Apr 09

4/9/2018 – Bring on the Heat!

Hopefully everyone had a great weekend, the weather was a bit cool, a bit windy and even snowy for some folks. Monday featured another quick show of moisture with rain, snow and sleet especially for areas South of Denver.

The good news is; spring will make a return this week!

A warm blob of air moves into the area on Tuesday with highs up and down the front range reaching into the 60’s and even a few 70’s in some places. The air will be dry and fire danger will be a concern but Tuesday will be on of the less windier days we will see this week.

Wednesday features more warm air and stronger winds. Downsloping conditions will warm temperatures into the 70’s once again at lower elevations and 60’s in slightly higher elevations. Most areas along the Palmer divide should end up in the mid to upper 60’s during the day and low 40’s to upper 30’s by nighttime. Downslope winds will make for a warmer night.

Thursday continues the warm and dry trend with strong winds, fire danger looks to be high in the middle of the week. Here’s a look at the next 3 days for Castle Rock, Colorado:

We’ll keep an eye on the forecast, but expect windy conditions, above average temperature and critical fire weather conditions over the next few days.

We’ll try to keep up with the fire weather alerts and have a post about them, but in the meantime you can get near real-time weather alerts for Castle Rock on our Castle Rock Weather Warnings’ page. (These are automatically updated about every 15 minutes, 24 hours a day and 7 days a week.


Apr 06

04/06/2018 – Storm System Features Snow, Cold Temps

The storm system moving today won’t be super impressive in terms of snowfall… the main impact will be the wind and the cold temperatures. Many of the local TV stations have been harping on this all week, but if you’re going to the Rockies game today… it’s going to be cold!

Colorado Weather | Denver Weather | Colorado Rockies | Cold | Colorado Rockies Home Opener 2018 Weather | Home Opener weather Denver

Today’s home opener for the Rockies could be one of the coldest in history.

For those of us along the Palmer Divide (a bit closer to home) we can expect the front to move through very shortly. Temperatures were already dropping and winds were picking up at the writing of this article. We expect upslope flow to kick in along with this front and bring the area some snowfall. Temperatures in the middle and lower atmosphere should be cool enough to support snow.

Snow in Castle Rock | Forecast snow | Castle Rock Weather | Castle Rock Colorado Weather | Palmer Divide Weather | Palmer Divide Snow

Models show snow moving through the area as early as 12PM and lasting in to the afternoon hours

The snapshot above from the HRRR model shows a good bit of snow moving through early this afternoon from North to South. Don’t expect a ton of snow accumulation from this system, while it’s not moisture starved it simply moves through too quickly to accumulate much snow.

Castle Rock Weather | Weather in Castle Rock | Forecast Low Temperatures | Cold Weather | Colorado Weather | Palmer Divide Weather

Colder temperatures will be the big story this afternoon

The temperatures this afternoon and tonight will be cooler than we’ve seen for awhile. The snapshot above shows forecast temperatures around 3:30PM this afternoon. Expect those to continue to fall into the evening and overnight hours with many areas ending up in the upper teens and low 20’s for nighttime lows.

Snowfall Accumulation

Castle Rock Weather | Castle Rock Co Weather | Palmer Divide Weather | Snowfall amounts | Castle Rock Snow | Palmer Divide Snow

Not going to dwell too much on snowfall with this storm… models do show some areas getting a bit of accumulation but I think the ground is warm enough where some of these numbers are a bit overdone. The main jist here is many areas along the Palmer Divide will end up with little to no accumulation; areas that do see snow stick could see an inch or two of accumulation.

Areas Southwards towards the Springs (think Monument, Palmer Lake, Black Forest) will see very minimal accumulation and strong winds from time to time. Like many of the Northwesterly storms we’ve seen this year, the big winners with snowfall will be the mountains and foothills adjacent to the front range. Areas West of Manitou Springs could see 4-8 inches with locally higher amounts in some areas.


All in all, we will be glad to get a bit of moisture out of this storm but we don’t see a lot of snow and not a huge impact with this storm system. The main thing to remember is how cold it will be Friday afternoon and into the evening and nighttime hours. If you have plans, be sure to bundle up… it will feel more like January this evening than April.

Record cold | Colorado Weather | Colorado Snow | April 2018 snow | Cold Temperatures in April 2018

It could be worse, you could be hanging out in North Dakota tonight!

Mar 26

Monday PM – Tues AM Storm Update

Colorado Weather Alerts and Information as of 7AM Monday March 26, 2018

You can view Castle Rock specific Weather Warnings on our Page Here!

Dense Fog Advisory


Fort Collins, Hereford, Loveland, Nunn,
Briggsdale, Grover, Pawnee Buttes, Raymer, Stoneham, Bennett,
Byers, Deer Trail, Leader, Agate, Hugo, Limon, Matheson, Forder,
Karval, Kutch, Punkin Center, Akron, Cope, Last Chance, Otis,
Amherst, Haxtun, and Holyoke




A Dense Fog Advisory means visibilities will frequently be
reduced to less than one quarter mile. If driving...slow down...
use your headlights...and leave plenty of distance ahead of you.

Winter Weather Advisory

Locations (Palmer Divide):

Castle Rock, Elbert, Fondis,
Kiowa, and Larkspur




Plan on slippery road conditions. Expect
reduced visibilities at times.
A Winter Weather Advisory for snow means periods of snow will
cause primarily travel difficulties. Expect snow covered roads
and limited visibilities, and use caution while driving.

Storm Update

Everything for the most part seems to be on track with this storm with the data coming in this morning. Models are still showing a system moving in this afternoon, initially with rain showers (and even a few thunderstorms) and changing over to snow at some point. The instability in the atmosphere will lend itself to some areas seeing short and intense bursts of snowfall (very similarly to the last storm) so be prepared for that this evening.

snow storm | spring storm | castle rock weather | castle rock co weather | palmer divide snow | palmer divide weather

Nam3K model prediction of precipitation around 8PM tonight

Notice the fine line between rain and snow setting up somewhere South of Castle Rock in the early evening hours. Where this line ends up and when it ends up there will be very important to how much snowfall we see.  Models can spit out expected snowfall amounts all day, but they sometimes struggle with pinning those amounts down when you have fine temperature line like that. It’s the main reason we see so many busted forecasts (both high and low) in the spring months along Colorado’s front range.

snow storm | spring storm | castle rock weather | castle rock co weather | palmer divide snow | palmer divide weather

Nam3k precipitation forecast for midnight (12AM Tuesday morning)

By later in the evening hours we transition all to snow, this time period could contain intense bursts of snowfall, strong winds and low visibilities… much like the last storm. Travel conditions will deteriorate into the evening and overnight hours.

What To Expect

Snowfall Amounts

There’s still a lot of uncertainty here mainly due to the temperature and when the rain changes to snow (which models can’t predict too well) so you may hear widely varying amounts of snow based on who or what TV station or source you listen to for weather. Due to the high uncertainty, for our forecast strategy we took the probabilistic totals as a start and base our forecast on those and some of our own data…

Parker: 2-5 inches total
Highlands Ranch: 3-6 inches total
Castle Rock: 3-7 inches total
Larkspur: 4-8 inches total
Franktown: 3-7 inches total

Elbert County (Elizabeth, Elbert, Limon, Kiowa)


Elizabeth: 3-7 inches total
Elbert: 3-7 inches total
Kiowa: 3-7 inches total
Limon: 1-4 inches total

First thing you’ll notice is the ranges are a bit wider than our past storm’s forecast. Again this is because the temperature setup and atmosphere are slightly different and depending on exactly when things change form rain to snow makes the difference as to whether you’ll see the higher or lower end of those snowfall ranges.


Rain will start moving in after 2 or 3 PM on Monday. That precip should change over to snow as you make your way towards the evening hours. Remember, the Palmer Divide will change over fast than lower elevation areas like Denver.

Probably a good idea to have everything wrapped up and be off the roads by 8PM.


Just like the last storm, any areas under intense bursts of snowfall will see road conditions deteriorate quickly. Expect slushy and icy roads especially in the evening and overnight hours. I suspect the Tuesday morning commute will be impacted at least moderately, especially on the South side of town.


Lots of similarities with this storm and the last one we had, but some differences too. I don’t think we will see quite as much snow as the last storm but accumulations could be close if the rain changes over sooner. Of course, this entire forecast is riding on the low pressure systems to set up correctly and take the right track. Any wobble in those could make a big difference.

Be sure to stay tuned and we will pass along any updates we see with this storm. Be sure to stay tuned for other updates as well as there are potentially 2… YES 2… more storm systems slated to impact our area this week. Each of which could bring snow and much needed moisture!

Mar 25

Fire Weather Warnings Ahead of Unsettled Week

Red Flag Warnings are up for high fire danger across the Palmer Divide and most of the East Central and Southeast part of the state. Strong winds gusting to 35 mph will be likely on Sunday with low relative humidities and warm temperatures. Sadly, the combination of this weather the past week and still dormant vegetation has all but erased the moisture we received last week. Here’s the Red Flag Warning details:


The National Weather Service in Denver has issued a Red Flag
Warning FOR WIND AND LOW RELATIVE HUMIDITY, which is in effect
from noon today to 6 PM MDT this evening.

* Affected Area...Fire Weather Zones 241...246 and 247.

* Timing...12 PM TO 6 PM MDT Sunday.

* Winds...Southeast 10 to 20 mph with gusts up to 35 mph.

* Relative Humidity...As low as 11 percent.

* Impacts...Conditions will be favorable for rapid rates of fire
  growth and spread this afternoon and evening. The most favorable
  areas will be over southeast Douglas...Elbert and western areas
  of Lincoln county.


A Red Flag Warning means that critical fire weather conditions
are either occurring now....or will shortly. A combination of
strong winds...low relative humidity...and warm temperatures can
contribute to extreme fire behavior.

Unsettled Weather Week Could Bring Relief

There’s a few storm systems set to impact us this upcoming week, they’ll pretty much be lined up to hit us one after the other. We’ll look at the first one and update on the additional storm systems later in the week.

Here’s the setup for the Monday-Tuesday storm

500mb upper air pattern on Tuesday around 2AM

A strong upper level trough (low pressure) will move Southeastward into Southern California and Arizona through the day Monday. This system will tap into moisture and push it aloft towards Colorado. Through the day expect it to move Eastward but never really take a turn to the North, this means the main bit of energy remains too far South for us to see a setup like we had last week.

Surface winds on Tuesday around 3AM

Meanwhile on Monday evening and into Tuesday morning a surface low sets up as a cold front moves through and changes the wind direction at the surface. Winds should turn Northerly or Northeasterly, meaning upslope along the front range. This allows us a period of time to squeeze some of that moisture out of the atmosphere, but I suspect a lot of places will see rain or light snow accumulations. The areas to watch for heavier snowfall accumulations will be the foothills West of Denver and to a degree the Palmer Divide.


  • Location, location, location
    • Where exactly the surface low sets up and how strongly it can give the region upslope will make all the difference
  • Instability!
    • Just like the past storm bands of heavier convective snowfall will be possible
    • This means some areas may see short, intense bursts of snowfall

Expected snowfall range through Tuesday 5AM – these are preliminary numbers, expect them to change a bit either way

As of Sunday morning with the latest modeling data, here’s our thinking on snowfall accumulations. The snow will again be mainly oriented along the Palmer Divide but given the less desirable moisture and atmospheric setup snow totals don’t look nearly as impressive at this time. The above model shows snowfall through Tuesday 5AM, most areas in and around Castle Rock look to end up in the 1-4 inch range. Areas to the East and West will see slightly more will areas North and South will see less snowfall.

Stay tuned for updates to the forecast throughout the day later on Sunday and into Monday as you know, the forecast can always take a hard right hand turn with these spring storms. Enjoy your Sunday!


Mar 20

March 18-19 Storm Recap

Palmer Divide Snowfall Totals

March 18 snowstorm | Snowfall Totals | Palmer Divide Storm | Snow

Snowfall totals through March 19, 2018 from NWS, Trained Spotters and CoCoRaHs stations

There were a few surprises with the snowfall totals but overall our snowfall forecast matched up pretty well. The main surprise was the near instantaneous switch to snowfall over the Northern part of the Palmer Divide (think Parker, Lone Tree, Highlands Ranch) and higher snowfall totals than forecast in those areas. Areas in and around Castle Rock and eastward towards the higher elevations of the Palmer Divide performed as forecast as well.

I don’t like to do this too often mainly because we believe on forecasting impacts more than actual snowfall totals (who cares whether you get 12 inches or 15 inches if driving is miserable, roads are bad and people are getting stuck), but every once and awhile i find it useful for evaluation.

Our Forecast Vs. Recorded Snowfall

Douglas County (Castle Rock, Franktown, Larkspur, Parker, Highlands Ranch)

Parker: 1-3 inches total – Bust high *5 inches recorded*
Highlands Ranch: 1-3 inches total – Bust high *7 inches recorded*
Castle Rock: 4-8 inches total – Forecast verified *5.4 inches recorded*
Larkspur: 5-10 inches total – Forecast verified *7 inches recorded*
Franktown: 6-12 inches total – Forecast very close *12.5 inches recorded*

Elbert County (Elizabeth, – Forecast very close *12.5 inches recorded* Elbert, Limon, Kiowa)

The higher terrain and the fact that the storm is set to move Eastward rather quickly once it gets organized puts the bulls-eye right along eastern Douglas and most of Elbert County. For that reason, we expect higher snowfall totals over this region.


Elizabeth: 4-8 inches total – Forecast verified *6 inches recorded*
Elbert: 5-10 inches total  – Forecast very close *10.5 inches recorded*
Kiowa: 5-10 inches total – No Reports
Limon: 5-10 inches total – No reports, about 3-5 inches based on nearby reports

Interpolated snowfall analysis map. This map shades in areas of snowfall based on NWS reports


No doubt about it, our forecast placed a bullseye right on the Palmer Divide and it does look like that panned out quite nicely. Hopefully everyone made it in safely and was ready for this storm and of course the moisture is invaluable at this point from this storm.

Rest of This Week — More Snow or Spring Arrives?

As you can tell from the forecast graphic above, this storm really was our best shot at moisture for some time. Luckily it delivered for us, sadly not everyone was so lucky. Expect temperatures to warm with each day and expect the end of the week to feature above average temperatures and gusty winds.

Keep in mind, a string of warm and windy days like we’ve seen can very quickly dry the conditions out again unless we see more storms like this regularly. We see a few small chances for bits of precipitation in the next 7-10 days, none of those storms look impressive as of now but there’s always a chance that could change. We’ll keep an eye out and be sure to pass on any updates!

Mar 18

Update on Tonight’s Storm System – March 18, 2018

Palmer Divide Weather Alerts | Spring Storm | Snow | Castle Rock Weather | Castle Rock CO Weather

Current weather alerts for Colorado as of 9AM March 18, 2018

There has been a ton of uncertainty with this storm system and there still remains quite a bit, but the good news things are coming a bit more into focus. Along the front range, the main area of concern with this storm is right in our neck of the woods along the Palmer Divide. The National Weather Service has issued weather advisories along the Palmer Divide, here are the details:

Castle Rock-Limon-
Including the cities of Castle Rock, Elbert, Fondis, Kiowa,
Larkspur, Agate, Hugo, Limon, and Matheson
356 AM MDT Sun Mar 18 2018


* WHAT...Snow and blowing snow expected. Total snow accumulations
  of 3 to 6 inches are expected.

* WHERE...Castle Rock and Limon.

* WHEN...From 7 PM this evening to 6 AM MDT Monday.

* ADDITIONAL DETAILS...Plan on slippery road conditions. In
  addition, areas of poor visibility are likely. Winds gusting
  as high as 50 mph will cause areas of blowing and drifting


A Winter Weather Advisory for snow and blowing snow means periods
of snow and blowing snow will cause primarily travel
difficulties. Be prepared for snow covered roads and limited
visibilities, and use caution while driving. The latest road
conditions for the state you are calling from can be obtained by
calling 5 1 1.

More Than 1 Forecast For This Storm

How much snow you get out of this storm will largely depend on where you live, your elevation and how quickly the rain changes over to snow tonight. Areas around Denver and to the North will see little snow accumulation and may see little precipitation due to downsloping off the Cheyenne Ridge. We’ve talked about this downsloping in articles here on MountainWave WX before…

Strong Northerly winds accompanying this storm will mean downslope (dry air) for areas around and North of Denver… but means stronger upslope (better moisture) around the Palmer Divide Region.

Douglas County (Castle Rock, Franktown, Larkspur, Parker, Highlands Ranch)

Due to the warmth of this storm, elevation will make all of the difference here. Areas like Parker and Highlands Ranch (areas generally below 6,000 feet) will get significantly less snow accumulation… but not to say they won’t see moisture. Most of their precipitation will fall as rain however.


Parker: 1-3 inches total
Highlands Ranch: 1-3 inches total
Castle Rock: 4-8 inches total
Larkspur: 5-10 inches total
Franktown: 6-12 inches total

Elbert County (Elizabeth, Elbert, Limon, Kiowa)

The higher terrain and the fact that the storm is set to move Eastward rather quickly once it gets organized puts the bulls-eye right along eastern Douglas and most of Elbert County. For that reason, we expect higher snowfall totals over this region.


Elizabeth: 4-8 inches total
Elbert: 5-10 inches total
Kiowa: 5-10 inches total
Limon: 5-10 inches total



This is the really important part, because I imagine a lot of folks will be out and about this afternoon and evening.

Spring Storm | Castle Rock Weather | Snow

5PM snapshot of conditions along the front range. Most precipitation is still falling as rainfall but the main energy of the storm is moving in.

After about 3pm most models show showers and even a few thunderstorms moving in.

Spring Storm | Castle Rock Weather | Snow

Transition over to snow begins around 6-7PM.

One thing to pay close attention to is when the rain to snow switch over begins. Due to the convective nature of this storm (lots of instability and lift in the atmopshere) snowfall could be quite heavy at times.

Spring Storm | Castle Rock Weather | Snow

Around 8 to 9PM models show all snow in Douglas and Elbert county

By 8 or 9pm we show a transition all to snow, keep in mind this will be moderate to heavy snowfall so road conditions will deteriorate quickly.


  • Main impacts will be moderate to heavy falling snow


  • High winds will be possible, especially East of the I-25 corridor


  • Roads will become icy and snow packed very quickly under the heavier snowfall bands


  • Travel conditions will be the toughest across the Palmer Divide



  • Good idea to be home and off the roads by 6 or 7
  • Strong winds and heavy snowfall could create blizzard conditions, especially over the Palmer Divide
  • Monday morning commute could be impacted, especially South of Denver

We’re getting a good grasp on this storm, but like most spring storms this time of year; this one could still throw some curveballs our way. Wouldn’t  be surprised to see higher snowfall amounts become likely as we move through the afternoon, but then again I wouldn’t be surprised to see the storm completely fall apart either.

My advice right now is treat this storm like it means business, be off the roads by the evening and make sure you’ve got everything ready. This storm will be here and gone before you know it so this is not a “go to the grocery store and grab all the food” type of storm. It will be out of here before you even wake up Monday morning.

If this storm looks like it’s strengthening or falling apart with this afternoon’s data I’ll be sure to let you know!


Mar 15

Strong Storm System to Bring Heavy Snow… For Some

The first in a series of storm systems will begin to move through on Thursday and the National Weather Service has issued some weather alerts in advance of the storm.

National Weather Service Weather Alerts as of 11AM on Thursday March 15, 2018

You’ll notice the Winter Weather Alerts are confined mainly to the mountains and foothills, while wind alerts and fire alerts to the plains. Another interesting thing to look for is the lack of fire weather warnings for the Northeaster part of the state. This is mainly because northeastern sections of the state stand the best chance of seeing precipitation, while the odds don’t look too good for areas South and East of Denver.

Storm Analysis — Why We’re Not Excited About This One

Sadly this is the type of storm that will bring more wind to the front range of Colorado… the National Weather Service put together this handy graphic this morning of what’s going on.

This is excellent in one regard; it is exactly what we look for in a big storm, spring snow storm. There’s a ton of moisture, lots of lift due to upsloping and a strong low pressure system. The only problem is; it’s much further North than what we’d like to see.

GIF image, click to see the image animated. HRRR composite reflectivity model

Models have been pretty consistent about bringing moisture to the front range with the main bullseye over the Northeaster corner of the state.

What To Expect Along the Palmer Divide


I do thing we will see a bit of rain and even snow out of this system. The question is how much? While the low is pulling a ton of moisture in the return is on the Northeastern and Northern sides so those areas tend to see the most out of storms like this.

Expect: chance of thunderstorms, rain into the evening hours… possibility of snow later tonight. Doesn’t look like any major accumulation at this point but any shift in the location of these spring storms can make a huge difference!


Strong winds will accompany the back side of the storm system. Expect winds along the Palmer Divide to be gusty and even strong late Thursday and into early Friday. High Wind Watches are up for the foothill locations of the Palmer Divide.

Travel Impacts?

The main travel impacts will be the high winds, but we can’t rule out a convective snow shower putting down a quick shot of snow and making driving tricky. Odds are low for snow related impacts along the Palmer Divide and chances increase the further North and East of the area you go.


I suspect this storm like many storms when we get into spring may have a curveball or two to throw our way. Any shift in that track will mean more wind and less moisture or less wind and more moisture. We’ll keep an eye on the models and data today and be sure to pass along any updates this evening.

Mar 10

Drought Expanding Across Colorado

Colorado Drought Status | March 2018 | Moderate Drought | Severe Drought

Current drought conditions for Colorado as of March 8, 2018

The latest release by the U.S. Drought Monitor kept most of Colorado in some sort of drought status, the biggest change was that areas of moderate and severe drought began to creep North towards the central and Northern part of the state. The latest high plains update mentions deterioration  of conditions in areas like Texas, Oklahoma and Kansas along with Colorado.

Southern parts of the Plains (above central Texas) experienced another week with little or no precipitation, prompting large-scale deterioration across the Texas and Oklahoma Panhandles, northeastern New Mexico, and central and western Kansas. This results in a broad area of D3 (Extreme Drought) as noted in the South region write-up, with D1 (Moderate Drought) and D2 (Severe Drought)areas also expanding northward through parts of central Kansas.and east-central Colorado

How Did We Get Here?

To put it simply, fall and most of winter were absolutely brutal for precipitation around Eastern Colorado. Many areas saw between 0%-20% of average precipitation for several months  in the fall and winter… November and December were particularly brutal.

November 2017 Precipitation | Percent of Average | Colorado Drought | Spring 2018

November % of average precipitation. Most of Eastern Colorado was below 30% of normal.

December 2017 Precipitation | Percent of Average | Colorado Drought | Spring 2018

December % of average precipitation. Most of Eastern Colorado was below 20% of normal with some areas reaching below 5% of normal

It’s not just the precipitation that’s been giving us problems this year. Fall and early winter were extremely warm and that combined with the dryness experienced is why we are in our drought conditions today. Here’s a look at the daily mean temperature anomaly for November and December; these maps tell us how much above or below average daily mean temperatures for the month finished:

November 2017 was absolutely scorching for nearly all of Colorado. Below average snow and well above average temperatures are why our mountain snowpack never really got going this year.

December, while slightly closer to average was still warm

Heck, we’ll throw January 2018 in just to make the  point of how warm it’s been this year:

January 2018 was another above average temperatures month, surprisingly snowfall was close to average for many locations along the Palmer Divide.

Any Relief in Site?

The Climate Prediction Center’s outlook for spring was released recently and paints a pretty abysmal picture for our drought conditions at least through the end of May.

Climate Prediction Center | Drought Outlook | Spring 2018 Drought

CPC says drought conditions likely to persist for Colorado at least through the end of May.

That’s not to say we will see no rain and  snow at all over this period, it just means that if you take monthly precipitation we get from March through May it is highly likely we will end up below or well below average. This graphic is indicative of the pattern we are seeing set up over the next couple of weeks, areas like California and Nevada look to get decent amounts of moisture but a lot of that will wrap around to the North of Colorado.

Colorado Drought Status | March 2018 | Moderate Drought | Severe Drought

Severe drought conditions haven’t quite made it to the Palmer Divide yet, but it may just be a matter of time. Most of the area is currently under Moderate Drought classification

Models do show a couple chances at storms later into March (think after March 15) but given the overall weather pattern we are a bit skeptical about their ability to organize into anything substantial. We will keep a close eye on these storms in case any of them start to show promise.

In the meantime, enjoy the warmer weather and be careful with those fires and sparks!


Feb 18

Tricky Forecast for Next Storm

Another storm system and a couple of cold fronts will move into the area beginning late Sunday night and into Monday morning, the big story on Monday will be the temperature shock and the chance for freezing fog and maybe even a bit of freezing rain!

Monday Morning — Ice Will be a Concern

Ice Accumulation | Castle Rock Ice | Palmer Divide Weather | Nam3k Ice Accumulation Colorado

Some models are picking up ice accumulations in a few areas, this will have to be watched closely for Monday morning.

Models are picking up on the potential for ice accumulation for some areas of the front range. In the NAM3K model to the left, don’t focus on the exact areas so much. Focus more on the fact that ice accumulation  is possible in some areas.

As a cold front sweeps across the area Sunday night, a layer of shallow moisture and much colder temperatures will condense to form fog. Since temperatures will drop below freezing, fog and any precipitation could possibly freeze to create ice.

This is something we will need to watch closely but expect the potential for travel impacts Monday morning for areas that see ice.

Monday Evening — Shot of Snow and Travel Impacts Possible

Nam3k shows banded snowfall pushing onto the plains sometime after 3pm. We will have to watch this closely to see if it will impact Monday evening commute!

As we continue through the day Monday, a reinforcing shot of cold air will push across the mountains and onto the plains. Notice the bands of snowfall predicted by the Nam3K model on the right, this is a snapshot of what this model thinks things will look like right around 5pm.

The issue here is snow looks to start sometime around the rush hour (maybe at the tail end, we’ll wait for more detials) and persist through the evening and into the nighttime hours. This could cause travel difficulties for any folks caught under these snow bands.

Remember, snow can fall with moderate to heavy intensity under snowfall bands and cause road conditions to quickly deteriorate!

Long story short; we will need to keep a close eye on model and forecast data during the day Monday to see how this evolves. For now, count on the possibility of a rough commute on Monday evening.

Storm Snowfall Totals and Impacts

Anytime you see models showing banded snowfall it introduces uncertainty to snowfall forecasts. The reason for this is that while models are great at showing a storm will have banded snowfall, they’re not great at showing exactly where they end up. Since snowfall can be intense under these bands areas under them tend to over perform on snow while areas just 5-10 miles away from them may see no snow at all. The best way to forecast snowfall in cases like these is to look at probabilities, or the most likely ranges for snowfall and tailor a forecast around those numbers.

If you look at a place like Castle Rock you see the highest probability is that snowfall will end up between 0 and 4 inches. We can use this combined with that the models are showing to make a forecast. Similarly we can look at snowfall probabilities for areas in Elbert County:

You can see similarities for places in Elbert County but notice how much higher the chances are at receiving 0 inches of snow area. This is something to consider because most locations in Elbert County are further away from upslope along the front range and the Northern bias the models are showing with this storm verifies these numbers a bit more as well.

So with that, here are the most likely total storm snowfall accumulation ranges with the data we have as of tonight:

Castle Rock: 0-3 inches
Highlands Ranch:
1-4 inches
1-4 inches (terrain helps upslope a bit here!)
1-4 inches

Elbert: 0-3 inches
0-3 inches
0-3 inches
**Don’t forget the higher chance of no accumulation for areas in Elbert County!


That’s a wrap for this forecast analysis! Monday is going to be an unsettled day with a chance of freezing precip in the morning and snow in the evening. Keep a close eye on the potential for travel impacts especially if snow bands set up along the Palmer Divide or Tech Center of Denver on Monday evening.

We will keep an eye on things Monday and pass along any updates as needed. Have a great Sunday evening!


Feb 14

Midweek Update – More Snow on the Way?

The big story along the front range of Colorado today has been the wind gusts. Most stations in the Castle Rock area reported between 40-50mph gusts with our place near Elbert reaching over 60mph. No surprises here as La Nina later winters and early springs are notoriously windy.

Castle Rock Co Weather | Weather Castle Rock CO | Castle Rock Weather | High Wind Gusts | Weather Summary

Castle Rock Weather Summary for February 14, 2018, notice the high winds from the Southwest!

The wind is the major story across most of the state but in the mountains the story will be snowfall combining with the wind to create hazardous travel conditions.

Closer to Home

Winds will decrease slightly tonight after sunset but expect gusty conditions to remain through the night into tomorrow morning with strong winds mainly out of the West.

A cold front will move through tomorrow afternoon and you’ll notice it due to a drop in temperature and a big shift in wind direction. Winds today have mainly been out of the Southwest and West, the frontal passage will shift winds to the North and drop temperatures.

Colorado Weather | Castle Rock Weather | Palmer Divide Weather

We are still tracking a slight chance of snow with this storm system but just like many we’ve seen this past year, the direction out of the Northwest means there is limited moisture available. You know what that means! Wind, colder temperatures and small amounts of snow.

Castle Rock Co Weather | Castle Rock Weather | Palmer Divide Weather | Snow chance

Nam3k Snowfall Model through 11PM Thursday

The latest Nam3K shows scant snowfall across the plains for Thursday night into Friday morning. It is worth keeping an eye on the Palmer Divide region especially East of Castle Rock as many models have a “bullseye” over that area, but keep in mind a bullseye in this case means an inch of snow where most other areas get nothing.

The timing with models varies with the snowfall but suffice to say, be prepared for the POTENTIAL of travel impacts late Thursday night into Friday morning. With the warmer mid levels of the atmosphere we can’t count out the possibility of freezing rain or fog creating some ice on the roads for Friday morning.

Stay tuned here, we’ll keep an eye on this storm and be sure to pass  any updates along. This storm looks pretty minor overall, but as you know things can change in an instant!

Curious to why we get freezing rain and fog? I posted this nifty article explaining why!