Special Weather Statement, NWS Bismarck, ND

Area Forecast Discussion
National Weather Service Bismarck ND
858 PM CDT Tue Aug 8 2017

.UPDATE...
Issued at 852 PM CDT Tue Aug 8 2017

Sufficient warm advection ahead of the cold frontal boundary
across northwest North Dakota seems to be supporting a weak MCS
across Central South Dakota that has expanded a large stratiform
rain region across south central North dakota this evening. The
same WAA combined with the h500 short wave setting up elevated
convection across west central into northwest North Dakota. For
these reasons have expanded the likely POPs area across south
central North Dakota and the chance area northwest this evening
and early morning.

UPDATE Issued at 657 PM CDT Tue Aug 8 2017

Current forecast trending about as expected with scattered
thunderstorms west and south central now trending down after the
peak heating. However as the short wave trough to the northwest
continues to approach expect better dynamics and VM overnight
that will support scattered thunderstorms tonight. So do not
expect the activity is over. Current forecast looks good with
short range adjustments to the POPs.

&&

.SHORT TERM...(This evening through Wednesday)
Issued at 108 PM CDT Tue Aug 8 2017

Shower and thunderstorm potential this afternoon through Wednesday
highlights the short term forecast.

Surface based convection across western into North central North
Dakota is expected to increase over the next 2-3 hours, between
20-22 UTC, ahead of the shortwave across eastern Montana evident
on water vapor imagery. MLCAPE around 800-1000 j/kg and marginal
deep layer shear of 25-30kts suggest that the potential for severe
convection is low.

Scattered showers and thunderstorms will continue through
the night across most of western and central North Dakota
reinforced by the stronger wave that will propagate out of
Saskatchewan. Scattered showers and storms are favored to continue
through much of the day northwest and central per the 12 UTC
global consensus and 12-15 UTC CAM suites. Certainly cannot rule
out a strong to severe thunderstorm south central where MLCAPE
values of 1000-1500 j/kg are expected with marginal deep layer
shear of 25-30 kts ahead of the strong upper level wave. Large
hail to quarter size, damaging winds to 60 mph, and dangerous
lightning are the primary threats.

.LONG TERM...(Wednesday night through Tuesday)
Issued at 108 PM CDT Tue Aug 8 2017

Slightly below normal temperatures through the weekend highlight
the extended forecast.

The 12 UTC global consensus is in agreement on mean cyclonic
northwest flow aloft to continue into the weekend across western
and central North Dakota. This favors slightly below normal
temperatures in the 70s to the lower 80s. Thereafter, there are
some hints at possibly at least shortwave ridging early next week
that could mean a brief return to a bit warmer temperatures.
However, this is somewhat uncertain. There is a chance of
thunderstorms Friday through Saturday with a series of shortwaves
embedded in the flow. While the severe threat is non-zero,
widespread severe weather is also not favored at this time.

&&

.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 657 PM CDT Tue Aug 8 2017

Surface low pressure across southwest Manitoba with a cold front
extending southwest into southeast Montana. A secondary trough of
low pressure extended northwest into Saskatchewan. The cold front
and trough will be the focus for scattered thunderstorms tonight.
MVFR ceilings will follow the front into northwest North Dakota
(KISN-KMOT) after 10z.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

UPDATE...WAA
SHORT TERM...PA
LONG TERM...PA
AVIATION...WAA

Hazardous Weather Outlook
National Weather Service Bismarck ND
712 PM CDT Tue Aug 8 2017

NDZ001>005-009>013-017>023-025-031>037-040>048-050-051-100015-
Divide-Burke-Renville-Bottineau-Rolette-Williams-Mountrail-Ward-
McHenry-Pierce-McKenzie-Dunn-Mercer-Oliver-McLean-Sheridan-Wells-
Foster-Golden Valley-Billings-Stark-Morton-Burleigh-Kidder-
Stutsman-Slope-Hettinger-Grant-Bowman-Adams-Sioux-Emmons-Logan-
La Moure-McIntosh-Dickey-
712 PM CDT Tue Aug 8 2017 /612 PM MDT Tue Aug 8 2017/

This Hazardous Weather Outlook is for portions of north central
North Dakota, northwest North Dakota, south central North Dakota,
southeast North Dakota, and southwest North Dakota.

.DAY ONE...Tonight

Scattered showers and thunderstorms west and central through
tonight. Severe weather is not expected.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday

Chances for showers and thunderstorms will continue through
Wednesday across northwest and central North Dakota. A few
thunderstorms could be strong to severe far south central in the
afternoon and evening. Large hail to quarter size, damaging winds
to 60 mph, and dangerous lightning are the primary threats.

Chances for thunderstorms return Friday through Saturday. Severe
weather is not expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed south central Wednesday afternoon
and early evening.

waa

Special Weather Statement
National Weather Service Bismarck ND
425 PM MDT TUE AUG 8 2017

NDZ031-082315-
Golden Valley ND-
425 PM MDT TUE AUG 8 2017

...A STRONG THUNDERSTORM WILL AFFECT CENTRAL GOLDEN VALLEY COUNTY
UNTIL 515 PM MDT...

At 424 PM MDT, Doppler radar was tracking a strong thunderstorm 9
miles north of Beach, moving southeast at 10 mph.

Half inch hail will be possible with this storm.

Locations impacted include...
Beach and Sentinel Butte.

LAT...LON 4713 10405 4715 10404 4716 10368 4683 10369
      4691 10405
TIME...MOT...LOC 2224Z 296DEG 9KT 4706 10396

ABELING

Special Weather Statement
National Weather Service Bismarck ND
559 PM CDT TUE AUG 8 2017

NDZ034-042-045-046-082345-
Grant ND-Sioux ND-Morton ND-Emmons ND-
559 PM CDT TUE AUG 8 2017

...A LINE OF STRONG THUNDERSTORMS WILL AFFECT SIOUX...SOUTHEASTERN
MORTON...SOUTHEASTERN GRANT AND NORTHWESTERN EMMONS COUNTIES UNTIL
645 PM CDT/545 PM MDT/...

At 557 PM CDT/457 PM MDT/, Doppler radar was tracking strong
thunderstorms along a line extending from 8 miles southeast of St.
Anthony to near Mcintosh. Movement was east at 15 mph.

Penny size hail and wind gusts to 40 mph will be possible with these
storms.

Locations impacted include...
Selfridge, Solen, Cannon Ball, Shields, Prairie Knights Resort,
Porcupine, Fort Rice, Breien and Hazelton Recreation Area.

If you are on or near the Missouri River between Huff and Prairie
Knights Casino, these storms were approaching you from the west. Get
out of the water and move indoors or inside a vehicle. Remember, If
you can hear thunder, you are close enough to be struck by
lightning. Do not be caught on the water in a thunderstorm.

&&

LAT...LON 4595 10147 4657 10087 4660 10024 4594 10086
TIME...MOT...LOC 2257Z 273DEG 15KT 4651 10084 4596 10135

VINING

Special Weather Statement
National Weather Service Bismarck ND
506 PM MDT TUE AUG 8 2017

NDZ044-082345-
Adams ND-
506 PM MDT TUE AUG 8 2017

...A STRONG THUNDERSTORM WILL AFFECT SOUTHWESTERN ADAMS COUNTY UNTIL
545 PM MDT...

At 506 PM MDT, Doppler radar was tracking a strong thunderstorm 6
miles south of Reeder, or 12 miles west of Hettinger, moving east at
15 mph.

Penny size hail and wind gusts to 40 mph will be possible with this
storm.

Locations impacted include...
Hettinger, Reeder and Bucyrus.

LAT...LON 4595 10299 4613 10300 4613 10247 4595 10248
      4594 10261
TIME...MOT...LOC 2306Z 273DEG 15KT 4602 10290

VINING

Special Weather Statement
National Weather Service Bismarck ND
623 PM CDT TUE AUG 8 2017

NDZ045-082345-
Sioux ND-
623 PM CDT TUE AUG 8 2017

...A STRONG THUNDERSTORM WILL AFFECT SOUTHEASTERN SIOUX COUNTY UNTIL
645 PM CDT...

At 623 PM CDT, Doppler radar was tracking a strong thunderstorm over
Selfridge, moving east at 35 mph.

Nickel size hail will be possible with this storm.

Locations impacted include...
Fort Yates and Selfridge.

Very heavy rainfall is also occurring with this storm, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 4595 10122 4619 10116 4621 10059 4620 10059
      4615 10063 4613 10063 4612 10062 4607 10062
      4601 10056 4600 10053 4595 10052
TIME...MOT...LOC 2323Z 264DEG 33KT 4605 10097

ABELING

Special Weather Statement
National Weather Service Bismarck ND
540 PM MDT TUE AUG 8 2017

NDZ032-090030-
Billings ND-
540 PM MDT TUE AUG 8 2017

...A STRONG THUNDERSTORM WILL AFFECT NORTHEASTERN BILLINGS COUNTY
UNTIL 630 PM MDT...

At 540 PM MDT, Doppler radar was tracking a strong thunderstorm 8
miles northwest of South Fairfield, or 30 miles southwest of
Killdeer, moving southeast at 15 mph.

Penny size hail will be possible with this storm.

This strong thunderstorm will be near...
  South Fairfield around 615 PM MDT.

Other locations impacted by this storm include Fairfield.

Very heavy rainfall is also occurring with this storm, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 4730 10330 4711 10303 4702 10303 4698 10312
      4698 10323 4692 10323 4690 10328 4719 10351
TIME...MOT...LOC 2340Z 323DEG 12KT 4719 10335

ABELING

Special Weather Statement
National Weather Service Bismarck ND
914 PM CDT TUE AUG 8 2017

NDZ010-090230-
Mountrail ND-
914 PM CDT TUE AUG 8 2017

...A STRONG THUNDERSTORM WILL AFFECT SOUTH CENTRAL MOUNTRAIL COUNTY
UNTIL 930 PM CDT...

At 914 PM CDT, Doppler radar was tracking a strong thunderstorm 9
miles south of New Town, or 33 miles south of Stanley, moving
northeast at 20 mph.

Penny size hail will be possible with this storm.

This strong thunderstorm will be near...
  Van Hook Park around 930 PM CDT.

Other locations impacted by this storm include Pouch Point Recreation
Area.

Very heavy rainfall is also occurring with this storm, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 4805 10236 4785 10227 4785 10238 4784 10239
      4780 10239 4777 10248 4778 10252 4778 10258
      4785 10265 4790 10265 4795 10259
TIME...MOT...LOC 0214Z 239DEG 17KT 4784 10250

ABELING