610
FXUS63 KABR 182333 AAA
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
633 PM CDT Mon May 18 2026

.KEY MESSAGES...

- Rain showers (embedded thundershowers) into the evening hours.
  Most areas less than a half inch. No severe storms expected.

- Frost possible (33 to 36 degrees) across portions of central
  SD early Tuesday morning. Much better potential for
  widespread frost/freeze conditions Wednesday morning.
  Temperatures forecast around 29-33 degrees.

&&

.UPDATE...
Issued at 625 PM CDT Mon May 18 2026

Due to the cloud cover, temperatures should remain fairly steady
overnight. Increased lows a few degrees across the board,
leaning toward the HRRR and ConsShort. That leaves lows on the
cusp of frost advisory under the current headlines. Will leave
headlines as-is for now, but confidence is low in temperatures
below 37 degrees except in valleys.

&&

.DISCUSSION...
Issued at 237 PM CDT Mon May 18 2026

Starting to see an uptick in areal coverage of showers (embedded
thundershowers) as activity continues moving north-northeast across
the region. Instability is lacking today, so don`t expect anything
in the way of severe storms. Did some massaging of PoPs through late
afternoon into early evening to account for radar trends and
expectations. Total rainfall amounts forecast to remain less than a
half inch for most areas.

Later tonight into early Tuesday morning, surface high pressure
settles in across the western Dakotas. Chilly temperatures in the
30s are forecast across the CWA tonight, and there are some concerns
about frost potential with temps dropping to between 33 and 36
degrees. Clouds are expected much of the night, along with a
northwest breeze, so certainly not ideal radiational cooling
conditions. In fact, inherited NBM lows seemed a tad too cool, so
blended in some warmer (ConsMOS) readings to bring readings up a
couple degrees in spots. All said and done, forecast lows across
central SD are generally between 33 and 36 degrees, so have
therefore issued a Frost Advisory for the western CWA. Much better
potential for more widespread frost/freeze conditions late Tuesday
night into Wednesday morning as the surface high is more overhead.
Winds are expected to be lighter, with mostly clear skies
(especially for eastern areas) leading to better radiational cooling
conditions. Current forecast lows are closer to 30-32 degrees for
many areas. Highly likely more headlines are in store.

&&

.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 625 PM CDT Mon May 18 2026

Terminals KABR,KATY,KPIR,KMBG

A mix of MVFR/IFR conditions will persist into Tuesday morning
with the continuing rain and cloud cover. As high pressure moves
in Tuesday, cigs should improve.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...Frost Advisory from 4 AM CDT /3 AM MDT/ to 9 AM CDT /8 AM MDT/
     Tuesday for SDZ003>005-009-010-015-016-033>035-045.
MN...None.

&&

$$

UPDATE...20
DISCUSSION...TMT
AVIATION...20