wxgeeks upcoming snow chances-Update March 4

Update Fri Mar 4

Snow currently in the mountains will spread east this afternoon and evening. Latest guidenace consistent with previous forecasts in bringing snow over the foothills and Urban Corridor this afternoon and evening. Air aloft is cold enough for all precip to fall as snow, although below 6500 ft snow likely to initially melt due to surface temps above freezing. As more precip occurs, accummulation even in the Urban Corridor likely by late this afternoon and evening. Latest snowfall forecast looks like 1-3 inches in the Urban Cirridor, and 2-6 inches in the foothills. However, since much of the precip will be convective/showery in nature, amounts will vary widely with some areas receiving little if any snow, and other areas a fair amount. Heaviest snow likely to be along the southern JeffCo foothills and Palmer Divide. Convective showers are likely, which could produce brief heavy snow with snowfall rates of 1-2 inches per hour. Snow should end between 9 pm and midnight.

Saturday is the in-between storms day, so dry across the state and a good day to be outside if possible. A weak upper trough will pass over CO on Sunday, bringing snow to the mountains, mostly west of the Divide, with a slight chance for light snow or flurries along the foothills Sunday afternoon and evening. Snow level will be between 6500-7500 ft Sunday. Accumulations in the foothills expected to be less than an inch or two.

Focus then turns to our potential big snowstorm. Latest model guidance continues to keep the track in a favorable location, with a closed upper low moving across the southern border of CO from Monday night into Tuesday night when the low is expected to be in northwest KS. A deep surface low is expected to track from southwest CO to southeast CO on Tuesday. This puts the foothills and northeast CO under deep upslope flow. If the current forecast stays on track, snow would begin late Monday afternoon in the foothills, earlier in the day in the mountains, and become heavy overnight Monday and persist all day Tuesday. Snow level would begin around 6000 ft Monday evening, lowering to Plains level by midnight. If forecast track remains as is, I expect a Winter Storm Warning and possibly Blizzard Warning will be issued for the foothills and Plains. The big question is whether future model runs keep the track as it is or move it north. If the track were to move north by as little as 100-200 miles, snow amounts would be greatly reduced and keep the snow farther north into WY. If models are correct, we will likely be looking at a major snow event, with 5-10 inches on the Plains, and 6-18 inches in the foothills. I will keep my fingers crossed that this storm stays on its current track and provides some much needed moisture. Snow would end sometime Tuesday night before midnight.

Long range progs keep the rest of next week dry with seasonal temps. Next snow would be next weekend, with additional chances the following week. Somewhat typical March weather for CO.

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Snow currently falling in the high country will continue into Friday. As upper trough passes over eastern Co this afternoon, chances for rain and snow showers increase. Current snow level quite high, between 9000 and 10,000 ft but will lower to around 8000-9000 ft by this evening. With warm temps this week, suspect most snow that falls will melt on asphalt surfaces, but some could stick on other surfaces. I would not expect more than an inch or so to accummulate at higher elevations this afternoon into this evening.

Some showers could linger into tonight and persist overnight in isolated areas, mostly along the foothills and Palmer Divide. Latest model guidance brings the next upper trough across CO on Friday, which will once again increase chances for snow. Snow level should drop to 5000-6000 ft by Friday morning, so any precipitation that falls on Friday should fall as snow, although likely to melt at lower elevations. Snow chances increase through the day on Friday with snow likely in the afternoon and evening, as some convective enhancement is likely. Amounts tough to predict due to the convective nature, so amounts could vary widely. In general I will stick with 1-2 inches across the Urban Corridor and 2-4 inches across the foothills, knowing some areas may receive little if any precipitation, and other areas could even go higher than 4 inches. Snowfall rates could be high (1-2 inches per hour) in brief convective showers, so roads could get slick in areas. The commute back up the hill could be difficult at times. Snow should end by midnight.

The weekend still looks nice for the foothills and plains. Snow looks to return to the mountains west of the Divide on Sunday. Next system still predicted to be a significant storm for eastern CO. Latest track has the upper trough and closed low into southeast CO on Tuesday with a deep surface low also over southeast CO providing good upslope flow. Snow will increase over western CO Monday with snow level betwen 8000-9000 ft. Precip to spread into northeast CO by late Monday afternoon, and then increase across all of eastern CO Monday night. Snow level will lower overnight Monday down to 5000-6000 ft by Tuesday morning, and colder air will turn all precip to snow during the day on Tuesday. Snow should end sometime Tuesday evening or night. If current forecast track is accurate, then amounts would likely be in the 3-6 inch range for the Urban Corridor, with 4-10 inches in the foothills. Obviously the track of this system could change between now and next week, so amounts could go either way depending on the intensity and track.

Long range models indicate the remainder of next week will be dry with seasonal temps. Next chance for precip looks to be next weekend, with models indicating the storm track remains active for CO beyond that.

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Update Wed Mar 2

Latest model guidance suggest a series of 3 upper level troughs will pass over CO over the next 72 hours. The first and very wek impulse will move across tonight, bringing only light snow to the northwest mountains. The second impulse will move across CO on Thursday and this system will bring heavier snow to the mountains west of the Divide during the day on Thursday, and also bring a chance for rain and snow showers to northeast CO Thursday afternoon/night. Snow levels on Thurday will be 7000-8000 ft west of the Divide, and 8000-9000 ft east of the Divide Thursday afternoon, lowering to 6000-7000 ft by midnight. Snow amounts from this system for the foothills would likely be less than an inch or two, with much of the initial snow melting on asphalt due to the warm temps this week. The mountains west of the Divide are likely to see several inches of snow, where NWS has issued winter weather advisory from 3 pm Thursday through 6 pm Friday for 4-8 inches of snow.

The third and strongest inpulse will move across CO on Friday. The impulse from Thursday will leave cooler air in its wake, so snow levels on Friday expected to be down to Plains level. Snow will increase in the mountains west of the Divide early Friday, and spread east during the day. Models have some timing differences for this system, with the GFS being about 6 hours faster than the NAM/WRF, so will use a compromise in timing. Thus, for the foothills, snow to begin sometime late Friday morning and persist into Friday evening, with heaviest snow late Friday afternoon into early evening, perfect for the commute home. Understand snow could start as early as early Friday morning or as late as Friday early afternoon. Snow totals look like 2-4 inches for most foothill locations, with up to 6 inches possible in favored areas, or areas in heavy convective showers which will be possible. Probably 1-2 inches for the Urban corridor, so the earlier you can leave work on Friday, the better the drive back up the hill will be. Snow should end by midnight.

The weekend looks dry for the foothills and Plains, but snow will return to the mountains west of the Divide on Sunday with snow level 7000-8000 ft. The next and potentailly larger storm to affect CO will move into western CO on Monday and across eastern CO on Tuesday. Snow to become heavy in the mountains on Monday, and move into eastern CO by Monday afternoon/evening. Snow level initially will be around 8000-9000 ft Monday evening, but lowering to Plains level by midnight. Potential for heavy snow Monday night into Tuesday across most of CO, including the foothills and Plains. Models still a bit uncertain about the track, so too early to predict amounts. Storm will have the potential to be significant if the track stays far enough south where models currently have it. If the track moves farther to the north, then much less snow. Will continue to monitor this system.

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Update March 1
March has certainly entered like a lamb, but hopefully March becomes much more lion like. Anotehr couple of warm days ahead before the next system affects CO. The western mountains could see some light snow on Wed, but better chances and heavier snow is forecast to move into the mountains during the day on Thursday, mostly west of the Divide. Some showers are possible across northeast CO Thusday afternoon, but mostly north of I-70 and east of I-25. Snow level will be around 8000-9000 ft Thursday, so all rain on the Plains. Snow increases in the mountains Thursday night into Friday, so winter advisories will be likely for this time period. Snow level should drop to around 6000-7000 ft by Friday morning.

A good chance for accumulating snow will occur over the foothills and Plains Friday into Friday night. Best period will be Friday afternoon and evening as an upper trough passes over the area. Latest model guidance indicates the possibility of convective snow showers during this period, which could drop several inches of snow quickly. Snow level will be down to 5500-6000 ft by Friday evening, so snow could accumulate in the Urban corridor during the Friday evening commute, and roads above 6500 ft could become snow and ice packed. With convective showers, snow amounts could vary drastically, but in general looks like anywhere from an inch at lower elevations, to 3-6 inches at higher elevations. Heaviest snow looks to be between 3 pm and 9 pm Friday, with snow ending by midnight.

More snow on tap for the mountains west of the Divide late Saturday into Sunday, but the foothills and Plains should remain dry. The next, and potentially stronger system is forecast to affect the foothills and Plains by late Monday and persist into Tuesday night. Models still not in total agreement on the track of this system, but it has the potential to be a significant snow event for the foothills and Plains, so will keep everyone posted on the development of this system. The mountains would also collect a fair amount of snow from this system on Monday and Tuesday if current guidance is anywhere close to accurate.

In general, long range progs indicate better chances for snow across CO, including the foothills and Plains over the next 7-14 days as systems move from the Pacific Northwest into CO.

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This week will start out warm and dry, with some gusty westerly winds possible Monday night. Temps Monday through Wednesday will be 10-15 degrees above seasonal norms. Models suggest mountain snows will return late Wednesday into Thursday, but the foothills should remain dry, although cooler on Thursday. Snow should be confined to areas west of the Divide, and mostly north of I-70 with the snow level around 7000-8000 ft. A weak disturbance could bring some snow to the foothills and Plains Thursday night into Friday, with the snow level between 5500-6500 ft Thursday night, lowering to Plains level on Friday. Currently looks like snow amounts would be in the 1-3 inch range, but still very early for definitive snow amounts. Snow should clear by early Friday morning with mostly clear skies by Friday afternoon.

The weekend looks mild and dry for the foothills and Plains, with some snow returning to the mountains west of the Divide on Sunday, with snow levels up around 8000 ft. Long range models indicate the potential for a more significant snow event early next week for the foothills and Plains. A deep upper trough would bring much cooler air and upslope conditions by Monday afternoon, and moderate to heavy snow Monday night into Tuesday. This is still a long ways off, but both the GFS and ECMFW models have had this solution for the past couple of days now, so certainly something to keep an eye on.

As for our climatology this year, we ended February with 59 inches of snow recorded on Conifer Mountain. That is 67 percent of normal for this time of year. By comparison, we recorded 69 inches last season by the end of October. The season will be determined over the next 3 months however. We normally receive 50% of our annual average snowfall from March 1 through May 31, with 75 inches on average during March and April. We will be ok if we receive average snow for the next 3 months, which would leave us at 83% of normal for the season. However, if we receive less than normal the next 3 months, we could be in for a very dangerous fire season, especially during the months of May and June when ground moisture is still very low and grasses are still dry. If our seasonal monsoon rains arrive late or are below average, then fire season could extend into our normally wet summer months of July and August. The second peak in fire season usually occurs in September when summer rains end and before snows begin. Hopefully we get a late surge of Spring moisture to keep fire danger down, but all foothill residents should begin to prepare for a potentially bad fire season, and have evacuation plans in order and critical documents in a secure location. Hopefully all pertinent fire bans will be in effect long before they are needed.

Bump for March 1 update

Bump for March 2 update

Bump for March 3 update

Bump for March 4 update