Severe Thunderstorm Warning 191, NWS Sioux Falls, SD

935 
WWUS53 KFSD 200121
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
821 PM CDT Sun Jul 19 2026

SDC053-200145-
/O.CON.KFSD.SV.W.0191.000000T0000Z-260720T0145Z/
Gregory SD-
821 PM CDT Sun Jul 19 2026

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 845 PM CDT
FOR NORTHWESTERN GREGORY COUNTY...

At 820 PM CDT, severe thunderstorms were located along a line
extending from near Iona to near Dallas, moving east at 20 mph.

HAZARD...60 mph wind gusts and penny size hail.

SOURCE...Mesonet. At 8:10 PM CDT, a 59 mph wind gust was reported 6 
         mles north-northeast of Dixon.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
Gregory, Dallas, and Dixon In Gregory County.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

To report severe weather contact your nearest law enforcement agency.
They will send your report to the National Weather Service office in
Sioux Falls.

&&

LAT...LON 4350 9931 4345 9931 4315 9943 4320 9954
      4350 9953
TIME...MOT...LOC 0120Z 291DEG 17KT 4349 9948 4327 9960 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...OBSERVED
MAX WIND GUST...60 MPH

$$

Samet

Area Forecast Discussion
National Weather Service Sioux Falls SD
659 PM CDT Sun Jul 19 2026

.KEY MESSAGES...

- A Heat Advisory remains in effect until 9PM for areas along
  and west of the James River. Another Heat Advisory will go
  into effect Monday afternoon for areas south of I-90.

- A very isolated strong to severe storm is possible in south-
  central South Dakota this evening mainly near and south of a
  Chamberlain to Mitchell line. 60 mph wind gusts will be the
  main threat if a storm can become severe.

- Another round of showers and storms is possible late tonight
  into tomorrow morning. The bulk of the showers look to stay
  just northeast of the area, but some could make it into parts
  of southwest Minnesota.

- Chances for strong to severe storms return to the area Monday
  afternoon and evening near and south of highway-20. Large
  hail up to the size of golf balls and damaging winds to 70 mph
  are the main hazards.

&&

.DISCUSSION...
Issued at 229 PM CDT Sun Jul 19 2026

A few light showers persist across the area this afternoon. These
showers are also accompanied by a mid level cloud deck which has
kept temperatures a bit cooler than previously expected. However,
sunshine remains across parts of south central South Dakota. Thus,
temperatures have warmed to the upper 70s, 80s, and a few locations
pushing into the 90s. With dew points remaining in the 60s to low
70s, heat indices have warmed to the 80s and 90s with a few
locations hitting 100F. With some diurnal warming left to go, should
still see the heat indices nudge a little higher, allowing for the
Heat Advisory to remain in effect until 9PM this evening. Another
round of showers and thunderstorms remains possible late tonight
into tomorrow morning (11PM to 6AM). These storms will develop along
a cold front in North Dakota and move southeastwards through the
evening hours. These storms may grow into a line as they push
southeastwards. However, there remains some uncertainty in whether
these storms will push into southwest Minnesota or stay just outside
the forecast area. These storms look to be focused on the nose of
the low level jet where convergence and the strongest warm air
advection (WAA) will lie. The bulk of the hi-res guidance and the
ensembles also support the storms remaining in this location. Still
have left light chance to chance PoPs across southwest Minnesota in
case lingering showers and storms pass through the area.

The thermal ridge will push directly over the forecast area on
Monday, pushing 850 mb temperatures up to +25C to about +30C. Mixing
these temperatures down to the surface will result in widespread
high temperatures up to the 90s to low 100s, hottest along the
Missouri River Valley. With dew points remaining in the 60s to low
70s, heat indices will warm up to 100F to 105F south of I-90. As
such, have issued another Heat Advisory for this area. The Advisory
is in effect from noon to 8 pm. The previously mentioned cold front
will be pushing through the area throughout the day. While this
front will cool temperatures, the main cold advective push from the
front will come in the late afternoon and evening timeframe, thus
allowing for hot and humid conditions to continue. This front will
serve as the focal point for additional showers and storms between
4PM and 10PM. The front will push through rather quickly, limiting
the severe weather threat to near and south of highway-20. Storms
look to remain more discrete as the develop and quickly race out of
the area along the boundary. The moisture pooling along the boundary
will push CAPE values up to 2,000 to 2,500 J/kg. Hodographs show
deep layer shear values on the order of about 45 knots. Hodographs
are generally straight with slight backing aloft. This should allow
for large hail up to the size of golf balls. DCAPE will also be high
around 1,500 J/kg, resulting in the potential for damaging winds to
70 mph. Since these storms are discrete and look to only impact a
small area, should only see isolated impacts from severe storms.
Once the front pushes through, temperatures will fall to the 60s to
low 70s overnight.

Tuesday will be a cooler day with the post frontal airmass in place.
High temperatures will be seasonable in the 80s with dew points
falling to the 50s. While this would usually make for a pleasant
Summer day, smoke will filter in behind the front which could affect
sensitive individuals. Fortunately, it looks like the highest
concentration of smoke will come Monday night into Tuesday morning
and be slowly decreased thereafter. These seasonable conditions will
persist for the rest of the work week as northwest flow persists
aloft. Next chances for rain look to come on Thursday and Friday as
a shortwave trough pushes through the area. The ensembles support
this as they show a 40-60% chance for rainfall amounts exceeding a
tenth of an inch for this period of time. Instability looks to be
quite limited, so severe storms are not expected at this time. Upper
level ridging looks to potentially make a comeback next weekend,
leading to a return of above average temperatures. This potential
remains uncertain so will keep an eye on how the pattern evolves
over the next week.

&&

.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 654 PM CDT Sun Jul 19 2026

Scattered showers and storms have developed over central South
Dakota this afternoon and may impact areas from a K9V9 to KMHE line
and points south over the first few hours of the period. It looks
like this should remain south of KHON and should weaken or move
further south before reaching KSUX or KFSD, so left out any mention
in the TAFs at this time, though trends will be monitored.
Additional showers and storms may clip portions of southwest
Minnesota overnight into early Monday morning. By Monday afternoon
and early evening, the area to watch will be the Highway 20 corridor
for new thunderstorm development. Uncertainty in the timing of a
cold frontal passage precludes mention of TSRA at KSUX at this time.

Southerly winds will continue through the night, but will begin to
turn to the west and then northwest through the day on Monday as a
cold front moves across the area from north to south. Lastly, a
strengthening low level jet tonight will lead to LLWS concerns
mainly at KFSD and KHON early Monday morning.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...Heat Advisory from noon to 8 PM CDT Monday for SDZ050-063>071.
     Heat Advisory until 9 PM CDT this evening for SDZ038-050-052-
     053-057>060-063>065-068-069.
MN...None.
IA...Heat Advisory from noon to 8 PM CDT Monday for IAZ001>003-
     012>014-020>022-031-032.
NE...Heat Advisory from noon to 8 PM CDT Monday for NEZ013-014.

&&

DISCUSSION...Meyers
AVIATION...Samet

Hazardous Weather Outlook
National Weather Service Sioux Falls SD
420 AM CDT Sun Jul 19 2026

IAZ001>003-012>014-020>022-031-032-MNZ071-072-080-081-089-090-097-
098-NEZ013-014-SDZ039-040-054>056-061-062-066-067-070-071-200930-
Lyon-Osceola-Dickinson-Sioux-O'Brien-Clay-Plymouth-Cherokee-
Buena Vista-Woodbury-Ida-Lincoln-Murray-Cottonwood-Nobles-Jackson-
Pipestone-Rock-Dixon-Dakota-Kingsbury-Brookings-Miner-Lake-Moody-
McCook-Minnehaha-Turner-Union-
420 AM CDT Sun Jul 19 2026

This Hazardous Weather Outlook is for northwest Iowa, west central
Iowa, southwest Minnesota, northeast Nebraska, east central South
Dakota and southeast South Dakota.

.DAY ONE...Today and tonight.

Isolated strong to severe storms are possible Sunday night with wind
gusts up to 65 mph as the main threat.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Heat increases through early next week with highs Monday well into
the 90s and possibly around 100 south of I-90.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

SDZ038-050-052-053-057>060-063>065-068-069-200930-
Beadle-Gregory-Jerauld-Sanborn-Brule-Aurora-Davison-Hanson-
Charles Mix-Douglas-Hutchinson-Bon Homme-Yankton-
420 AM CDT Sun Jul 19 2026

This Hazardous Weather Outlook is for central South Dakota, east
central South Dakota, south central South Dakota and southeast
South Dakota.

.DAY ONE...Today and tonight.

Scattered showers with isolated thunderstorms will be possible this
morning, but severe weather is not expected. Isolated strong to
severe storms will be possible this evening with wind gusts up to 65
mph as the main threat.

Dangerous heat is expected this afternoon as heat index values top
out in the low 100s.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Another chance for 100+ heat indices is in store for Monday,
especially south of I-90.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.