Severe Thunderstorm Warning 7, NWS Aberdeen, SD

706 
WWUS53 KABR 082323
SVSABR

Severe Weather Statement
National Weather Service Aberdeen SD
623 PM CDT TUE MAY 8 2018

SDC037-082333-
/O.EXP.KABR.SV.W.0007.000000T0000Z-180508T2330Z/
Day SD-
623 PM CDT TUE MAY 8 2018

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN DAY COUNTY WILL
EXPIRE AT 630 PM 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 heavy rain
is still possible with this thunderstorm.

To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
Aberdeen.

LAT...LON 4517 9761 4519 9773 4538 9765 4530 9738
TIME...MOT...LOC 2323Z 210DEG 13KT 4531 9756 

$$

Vipond

Area Forecast Discussion
National Weather Service Aberdeen SD
136 PM CDT Tue May 8 2018

.SHORT TERM...(This Evening through Wednesday)
Issued at 135 PM CDT Tue May 8 2018

Forecast challenges include coverage/timing/intensity of convection
early this evening, and then again Wednesday afternoon in
"northwest" unidirectional flow through the column. Temperatures
will also prove challenging tonight/Wednesday.

Currently, a large occluded low pressure system is spinning/moving
slowly eastward over the region. Under a partly to mostly sunny sky,
temperatures are warming through the 60s and 70s on generally light
north-northwest winds west of the Prairie Coteau of northeast South
Dakota, and light and variable winds over the Coteau eastward into
MN. A few showers and thunderstorms dot the regional radar mosaic
this afternoon, but the main focus areas over the next 3-6 hours
will be central/south central South Dakota and extreme eastern South
Dakota/western Minnesota.

Most of the instability and shear that's around through early this
evening is in the bottom of the atmosphere, rather than the whole
depth of the column. It's rare, but every once in a while the set-up
that's in play today through the end of heating this evening
supports rapid initial updraft development and "shallow" or low-
topped thunderstorms that have the capacity to spin up a very
brief/weak tornado or two near the surface low center and within the
warm sector near the warm front that extends from northeast SoDak
down across far swrn MN. This is also talked about briefly in the
late morning SPC Day 1 Convective Outlook. Have also attempted to
increase the visibility of this potential via social media and the
Hazardous Weather Outlook (HWO).

Beyond this evening, precipitation chances dwindle with the loss of
daytime heating, and the remainder of tonight/Wednesday morning
should be dry. Wednesday afternoon, an area of low pressure over
Alberta/Saskatchewan will be working southeast through the region.
Deep unidirectional steering flow/shear environment combined with
modestly steep low/mid-level lapse rates could end up producing some
heat of the day scattered showers and thunderstorms over this cwa.

Temperatures over the next 24 hours will not show much low level caa
influence, even though the low level advection pattern will be one
of weak caa. Meaningful low level caa does not look to get started
until beyond the short-term forecast period.

.LONG TERM...(Wednesday Night through Tuesday)
Issued at 135 PM CDT Tue May 8 2018

At 00Z Thursday, we'll be under northwest flow aloft, as a ridge
extends from northern Mexico through Alberta as surface high
pressure over south central Canada pushes a ridge across our
northeastern counties. While the 500mb ridge does flatten out
significantly, it will slide across the Northern Plains states
during the day Thursday. Right now, the best chance of rain looks to
be Thursday night into Friday morning, associated with embedded wave
in the otherwise west-southwest flow behind the ridge. At the
surface, low pressure looks to track west to east across NE and KS,
with a trough extending up into our area. Expect the threat of
thunderstorms to stay mainly to our south, closer to the sfc low
itself. Still, the 12Z GFS, like its 06Z run, remain robust in
amounts. GEFS plumes show the potential for over 0.5in across most
of the area, with a few locations getting closer to 1in. The sfc
trough exits to our east Friday morning, with the sfc low lingering
will to our south. The Pacific Northwest 500mb low will sink
southeast across southern ID/UT Friday, and then retrograde across
NV by Sunday.

Expect a large area of high pressure at the surface to slowly build
in from the northwest this weekend, and be overhead during the day
Sunday, with a mostly dry weekend anticipated. There is some larger
than normal uncertainty in the forecast Tuesday and beyond, where
the Canadian becomes out of phase with the ECMWF and GFS. Will throw
out much of that solution. Either way, it looks like warmer
temperatures and the mention of showers and thunderstorms will
return.

&&

.AVIATION...(For the 18Z TAFS through 18Z Wednesday Afternoon)
Issued at 1221 PM CDT Tue May 8 2018

VFR conditions are expected through appx 03 this evening, at all
four terminals. In fact, KMBG and KPIR probably stay VFR the entire
TAF valid period. KABR/KATY terminals could fall into some MVFR/IFR
cigs later tonight at or after 03z as low stratus clouds off to the
north shift down across northeast South Dakota behind the area of
low pressure that is over the region today, with improvement
expected heading into the mid to late morning hours on Wednesday.
WRT this area of low pressure, isolated to widely scattered showers
and thunderstorms are expected to develop this afternoon into this
evening, and could impact any of the four terminals.  But the
thinking right now is the terminal with the highest probability of
seeing a thunderstorm over terminal airspace is KATY. Precipitation
chances begin to disappear by 04z-05Z tonight.

&&

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

SHORT TERM...Dorn
LONG TERM...KF
AVIATION...Dorn

Hazardous Weather Outlook
National Weather Service Aberdeen SD
131 PM CDT Tue May 8 2018

MNZ039-046-SDZ008-011-018>023-091845-
Traverse-Big Stone-Roberts-Day-Spink-Clark-Codington-Grant-Hamlin-
Deuel-
131 PM CDT Tue May 8 2018

This Hazardous Weather Outlook is for portions of west central
Minnesota and northeast South Dakota.

.DAY ONE...This Afternoon and Tonight

Isolated to scattered thunderstorms are possible this afternoon
and evening. Brief gusty winds, small hail, and perhaps a brief
weak tornado spin-up or two are possible with thunderstorms this
afternoon into this evening.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed.

SDZ003>007-009-010-015>017-033>037-045-048-051-091845-
Corson-Campbell-McPherson-Brown-Marshall-Walworth-Edmunds-Dewey-
Potter-Faulk-Stanley-Sully-Hughes-Hyde-Hand-Jones-Lyman-Buffalo-
131 PM CDT Tue May 8 2018 /1231 PM MDT Tue May 8 2018/

This Hazardous Weather Outlook is for portions of central South
Dakota, north central South Dakota, and northeast South Dakota.

.DAY ONE...This Afternoon and Tonight

Isolated thunderstorms are possible this afternoon and evening. No
severe weather is expected, though.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed.

Dorn

Special Weather Statement
National Weather Service Aberdeen SD
420 PM CDT TUE MAY 8 2018

SDZ011-082145-
Day SD-
420 PM CDT TUE MAY 8 2018

...SIGNIFICANT WEATHER ADVISORY FOR WEST CENTRAL DAY COUNTY UNTIL 445
PM CDT...

At 420 PM CDT, Doppler radar was tracking a strong thunderstorm near
Andover, or 12 miles southeast of Groton, moving northeast at 5 mph.

Nickel size hail and winds in excess of 40 mph will be possible with
this storm.

Locations impacted include...
Bristol and Andover.

LAT...LON 4525 9791 4529 9798 4544 9796 4533 9772
TIME...MOT...LOC 2120Z 210DEG 6KT 4531 9793

SRF

Special Weather Statement
National Weather Service Aberdeen SD
425 PM CDT TUE MAY 8 2018

SDZ011-018-019-082200-
Clark SD-Spink SD-Day SD-
425 PM CDT TUE MAY 8 2018

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN DAY...NORTHWESTERN
CLARK AND NORTHEASTERN SPINK COUNTIES UNTIL 500 PM CDT...

At 425 PM CDT, Doppler radar was tracking a strong thunderstorm over
Conde, or 21 miles south of Groton, moving north at 10 mph.

Nickel size hail and winds in excess of 40 mph will be possible with
this storm.

Locations impacted include...
Conde and Crandall.

LAT...LON 4509 9792 4513 9818 4524 9818 4523 9792
TIME...MOT...LOC 2125Z 188DEG 7KT 4514 9807

SRF

Special Weather Statement
National Weather Service Aberdeen SD
435 PM CDT TUE MAY 8 2018

SDZ017-036-037-082215-
Hand SD-Hyde SD-Faulk SD-
435 PM CDT TUE MAY 8 2018

...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN HAND...NORTHEASTERN
HYDE AND SOUTHWESTERN FAULK COUNTIES UNTIL 515 PM CDT...

At 434 PM CDT, Doppler radar was tracking a strong thunderstorm 9
miles south of Burkmere, or 14 miles southwest of Faulkton, moving
southeast at 15 mph.

Dime size hail and winds in excess of 40 mph will be possible with
this storm.

Locations impacted include...
Orient.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 4494 9944 4500 9939 4498 9898 4475 9931
TIME...MOT...LOC 2134Z 310DEG 12KT 4493 9937

Dorn

Special Weather Statement
National Weather Service Aberdeen SD
503 PM CDT TUE MAY 8 2018

SDZ011-082230-
Day SD-
503 PM CDT TUE MAY 8 2018

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN DAY COUNTY UNTIL 530
PM CDT...

At 503 PM CDT, Doppler radar was tracking a strong thunderstorm near
Crandall, or 19 miles southwest of Webster, moving northeast at 15
mph.

Nickel size hail and winds in excess of 40 mph will be possible with
this storm.

Locations impacted include...
Butler.

LAT...LON 4526 9766 4515 9786 4518 9798 4530 9798
TIME...MOT...LOC 2203Z 231DEG 13KT 4520 9786

SRF

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ABERDEEN SD
517 PM CDT TUE MAY 8 2018

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0517 PM     HAIL             2 SW BRADLEY            45.06N 97.67W
05/08/2018  E0.25 INCH       CLARK              SD   TRAINED SPOTTER

&&

ALD

Special Weather Statement
National Weather Service Aberdeen SD
548 PM CDT TUE MAY 8 2018

MNZ039-046-082330-
Traverse MN-Big Stone MN-
548 PM CDT TUE MAY 8 2018

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN TRAVERSE AND
NORTHWESTERN BIG STONE COUNTIES UNTIL 630 PM CDT...

At 548 PM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Graceville to near Bonanza Grove. Movement
was northeast at 30 mph.

Nickel size hail and winds in excess of 40 mph will be possible with
these storms.

Locations impacted include...
Graceville, Clinton, Dumont, Johnson, Barry, Trinity Lutheran Country
Church, Siloah Country Church, Collis, Bonanza Grove and Big Stone
Lake.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

These storms may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

&&

LAT...LON 4546 9639 4541 9669 4546 9673 4580 9648
      4587 9626 4560 9625
TIME...MOT...LOC 2248Z 217DEG 26KT 4554 9648 4549 9663

Dorn