Severe Thunderstorm Warning 105, NWS Sioux Falls, SD

806 
WWUS53 KFSD 060953
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
453 AM CDT Mon Jul 6 2020

SDC087-061003-
/O.CAN.KFSD.SV.W.0105.000000T0000Z-200706T1015Z/
McCook SD-
453 AM CDT Mon Jul 6 2020

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN MCCOOK COUNTY IS
CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

LAT...LON 4379 9705 4395 9723 4409 9692 4385 9676
TIME...MOT...LOC 0953Z 244DEG 21KT 4393 9702 

$$

SDC079-099-101-061015-
/O.CON.KFSD.SV.W.0105.000000T0000Z-200706T1015Z/
Moody SD-Lake SD-Minnehaha SD-
453 AM CDT Mon Jul 6 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 515 AM CDT
FOR SOUTHWESTERN MOODY...SOUTHEASTERN LAKE AND NORTHWESTERN MINNEHAHA
COUNTIES...

At 453 AM CDT, a severe thunderstorm was located near Wentworth, or
near Madison, moving northeast at 25 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

This severe storm will be near...
  Chester around 500 AM CDT.
  Wentworth around 505 AM CDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4379 9705 4395 9723 4409 9692 4385 9676
TIME...MOT...LOC 0953Z 244DEG 21KT 4393 9702 

HAIL...<.75IN
WIND...60MPH
 
$$

JM

773 
WWUS53 KFSD 061006
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
506 AM CDT Mon Jul 6 2020

SDC079-099-101-061016-
/O.EXP.KFSD.SV.W.0105.000000T0000Z-200706T1015Z/
Moody SD-Lake SD-Minnehaha SD-
506 AM CDT Mon Jul 6 2020

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN MOODY...
SOUTHEASTERN LAKE AND NORTHWESTERN MINNEHAHA COUNTIES WILL EXPIRE AT
515 AM CDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  However gusty
winds are still possible with this thunderstorm.

LAT...LON 4379 9705 4395 9723 4409 9692 4385 9676
TIME...MOT...LOC 1006Z 244DEG 21KT 4396 9693 

$$

JM

AREA FORECAST DISCUSSION
National Weather Service Sioux Falls SD
411 AM CDT Mon Jul 6 2020

.SHORT TERM...(Today and Tonight)
Issued at 410 AM CDT Mon Jul 6 2020

Active forecast today with a series of disturbances moving through
the forecast area leading to rounds of convection. As of 08Z,
complex of thunderstorms across southwest Minnesota associated with
warm air advection ahead of shortwave/MCV over central South Dakota.
 Expect this round to work east of the forecast area this morning
with minimal severe weather threat. Early morning convection could
kick out an outflow boundary or two, which will need to be monitored
closely throughout the day as this will likely be a focusing
mechanism for additional rounds of convection later in the day as
short waves continue to train across the area.

With ample clearing and surface heating this morning, models are
suggesting 2000- 2500 J/kg of surface based CAPE by early
afternoon with only a weakly capped environment. Jet dynamics are
concentrated to the north across North Dakota; however, 0-6 km
bulk shear increases through the day towards 30-40 knots west of
I-29 by 00Z Tuesday.

CAMs have suggested two schools of thought for today.  The first
suggests convection will continue to backbuild through the day along
lingering boundary gradually working south through the day.  Corfidi
vectors suggest storms will be moving east at 20-25 knots, so there
should be enough movement to limit heavy rain potential unless
storms are able to train along the boundary.  With precipitable
water values 1.5-1.6 inches (~90 percent of the moving average),
certainly dealing with the potential for heavy rain.  However, warm
cloud depths are only 7500-8000 feet thick, limiting the efficiency
some. WPC has outlined the area in marginal threat for excessive
rainfall which seems reasonable based on the above parameters.

The second camp of CAM solutions suggests the next round of storm
development will hold off till later in the day as a series of
shortwaves move across the Dakotas.  The trajectory of the
shortwaves look to be focused across the northern half of South
Dakota, so expect convective initiation to be north of I-90, building
south with time.

Am expecting storms to be organized in clusters that may at times
try to evolve into convective lines. With fair amount of dry air in
the mid levels, downdraft CAPE values approach 1500-2000 J/kg by
late this afternoon, with the highest values south of I-90.  If
storms are able to hold off till later in the day, hail threat may
also be greater as storms will have more shear to organize and
develop mid level rotation.

With only weakly capped environment, boundaries lingering around and
additional midlevel waves passing through the region, could see
additional rounds of convection on Monday night into Tuesday.

.LONG TERM...(Tuesday through Sunday)
Issued at 410 AM CDT Mon Jul 6 2020

With upper level ridge expected to develop across the desert
southwest and a series of ridge riders expected to move across the
northern half of the US, expect warm and sultry conditions to
continue this week with periodic chances for thunderstorms.  With
active weather in the short term, left the blend as is in the
extended.

&&

.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1150 PM CDT Sun Jul 5 2020

The forecast over the next 24 hours is notably challenging, with
multiple waves of showers and thunderstorms possible. For this
reason, there is low confidence overall in the TAF forecasts.
That being said, high resolution models focus on two distinct
periods of enhanced potential for storms. During the early AM
hours, thunderstorms currently over central SD will move eastward,
causing a round of showers and isolated thunderstorms for
portions of SD and southwest MN during the morning hours, mainly
north of I-90. Later in the afternoon and evening on Monday, a
second round more widespread thunderstorms are possible as a
compact weather system moves through. Have avoided timing out
this period of storms in the late portion of the TAF for now, as
model solutions vary widely with little agreement. Generally south
winds prevail; however, many outflow boundaries may switch winds
unexpectedly at times in the vicinity of storms.

&&

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

SHORT TERM...BT
LONG TERM...BT
AVIATION...VandenBoogart

Hazardous Weather Outlook
National Weather Service Sioux Falls SD
401 PM CDT Sun Jul 5 2020

IAZ001>003-012>014-020>022-031-032-MNZ081-089-090-098-NEZ013-014-
SDZ062-066-067-069>071-062115-
Lyon-Osceola-Dickinson-Sioux-O'Brien-Clay-Plymouth-Cherokee-
Buena Vista-Woodbury-Ida-Cottonwood-Nobles-Jackson-Rock-Dixon-Dakota-
Minnehaha-Turner-Lincoln-Yankton-Union-
401 PM CDT Sun Jul 5 2020

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

.DAY ONE...This afternoon and tonight.

Heat index values from the upper 80s to mid 90s will continue into
the evening.

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

Thunderstorms are also possible Monday afternoon into Monday
evening. A few of the stronger storms may produce gusty winds.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

MNZ071-072-080-097-SDZ038>040-050-052>061-063>065-068-062115-
Lincoln-Lyon-Murray-Pipestone-Beadle-Kingsbury-Brookings-Gregory-
Jerauld-Sanborn-Miner-Lake-Moody-Brule-Aurora-Davison-Hanson-McCook-
Charles Mix-Douglas-Hutchinson-Bon Homme-
401 PM CDT Sun Jul 5 2020

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

.DAY ONE...This afternoon and tonight.

Heat index values from the upper 80s to mid 90s will continue into
the evening.

A few thunderstorms will continue along the Highway 14 corridor late
this afternoon. Additional thunderstorms are possible later this
evening. A couple strong to severe storms may produce winds to 65
mph and hail of one inch in diameter.

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

Thunderstorms are also possible Monday afternoon into Monday
evening. A few of the stronger storms may produce gusty winds.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed. Any reports of severe weather would
be appreciated.