463
FXUS63 KABR 151945
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
245 PM CDT Sat Mar 15 2025

.KEY MESSAGES...

- Dry fuels, increasing winds, and warmer temperatures will lead to
very high grassland fire danger Monday.

- Another storm system will move east across the Central Plains
Tuesday into Wednesday. Some light snow accumulations are possible
over central and eastern SD.

&&

.SHORT TERM /THIS EVENING THROUGH SUNDAY NIGHT/...
Issued at 245 PM CDT Sat Mar 15 2025

Watching snow melt across central SD this afternoon on satellite
even though temperatures have been slow to rise today. Lowered max T
forecasts across the board this afternoon, accordingly. Winds are
diminishing, but continue to gust as high as 50 mph in the Sisseton
Hills. Will likely cancel the existing wind advisory a little early
since the higher winds are very isolated at this point.

High pressure builds in this evening over the region. Winds quickly
diminish with the encroaching high. A low moves off the Rockies in
Montana on Sunday. Associated precipitation will remain over North
Dakota. Over South Dakota, expect winds to become southerly and
usher in a strong push of waa from west to east through Sunday
evening. H85 temps will rise from -4C this afternoon to +8C by
Sunday evening across central SD. At the surface, the timing of the
waa will set up a marked thermal gradient across the forecast area.
Highs are forecast to range from the lower 30s in west central MN to
the upper 50s west river.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Issued at 245 PM CDT Sat Mar 15 2025

Monday, there is an upper-level ridge over SD that is moving east
during the day. With the ridge over the state, warm air is advected
into SD. This warm air helps to increase temperatures, leading to
highs being 15-25 degrees warmer than normal, in the mid 60s to
lower 70s. During the day, the relative humidity values will be
lower, with model guidance showing them in the low 20s to 30s. As a
weak surface low moves over northern SD Monday, the wind gusts look
to stay around/below 20kts in central and eastern SD, though areas
to the west of the Missouri River could see gusts around 25kts. The
combination of lower relative humidity values and slightly stronger
winds could increase the fire danger in central and eastern SD.

While this is happening, an upper-level trough is pushing a surface
low east over NE. On the northwest side of this low, a line of
precipitation starts to develop. The models vary the location of the
low pressure as well as the location and timing of the precipitation
as it enters central and eastern SD. Some models have the
precipitation moving over SD Monday evening while others hold off
until the overnight hours. The precipitation then looks to move
southeast over the state as a line, exiting central and eastern SD
by early Wednesday morning.

The variations in the models location and timing of the
precipitation also leads to differences in the type of precipitation
falling. Some models, cluster members, and ECMWF ensemble members
have the precipitation starting as rain and then transitioning to
snow once the sun sets as temperatures near the surface cool.
However, there are a few members that show rain occurring through
the event, as well as occasional members with sleet and freezing
rain. This then leads to variations in snowfall amounts, as models
that transition over to snow faster will have more time for snow to
accumulate. NBM snow amounts mainly show snow accumulation of less
than 2 inches over central and eastern SD. The clusters have a 20-
30% chance for 2 inches of snowfall Tuesday and a 30-60% chance for
an inch of snow. Additionally, winds increase Tuesday and Wednesday
afternoons, with gusts above 25kts Tuesday and widespread gusts over
30kts Wednesday. This could cause drifting and blowing snow if there
is snow occurring or accumulated on the ground. This could then
reduce visibilities at times and adding to potentially hazardous
driving conditions that could be caused by the precipitation type
and transition.

After Wednesday, the upper-levels have a ridge starting to move east
towards SD, though the deterministic models and clusters vary
whether the ridge moves over the state or gets suppressed and more
zonal flow moves over. This, in addition to other variations in the
models, causes there to be lower confidence in what will occur after
Wednesday. Precipitation will likely stay out of central and eastern
SD through Saturday, though some models are picking up on a
potential shortwave moving along the zonal flow over SD. This causes
a slight increase in the chance for precipitation Friday, though it
stays below 20%. The mid-levels do not have a dominate type of
temperature advecting into SD after Wednesday, which will help to
keep the temperatures around normal for this time of the year.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1221 PM CDT Sat Mar 15 2025

Terminals KABR,KATY,KPIR,KMBG

VFR conditions are expected through Sunday morning. Northwest
winds will diminish this evening.


&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
&&

$$

SHORT TERM...Wise
LONG TERM...Vernon
AVIATION...Wise