895
FXUS63 KBIS 040551
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
1251 AM CDT Sat May 4 2024

.KEY MESSAGES...

- Chances (20 to 40 percent) for rain showers continue this
  evening over much of western and central ND, then mainly
  across the north overnight.

- Temperatures are forecast to warm up through the weekend,
  with windy conditions on Sunday.

- Chances for rain return late Sunday night and continue through
  the work week. The wettest period will be Monday through
  Tuesday when most of western and central North Dakota will see
  medium to high chances (60 to 90 percent) of rain.

&&

.UPDATE...
Issued at 1243 AM CDT Sat May 4 2024

The forecast looks to be in good shape for the late night
update. A few showers continue along and just to the south of
the International Border over the north central. For this
update, just blended in the latest observations to the going
forecast.

UPDATE
Issued at 905 PM CDT Fri May 3 2024

Modified POPs a bit based on latest radar imagery and trends,
otherwise the forecast remains in decent shape.

Isolated to scattered showers across the south are diminishing
as expected, with lingering showers north along the sfc trough
axis/frontal boundary.

UPDATE
Issued at 637 PM CDT Fri May 3 2024

S/WV mid level trough swinging east-southeast across eastern
Montana into western North Dakota continues to generate enough
lift to maintain scattered showers across the local area late
this afternoon/early this evening. Showers and clouds across
the south should dissipate as we cool this evening, with clouds
and chances for showers persisting across the north near an
inverted sfc trough moving slowly south across the US/Canadian
border tonight. Temperatures will drop into the mid 20s to lower
30s where we clear, remaining above freezing where clouds linger
tonight.

UPDATE
Issued at 526 PM CDT Fri May 3 2024

Just a quick update to increase shower coverage across southern
ND for the next few hours, based on latest radar imagery and
trends.

&&

.DISCUSSION...
Issued at 302 PM CDT Fri May 3 2024

An upper level low located over southern Ontario will continue
to push eastward. Wrap around showers will continue across the
northern half of the state. Instability is a bit lacking this
afternoon for thunderstorms, but a rumble or two is still
possible. Showers will decrease later this evening as
instability from daytime heating decreases. Overcast skies from
low cumulus has resulted in below normal temperatures with high
temperatures in the lower 50s. Breezy winds are being observed
across the state from a surface pressure gradient from the
aforementioned upper low. A surface trough continues to push
across the central half of the state turning winds from
southwesterly to northwesterly. Overnight lows could drop into
the upper 20s across the southwest as surface high pressure
passes through the region.

High temperatures Saturday will begin to trend upward to near
normal as surface high pressure clears out the region and
ridging begins to build out west over the Northern Rockies.
Sunday is forecast to be the warmest day as temperatures are
forecast to climb into the 60s to 70s out west due to the upper
level ridge pushing into the region. In addition a strong
surface low will move into eastern Montana with a tight surface
pressure gradient leading to windy conditions across western
and south central North Dakota. Forecast soundings at this time
have around 45 kts mixing down to the surface which will result
in advisory level winds. This short term warm up will be short
lived as another broad trough pushes across Western CONUS.

A strong upper level low pressure system will move up from the
Rocky Mountains Monday leading to widespread precipitation
across the Northern Plains. The NBM has 50 percent chance of 1
inch rain across the Northern half of the state where the
deformation band will likely set up. PWATs are pretty impressive
for this event with values around 1.1 inches. Heavy rain is
possible from stronger storms. However, there are some areas
that could see significantly less rain depending on where the
dry slot sets up. Thunderstorms are possible as the system first
moves into the region. Instability around 500 j/kg which
continues to decrease, however 0-500 mb shear is around 40 kts.
CSU Machine Learning Program has backed off on severe weather
parameters due to the ensembles having decreased instability,
but there still is low chance for severe weather Monday. In
addition to rain, windy conditions are expected Monday as a
strong surface low with a tight pressure gradient moves through
the region. Wrap around precipitation will continue through
Wednesday leading to showers and cooler conditions. Temperatures
are forecast to sit in the 50s through the middle of the week.
After this system washes out near normal temperatures will
continue until potential ridge moves into the region late next
week.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1243 AM CDT Sat May 4 2024

A few showers will continue overnight, mainly along the
International Border across the north central and northeast. A
band of MVFR to IFR stratus will move in from Canada overnight
and sag into the northwest, north central, and perhaps to the
northern fringes of the James River Valley. KMOT will likely see
MVFR to IFR ceilings until late Saturday morning or early
afternoon. Sites KXWA, KBIS, and KJMS will be right on the
western and southern edges of this stratus band. Therefore, it
isn`t out of the question that some MVFR ceilings will
occasionally impact these sites at times through Saturday
morning. KDIK should remain in VFR conditions through the
period. A few isolated showers may once again develop across the
north central and northeast Saturday afternoon.

&&

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

&&

$$

UPDATE...ZH
DISCUSSION...Johnson
AVIATION...ZH