wxgeek's weather-Windy, Warmer then Snow chance-Update 3/20

Update Wed Mar 20

Not a bad day for the first day of Spring today. Warm temps with some mid and high clouds streaming in from the Pacific. Some showers beginning to develop west of Vail Pass over the mountains with snow level currently 9000-10,000 ft. Precip will increase across the mountains west of the Divide this evening into Thursday morning. Winter Weather Advisories are in effect from 6 pm today through noon on Thursday for 4-8 inches of snow west of the Divide. A cold front will push east across the state on Thursday lowering snow level to 7000-8000 ft by Thursday evening. As cold front pushes east through the foothills Thursday afternoon, some precip is possible, but with westerly flow amount will be limited. Plains could see slightly higher precip amounts. In general, areas above 7000-8000 ft may see a dusting to an inch or two of snow, but feel amounts will be towards the lower side. Could even see a few isolated thunderstorms develop across the far eastern plains where better low level moisture will exist.

Today, the next system is looking much less potent. Model runs from last night and today drop an upper level trough south across CO Friday into Saturday, but keep the main circulation over MT, and do not develop a closed circulation over southwest CO like models did yesterday. This translates to much less snow for eastern CO. The forecast today would bring snow to northwest CO Friday during the day, with snow moving into the foothills and plans Friday late afternoon and evening. Snow still looks likely Friday night into Saturday, but amounts now look like a few inches, perhaps 2-5 inches for the foothills and 1-4 inches for the plains. Heavier snow amounts have moved farther east into the Central Plains. Snow should diminish by Saturday afternoon, with some lingering flurries into Sunday morning. Upper trough hangs over the Rockies, so models generate some additional snow Sunday afternoon into Monday afternoon, mostly in the form of showers and flurries during afternoon hours. I doubt these will generate mush more than a dusting to an inch or so of snow to most areas, but temps will remain well below seasonal averages through Monday.

Upper ridge builds across CO next week Tuesday through Thursday keeping things mostly dry and temps near or above seasonal norms. Models continue to suggest more precipitation for CO late next week into next weekend. Snow levels currently look to be in the 7000-8000 ft range with that precipitation.

_________________
"Climatology is what you expect, Weather is what you get".

"It is better to be roughly right than precisely wrong".

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Update Tue Mar 19

Mostly sunny across the state today with a few mid and high clouds, mostly across the southern half of the state. Still breezy at times across the foothills and plains, which has prompted a Reg Flag Warning for foothill areas below 6000 ft and far eastern plains until 6 pm today. Upper level ridge will move across CO late today into Wednesday, which will create warmer temps on Wednesday and less wind. Despite the vernal equinox occurring at 5:02 am MDT Wednesday, some winter weather will be heading our way later this week and weekend.

The first system will be associated with a short wave upper trough ejecting from a larger parent upper trough over the northern Rockies. Precip will move into western CO Wednesday afternoon with the snow level initially 9000-10,000 ft. Snow will become heavy at times west of the Divide Wednesday evening into Thursday morning with snow level lowering to 7000-8000 ft. I suspect winter advisories will be issued for the mountains Wednesday evening into Thursday as 5-10 inches of snow looks to be possible. System will push east during the day on Thursday and bring precip chances to eastern CO. Snow level looks to be 7000-8000 ft over the foothills and rain on the plains. Currently looks like only 1/2 to 2 inches of snow possible across the foothills with precip ending by Thursday evening.

The next system will be associated with the parent upper level trough moving south from the northern Rockies into the central and southern Rockies Friday into Saturday. This system will be colder and have the potential for more snow across eastern CO. Snow will move south across CO during the day on Friday, reaching the Palmer Divide by Friday evening. Snow level initially 6000-7000 ft during the day on Friday lowering to plains level by Friday evening. Snow will increase Friday night into Saturday morning across eastern CO, mostly east of the Divide and persist into Saturday night or early Sunday morning. Models still tweaking the trajectory and intensity of the upper trough, but it looks fairly certain we are in for colder temps and snow this weekend, then just the "how much" part to figure out. Latest models would suggest that 6-12 inches of snow would be common across portions of eastern CO from this system, but as models are likely to have many different solutions between now and this weekend, amounts will vary. At this time the Euro and Canadian models are deeper and farther south with the system which would have even higher snow amounts. So we will have to wait and see how models handle this system throughout the week, but be prepared for a decent snow event Friday into Sunday morning at this point. Sunday and Monday currently look cool with some flurries across the foothills and High Country. The remainder of next week looks warmer and dry until another system is expected to bring more precipitation next weekend. Despite the timing being on the weekends, all moisture is currently welcome in my opinion.

_________________
"Climatology is what you expect, Weather is what you get".

"It is better to be roughly right than precisely wrong".

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Update Mon Mar 18

Cool and breezy day across the foothills and plains, with snow continuing across the High Country extending east to about the Front Range crest (Long Peak to Mt. Evans to Kenosha Pass). Snow will persist much of the day and gradually diminish tonight. Breezy winds may become stronger tonight across the foothills as a stable layer forms above mountain top level which may induce a mountain wave under strong northwest flow. Highest winds expected to be north of I-70, but strong winds could extend south into southern JeffCo. Wind speeds of 25-50 mph possible with some gusts to 60 mph.

Tuesday should be warmer with temps back near seasonal norms and less wind. Mostly clear across the state on Tuesday into early Wednesday. Weather then becomes unsettled into this coming weekend. Models currently have two distinct systems that will affect CO. First system moves into western CO Wednesday afternoon, and spreads snow east to the foothills and plains during the day on Thursday. Snow level Thursday looks to be around 7500-8500 ft initially lowering to near plains level by Thursday evening. Currently looks like a few inches of accumulation possible above 7000 ft Thursday. Second system will move down from the northwest on Friday and will be a colder system. Snow looks to move into the High Country Friday morning spreading east into the foothills and plains by Friday afternoon with snow persisting overnight. Amounts still look to be on the light side, maybe a few more inches for the foothills and adjacent plains. The weekend looks to be a mixed bag of partly sunny with isolated flurries, mostly over the High Country. Long range models indicate warm and dry weather early next week, followed by a chance for precipitation late next week and into the following weekend.

I know we need every pittance of moisture, but my preference would be nice to have the warm and sunny days occur on the weekend, and have the cool and moist weather during the week.

The annual "green up" is just beginning to occur at lower elevations on the plains and urban corridor, probably won't reach full stage until mid April. Until then, fire danger will remain very high while grasses are dry. As snow melts, fire danger will extend to higher elevations in the foothills before the foothill green up, which usually occurs in late April to May (below 9000 ft) into mid May to June (above 9000 ft). The annual green up helps to mitigate fire danger to some degree, but certainly does not eliminate the danger completely. Once a fire gets into the trees, ground fuels become less important.

_________________
"Climatology is what you expect, Weather is what you get".

"It is better to be roughly right than precisely wrong".

Bump for March 19 update

Bump for March 20 Update