496
FXUS63 KBIS 220524
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
1224 AM CDT Sun Sep 22 2024

.KEY MESSAGES...

- Areas of frost tonight west and parts of south central as
  skies clear, winds diminish, and temperatures dip into the
  lower to mid 30s.

- Gradual warming trend as we progress through the upcoming
  week.

- Dry weather prevails.

&&

.UPDATE...
Issued at 1219 AM CDT Sun Sep 22 2024

No major changes were needed for the late night update. We are
already seeing several sites in the mid to upper 30s across the
west. Should just continue to get even cooler with light winds
and a clear sky overhead.

UPDATE
Issued at 943 PM CDT Sat Sep 21 2024

Surface high pressure currently analyzed across eastern Montana
is forecast to slowly make its way east into the western
portions of North Dakota. With clear skies and calm winds
expected, temperatures are forecast to cool into the low to mid
30s in much of the west and parts of south central North
Dakota. The Frost Advisory remains as planned. No major changes
were made to the forecast for this update.

UPDATE
Issued at 623 PM CDT Sat Sep 21 2024

No major changes were made to the forecast for this update.
Winds continue to decrease through the evening, along with the
cumulus field continuing to erode closer to sunset. Otherwise,
just blended the current observations into the forecast.

&&

.DISCUSSION...
Issued at 129 PM CDT Sat Sep 21 2024

Current surface analysis places low over western Minnesota with
cold front sweeping to the southwest, while high remains over
central Montana into Alberta/Saskatchewan. Upper level analysis
places trough over Manitoba, with fast cyclonic flow over our
area. Gusty northwest winds continue over much of our area
between systems, but have remained rather steady over the past
few hours as the main pressure rises have pushed well to the
east. Scattered to broken cloud cover has developed over the
area with fair weather cumulus in the cyclonic flow.

For the rest of this afternoon into this evening, winds will be
steady before diminishing as evening approaches and high
settles southeastward. Cloud cover will also diminish with the
loss of daytime heating, leading to mainly clear skies. With the
cold airmass settling in, winds going light, and skies clearing
frost becomes a concern. NBM50 has remained quite consistent
with dipping temperatures well into the 30s over the west, and
latest run of the NBM has somewhat caught on with that scenario.
Although a bit old school, MAV and MET guidance, which have
historically worked quite well with low temperatures in
frost/freeze situations, continue to show lows dipping well into
the 30s over these areas. Therefore, have gone ahead and issued
a frost advisory for most of the west including all areas east
of the Missouri River on the south end.

Frost advisory goes into early Sunday morning. Thereafter, a
rather pleasant fall day is expected with highs running mainly
in the 60s which is only a bit below average.

Monday we will see an upper level trough push through the area,
but really do not expect any precipitation to come of this,
just an increase in cloud cover. Upper ridge builds into the
area through mid week resulting in a warming trend and continued
cool conditions. Ridge pushes east late-week but most systems at
this time appear to continue sliding to the north of the area,
so dry forecast continues at this time.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 1219 AM CDT Sun Sep 22 2024

VFR conditions are expected through the period. Winds will be
light and variable through the rest of tonight and into Sunday
morning. Then, winds will predominately be coming out of the
southwest by mid to late morning, only topping out around 10
knots or so, shifting to out of the south towards the end of the
period.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
Frost Advisory until 9 AM CDT /8 AM MDT/ this morning for
NDZ001-002-009-010-017>020-031>034-040>045.

&&

$$

UPDATE...ZH
DISCUSSION...JJS
AVIATION...ZH