11/22 Forecast Discussion: Updated snow forecast, and a little Thanksgiving

A warm Thanksgiving will give way to a winter wonderland on Saturday. Let's break down the details.

A moment of Thanksgiving: My mother and my grandfather always shared their excitement for the natural world with me. I have been blessed to have my understanding of the world be shaped by the passion of my own family. All I’ve ever wanted to do since I was a kid was share the gift they gave me: loving our natural world. I want to thank Mr. Dancy, Mr. Simpson and everyone who has given me a chance to share my excitement for meteorology with the Black Hills. I’m truly thankful for this community and the privilege to be your meteorologist. There’s not a day I wake up (even on those really tough mornings) that I don’t feel supremely blessed to be given the opportunity to do what I do for a living.

Let’s get to it.

GOES-16 Satellite, clouds march eastward over the hills on Thanksgiving morning 11/22/2018

THANKSGIVING: Other than a few showers near the Bighorns of Wyoming, the Hills are staying dry. Temperatures in the high 50s/low 60s for most of us, with increasing clouds throughout the day. Winds will be shifting from the southwest to the northwest at some point today.

Surprisingly enough, exactly when that wind shift takes place could have subtle impacts on our snow forecast on Saturday. Be wary of elevated fire danger, especially in areas of Wyoming and our southern counties as relative humidity levels drop to the teens in some cases. Let’s keep our fires to our bad cooking and out of our grasslands and forests.

THANKSGIVING EVENING: A few models show the possibility of a spot shower or flurry in the Hills this evening. The lower levels may end up being too dry, but regardless, cloud cover will be on the increase. Temperatures should hold to the mid-30s for most of us, with lower temperatures out in the Plains. Northwest winds will be around 10-15 mph.

GFS Wind Model for Friday – Notice the uptick in winds on Friday in Wyoming. Those winds could be more widespread in our area, depending on if winds aloft mix with the surface

FRIDAY: Mostly cloudy skies with increasing northwesterly winds will greet us in the morning. High wind warnings are posted for areas of southeastern Wyoming, but no wind advisories for our viewing area just yet.

Depending on how much winds aloft get mixed with the surface will partly determine wind speeds, northwest winds could gust up to 30 mph or more. Temperatures will struggle to top the low 50s, with little sunshine to help boost those numbers. Friday evening will dip into the high 20s with mostly cloudy skies.

NAM Precipitation Model – Saturday Morning into Sunday. This is one of the more aggressive models and doesn’t always verify. It does seem to have a good track on timing, however, and does show us a possible scenario

SATURDAY: Latest trends have the first waves of precipitation crossing the Northern Hills around 6 a.m. Saturday morning. At this time, it shows to be in the form of rain, but that could change given a few degrees of temperature difference. Areas of Deadwood and Lead could see all frozen precipitation or mixed as early as Saturday morning.

By noon, activity ramps up, with large sections of our viewing area under an aggressive snow band pushing southward toward the Nebraska panhandle. The NAM model is aggressive with snow amounts and coverage, so we must keep in mind that other models show less impacts.

Given our warm afternoons this week, it may take some time for snow to collect on paved surfaces, but temperatures will quickly drop into Saturday evening, increasing the likelihood of snow cover across roads in our viewing area.

The tree lighting ceremony at 4:30 p.m. and the Festival of Lights Parade look to be happening right when these snow bands are coming through, so make sure to give yourself plenty of time when planning for travel.

GFS Snow Accumulation Model Saturday through Monday – This is one of the less aggressive models. Notice on Sunday evening, a slight uptick in accumulation in the Hills. That’s the slight chance of snowfall that is still being debated for Sunday evening.

SATURDAY EVENING: Temperatures will plummet with the advancing cold front toward the evening hours, with mid-20s to high teens possible. Snow accumulations look to be around 1-4 inches in places like Rapid City while 3-6 inches look possible in higher elevations, particularly the Northern Hills.

Snow amounts are still fuzzy, and these are just preliminary, but travel impacts look all too real for those traveling to and from the Hills. Other areas of the country look to have impacts as well going into Monday morning. If you are traveling, be sure to check the forecast BEFORE you head out the door. Just because it’s sunny in Custer, doesn’t mean things are necessarily clear in Rapid City.

SUNDAY AND BEYOND: Sunday morning could see a few remnant pockets of resistance in the Hills and elsewhere, but the major system will be pushing off toward Nebraska, Iowa and the Great Plains through Monday. Sunday evening into Monday could see brief periods of light snow, but models disagree on this happening.

Temperatures will be chilly, with lows in the high teens and high only reaching the 30s Sunday, Monday and Tuesday. Mostly cloudy skies will give way to partly cloudy skies Sunday through Tuesday. Wednesday looks to see the return of precipitation chances. What that system looks to bring exactly is a little far out to determine at the moment, but we will be watching carefully.

Happy Thanksgiving everyone! Stay safe out there.


Categories: Local News, Weather Daily