Clouds and thunderstorms return Friday

12:10 PM, Thursday, May 17, 2018

Thunderstorms, some severe, may return to the northeastern plains of Colorado this afternoon, but the threat is mainly east of the Front Range urban corridor. On Friday a storm system developing to our west should draw moisture westward into the Front Range.  The result is likely to be showers and thunderstorms Friday and Friday night for the Front Range and plains. Some areas may experience heavy rain and hail.

The location of the heavier precipitation on Saturday is uncertain. The surface storm system is likely to be in Kansas, but the mid & upper level storm should be near or over the Front Range. If it is a little west/southwest of the Front Range we could see steady rain early and then thunderstorms. But if the upper storm is over or a little east of the Front Range the tendency will be for the heavier precipitation to shift to the east on Saturday. The current modeled data favor the more eastern location of heavy rain on Saturday, but that is not a high confidence forecast. I will update tomorrow.

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Numerous thunderstorms today, gradual drying out mid week

12:00 Noon, Monday, May 14, 2018

At noon the first heavy thunderstorm of the day is developing in Denver, and the afternoon and evening will likely bring numerous showers and thunderstorms across the Front Range and high plains. Most of us will experience at least a brief shower or thunderstorm, and a few localities are likely to experience a strong thunderstorm with heavy rain and hail.

 

On Tuesday afternoon thunderstorms will likely re-develop, but overall the atmosphere may be a little drier so that the coverage and duration may be a little less than today. By Wednesday and Thursday the chance for thunderstorms gets pretty small, and the sunshine more abundant.

 

The mid spring wet pattern will ease off, but probably not go away. It’s looking like another period of cool, wet weather may move into the Front Range region on Friday or early Saturday, but more on that later in the week.

Weekend: Moister and cooler

11:45 AM, Friday, May 11, 2018

A large (but not very strong) storm system to the west of Colorado and a cool air mass to the northeast of the Front Range will make for a cooler weekend and maybe wet at times. The storm will probably never move through the Front Range region, but will instead weaken in place over the next few days. The circulation around it will draw low level moisture to the Front Range from the Great Plains.

 

The most likely result for the Front Range region is for a few periods of clouds and some showers and thunderstorms mainly in the afternoon and evenings. The chance for rain is small today but will increase a little Saturday afternoon through Monday.  Up in Cheyenne the chance for rain and thunder is greater today than for most of the Front Range.

 

There is a small chance that a low level surge of moisture from the east will result in solidly overcast a damp conditions for a 1/2 day to a day this weekend for the eastern foothills and high plains.

 

West slope areas should be drier despite being closer to the storm system.

Wet today

6:00 AM, Wednesday, May 2, 2017

Expected periods of rain to develop today and continue into tonight, perhaps punctuated by some brief heavier showers or thundershowers. Accumulating wet snow is likely in the mountains with the heavier accumulations (6 or more inches) mainly above 9000 feet and, and light accumulations above 7500 feet. The snow level may work it’s way into parts of the lower elevations later tonight, but little or no accumulation is expected in the lower foothills and plains.

As the storm moves east late tonight and Thursday morning the precipitation will likely become more intermittent. Prepare for a possible frosty morning on Friday in the low elevations followed by a nice warmup Friday afternoon.

Cooler & more moist toward midweek

12:40 PM, Monday, April 30, 2018

April is ending drier than average for most of the Front Range region, but the first few days of May are likely to bring some moisture to the area. A large, slow-moving, and somewhat diffuse storm system is developing to the west of Colorado and it may be Thursday before it moves to the east of us.

Cooler temperatures and more cloudy periods are likely Tuesday-Wednesday with a small chance of showers or thunderstorms Tuesday (mainly afternoon and evening). There appears to be a better chance for showers or thunderstorms Wednesday afternoon and evening, and possibly a period of steady rain or drizzle Wednesday night and/or early Thursday. Wet snow is likely in the mountains and foothills by Wednesday evening (mostly above 7500 feet).

 

Frosts?

Although there is variability in the date for last 32-degrees across the lower elevation communities, this week is the median date for most places (that means that about half the time 32 degrees occurs after this date). Once we get beyond May 15th most low elevation areas only have a 1-in-10 chance of another 32-degree night. It’s too early to say whether this will be one of the late-frost seasons or not, so your willingness to cover your plants on cold nights will help determine how soon you will get the tender annuals in the ground.

Warm Monday, Cold Tuesday, Mild Wednesday

6:00 AM, Monday, April 23, 2018

After a warm day, a cold front this evening will result in clouds and colder weather tonight and Tuesday. Mild, sunny weather should return on Wednesday.  Several inches of snow is likely in the mountains and foothills tonight and Tuesday. For the lower elevations there is likely to be some rain showers (maybe a thundershower) scattered around late today and tonight. Some snow is possible later tonight, but only minor accumulation, if any, is expected.

Wetter and cloudier by late Friday

12:15 PM, Thursday, April 19, 2018

A moderately strong Spring storm will move through southern Colorado Friday afternoon and night bringing a good chance of both rain and snow (depending on elevation) for the Front Range region. As with the last few weekends, Saturday might be cold and damp in the morning, but better by afternoon. Sunday looks like a mild Spring day.

Mountains and Foothills

The foothills are likely to see rain and then wet snow Friday afternoon and night, and maybe some thunder early in the storm. Between 6000 and 8000 feet 1-4 inches of accumulation of wet snow is most likely. Above 8000 feet 3-8 inches is most likely (some local areas over 8). The occurrence of some brief convective snow could cause a lot of variability over short distances.

Front Range urban corridor and plains

For areas below 6000 feet there is an 80% chance that there will be little or no snow accumulation. Intermittent rain Friday afternoon, maybe with thunder, might mix with snow at times in the evening and overnight. There is a 20% chance of a changeover to snow resulting in some accumulation, mainly in grassy areas.

Enjoy the moisture!