Special Weather Statement, NWS Aberdeen, SD

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
1235 PM CDT SAT JUL 16 2016

.UPDATE...
Issued at 1030 AM CDT SAT JUL 16 2016

Made some significant changes to pops and wx grids this morning,
mainly to reduce pops through this afternoon. Showers and
thunderstorms are currently moving eastward across Ziebach and
Dewey Counties. These storms should continue progressing eastward
through the early afternoon hours, reaching Aberdeen around 1 pm.
That is assuming they hold together. If they dissipate, then
convection for this CWA looks best after 0Z.

UPDATE Issued at 638 AM CDT SAT JUL 16 2016

See below for an updated aviation forecast discussion.

&&

.SHORT TERM...(Today through Sunday Night)
Issued at 421 AM CDT SAT JUL 16 2016

Severe weather potential is main focus for this afternoon. Aloft,
the left exit region of a 90kt 200mb jet is expected to move into
the Dakotas today. Warm advection at 700mb will result in
temperatures at that level to increase between +6 and +13C, with a
southwest to northeast gradient. A surface low will develop in
eastern Wyoming with an inverted trof/warm front extending to the
northeast into western/north-central South Dakota. A plume of
850/700mb moisture will extend up along the east side of this low,
and wrap around to the northwest, co-located along and just ahead of
the warmest mid level temperatures. This gives us a broad ribbon of
potentially uncapped environment during the mid afternoon hours
between KMBG-KABR. Shear appears favorable for Supercells. Now we
introduce the uncertainty brought by the broad area of convection
across western North Dakota. This feature will have widespread
influence on todays severe weather setup, thanks to cirrus and
outflows. With zonal flow/weak ridging aloft, anticipate cirrus to
persist across the northern tier of the cwa. The expectation is that
outflows south of this convective cluster/cirrus shield will provide
the focus for afternoon initiation. A majority of CAM solutions
support this narrative, however the variety of solutions between the
suite of high resolution guidance suggests there remains quite a bit
of uncertainty concerning the overall outcome. The environment
remains primed for severe storms however, with a risk for hail,
winds, and possibly a tornado or two.

.LONG TERM...(Monday through Friday)
Issued at 421 AM CDT SAT JUL 16 2016

As the previous shift so effectively put it, the extended is going
to be extremely warm, starting Tuesday across portions of the
Missouri River valley and west river and then spreading into the
rest of the cwa on Wednesday and Thursday. It's possible there could
be a brief reprieve on Friday before the heat would return over the
weekend just beyond the scope of this 7-day forecast. Once again,
collaborated higher than guidance max temperatures in a few spots
for Wednesday and Thursday.

Monday actually looks to be the coolest day of the extended with
high temperatures forecast to range from around 80 near Wheaton, MN
to around 90 near Murdo, SD /which is actually close to climo normal
for mid-July/. Beyond that, the above normal warmth begins to surge
into the cwa. And with the extreme warmth, heat indices also climb
into, at the very least, heat advisory range by mid-week.

Compared to 24 hours ago, models have really backed off producing
any sort of chances for organized or meaningful rounds of
precipitation in the out periods. Kept in Superblend pops as needed
for collaboration, but buy and large the extended is looking mainly
dry at this time.

Fire Weather: When the really warm air shows up by mid-week,
dewpoint forecasts currently are for lower-value dewpoints over the
western half of the cwa and higher-value dewpoints over the eastern
half of the cwa. This is causing relative humidity values in the
extended forecast periods to fall to between 20 and 25 percent
across, at least, fire weather zones 267 and 268. At this point,
wind speeds are not thought to be problematic. Something to watch
into the short-term portion of the forecast, though.

&&

.AVIATION...(For the 18Z TAFS through 18Z Sunday Afternoon)
Issued at 1227 PM CDT SAT JUL 16 2016

VFR conditions are expected through the period except in or near
thunderstorms. The storm forecast is still uncertain at this time.
Only have a VCTS mention at KATY this evening for now. May need
to add a mention in at either KMBG or KABR by the 0z TAF issuance
for storms occurring between 0z and 9z.

&&

.ABR Watches/Warnings/Advisories...
SD...NONE.
MN...NONE.
&&

UPDATE...SD
SHORT TERM...Connelly
LONG TERM...Dorn
AVIATION...Wise

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE ABERDEEN SD
435 AM CDT SAT JUL 16 2016

MNZ039-046-SDZ003>011-015>023-033>037-045-048-051-170945-
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-
435 AM CDT SAT JUL 16 2016 /335 AM MDT SAT JUL 16 2016/

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF WEST CENTRAL
MINNESOTA...CENTRAL SOUTH DAKOTA...NORTH CENTRAL SOUTH DAKOTA AND
NORTHEAST SOUTH DAKOTA.

.DAY ONE...TODAY AND TONIGHT

THE FORECAST AREA IS UNDER A SLIGHT RISK FOR SEVERE WEATHER THIS
AFTERNOON AND EVENING. THE ENVIRONMENT IS FAVORABLE FOR SEVERE
STORMS WITH A RISK FOR HAIL...STRONG WINDS...AND POSSIBLY A
TORNADO OR TWO.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

A HEAT WAVE IS EXPECTED TO DEVELOP ACROSS THE PLAINS AND MIDWEST
FOR NEXT WEEK. TEMPERATURES WILL PEAK AT OR ABOVE THE CENTURY MARK
BY THE MIDDLE OF THE WORK WEEK.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVITY IS POSSIBLE THIS AFTERNOON AND EVENING.

CONNELLY

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE ABERDEEN SD
1024 AM MDT SAT JUL 16 2016

SDZ015-161715-
DEWEY SD-
1024 AM MDT SAT JUL 16 2016

...SIGNIFICANT WEATHER ADVISORY FOR WEST CENTRAL DEWEY COUNTY UNTIL
1115 AM MDT...

AT 1024 AM MDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM
OVER LANTRY...MOVING EAST AT 20 MPH.

DIME SIZE HAIL AND WINDS IN EXCESS OF 40 MPH WILL BE POSSIBLE WITH
THIS STORM.

LOCATIONS IMPACTED INCLUDE...
EAGLE BUTTE...LANTRY...GREEN GRASS...BEAR CREEK AND PARADE.

LAT...LON 4504 10148 4509 10148 4523 10121 4494 10100
      4492 10114 4499 10114 4500 10150 4503 10150
TIME...MOT...LOC 1624Z 248DEG 18KT 4499 10139

WISE

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ABERDEEN SD
1147 AM CDT SAT JUL 16 2016

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

1135 AM     HAIL             1 W EAGLE BUTTE         45.00N 101.26W
07/16/2016  E0.88 INCH       DEWEY              SD   PUBLIC

&&

EVENT NUMBER ABR1600283

KG

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ABERDEEN SD
1148 AM CDT SAT JUL 16 2016

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

1140 AM     HAIL             EAGLE BUTTE             45.00N 101.24W
07/16/2016  E0.75 INCH       DEWEY              SD   PUBLIC

&&

EVENT NUMBER ABR1600284

KG

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ABERDEEN SD
1155 AM CDT SAT JUL 16 2016

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

1150 AM     HAIL             3 W PARADE              45.02N 101.17W
07/16/2016  E1.00 INCH       DEWEY              SD   PUBLIC

            A FEW STONES LIKE QUARTERS.

&&

EVENT NUMBER ABR1600285

KG

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE ABERDEEN SD
159 PM CDT SAT JUL 16 2016

SDZ009-010-016-017-161945-
FAULK SD-EDMUNDS SD-WALWORTH SD-POTTER SD-
159 PM CDT SAT JUL 16 2016

...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN FAULK...SOUTHWESTERN
EDMUNDS...NORTHEASTERN POTTER AND SOUTHEASTERN WALWORTH COUNTIES
UNTIL 245 PM CDT...

AT 158 PM CDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM
OVER TOLSTOY...OR 20 MILES NORTHEAST OF GETTYSBURG...MOVING EAST AT
35 MPH.

DIME SIZE HAIL AND WINDS IN EXCESS OF 40 MPH WILL BE POSSIBLE WITH
THIS STORM.

LOCATIONS IMPACTED INCLUDE...
BOWDLE...HOVEN...ROSCOE...LEBANON...AKASKA...TOLSTOY...ONAKA...
LOWRY...NORBECK...LOYALTON AND BRENTWOOD COLONY.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 700 PM CDT FOR
NORTH CENTRAL SOUTH DAKOTA.

LAT...LON 4551 9927 4508 9913 4506 10011 4541 10022
TIME...MOT...LOC 1858Z 258DEG 30KT 4522 9966

WISE

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE ABERDEEN SD
249 PM CDT SAT JUL 16 2016

SDZ006-010-017-162045-
FAULK SD-EDMUNDS SD-BROWN SD-
249 PM CDT SAT JUL 16 2016

...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN FAULK...SOUTHEASTERN
EDMUNDS AND SOUTHWESTERN BROWN COUNTIES UNTIL 345 PM CDT...

AT 248 PM CDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM 7
MILES SOUTHWEST OF PEMBROOK COLONY...OR 10 MILES SOUTHWEST OF
IPSWICH... MOVING EAST AT 20 MPH.

NICKEL SIZE HAIL AND WINDS IN EXCESS OF 40 MPH WILL BE POSSIBLE WITH
THIS STORM.

LOCATIONS IMPACTED INCLUDE...
MINA...NORTH SCATTERWOOD LAKE...MINA LAKE REC AREA...
SOUTH SCATTERWOOD LAKE AND PEMBROOK COLONY.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 700 PM CDT FOR
NORTH CENTRAL AND NORTHEASTERN SOUTH DAKOTA.

LAT...LON 4517 9872 4522 9923 4541 9925 4546 9873
TIME...MOT...LOC 1948Z 269DEG 17KT 4530 9912

WISE