Milbank, South Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

900
FXUS63 KABR 200031 AAA
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
731 PM CDT Mon May 19 2025

.KEY MESSAGES...

- Rain continues into Tuesday and diminishes through Wednesday.
  Probabilities for additional rainfall in excess of 1 inch ranges
  from about 50 to 90 percent, highest from Roberts County in SD and
  eastward into west central MN.

- Below normal temperatures, by 15-25 degrees, continue through Wednesday
  before we see a warming trend toward normal (upper 60s to mid
  70s) for the weekend that lasts into next week.

&&

.UPDATE...
Issued at 720 PM CDT Mon May 19 2025

Aviation discussion updated below for the 00Z TAFs. Also decided
to cancel the Wind Advisory for areas west of the Coteau as speeds
just aren`t hitting criteria. Will maintain the advisory for the
Coteau region into Spink county as stronger winds are occurring
here with the low-level jet in place affecting higher terrain
more. Plus, western slopes of the Coteau continue to see downslope
easterly gusts from 40 to 50 mph that are affecting areas as far
west as the eastern half of Spink county.

&&

.DISCUSSION...
Issued at 257 PM CDT Mon May 19 2025

The main story will be the ongoing rain and below average temps
through the midweek before we start to see a gradual warmup towards
the end of the week. As of 2pm, water vapor imagery continues to
show the cutoff mid low spinning over eastern WY/western SD. Models
are consistent on this cutoff low continuing to spin nearly
stationary over this area (with several vort max`s spinning around
it) as a shortwave trough`s axis is positioned south of this low
over the southern CONUS through tonight. At the surface, an inverted
trough extends northward over the CWA from the main area of low
pressure over the central CONUS. The mid level trough pivots
northeastward, and becomes negatively tilted, tonight through
Tuesday with the inverted surface trough becoming positive tilted as
the surface low tracks east/northeast and over IA by Tuesday
morning. During this time, the mid level low only really pushes a
bit eastward and over central SD to western MN by 00z Wednesday. It
then shifts northward into ND by Wednesday morning.

Throughout today much of south central SD has been in the dry slot
of the mid low with WAA return flow ahead of it aloft over portions
of northeastern SD into western MN. This has led to elevated showers
and thunderstorms over this area with even a couple reports of
pea size hail in Watertown around 115pm. RAP soundings continue to
indicate this very narrow area of elevated skinny cape (MUCape up
to 500 j/kg) above more of a stable/cooler layer near the
surface, mainly James River and eastward leading to ongoing
thunderstorm and/or heavier rain showers over portions of eastern
to northeastern SD this afternoon and evening. We will lose this
elevated instability through the night as just general rain
showers continue. With the track of the mid low, surface trough,
and high RH`s, CAMs indicate several waves of rain showers through
Tuesday into Wednesday, with the likely pops (80-100%) over the
eastern CWA. Precip will start to taper off southwest to northeast
over the CWA Wednesday afternoon. With the slow movement of this
system, probability of additional 24hr rainfall exceeding 1",
ending Tuesday evening is 50-90% along and east of the James
River, highest from Roberts County into west central MN. With much
colder air filtering into the backside of the low, NAM soundings
indicate a pretty saturated column with moisture in the DGZ zone
(and lift) over north central SD and the Coteau early Wednesday
morning. The entire column just above the surface will be below
freezing with surface temps hovering just at or a bit below
freezing (NBM prob of 32 and below is 55-75% over north central
and portions of northeastern SD). I would not be surprised if we
saw a bit of snow mixed in with the rain before temps warm back up
and Ptype becomes all rain. NBM backs this up and has this chance
as well, so left it in the grids. If we see any dusting in
accumulation (NBM is not showing anything for probsnow), it would
be in the higher elevations of the Leola Hills and Coteau.

Ongoing easterly winds are leading to downsloping winds on the
western side of the Coteau through the evening, with gusts up to 45
mph and diminishing a bit through the overnight. With the tight
pressure gradient overhead, wind gusts are forecasted to range
between 20-30kts by 06Z, highest over the Coteau. Through Tuesday,
it will not be as windy with gusts between 20-30kts. With the higher
humidity in place and clouds, temperature will remain steady in the
upper 30s to the lower 40s tonight. Tuesday marks the latter half
May, however, with this colder air filtering in behind the system,
highs are only forecasted in the 40s to maybe around 50 over south
central SD. EC EFI for MaxT Tuesday is -0.7 to -0.9 over northern
and northeastern SD as temps will be 20 to 25 degree below average!
This could either break or tie record low Max temperatures for
MBG,ABR, and 8D3 per NDFD records display. Highs will still be
around 20-25 degrees below average for Wednesday ranging in the mid
to upper 40s/lower 50s.

Thursday, the CWA will be on the northern crest of the ridge and a
surface high keeping the area dry. A brief flatting of the ridge
Thursday night into Friday is forecasted as a weak disturbance moves
across it. This may bring a 40-55% chance of precip, per NBM.
Additional moisture looks possible through Memorial Day weekend.
Temperature will overall range in the 60s with temps back in the
lower 70s early next week.

&&

.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 720 PM CDT Mon May 19 2025

Terminals KABR,KATY,KPIR,KMBG

MVFR/IFR CIGs in -SHRA/SHRA and -RA/RA will continue through the
TAF period. In fact, CIGs may go predominately IFR overnight into
Tuesday. MVFR/IFR VSBY also forecast through the TAF period in
periods of precipitation and BR. Still some TS potential around
KATY this evening and have included mention of this.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...Wind Advisory until 1 AM CDT Tuesday for SDZ007-008-011-018>023.

MN...None.
&&

$$

UPDATE...TMT
DISCUSSION...MMM
AVIATION...TMT