Winter Storm Warning Issued for the Black Hills: Timeline and expected impacts

The NewsCenter1 Weather Team is constantly monitoring the changing conditions and will provide the latest information.

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6:15 AM UPDATE: The National Weather Service continues Winter Storm Warnings for the Central and Northern Black Hills – including most of Northeastern Wyoming until Wednesday evening.

Winter Weather Advisories have been expanded to include Harding and Butte County, where the volatility of the forecast could yield large variations of results in snow amounts and impacts.

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SNOW TOTALS: I’ve used one of the more aggressive models that shows the higher potential for snow to properly prepare residents for impacts from this storm. The timeline of temperatures and wind speeds can be found below along with previous forecast discussions.


FORECAST DISCUSSION FOR RANCHERS AND PRODUCERS:

  • I wanted to talk a little bit about impacts outside of the indicated warning and advisories – as there is still some uncertainty regarding how far impacts could push into South Dakota, particularly Butte and Harding County.
  • We will have a very thin rain/snow line pushing Eastward Tuesday night into Wednesday morning and afternoon. 1″-3″… in some cases 4″ of moisture will fall in portions of our area. Most of the South Dakota Plains is expecting wind and heavy rain with this system – but there are models that push that rain/snow line across the SD state line, towards Highway 85. Given the strength of this system, and the way models are trending over the last 48-72 hours, I would caution residents of Harding and Butte County that windy conditions and cold rain could quickly turn into heavy, wet snow with gusty winds late Tuesday into Wednesday morning.
  • I think 6″+ of snow for areas west of Highway 85 in South Dakota is reasonable given the conditions and colder trending system. There is an argument to be made that warm air *could* hold back the rain/snow line in Crook County, Wyoming and Carter County, Montana to where most of the SD plains sees only windy, heavy rain… but it’s -far- from a guarantee. Several inches of snow can quickly fall when heavy rain converts to a heavy snowfall. Winds would complicate these conditions further with visibility issues and dropping temperatures.
  • Winter preparations should absolutely be made for the higher elevations of the Central and Northern Black Hills, Northeastern Wyoming, and Carter County Montana. This is where heavy snow exceeding 6″+ is reasonable, with shifting high winds – but relevant parties in Butte, Harding, Lawrence, and even western portions of Meade County and The I-90 corridor through Rapid City should carefully watch trends and consider some light preparation in case models swing before tomorrow evening. A quick swing in the models, with this kind of moisture, can quickly turn several inches of rain into several inches of snow.
  • Once again – these are preparations in regards to ranchers and producers. Travel along I-90 between Rapid City and Spearfish is *not* expected to be significantly impacted, nor will anybody’s ability to get to *most* work places in our South Dakota high populations centers in the lower elevations (AS OF NOW).
  • We will see what progress our developing system has made and adjust the forecast as needed early tomorrow morning. Once again, the full breakdown is in the article below. There’s a lot riding on this for those who require time and resources to make preparations – We want to give as much heads up to *potential* complications and scenarios as possible. There will be frequent updates to this. Thanks for trusting us with your forecast.
Stay alert.
Brant


3:39 PM UPDATE:
The National Weather Service has issued a *WINTER STORM WARNING* for the following areas;
IN WYOMING: Sheridan, Johnson, The majority of Crook & NE Weston County
IN SOUTH DAKOTA: Central & Southern Lawrence County, and Western Pennington County
TIMING: This Winter Storm will start at Midnight, and last until 6:00 PM Wednesday.

Warnings

A *WINTER WEATHER ADVISORY* has been issued for the following areas:
IN WYOMING: The Majority of Weston County
IN MONTANA: Carter County
IN SOUTH DAKOTA: Northeastern Lawrence County.

Advisories

THE THINKING: As of this afternoon, we are going with 12-18″ in the Central & Northern Hills, with locally greater amounts possible. The Southern Hills, we are looking at 2-4″ with a wintry mix in the Prairies. The Snow will start tomorrow morning in the Hills, and it’ll continue to snow until Wednesday Afternoon. As for the eastern part of the NewsCenter1 Viewing Area. It’ll be more of a rain/wintry mix event. Some places could see as much as 2-3″ of Rain in the prairies.

PLEASE USE EXTRA CAUTION IF YOU HAVE TO TRAVEL OVER THE NEXT SEVERAL HOURS! TRAVEL WILL MORE THAN LIKELY BECOME HAZARDOUS!

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  • The first impacts of this storm could be felt as early as Monday evening out West.
  • Precipitation will begin to pick up towards Sheridan and Johnson County, Wyoming by late Monday.
  • Campbell County could hold off until Tuesday, but its safe to assume a few bands of heavy rain/Mix could strafe the area before then.
  • South Dakota is expected to remain mostly dry through this early stage.
  • Winds will begin to pick up out of the North and Northeast in Wyoming, as Easterly and Northeasterly winds pick up for South Dakota.
  • Temperatures will begin to drop West to East Monday night going into Tuesday morning into the 30s for Wyoming, with temperatures expected to hold in the 40s for South Dakota.

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  • Going into Tuesday morning, precipitation will start pushing East in the form of heavy, windy rain bands with some areas getting a Mix of rain and snow.
  • Portions of Campbell County, Wyoming and the higher elevations of the Black Hills could see heavy, wet snow during this time period with many transitions.
  • Temperatures will continue to drop into the 30s for Wyoming and lower 40s and upper 30s for South Dakota… but are expected to recover slightly going into Tuesday afternoon.

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  • Winds will begin to pick up out of the east and northeast 15-25 with gusts up to 30 MPH through noon Tuesday.

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  • By Tuesday afternoon heavy bands of Rain, rain/snow mix and heavy wet snow is moving through most of the Black Hills Region.
  • Most of the SD plains is seeing heavy rain bands, with only a few areas seeing a steady pace of heavy, wet snow.
  • Temperatures will recover into the 40s for most of the area, with a few upper 30s in the higher elevations of the Black hills – this will allow for lots of transitions into a mix of rain/snow.
  • Winds will continue to increase out of the East and Northeast through Tuesday evening, starting to gust over 35 MPH in some cases.

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  • Late Tuesday into Wednesday will feature increasing rain/snow bands and cooling temperatures into the 30s and 40s.
  • Winds will start to become more Northeasterly/Northerly through the overnight, with steady winds around 15-25.

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  • By Wednesday morning, the rain/snow line could move as far East as the SD state line, if not a little further.
  • Winds have shifted North and Northwest with gusts up to 40 MPH
  • Temperatures will fluctuate in the 30s and 40s, with mostly 40s across the SD plains… dropping through Wednesday.

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  • Wednesday afternoon will be the peak of our anticipated impacts across NE Wyoming and Western South Dakota.
  • This is the critical time period where cold, dry air pushes into our area out of the northwest and begins to convert any leftover precipitation from rain to snow.
  • *THIS* is the time period of the forecast that has the most uncertainty, and could see the most changes in the next 48 hours.
  • Most of the area is expected to plunge into the 30s, with Northwesterly winds gusting to 40 MPH, in some cases higher.
  • This is where heavy, wet snow could start accumulating in the higher elevations of the Black Hills, and in some cases in the foothills and surrounding plains.

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  • By late Wednesday into Thursday, the system is expected to exit the region to the East and Northeast – leaving behind much colder temperatures and in some cases high wind gusts.
  • Wind chill factors could push the 20s, and in some isolated cases the teens through Thursday morning.
  • By late Thursday morning, temperatures will begin to recover into the 40s and NW winds will start to subside into the 10-20  range as sunshine comes back into the area.

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If it feels like this forecast is a mess, it’s because it is. One of the more difficult challenges is figuring out how far into the foothills and SD plains a snow/rain mix makes it. Regardless of what form precipitation takes, 2″-4″ of liquid water is expected to drop across the region Monday night through late Wednesday – and that’s good news for everyone.

I can *guarantee* this forecast will change in the next 48 hours, but to recap what we are confident about…

  • Its gunna be chilly
  • Its gunna be rainy
  • Its gunna be windy

As far as travel impacts go – there isn’t anticipation of slushy roads outside of the Black Hills and NE Wyoming – you shouldn’t have a problem getting across Rapid City to get groceries for example. Northeast Wyoming would be the one exception… where high winds and heavy wet snow could transition into a few areas of blowing snow and low visibility Wednesday.

Once actual advisories and warnings are put out in the next 24-36 hours, we’ll post another update with a more detailed and updated timeline. There’s a still a chance this system trends colder, slower, warmer, faster, windier, calmer, drier, wetter… you get the point… Hopefully this timeline gives you a running start on whatever projects you are trying to complete.

We appreciate you trusting us with your forecast – we know preparation takes time and resources, and we put out our forecasts with this in mind, knowing that you may be making a big decision based upon it. Stay safe out there – make sure to download the Nc1 Weather app on apple or android to get these blogs and forecasts directly to your phone. It’ll let you know as *soon* as any sort of warning or advisory is posted for your area.

Stay safe out there,

Nc1 Weather team

 

Categories: Local News, Weather Daily