104
FXUS63 KABR 192023
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
323 PM CDT Wed Mar 19 2025

.KEY MESSAGES...

- Winds out of the north gusting 30 to near 40 mph will continue to
slowly diminish this evening.

- Very High Grassland Fire Danger Values are expected over much of
northeastern SD and Lyman/Jones Counties of south central SD
Thursday afternoon. Winds gusting 20-30 mph and relative humidity
values near 20 percent created elevated fire weather concerns,
especially near the ND/SD border east of the MO River Thursday
afternoon.

- Two opportunities for precipitation with one on Friday (20-35%),
then again Saturday night through Sunday (30-50%). Although, amounts
look light with generally less than 20% chances for precipitation
greater than 0.25 inch.

&&

.SHORT TERM /THIS EVENING THROUGH THURSDAY NIGHT/...
Issued at 323 PM CDT Wed Mar 19 2025

Fire weather concerns will be the main theme of this short term
discussion. Winds gusting 30 to 40 mph out of the north will slowly
diminish during the evening hours, and be mainly out of the west
around 10 mph by early Thursday morning. Relative humidity recovery
will be 70 percent or higher, with a few pockets struggling to get
to 60 percent near the Leola Hills as a ridge of dry high pressure
quickly shifts across the forecast area.

Expect winds to increase out of the southwest during the day
Thursday, out ahead of a low pressure shifting across North Dakota
that will drag a cold front Thursday night. Relative humidity values
on Thursday will bottom out in the 15 to 25 percent range, with the
strongest winds gusting to 20 to 30 mph. The strongest winds, and
elevated fire weather concerns, are expected over portions of far
northern South Dakota mainly east of the Missouri River Thursday
afternoon into the early evening hours. A Fire Weather Watch has
been issued for McPherson, Brown, Marshall, Edmunds, and Day
counties for Thursday afternoon. Roberts County, although has
similar winds, has not been included because relative humidity
values there look to stay just above criteria. This is a low end
Fire Weather Watch, with additional adjustments expected to
headlines. Along our southwestern border, relative humidity values
are lowest in the forecast area, but winds are expected to be
lighter.

We do have a 20-30% chance of light rain or snow 09-12Z Friday over
north central SD. However, CAMs do indicate that there may be light
precipitation will be farther east, so we`ll need to monitor the
latest model trends. A reinforcing west to east oriented cold front
near the ND/SD border around 12Z Friday.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Issued at 323 PM CDT Wed Mar 19 2025

The long term portion of the forecast begins on Friday with a cold
front sliding southward across the CWA. Timing of the cold front
could play a role with forecast temperatures as some deterministic
models move the front into the CWA between 12-18Z. Consensus among
models suggests temps in the upper 30s and 40s around 15Z, with the
eastern CWA dropping to the low and mid 30s at 18Z, before warming
some at 21Z. The p-type associated with the frontal boundary may be
a mix of rain and snow, with perhaps snow the dominate p-type. The
12Z NAM supports mostly a snow event with only minor accumulations,
or under an inch. The grand ensembles probability of 0.05 inches of
QPF in 6 hours is under 15 percent. Friday could be a high pop, low
QPF event.

Temperature warm on Saturday ahead of a surface low pressure system.
925 mb temps in the single digit and mid teens should produce highs
in 50s and low 60s. While the NBM does not support it, will need to
monitor the potential for warm air advection over the northeastern
CWA Saturday afternoon and evening per the 6Z GFS. The surface low
pressure progress eastward across the region Saturday night through
Sunday, with a 20 to 60 percent chance of precipitation. The NBM and
the grand ensemble both highlight northeastern SD and western MN as
having the best potential, 40-60 percent chance, of seeing
measurable pcpn. The surface low does strengthen east of the CWA,
with gusty northerly winds expected across the CWA. The grand
ensembles probability of seeing gusts of 35 to 40 mph at KABR is 36
percent. Gusts over 40 mph is 26 percent. The combination of falling
snow and gusty winds may promote blowing snow issues on Sunday. The
storm system exits the region by Sunday night, leaving behind
northwesterly flow aloft for the reminder of the forecast period.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1225 PM CDT Wed Mar 19 2025

Terminals KABR,KATY,KPIR,KMBG

VFR conditions will continue to push in from ND and central SD.
Expect the lingering MVFR to temporary MVFR conditions to end
20-22Z at ATY. While lighter winds are moving in at and just above the
surface, daytime mixing will keep the winds gusting 25 to 35 mph
with a few gusts nearing 45 mph through the afternoon hours at
ATY.


&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...Fire Weather Watch from Thursday afternoon through Thursday
     evening for SDZ005>007-010-011.

MN...None.
&&

$$

SHORT TERM...06
LONG TERM...SD
AVIATION...06