Severe Thunderstorm Warning 57, NWS Aberdeen, SD

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
628 PM CDT Thu Jul 22 2021

.UPDATE...
Issued at 624 PM CDT Thu Jul 22 2021

See updated aviation discussion below.

&&

.SHORT TERM...(This Evening through Friday Night)
Issued at 351 PM CDT Thu Jul 22 2021

The heat and humidity has overlapped enough for some 100 F plus heat
index readings this afternoon across the CWA, as the upper-level
ridge remains in place. Lofted smoke continues to meander across the
area as well, although a gradual improvement in haziness is possible
into Friday per the HRRR's Vertically Integrated Smoke output.

A large upper-level low across central Canada will continue
advancing eastward tonight. As it does so, it's associated upper
trough will increasingly infringe on and temporarily flatten the
Northern Plains' upper-level ridge. Increasingly westerly flow aloft
will help develop downslope winds on the leeward side of the Prairie
Coteau into Friday morning. Shortwaves within the flow will provide
support for any frontal boundary-induced showers and thunderstorms
that track through or develop in the area tonight through the day
Friday. Due to its closer proximity to stronger winds aloft, this
activity has the potential to interact with enough shear to reach
strong to severe limits at times. This is particularly the case
during the afternoon and evening hours, with any storms that
initiate in a fairly moist environment along/ahead of the slowly
advancing cold front/sfc trough.

.LONG TERM...(Saturday through Thursday)
Issued at 351 PM CDT Thu Jul 22 2021

The overall theme through this forecast period will be the
continuation of hot and dry conditions. There will be a couple of
sporadic chances for precip early in the week, but the trend will be
for continued dry conditions. High pressure will be building into
the region for the beginning of the weekend in the wake of an
eastward departing frontal boundary. Temperatures behind this front
will be relatively cooler, especially across our eastern zones with
daytime readings Saturday and Sunday in the 80s to near 90 degrees.
Everyone else looks like they will continue to top out in the 90s
for highs.

The upper ridge is expected to amplify again across the western
CONUS and northern High Plains through the early portion of next
week. Temperatures will respond with daytime highs well into the 90s
for most of the CWA with perhaps some low 100s across western zones.
Precip chances next week look fairly nil for most of the region. The
best opportunity for any pcpn looks to occur Sunday into Monday.
Warm air advection along with a weak mid level wave traversing south
of our area may touch of some thunderstorm activity.

&&

.AVIATION...(For the 00Z TAFS through 00Z Friday Evening)
Issued at 624 PM CDT Thu Jul 22 2021

Terminals KABR,KATY,KPIR,KMBG

May see a few showers or thunderstorms affect the northwestern CWA
this evening before they dissipate. Otherwise, VFR conditions will
prevail across the area tonight and through the day Friday. Cannot
rule out a few thunderstorms developing somewhere in the CWA after
22Z Friday, with the northwest being the most likely area to see
that happen.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
&&

SHORT TERM...Lueck
LONG TERM...Vipond
AVIATION...Parkin

Hazardous Weather Outlook
National Weather Service Aberdeen SD
357 AM CDT Thu Jul 22 2021

MNZ039-046-SDZ003>011-015>023-033>037-045-048-051-230900-
Traverse-Big Stone-Corson-Campbell-McPherson-Brown-Marshall-Roberts-
Walworth-Edmunds-Day-Dewey-Potter-Faulk-Spink-Clark-Codington-Grant-
Hamlin-Deuel-Stanley-Sully-Hughes-Hyde-Hand-Jones-Lyman-Buffalo-
357 AM CDT Thu Jul 22 2021 /257 AM MDT Thu Jul 22 2021/

This Hazardous Weather Outlook is for west central Minnesota,
central South Dakota, north central South Dakota and northeast
South Dakota.

.DAY ONE...Today and tonight.

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

Showers and thunderstorms are possible around a cold front on Friday.
Some of these may be strong to severe.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.