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000
FXUS63 KBIS 220314
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
1014 PM CDT Sun Apr 21 2024

.KEY MESSAGES...

- Rain shower chances late tonight, Monday, lingering through
  Monday night. Greatest chances (~20 to 50 percent mainly north
  of Interstate 94) Monday afternoon and evening. An isolated
  thunderstorm possible Monday afternoon and evening.

- Critical fire weather conditions possible Monday over much of
  southwest and south central North Dakota including the James
  River Valley. A Fire Weather Watch remains in effect for these
  areas.

- West to northwest winds with gusts to 50 mph possible Monday,
  with the highest gusts over western and far south central
  North Dakota.

- Warming temperatures mid week, with chances for rain showers
  and a few thunderstorms returning late week into the weekend.

&&

UPDATE
Issued at 950 PM CDT Sun Apr 21 2024

Currently, a cold front was located over eastern Montana. Skies
were partly to mostly cloudy with high level clouds. Strong
south to southwest winds have diminished over the forecast area.

A weak cold front will move through the forecast area tonight
with isolated to scattered showers along and behind the front.
Little if any significant precipitation is expected. Light to
moderate reflectivities over eastern Montana have yet to yield
precip at an observation site but expect there may be a few
sprinkles under the highest reflectivities. Could also be a
brief period of gusty winds over 30 mph with the shower activity
as it moves through tonight. As for the forecast, only modest
changes were made to pops, blending in the latest short term
guidance.

UPDATE
Issued at 553 PM CDT Sun Apr 21 2024

Thickening high level clouds continue to push into western and
central North Dakota. Gusty south to southwest winds will
continue into early evening then diminish, but it will remain a
bit breezy tonight. Made some minor chances to sky cover and
pops late tonight based on latest short term guidance. Updated
text products will be transmitted shortly.

&&

.DISCUSSION...
Issued at 355 PM CDT Sun Apr 21 2024

An increased gradient ahead of an approaching cold front will
continue to bring some breezy and dry conditions through this
evening. This could lead to near critical fire weather
conditions during this time period. Meanwhile, clouds will start
increasing from west to east across the CWA this evening and
continue this trend through tonight. Surface cold front then
looks to push through the area tonight through Monday morning.
Along this front will be some shower chances if they can
overcome the dry air currently in place. Lows tonight will near
40 limiting any chances for snow. Clipper system then moves
through the area Monday. With that will bring the potential for
strong winds, especially in the west. The HREF ensembles lead to
some uncertainty today as to how high winds can gust, although
there seems to be a decent signal for sustained winds at
advisory level especially in the west. There still appears to be
fair mixing tomorrow, although pressure rises do not quite pick
up till tomorrow evening. Given this uncertainty, confidence
was not quite there today to issue a Wind Advisory for Monday
although will be closely monitored. These strong winds combined
with low RH could lead to critical fire weather conditions
especially along and south of the Highway 200 corridor. A Fire
Weather Watch remains and has been expanded based on the latest
forecast. See the Fire Weather Discussion below for more
details. Wrap around showers still look possible Monday
afternoon through Monday night. Modest mid level lapse rates and
some weak MUCAPE could lead to some isolated non-severe
thunderstorms during the afternoon and evening hours. SPC has
introduce general risk in the north, which is now also reflected
in the forecast. A few showers and breezy winds could then
linger Monday night, with lows generally in the 30s to lower
40s. Mostly cloudy skies on Tuesday morning are expected to
clear up Tuesday afternoon. High temperatures Tuesday will be
slightly cooler and in the 50s behind Monday`s clipper system.
Some breezy winds may also linger in the east on Tuesday.

A warming trend under weak ridging then looks to be found mid
week. Look for high temperatures forecast in the 60s to perhaps
near 70 Wednesday and Thursday. A switch back to southerly flow
on Wednesday and Thursday could bring some breezy winds at
times. Thursday night into the upcoming weekend a more active
trough pattern is still being forecast for the area. This could
provide chances for showers and perhaps thunderstorms each day.
Uncertainty with this trough pattern still provides a fair
spread in NBM temperature probabilities. The overall trend
though is for at least near normal temperatures and lows above
freezing.

&&

.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 553 PM CDT Sun Apr 21 2024

VFR conditions expected through the 00Z TAF period.

Strong south to southwest winds to begin the taf period will
diminish by mid evening but remain breezy through the night.
Winds will shift west to northwest on Monday and increase to
around 20-30 mph during the morning and then 25 to 35 mph with
gusts to to 50 mph in the afternoon. Isolated showers will move
west to east across the area late tonight into Monday morning.
Another areas of showers and possibly a thunderstorm will drop
south into the northern ND including KXWA and KMOT Monday
afternoon. At this time uncertainty is to high to mention the
shower activity moving across the area late tonight. Monday
afternoon, the better chances of showers will remain along the
International border and will also hold off on including shower
or thunderstorm activity at the northern TAF sites.

&&

.FIRE WEATHER...
Issued at 355 PM CDT Sun Apr 21 2024

Dry conditions with humidity values in the 20s and breezy
southwest winds 15 to 20 mph will bring near critical fire weather
conditions late this afternoon into this evening. Clouds then
increase late this afternoon through tonight, which may help
limit critical fire weather conditions today. A frontal boundary
will shift winds back to westerly direction overnight tonight
from west to east along with a few showers. Humidity recoveries
will be 50 to 70 percent for most areas.

On Monday, winds will become west to northwest, increasing to 25
to 35 mph with gusts to 45 mph over much of the area. The
lowest humidity values of 20 to 25 percent are expected to be
mainly along and south of Highway 200. Given the strong winds
and low humidity values, a Fire Weather Watch has been issued
for much of southwest and south central North Dakota, including
the James River Valley, for possible critical fire weather
conditions. This was expanded north and eastward from this
morning given the latest forecast. Near critical fire weather
conditions are expected for most remaining areas in northern
North Dakota, although higher chances for cloud cover and
precipitation along with higher expected humidity values have
allowed to hold off on any fire weather product for these areas
at the moment.

The mentioned front will bring a chance of rain showers late
tonight through Monday morning from west to east. There is then
a 20 to 50 percent chance of rain showers mainly north of
Interstate 94 during the day and night Monday. An isolated
thunderstorm is also possible. With that said, most of these
showers are expected to be quite light with current QPF forecast
values of less than a tenth of an inch. Another concern at this
point is virga, very light showers, or even an isolated
thunderstorm passing through with dry air down low, which would
lead to erratic wind gusts.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
Fire Weather Watch from Monday afternoon through Monday
evening for NDZ017>023-025-031>037-040>048-050-051.

&&

$$

UPDATE...TWH
DISCUSSION...
AVIATION...TWH
FIRE WEATHER...Anglin