FXUS63 KBIS 312337
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
637 PM CDT Sat Aug 31 2024

.KEY MESSAGES...

- Seasonable temperatures through Sunday, with a warming trend
  to above average early next week.

- Dry weather continues through early next week.

- Cooling trend mid to late next week, with occasional low
  chances (20 percent) for showers and thunderstorms.

&&

.UPDATE...
Issued at 636 PM CDT Sat Aug 31 2024

Gusty northwest winds will diminish this evening as surface high
pressure slides from southern Saskatchewan into North Dakota.
This should set the stage for strong radiational cooling. We
have decreased our low temperature forecast for tonight to the
25th percentile of NBM guidance. This brings the entire forecast
area down into the 40s, which lines up well with observed
dewpoints from this afternoon. A few upper 30s cannot be ruled
out in low-lying areas across the west. No other forecast
changes are needed for this update.


&&

.DISCUSSION...
Issued at 230 PM CDT Sat Aug 31 2024

We are currently post-frontal with surface high pressure
building in from Canada. Aloft a large area of high heights is
centered near Utah, leading to a ridge in the western CONUS.
Over the Northern Plains, northwest flow will be present
through Sunday.

Monday the ridge axis moves east over North Dakota,
bringing a very warm thermal ridge with it. Most of the area
will see warmer than average high temperatures. Average right
now is about 80 degrees. The thermal ridge will be over the
southwest part of the state. With winds gusting, this thermal
ridge will mix down, leading to temperatures in the mid 90s in
the southwest. Elsewhere will be in the 70s and 80s. Fire
weather conditions could be near critical in the southwest with
humidity values around 15 percent and winds around 20mph.

Tuesday will be similar when the thermal ridge slides east. The
Montana border, to near the west edge of the James River Valley
will be in the low 90s. Tuesday evening flow starts to turn
southwest as a shorter trough digs through Montana. This will
flush out the warmer thermal ridge. With the lower heights
moving in, highs will be back down in the 70s the rest of the
week.

For chances of rain and thunderstorms for the forecast period,
we have slight chances in the southwest and south central
starting Wednesday. This is part of the short wave trough moving
in. These chances will last through Thursday morning when flow
goes back northwest.

&&

.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 636 PM CDT Sat Aug 31 2024

VFR conditions are expected through the forecast period. Gusty
northwest winds will diminish this evening, becoming
southeasterly around 10 kts in western North Dakota on Sunday
while remaining light and variable across central North Dakota.

&&

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

&&

$$

UPDATE...Hollan
DISCUSSION...Smith
AVIATION...Hollan