179
FXUS63 KFSD 250640
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
140 AM CDT Wed Sep 25 2024

.KEY MESSAGES...

- Dry conditions are expected through the period. Above average
  high temperatures in the 80s is expected through the weekend.

- Breezy southerly winds and lowering relative humidity levels
  may result in elevated fire danger for locations west of the
  James River on Thursday.

&&

.DISCUSSION...
Issued at 139 AM CDT Wed Sep 25 2024

Quiet conditions begin the day today as weak surface ridging slides
through the forecast area. This is keeping winds calm to nearly calm
which could result in patchy shallow fog. Any shallow fog that does
develop should develop along bodies of water and quickly dissipate
as mixing increases as the sun comes up.

The rest of today will be a gorgeous day as highs warm to the upper
70s and 80s while winds remain light and skies remain clear. Get
outside and enjoy it! Low temperatures will fall to the 50s
overnight. Winds look to stay a touch elevated tonight as surface
ridging pushes off to the southeast, allowing the surface pressure
gradient to tighten a bit. This will keep slightly elevated winds
through the night and will keep any new fog chances minimal.

Upper level ridging will be introduced to the Northern Plains aloft
on Thursday as it gets squeezed between a vertically stacked low
pressure system over parts of the Midwest and the Jet Stream across
the international border. This will keep above average temperatures
going with highs into the 80s expected. Locations across central
South Dakota may even have a shot to reach up to 90 degrees F. The
previously mentioned surface pressure gradient will further tighten
throughout the day, contributing to breezy southerly winds across
the area. The strongest winds will lie west of I-29 and especially
west of the James River where gusts up to around 30 mph are
expected. The warm and breezy conditions will lead to some elevated
fire danger west of the James River though as relative humidity
values fall to around 25-30%. The good news is that fuels are still
on the greener side which should mitigate the overall fire danger
threat a bit. As of now only moderate fire danger is expected. Winds
will wane through the evening hours as the surface pressure gradient
relaxes. Low temperatures will fall to the 50s overnight.

Friday through the weekend will see continued above average
temperatures as highs remain in the upper 70s and 80s. The
previously mentioned vertically stacked low looks to wobble
eastwards during this period of time which will keep our area dry.
Winds also look to be light as the surface pressure gradient remains
relaxed. This will make for quite a nice weekend across the area!

Temperatures look to cool early next week as stronger shortwave
trough amplifies as it passes east of the Northern Plains on Monday.
This wave will drag a stronger cold front through the region which
looks to return temperatures to near seasonable. As of now, it looks
to be a dry frontal passage so no rain is expected. But, highs will
return to the 60s and 70s on Monday, Tuesday, and Wednesday next
week, which will make for more Fall like conditions across the
area.

&&

.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 1028 PM CDT Tue Sep 24 2024

VFR expected throughout the period, though some patchy shallow fog
cannot be ruled out. Winds will remain calm and variable into
Wednesday, with a couple hours where wind direction doesn`t change
much by the late morning and early afternoon hours. However, winds
will become variable again into the evening hours as they further
turn to become out of the south-southeast early overnight into
Thursday.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
IA...None.
NE...None.

&&

$$

DISCUSSION...Meyers
AVIATION...APT