Black Hills Weather: System could bring potential relief – and potential impacts Tuesday
Areas along and south of I-90 are likely to see some sort of precipitation - which still leaves out areas north of the Black Hills that desperately need moisture
Happy Easter! Before we get into the meat and potatoes of Tuesday’s system, lets break down the next 36 hours.
- Conditions expected to be warm and dry across the Black Hills Region Sunday.
- A wind shift to the northeast is expected sometime this afternoon.
- Monday will be cooler, with an approaching cold front expected to increase winds – and with it fire concerns.
- The good news is relative humidity should recover to the 25%-35% level fairly quickly after the frontal passage.
- Temperatures will drop as we push into Monday evening.
- Eventually, the initial push of Northwest winds will turn North and eventually Northeasterly as we push later into Monday.
- Any winds with an easterly component *generally* increases relative humidity – so although we will need to be alert for fire weather, conditions will be slowly improving.
- A relatively small, compact system will begin approaching from the West Monday evening, traveling southeast and gathering steam as it moves.
- A mixture of rain and snow could begin as early as 6 PM for the Bighorns and portions of Campbell County, Wyoming.
- Variable, breezy conditions can also be expected – more than likely with a Northerly component.
- By Tuesday morning/midday rain and snow will be pushing into portions along and south of the I-90 corridor.
- Snow will be highly elevation dependent with this system, but there is *some* evidence that snow could find its way to lower elevations for extended periods of time.
- By late Tuesday, dry air will be wrapping around from Montana and Wyoming – undercutting precipitation and drying things out going into Wednesday.
- A consensus among short and long range models are starting to come together and it’s telling a story that is becoming all to familiar: Areas North of I-90 are likely to be left out.
- This is frustrating, as areas such as Harding, Perkins, Butte, Meade, Ziebach and Haakon county desperately need moisture to stave off Extreme drought and wildfire conditions.
- There will be many cases where you see rain/snow falling at your location according to radar – but dry air is absorbing this precipitation and evaporating it before it can reach the surface.
- We have seen this in Rapid City and the I-90 corridor several times this year already – drought conditions make these dry pockets much more common and those hoping for rain/snow may be made to wait later in the day or snubbed altogether.
- The farther North you travel in the Black Hills Region, the more likely you are to encounter these dry pockets.
- There are pockets in the higher elevations of the Black Hills such as Lawrence, Western Pennington and Custer County that could see moderate to heavy accumulations – 6″+ is not out of the question at this point.
- Lower elevations should temper their expectations as most heavy wet snow will more than likely melt on contact.
- There are SOME models that suggest colder air could switch rain over to snow even in the plains East of the Black Hills. Large, heavy snowflakes could quickly change a moderate rain into slick road conditions in a very short amount of time in these areas.
- Its a difficult forecast at this point but so far resident East and Southeast of the Black Hills such as New Underwood, Wall, Fairburn, Kyle, Pine Ridge, Oglala and Oelrichs should keep a close eye on the forecast over the next 24 hours.
- Those who are calving may need to take some precautionary measures as sustained 15-25 Northerly winds are expected to pick up in Tuesday and Wednesday – with either a cold rain or wet snow possible Tuesday morning through possibly early Wednesday.
- We will update the forecast with the latest as it becomes available.
- Regardless of whether rain or snow eventually does fall – latest guidance suggests up to a 3/4″ of moisture could fall in total for some areas.
- Amounts drop off significantly as you go North of I-90, and expectations should be kept low for appreciable moisture in those areas – hopefully the low tracks a little farther North over the next 24 hours to change this.
- As you can see, areas of NW and North Central South Dakota could really use a shift in precipitation expectations.
- The drier these areas get – the harder it will be for systems to overcome dry surface conditions.
- Don’t let the temperatures fool you on Tuesday – with winds blowing northerly and a steady cold rain/snow things could get chilly very quickly. Staying dry will be important.
- If this system Tuesday misses critical areas, the good news is we have another roll of the dice this next weekend that could bring more relief to the area.
- Expect an update on this forecast as things change – Here’s hoping mother nature answers the call so we can help firefighting efforts across the region.
Happy Easter from us to you and your families – stay safe out there.