873
FXUS63 KBIS 010555
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
1255 AM CDT Wed May 1 2024

.KEY MESSAGES...

- Widespread rain showers will continue moving across central
  and eastern North Dakota through tonight.

- Daily chances (low to medium) for rain (and maybe an isolated
  thunderstorm or two) through the rest of the week, with
  temperatures slightly below normal.

- Windy across the forecast area on Friday.

&&

.UPDATE...
Issued at 1255 AM CDT Wed May 1 2024

No major updates were required at this time. The broad area of
light rain showers and low stratus continues to pivot
northeastward, with only the north central continuing to observe
modest rainfall rates of 0.01-0.03" over the last hour. The
forecast remains on track.

UPDATE
Issued at 1028 PM CDT Tue Apr 30 2024

Rain showers continue in northern and parts of central North
Dakota late this evening, wrapping around the surface low that
is now in west central Minnesota. The most widespread area of
rain is in north central and northeast ND, with NDAWN stations
reporting generally 0.04-0.08" of rain in the last hour.

Upstream, scattered rain showers continue across northeast
Montana, although ceilings are a little bit higher with this
area of rain. Added in POPs to have slight chance of showers
mentioned across the northwest over the next few hours. High-res
guidance is relatively consistent in showers lifting north
through the night and exiting in the morning, with not long of a
break before additional showers move into southwest North
Dakota. Some of the latest CAMs seem a bit quicker on this
timing but will have to see if that stays a consistent trend.

UPDATE
Issued at 714 PM CDT Tue Apr 30 2024

Surface low has moved into southeast North Dakota, with
widespread rain showers continuing to wrap around the backside
of the low across central and eastern North Dakota. We are also
seeing strong winds in southwest North Dakota as cold air
advection filters in, with observed gusts around 50 mph in the
far southwest. There are a few isolated rain showers in
northeast Montana and northwest North Dakota associated with an
upper low, so will watch this activity through the evening.
Updated POPs to linger a few more hours across parts of the west
and central, otherwise going forecast looks good.

&&

.DISCUSSION...
Issued at 348 PM CDT Tue Apr 30 2024

Broad troughing continues to slowly progress across the Pacific
Northwest and the Northern Plains. The first system continues
to push across central North Dakota with a cold front extending
from Hebron down to the South Dakota border. A precipitation
axis from Crosby down to Linton continues to lift northeastward.
Stratiform rain will continue to pivot across the central half
of the state. A lack of instability continues which should
prevent thunderstorms across much of the state excluding the
southeast.

A surface low is located over the Bismarck Mandan area will
continue to pivot precipitation northeastward. Stronger winds
are wrapping around the backside of this low impacting the
southwest this afternoon. Winds are forecast to gust up around
30 to 40 mph before diminishing as the boundary layer
strengthens tonight. Critical fire weather concerns did not pan
out this afternoon as much of the southwest received up to
quarter inch of rain or more increasing relative humidity.

Broad troughing will continue across the Pacific Northwest with
an upper low parking over the southern Saskatchewan. This will
open the door for a weak ridge to move through the region
Wednesday leading to warmer temperatures. Highs are forecast to
reach the upper 50s to lower 60s east. A shortwave trough is
forecast to dig across the region leading to an increased
precipitation chances by the evening hours. Rain is most likely
across the south central and eastern half of the state while
the northwest still could see up to a quarter inch of rain. Rain
will continue through Thursday as the low wraps up around the
east. On the backside of the upper low cold air advection will
mix stronger winds aloft down to the surface resulting in windy
conditions Friday. Temperatures are forecast to sit in the 10
degree below normal until this weekend.

After the broad trough progresses eastward an upper level ridge
will settle over the region this weekend. Temperatures are
forecast to warm back into the 60s and 70s by Sunday. The upper
level ridge will pass eastward come early next week as the
pattern looks identical to this week. CSU Machine Learning
Program is highlighting severe weather for the southern half of
the state Monday afternoon as a stronger system is forecast to
move through the region. There are some model discrepancies
between the Euro and the GFS so we will see how this plays out.

&&

.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 1255 AM CDT Wed May 1 2024

A broad area of light rain showers and low stratus pivoting
around a surface low center in the southern Canadian Prairies
continues to exit the forecast area to the northeast. At the
start of the 06Z TAF period, only the southeastern terminal of
KJMS continues to observe MVFR to LIFR ceilings, and will soon
join all other terminals at VFR conditions through the late
afternoon. Another round of light showers and MVFR ceilings will
begin to push into the southwest just before noon today before
spreading to the southern terminals of KDIK and KBIS by the end
of the TAF period, then to all other sites through early
Thursday morning. Modest winds in KJMS will diminish by the
early morning, with winds remaining generally light through the
end of the TAF period.

&&

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

&&

$$

UPDATE...Adam/Jones
DISCUSSION...Johnson
AVIATION...Adam