924
FXUS63 KBIS 032351
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
651 PM CDT Fri May 3 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 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 /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 637 PM CDT Fri May 3 2024

VFR ceilings early this evening at all terminals. MVFR cigs
will then develop at KMOT after 06Z early Saturday morning, and
possibly at KXWA, KBIS, and KJMS after 12Z. MVFR cigs will
slowly improve to VFR late Saturday morning into the afternoon.
Breezy northwest winds will taper off after 01Z. Isolated
showers remain possible through 02Z, and across the north
through tonight.

&&

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

&&

$$

UPDATE...NH
DISCUSSION...Johnson
AVIATION...NH