Monthly Archives: December 2014

Very cold Tues night, then less cold

12:15 PM, Tuesday, December 30, 2014

This morning was probably the coldest morning for foothills locations, and tonight will likely be the coldest night for the lower elevations, especially river valleys. Occasional snow and ice crystals into this evening won’t amount to much more accumulation. The sun should continue to be dimly visible at times and won’t be enough to warm temperatures much more than the +1 to +7 range (maybe staying below zero in some foothills locations). There should be more sun on Wednesday as temperatures climb to the 20s.

The middle and upper atmosphere will begin to warm tonight, but because of clearing skies and radiational cooling, low spots like river valleys will probably drop into the minus teens. Other areas will probably drop into the -5 to -10 range in the early to middle part of the night. Toward morning the temperature may start to rise slowly, especially in and near the foothills.

Thursday and Friday will be warmer, but not really all that mild, and there is a good chance that many areas won’t quite make it to freezing on New Years Day. A cold upper level storm system over the desert southwest should move east across New Mexico on Thursday and Friday, likely bringing some light snow to southern Colorado, especially the mountains. There is a slight chance for some clouds and light snow in the Denver-Boulder area late on New Years Day, but it will probably stay dry.

Snow into Tuesday, very cold into Wednesday

12:00 noon, Monday, December 29, 2014

The frigid arctic cold will continue into Wednesday, and the snow is expected to continue into Tuesday evening, although it is likely to be lighter and intermittent on Tuesday.

Snow:

I’m still expecting two-day storm total accumulations through Tuesday to be in the 3-6 inch range for the Front Range urban corridor and eastern plains. But 5-9 inches is a more likely range in the foothills and in some areas immediately along the foothills like Boulder, Golden, and the far south and southwest suburbs of Denver. The clouds might thin enough at times on Tuesday to make the sun dimly visible, but don’t expect that to add much to the maximum temperature!

Temperature:

Temperatures will continue to drop Monday and be near zero around nightfall. Minimum temperatures on Tuesday and Wednesday mornings are likely to be mainly in the -5 to -15 range. Wednesday morning may be slightly less cold than Tuesday in the foothills, but in the lower elevations, Wednesday may be the coldest morning, especially in river valleys. On Tuesday the maximum temperature will probably be within a few degrees of zero. Expect to get above 20 on Wednesday.

The record low for Denver and Boulder on Tuesday morning is -11, and there is a chance we will reach that. The record low for Denver Wednesday morning is -19 and for Boulder it’s -18, and there is less chance for reaching that.

One record that is likely to get shattered is the record low maximum temperature for Tuesday, which is 8 for Denver and a balmy 16 for Boulder.

New Year’s Day:

A large piece of this cold storm system will break off and move into the desert southwest bringing cold weather there too. It is expected to move eastward Thursday and there is a slight chance that it will be close enough to bring a little bit of clouds and light snow to the Front Range on New Years Day. There is a better chance across southern Colorado.

Cold Wave Monday -Wednesday

12:15 PM, Sunday, December 28, 2014

The final three days of 2014 will be very cold, mainly cloudy, and with snow (at least Mon-Tue). This is due to a storm system from the west and a strong arctic cold front from the north.

Temperatures:

The cold front should move south through Wyoming overnight and southward through Colorado’s Front Range Monday morning, probably before daybreak in Denver and points north. Early morning temperatures on Monday are likely to be in the teens in the Denver to Fort Collins corridor and on the way down through the single digits in the afternoon and to around zero by nightfall. It may take a few hours longer from Colorado Springs and points south, but the day will turn very cold there too. On Tuesday, temperatures are likely to start in the -1 to -10 range and barely climb above zero during the day before falling to the -1 to -10 range Tuesday night (maybe around -15 in some valley areas and DIA). Wednesday is likely to see temperatures rise to the low 20s. We may even break the freezing mark on New Years Day.

Clouds and Snow:

Low stratus is likely to develop behind the cold front Monday morning and then it is expected to be mainly cloudy into Tuesday night. The clouds might thin a little at times in the high elevations on Tuesday. Periods of snow and ice crystals are likely Monday morning through Tuesday evening. During the period we are likely to see 3-6 inches, with 6-9 inches possible in the foothills and Palmer Divide area. The best chance for a period of moderate or heavy intensity snow along the Front Range is Monday afternoon and/or night, but most of the snowfall should be light. Mountain areas in western Colorado are likely to see 6-12 inches beginning today.  The final remnant of the storm is probably going to pass south of Colorado on Thu-Fri and may bring more clouds and snow to the San Juans and/or Sangre deCristo ranges.

Records:

The record lows for Tue and Wed morning in Denver are -11 and -19, and in Boulder they are -11 and -18. There is a small chance we will reach the Tue record, but very little chance for the Wed record. The record lowest maximum temperature  on Tue is +8 for Denver and +16 for Boulder. Both are likely to fall, and Boulder’s may get clobbered.

Arctic cold front Sunday night

1:00 PM, Friday, December 26, 2014

Showery snow should linger through this evening and result in some light additional accumulation in some areas. Then the Front Range region should be drier Saturday and through the day on Sunday.

The next cold front, probably Sunday night, will bring very cold air from the arctic regions of Canada. It will get colder statewide, but most notably for the Front Range, eastern Colorado & Wyoming. Even in the lower elevations daytime temperatures are likely to remain below 20 Monday through Wednesday, and maybe below 10 on Tuesday. Morning low temperatures will probably dip below zero on the coldest morning (Tue and/or Wed).

It does not look like a heavy snow situation for the Front Range, but that can’t be ruled out yet. What does look likely is a long period with clouds  and mainly light snow from Sunday night through Tuesday night that will probably add up to something in the 3-6 inch range.

The west slope is likely to see some mountain snow move back in on Sunday after a mainly dry day on Saturday, and then periods of snow during the early to midweek period.

Storm arriving a little faster

7:00 AM, Christmas Day, 2014

I have not changed my forecast on snow amounts, but the arrival of the cold front and snow is a little faster than originally predicted. At 7AM the cold front has reached Cheyenne and should move south through the Colorado Front Range this morning. Snow is developing in the Cheyenne area and will probably spread into the northern Front Range this morning and the Denver-Boulder area in the early afternoon. Snow may be moderate or heavy at times late this afternoon and this evening so expect winter road conditions in the area.

This forecast amounts from my post last night:

7-12 inches: Nederland, Georgetown, Evergreen, Monument

5-8 inches: Cheyenne, Boulder, Broomfield, Denver (and the west and south suburbs)

3-6 inches: Fort Collins, Longmont, DIA, Colorado Springs

Merry Christmas!

Christmas Snow Update

4:45 PM, Wednesday, December 24, 2014

It is still looking like a late-day white Christmas for the Front Range. Snow is likely to develop north-to-south from Cheyenne to Colorado Springs during the afternoon and early evening. Boulder and Denver will probably see snowfall begin mid to late afternoon. Accumulations should range from about 3 inches on the plains east and northeast of Denver, to 10 inches in some foothills locations west and southwest of Denver. Expect 6-10 inches in the mountains and high passes of western Colorado. Most of the Front Range snow will probably fall before noon on Friday, but intermittent light snow is likely to persist into Friday night.

Most likely amounts at given locations:

7-12 inches: Nederland, Georgetown, Evergreen, Monument.

5-8 inches: Cheyenne, Boulder, Broomfield, Denver (and its south and west suburbs).

3-6 inches: Fort Collins, Longmont, DIA, Colorado Springs

Significant snow late Christmas Day

5:30 AM, Wednesday, December 24, 2014

I won’t be able to update during the day today, but here is what the latest is…

A storm system late on Christmas Day will likely organize as a four-conrers low, a term that some weather enthusiasts are familiar with as it relates to Front Range snow. After a mild start to Christmas Day a cold front should sweep down the Front Range during the afternoon. Snow is likely to develop in the mid afternoon to early evening period. With falling temperatures and the possibility of some brief moderate to heavy snowfall rates, road conditions may deteriorate rapidly near or after nightfall on Christmas (could be during the afternoon in Cheyenne).

Expect 3-6 inches through much of the area by midday Friday, and probably 5-8 inches in some places in and very close to the foothills and Palmer Divide. Light snow and clouds may linger into Saturday morning. Accumulation should be lighter out on the high plains, but blowing snow will likely be a hazard there. To the west, winter travel conditions are likely to develop on Christmas Day, especially at the passes.

It still looks like a multi-day cold wave next week, possibly beginning Sunday night or early Monday. We could see some days with high temperatures below 20 and lows below zero.

Late day snow likely on Christmas

1:00 PM, Tuesday, December 23, 2014

Front Range residents should wake up to relatively mild, dry weather on Christmas morning, but it is likely to be snowing by nightfall.

A cold front is expected to move north-to-south from southeastern Wyoming in the late morning to the New Mexico border by early evening, probably through Denver-Boulder by early afternoon. Clouds are likely to increase and precipitation should start within a few hours of the front. Accumulating snow may make travel very icy along the Front Range by early evening on Christmas Day.

Expect a general 3-6 inches by midday Friday, but maybe a little more than 6 in the foothills. Some light snow and clouds may linger through Friday.

For western Colorado, expect winter travel conditions, especially at the passes on Christmas Day.

It still appears that there is potential for a very cold air mass and more snow early next week.

Scattered snow around today, another cold front late on Christmas Day

NOON, Monday, December 22, 2014

A secondary piece of the storm the brought heavy mountains snows over the weekend will continue to impact Colorado and Wyoming today. Several more inches of snow is likely in the mountains, including the high elevations of the Front Range. Strong gusty north-northwest winds will occur at times, but especially in the eastern Colorado plains and in southeastern Wyoming.

Snow in Denver or Boulder? The atmosphere is colder today, so showers that are developing will likely have more snow than rain. Once again, the coverage of snow will be uneven this afternoon through Tuesday morning. Many areas will receive little or no accumulation, but some locations may get and inch or two including some brief moderate snow squalls. So be prepared for some highways in eastern Colorado & Wyoming to have local areas of reduced visibility and icy roads. This is especially true for I-25 near and north of the Palmer Divide (between Denver and Colorado Springs), and also I-25 near the Colorado/Wyoming border.

Christmas Eve should be a good travel day statewide, but stormy weather along the eastern seaboard may impact air travel. Christmas morning will probably dawn mild and maybe a bit breezy along the Front Range. A cold front late in the day may bring a bit of snow (or rain changing to snow) late on Christmas Day or on Friday morning. At this point it appears there is a better than 50-50 chance for light accumulating snow along the Front Range sometime between late Christmas Day and early afternoon on Dec 26th.  In western Colorado moderate amounts (the 6-inch range) are likely mainly Christmas afternoon and night.

There is hint that some snow along with the coldest air mass this month may arrive late Sunday or Monday next week, but I’ll update that in the coming days.

Happy Solstice! It will be wintry in western Colorado

10:00 AM MST, Sunday, December 21, 2014

Winter arrives at 4:03 PM MST, and it will feel and look like the winter season in the mountains and valleys of western Colorado and Wyoming.

Heavy snow and blowing snow (1-2 feet) are likely to impact travel throughout the region, but especially from I-70 north into south-central Wyoming. Even along the Front Range, snow and blowing snow will be common near the continental  divide (mainly west of Peak-to-Peak Hwy). Winds gusts in the 50-70 mph range will create cold wind chills around Brainard Lake and Rocky Mountain Park.

The lower foothills and plains of eastern Colorado and southeastern Wyoming will have a mild day but with west/northwest wind gusts of 30-50 mph in some areas this afternoon. For this evening and Monday winds will become more north-northwest and there is a chance for some snow. The snow is likely to organize in northwest-southeast bands. Many areas from the lower foothills eastward will probably get little or nothing, while a few areas should see 1-2 inches.

If you’re dreaming of a white Christmas it might end up being just s dream along the Front Range and eastern plains. In fact it looks like we may be in mild chinook winds late Christmas Eve into Christmas morning. A cold front later on Christmas Day will bring only a small chance for snow.  Light snow is likely near and west of the continental divide.