Area Forecast Discussion
Issued by NWS Bismarck, ND

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS63 KBIS 012357
AFDBIS

AREA FORECAST DISCUSSION
National Weather Service Bismarck ND
657 PM CDT Sat Oct 1 2022

.UPDATE...
Issued at 655 PM CDT Sat Oct 1 2022

Minimal changes needed to the forecast this update. A line of
showers continues to lift across the north, with some isolated
showers lingering in the east. This is all ahead of an upper level
low located across in the ID, WY, MT area. Tonight could see a bit
of a lull in precipitation, with perhaps only an isolated shower
in the west and north. The low moves very slowly on Sunday. The
slow progression will bring only isolated shower activity through
the day, with perhaps some increased coverage Sunday night. For
now have made only minor PoP adjustments based on latest radar
trends. Any partial clearing could bring some patchy fog tonight.
Best chances would be in the north. Overall confidence was too low
to include at this time.

&&

.SHORT TERM...(This Evening through Sunday Night)
Issued at 218 PM CDT Sat Oct 1 2022

A mid level cut off low continues to spin, centered near the
border of Idaho and Wyoming. Across western and central North
Dakota, on the eastern periphery of that system, warm air
advection and shortwave energy will continue to lift north, along
with bands of rain showers. The best forcing and deepest moisture
(PWAT values in the 99th percentile or greater for this time of
year) will generally be across the west. Thus, showers will
continue to be likely over portions of the west into the evening
hours. As we move into central and eastern North Dakota, shortwave
energy becomes more diffuse with a drier atmosphere. Still,
isolated to scattered showers have been observed here and will
continue to be possible through the short term.

The cutoff low will not move much through the short term period,
drifting slowly north and maybe a touch east, centered over
central Montana by this time on Sunday afternoon. After a lull in
shower activity for many overnight tonight, showers will once
again develop on Sunday afternoon as more shortwave energy rotates
around the upper low, moving through the state from southwest to
north northeast. Some steeper mid-level lapse rates will start to
creep into the southwest and south central by late Sunday
afternoon and into the evening hours, which should lead to some
MUCAPE values in the 250 to 500 J/kg range. Thus, we will see some
chances of thunderstorms in the late afternoon through the
overnight. Deep layer shear values here will be in the 30 to 35
knot range, but the weak instability profiles should keep any
severe thunderstorm threat low.

Regarding temperatures, tonight`s lows will generally range from
the mid 40s across the northwest to the low to mid 50s over the
far south central and James River Valley. Highs on Sunday will
then be similar to today but a touch warmer, ranging from the mid
to upper 60s north to the mid to upper 70s south. We should also
see more appreciable clearing tomorrow afternoon across the west
and central (before the next wave increases clouds again from
south to north tomorrow night).

.LONG TERM...(Monday through Saturday)
Issued at 218 PM CDT Sat Oct 1 2022

The stubborn cutoff low will continue to spin and hang around the
Northern Plains/Northern High Plains through the first part of
the long term period, moving into eastern Montana by Monday
afternoon. We could see a better chance of thunderstorms across
the south on Monday afternoon/evening with MUCAPE values
potentially in the 500 to 1000 J/kg range but shear will be weak.

The cutoff low then finally slides southeast into South Dakota
Monday night and into Tuesday morning, becoming an open wave as
ridging builds over the Pacific Northwest. Precipitation chances
will then subside to the south central and southeast by Tuesday
afternoon, moving out of the area completely by Tuesday night.
When all is said and done, areas across the west should see the
most rain through Tuesday, generally from a couple tenths of an
inch to around a half inch where the heaviest showers/storms
track. Amounts should taper off to the east.

A strong (but dry) cold front comes through Wednesday, bringing a
major change to temperatures and some breezy winds on the back
side. Highs on Wednesday will range from the upper 50s northwest
to the lower 70s southeast. We should then see widespread lows
below freezing Wednesday night in the mid to low 20s north to the
lower 30s south. Highs will then only be in the lower 40s to lower
50s Thursday, well below normal. Thursday night will see almost
all of western and central North Dakota with lows in the mid to
upper 20s. We then start to see a gradual warmup at the end of the
week and into the weekend with highs back into the mid 50s to
lower 60s by Saturday. After Tuesday, the long term period looks
dry.

&&

.AVIATION...(For the 00Z TAFS through 00Z Sunday Evening)
Issued at 655 PM CDT Sat Oct 1 2022

Periodic showers may bring some MVFR conditions at times through
the forecast period, otherwise look for VFR conditions. A large
upper low will bring periods of showers through much of the
forecast period, although some lulls are expected at times. Any
site that sees a shower could also see some MVFR conditions at
times. Otherwise look for mostly cloudy to partly clear skies, and
VFR conditions. Some lower ceilings are possible across the
Highway 2 corridor later tonight into Sunday morning, perhaps
bringing some MVFR conditions as well. Patchy fog is also possible
tonight, although confidence is not high enough to include at this
time. Breezy easterly winds will diminish somewhat tonight, then
may return for a few eastern sites on Sunday.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

UPDATE...Anglin
SHORT TERM...ZH
LONG TERM...ZH
AVIATION...Anglin


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.