medium chances (about 40 to 60 percent) for
precipitation. Chances start out as mainly rain (except for
rain/snow mix near Turtle Mountains) during the day Saturday,
with a transition towards snow through the night Saturday as
colder air pulls into the area. Precipitation chances gradually
wane off Sunday. Temperatures will be notably cooler on Sunday,
with a warming trend to start the upcoming work week with
occasional low precipitation chances.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1225 PM CDT Thu Mar 20 2025

Expect breezy southwest winds and VFR conditions through the
rest of the afternoon. A weak storm system then approaches this
evening and moves across the state overnight. This system will
bring some low chances of rain showers in the evening, with
some snow mixing in at some locations overnight. Because of the
low probability at any one particular site, have relied on
PROB30 groups for the 18z TAF period. MVFR ceilings will also
accompany this system and these ceilings will likely hang around
through the end of the period at all sites with the exception
of KXWA, which may see some improvement towards the end of the
period.

&&

.FIRE WEATHER...
Issued at 415 AM CDT Thu Mar 20 2025

Low relative humidity values are expected over much of the area
this afternoon and early evening, especially over much of
southwest and south central North Dakota where minimum values will
dip into the upper teens to lower 20s. Over much of south central
North Dakota into the James River Valley, southwest winds are
expected to increase to around 20 mph with gusts to 35 mph
resulting in critical fire weather conditions. Thus, a Red Flag
Warning has been issued for this area. Over remaining locations of
southwest and south central North Dakota, winds will be a bit
lighter, thus near-critical fire weather conditions are expected.
Conditions will improve this evening.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 7 PM CDT this evening for NDZ036-037-
047-048-050-051.

&&

$$

UPDATE...ZH
DISCUSSION...JJS
AVIATION...ZH
FIRE WEATHER...JJS