Harvey, North Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

171
FXUS63 KBIS 221535
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
935 AM CST Sat Feb 22 2025

.KEY MESSAGES...

- Well above normal temperatures this weekend through much of
  next week. Southwest and south central North Dakota could have
  multiple days of highs in the 50s.

- Windy Sunday through Monday, especially in southwest North
  Dakota on Monday.

- Periodic low chances (20 to 30 percent) for light mixed
  precipitation beginning Sunday.

&&

.UPDATE...
Issued at 933 AM CST Sat Feb 22 2025

No updates needed at this time as the forecast remains on track.

UPDATE
Issued at 549 AM CST Sat Feb 22 2025

Mid and high clouds will continue streaming over the region through
the day due to persistent anticyclonic flow over the Northern
Rockies. The sky forecast for this morning was better aligned with
current observations and trends. Overall, the forecast remains on
track. Will leave a patchy fog mention in the forecast for northwest
to south central North Dakota and near the Turtle Mountains, but it
is becoming more and more unlikely that any will develop.

&&

.DISCUSSION...
Issued at 300 AM CST Sat Feb 22 2025

Anticyclonic flow over the Northern Rockies will continue to bring
milder Pacific air into the region through the weekend. The median
of the NBM high temperature distribution seemed to verify well
yesterday, so it was used again for forecast highs this afternoon.
This brings around 30 degrees to the Turtle Mountains area,
increasing to the lower and mid 40s in southwest and south central
North Dakota. Sunday`s high temperature forecast was raised to the
25th percentile of the NBM distribution, which for most areas is
warmer than the deterministic projection. Hesitant to go any warmer
at this time, as widespread lower to mid 50s in the southwest
quadrant of the state may be difficult to achieve with snow still on
the ground, though some may be melted by then. Nevertheless, still
anticipating at least upper 30s north to around 50 southwest and
south central for highs on Sunday. The milder pattern is expected to
continue through Tuesday, and both Monday and Tuesday have high
temperature forecasts on the colder side of the NBM distribution.
However, increased probabilities for clouds and precipitation
preclude a boost in temperatures for those 2 days at this time. Any
areas that do end up seeing at least partial/filtered sunshine
either of those days could see highs in the mid 40s north to upper
50s south, as much of the snow should be melted by then. Also worth
noting is that there is high confidence in near to above freezing
low temperatures Sunday night, which may help accelerate the snow
melt.

A couple of clipper type systems are forecast to cross the region
Sunday and Monday, along with several other much weaker impulses
embedded in the anticyclonic northwest flow that are unlikely to
greatly influence surface weather parameters. Precipitation chances
associated with the Sunday clipper have decreased and shifted
farther north. The NBM now only brings a 10 to 20 percent chance of
measurable precipitation across the north during the day Sunday, but
think trace amounts carry much higher probabilities. Any
precipitation should fall as liquid given warm temperatures aloft,
and there could be a brief window of opportunity for freezing
sprinkles Sunday morning. Given the expected very light nature of
the precipitation, little to no impacts are anticipated at this
time, and surface temperatures will rise above freezing by midday. A
strong pressure gradient will promote windy conditions on Sunday,
with sustained speeds around 25 mph and gusts around 35 to 40 mph in
the afternoon. A 10 to 20 mph westerly wind is forecast to persist
through Sunday night.

Monday`s clipper system is favored to track farther south, with the
surface low likely passing through some part of North Dakota. But
there are still large differences in placement and amplitude with
this wave in ensemble guidance. Some models/ensemble members
continue to show a potential for banded precipitation, while others
have little to no precipitation at all. Furthermore, those that do
show higher QPF place it as far northeast as Bottineau to Fargo and
as far southwest as Williston to Bismarck. The expectation is that
most precipitation on Monday should fall as rain, with the exception
of any heavier banding that may allow dynamic cooling to transition
precipitation to snow where rates are highest (this would be more
likely to occur with a more northern solution). The probability of
any winter impacts from this system remains very low.

The more concerning aspect on Monday is the potential for stronger
winds, especially in southwest North Dakota where a westerly low
level jet is forecast to pass over during peak diurnal boundary
layer mixing. 3 out of 4 ensemble clusters constituting around 80
percent of all global ensemble members are projecting 45 to 50 kts
of potential momentum transfer, and high-end outliers, such as the
00Z GFS, are well above warning criteria winds (50 kts) within the
well-mixed boundary layer. This signal has been in ensemble data,
including ECMWF EFI output, for several forecast cycles. As such, we
gave a slight increase to the wind and gust forecast Monday
afternoon, which calls for west-northwest winds around 30 to 35 mph
with gusts around 50 to 55 mph in the southwest. Other parts of
western and central North Dakota will still see windy conditions on
Monday, with sustained speeds around 25 mph and gusts as high as 40
mph.

A bit of a pattern shift is favored to occur by Wednesday as a
series of shortwaves ejects from the Canadian Rockies down into the
central and eastern CONUS. Deterministic guidance shows the forcing
to not be very well-organized as it crosses the region. Thus, NBM
precipitation probabilities have lowered below 30 percent Tuesday
afternoon through Tuesday night. Trailing this wave, a slight
cooldown is projected for Wednesday, but with highs remaining 5
(north) to as much as 20 (south) degrees above normal. Global
ensemble means then tend to establish a more highly-amplified
western CONUS ridge and eastern CONUS trough for the second half of
next week. This could place North Dakota near the dividing line
between a continuation of mild Pacific air with above normal
temperatures and a return of modified Arctic air bringing
temperatures back below normal (though not even close to as cold as
earlier this week). NBM temperature distributions seem to give a
slight preference for above normal temperatures continuing, though
spread increases greatly heading into the first weekend of
March.

&&

.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 549 AM CST Sat Feb 22 2025

VFR conditions are expected through the forecast period, with west-
southwest winds around 10 kts. There is a very low chance for patchy
fog developing early this morning. Mid to high clouds will continue
streaming over the region through the day.

&&

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

&&

$$

UPDATE...Johnson
DISCUSSION...Hollan
AVIATION...Hollan