469
FXUS63 KABR 262333 AAB
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
633 PM CDT Thu Mar 26 2026

.KEY MESSAGES...

- Highs in the 60s and 70s Saturday through Tuesday will be 15 to 25
degrees above normal for this time of year.

- On Saturday, winds will be out of a southerly direction gusting 35
to 45 mph. Combined with the dry air and dry fuels, very high
Grassland Fire Danger Index values are forecast Saturday for
portions of south central to northeastern South Dakota and west
central Minnesota, with extreme possibly over east central South
Dakota.

&&

.UPDATE...
Issued at 626 PM CDT Thu Mar 26 2026

Updated for 00Z Aviation discussion below.

UPDATE Issued at 547 PM CDT Thu Mar 26 2026

Minor updates to the forecast for tonight, largely to capture
latest trends in the higher res models for winds/snow behind the
cold front. Looks to be a 3-6hr period of increased winds behind
the front overnight tonight, primarily over central SD. Low level
lapse rates steepen up after the front and allow for mixing down
the 925mb winds around 25-30kts from northwest to southeast. Tried
to time the peak winds initially behind the front, then slowly
tapered them off into Fri morning. Similar theme for PoPs/Snow
over northeast SD and west central MN. While the initial push of
snow from MT and western ND this evening should diminish as it
moves into north central SD, another area associated with the
shortwave and steepening LRs behind the front may be enough to
produce shallow snow showers. While CAMs are mixed on it occurring,
when we`ve seen past situations like this with steep LRs and
moisture getting into the DGZ, we`ll usually get a few snow
showers. Thus, added in some slight chance PoPs and flurries to
account for it.

&&

.DISCUSSION...
Issued at 304 PM CDT Thu Mar 26 2026

A cold day continues, with temperatures steady to falling through
the day under thick clouds. At 20Z, the ABR 88D radar shows
reflectivity values stretching from north central SD through just
south of Aberdeen and southern Roberts county into west central MN.
This band has produced light snow with visibility down to 1.5 miles
over Mobridge when it passed, and has brought a wintry mix of light
snow and freezing rain to Milbank. The most pronounced/productive
portions of this line are over north central SD and west central MN.
The trend is for this time to continue its slow southern movement,
with a diminishing trend. We`ll need to continue to monitor the
southern progression, as an increase in chances of precipitation may
be warranted.

Temperatures will fall into the teens to low 20s tonight, and still
only rebound into the 30s and 40s Friday. Despite the cold air, drier
air will move in, with afternoon relative humidity values falling
into the 30 to 35 percent range. Winds will be much lighter Friday,
with gusts on the order of 20-25 mph.

Relative humidity recovery Friday night/Saturday morning will be in
the 30 to 60 percent range (lowest over central SD). Expect winds to
increase out of the south overnight with a 40-60kt low level jet.
While winds will diminish quickly over north central SD in the
afternoon, the winds will hold on longest over south central to
northeastern SD (especially over the eastern downslope areas of the
Prairie Coteau). The southerly direction gusting 35 to 45 mph, and
minimum afternoon humidity will fall between 15 and 25 percent. The
strongest winds will extend across south central to northeastern
South Dakota during the morning to early afternoon hours, before
diminishing. Very high Grassland Fire Danger Index values are
forecast Saturday for portions of south central to northeastern
South Dakota and west central Minnesota, with extreme possibly over
east central South Dakota. A Fire Weather Watch has been issued
Saturday for our 5 southeastern most counties, where the strongest
winds align with dry air/relative humidity less than 25%.

While we do have the mention of precipitation returning Tuesday-
tuesday night, it is only around a 20 percent chance. Cooler air,
and at least a 30% chance of precipitation will return for Wednesday
and Thursday.

&&

.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 626 PM CDT Thu Mar 26 2026

Terminals KABR,KATY,KPIR,KMBG

Lingering MVFR ceilings will remain for at least a few more hours
at KABR/KATY, although do have concern that they even leave at
KATY tonight. Otherwise, the rest of the forecast is tied to an
upper level disturbance and cold front that will moves through
overnight tonight. This may bring snow showers to KMBG, with the
line currently moving through western ND. Not too much south into
SD, but latest trends and hi-res models point towards it
approaching KMBG and potentially diminishing before reaching the
site. Did add a PROB30 to account for that potential. As the front
moves through overnight, expect northwest winds to pick up and
gust to 25-30kts over central SD and potentially into KABR through
through the first half of the morning before gradually
diminishing. Also, could see some snow showers behind the front in
northeast SD late tonight into Friday morning. Currently don`t
have them reaching KABR/KATY, but am seeing some trends farther to
the southwest, so may need to add a PROB30 for it with the 06Z
issuance.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...Fire Weather Watch from Saturday morning through Saturday
     evening for SDZ019>023.

MN...None.
&&

$$

UPDATE...SRF
DISCUSSION...06
AVIATION...SRF