794
FXUS63 KUNR 131125
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
525 AM MDT Mon Oct 13 2025

.KEY MESSAGES...

- Unsettled weather this week

&&

.DISCUSSION...(Today Through Sunday)
Issued at 136 AM MDT Mon Oct 13 2025

07z surface analysis had ridge over the CWA with clear skies and
light winds. Temperatures have responded by dropping into the
20s/30s. Frost/Freeze headlines in good shape. Water vapour loop
had upper low/trough over the northwest CONUS with southwest flow
aloft over the northern Plains. Evolution of the upper trough the
main forecast driver this week.

Today/Tuesday, upper low drops into the southwest CONUS as
perturbed southwest flow impacts the CWA. As surface high shifts
east today, upslope southeast return flow ramps up bringing
increasing low level moisture as well as gusty southeast winds.
Initial wave rides on 140kt jet streak traveling into the central
plains tonight allowing modest low level frontogenesis to develop,
mainly east of the Black Hills where best PoPs are painted.
Secondary wave arrives Tuesday night with the best forcing across
the north. Temperatures will be tricky the next couple of days
given probable development of lower clouds given low level flow
regime, but in general highest temperatures will be found over the
west.

Wednesday/Thursday, main upper low ejects into the northern
plains. Best synoptic forcing northwest of the CWA, but surface
low/trough passing through Wednesday night will gather weak MUCAPE
over the area with potential for weak convection. High PoPs
warranted given model consensus with a 30-60% chance of 0.25" QPF.
Temperatures will be near guidance.

For the end of the week into next week, progressive northwest
develops, but predictability/timing low. So, slightly unsettled
with a hint of a colder system for the start of next week.

&&

.AVIATION...(For the 12Z TAFS Through 12Z Tuesday Morning)
Issued At 522 AM MDT Mon Oct 13 2025

VFR conditions are expected through the forecast period. Ceilings
will gradually lower east of the Black Hills tonight, but still
remain VFR. Surface winds will increase from the south to
southeast with gusts of 25-35kts after 15z.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...Freeze Warning until 9 AM MDT this morning for SDZ001-002-
     012>014-025>027-030>032-041>044-072>078.
     Frost Advisory until 10 AM CDT this morning for SDZ046-047-049.
WY...None.
&&

$$

DISCUSSION/KEY MESSAGES...Helgeson
AVIATION...Helgeson