FXUS63 KABR 181937
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
237 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.

&&

.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 /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1236 PM CDT Mon May 18 2026

Terminals KABR,KATY,KPIR,KMBG

Areas of -SHRA will move northeast into and through the region
this afternoon and evening. VSBY may drop to MVFR in
precipitation. CIGs will generally be MVFR, although forecast is
for IFR at times in areas of precipitation and overall lower
cloud cover potential during the evening hours.

&&

.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.

&&

$$

DISCUSSION...TMT
AVIATION...TMT