Severe Thunderstorm Warning 112, NWS Sioux Falls, SD

AREA FORECAST DISCUSSION
National Weather Service Sioux Falls SD
248 PM CDT Thu Jul 13 2023

.SHORT TERM...(This Evening through Friday)
Issued at 247 PM CDT Thu Jul 13 2023

An upper shortwave with a compact jet max offers synoptic support
for some precipitation chances this afternoon. Winds from the
surface to around 700 mb are westerly, which should allow deep
mixing today. 850 mb temperatures in the 20-22 C range with
plentiful WAA should allow us to warm at the surface into the
upper 80s with low 90s west of the James River Valley. Winds as a
rusult will be a little bit gusty, 15-20 mph. Lapse rates
increasing to 7.3 to 7.5 C/km south of I-90. MLCAPE 1500-2500 J/kg
and 0-6km bulk shear 35-40 kts, in a weakly capped environment
may allow for some thunderstorm development late this afternoon
and evening. However with the better vorticity in south central SD
and the better instability east of I-29, there is low confidence
on timing and location of thunderstorm development for this
afternoon.

Overnight, another round of convection is possible, this time
focused more over southwestern MN. Some elevated instability coupled
with some convergence on the nose of a westerly LLJ may be enough to
trigger overnight thunderstorms over southwestern MN and
northwestern IA. Lows tonight will be in the mid to low 60s.

Another upper wave moves through Friday afternoon, again bringing
chances for precipitation. BUFKIT soundings show a little bit of a
stronger cap, that will limit mixing somewhat until later in the
afternoon. Smoke also moves back into the area from the Canadian
wildfires. These factors will likely limit day time heating to the
mid 80s. Mid level lapse rates are lacking and better instability is
to the east of I-29 while the better forcing is to the west. But, if
the wave progresses eastward a little faster, we could get some
convection to break the cap in the late afternoon and result in some
isolated storm development. Any showers that do develop will clear
out in the overnight hours and Saturday should dawn partly cloudy.

.LONG TERM...(Saturday through Thursday) Issued at 247 PM CDT Thu
Jul 13 2023

Saturday and Sunday: Pronounced closed upper low drifts southward
through the weekend out of Canada placing our area in a broad
northwest flow regime. This may keep occasional wildfire smoke
impacts in the cards. Otherwise, precipitation chances look low with
probably the best (yet still low) chance late Sunday as a jet streak
dives into the area. Temperatures keep a gradual cooling trend given
the flow trajectory with mid 70s to mid 80s for highs.

Monday through Wednesday: Brief period of mid/upper level ridging
slides east for late Monday into Tuesday. This may allow for some
convection chances late Monday night into Tuesday on the initial push
of theta-e/instability. A stronger shortwave moves along the
International Border by midweek with tandem front draped southward.
This again may provide additional convection chances. Prior to FROPA
midweek, temperatures will likely take on a warming trend through
early next week.

&&

.AVIATION...(For the 18Z TAFS through 18Z Friday Afternoon)
Issued at 1119 AM CDT Thu Jul 13 2023

A few remaining midlevel Cu remain as of midday but quiet
conditions should prevail for at least the next few hours. By late
afternoon, thunderstorm chances will be reintroduced across the
region although considerable uncertainty remains on placement or
even overall coverage of this activity. Any storms that do form
would carry some potential for severe hail and perhaps more so
gusty winds given inverted-V type soundings. With low confidence
on impacts to any one individual terminal from convection, will
leave out of TAF for now and continue to monitor.

Isolated to perhaps scattered showers and thunderstorms may linger
into the first half of the overnight. Additionally, upper level
wildfire smoke is expected to begin to drift southward late in the
TAF period with initial impacts aloft but perhaps eventual surface
impacts.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
IA...None.
NE...None.
&&

SHORT TERM...AJP
LONG TERM...Kalin
AVIATION...Kalin

Hazardous Weather Outlook
National Weather Service Sioux Falls SD
237 PM CDT Thu Jul 13 2023

IAZ001>003-012>014-020>022-031-032-MNZ071-072-080-081-089-090-097-
098-NEZ013-014-SDZ038>040-050-052>071-141945-
Lyon-Osceola-Dickinson-Sioux-O'Brien-Clay-Plymouth-Cherokee-
Buena Vista-Woodbury-Ida-Lincoln-Murray-Cottonwood-Nobles-Jackson-
Pipestone-Rock-Dixon-Dakota-Beadle-Kingsbury-Brookings-Gregory-
Jerauld-Sanborn-Miner-Lake-Moody-Brule-Aurora-Davison-Hanson-McCook-
Minnehaha-Charles Mix-Douglas-Hutchinson-Turner-Bon Homme-Yankton-
Union-
237 PM CDT Thu Jul 13 2023

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

.DAY ONE...This afternoon and tonight.

Scattered thunderstorms will be possible late this afternoon and
tonight. An isolated severe storm will be possible with half dollar
hail and 65 mph winds the main threats.

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

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.