Major Weather Pattern Shift Arrives This Week – 06/24/2019

No doubt, June and Spring in general was colder and wetter than average for a lot of places in and around Colorado. In fact, several mountain locations saw significant snowfall this past week while the front range was buried in moisture, low cloudiness and severe weather.

The good news (for summer weather and warm temperature lovers) is we are spying a rather large weather pattern shift starting this week. For the past several months low pressure systems have been riding the jet stream across the mountain west into Colorado, this has made for very unsettled weather so far.

The change is becoming very apparent in a lot of long and medium range models:

GFS 500mb upper air pattern for Wednesday June 26, 2019 around Noon

As you can see from the GFS snapshot above, high pressure is beginning to establish to the Southeast of Colorado. This is something we tend to see in typical summertime patterns in Colorado. As such, we’d expect our weather to shift away from cold and unsettled, to hot and summer-like.

GFS 500mb upper air on Friday June 28, 2019

As we move into the weekend we see the ridge intensify and shift the jet stream and thus the storm track away from Colorado. Notice the trough moving into the Northwest? That feature will struggle to make it into Colorado so while we may see a slight chance of storms from it over the weekend (very small, think 10% or less chance)

Here’s  peak at the GFS forecast temperatures on Friday…

Notice that hot air making its way up into the middle part of the country… right about where the high pressure ridge establishes. Now keep in mind, this model shows at noon on Friday so these aren’t the “true” high temperatures… probably need to add a few degrees to the ones in Colorado at least.

For those of us closer to home along the Palmer Divide, the Euro Ensembles show a pretty toasty week and weekend across our area as well. The official station for our area is Centennial Airport, so if you are higher elevation than there (most of us are) maybe subtract a degree or two.

True Long Term Shift or A slight Reprieve Before Back to Cold and Unsettled?

Stay tuned for another post, now that summer is finally here I’ll be crunching the data and looking at some models to see if this is just a short term pattern swing or if summer is truly here to stay.

For now, enjoy the warm temperatures and generally dry conditions for the next 5-7 days!

 

Friday Kicks Off Active Weather Weekend – Quick Update – 06/20/2019

A powerful storm system and associated cold front is slated to begin affecting Colorado starting as early as Friday. If you’ve been following our Facebook page, it should be no surprise to you that Friday will be active as we’ve been discussing it for a couple of days now…

Severe Weather Threat

SPC Day 2 (Friday) Severe Weather Outlook

The graphic above illustrates the Severe Weather Threat is defined tonight by the SPC for Friday June 21, 2019. Keep in mind, the Day 1 outlook will update a few times in the morning tomorrow so stay tuned as we anticipate a shift in the coverage for some of these severe areas.

Here’s the need to know details if you have plans tomorrow:

Threats

  • Large hail in excess of 1 inch in diameter
  • Heavy rain and localized flooding will be possible
  • Strong winds ahead of and under collapsing storms could cause damage
  • Large amounts of cloud to ground lightning… lightning can strike 15-20 miles away from the storm so keep that in mind.

 

Timing

Per current modeling storms will begin building in the late morning hours. Expect thunderstorms to begin affecting areas in and around the Palmer Divide after 12PM with strong to severe storms forming a bit later in the afternoon.

Preparedness Actions

  • Large hail could cause damage to vehicles, buildings and plants. Take necessary precautions.
  • Flooding could cause localized travel issues
  • Lightning can be extremely dangerous, move inside as soon as you hear thunder

 

Continue to monitor weather alerts from local and reliable weather resources.

HRRR model has consistently shown the Palmer Divide as a bullseye area tomorrow. This model can’t predict exact locations of storms or their effects; so when you see this don’t assume the storms will show up exactly where they do on the model.

A Quick Note About Severe Weather Outlooks and Forecasts

There seems to be a lot of confusion about the SPC outlook graphics like the one posted above.

I’ll use tomorrow’s threat as an example and try to explain it a bit better. A slight risk for hail and wind with a probability of 15% means you could pick any point within that risk area and there is a 15% probability that anywhere in that radius could see large hail and damaging wind.

So if you live in Castle Rock, there is a 15% chance your area or any area within 25 miles of that point could see a severe storm with these effects. As you can see that’s not a particularly strong probability… but it’s not 0% either.

So the likelihood (85% chance) is that most of us won’t see severe weather tomorrow. So why do we make a big deal about it? Preparedness! Unfortunately we cannot predict exactly when or where these severe thunderstorms will form and hit… but we know the environment will be favorable for a few storms to grow severe tomorrow anywhere in the yellow shaded area. That’s why we preach being prepared. If you find yourself in the path of the storm, it could cause damage and injury if you are not prepared.

I’ll probably be making a video to discuss this in the near future so stay tuned for that.

Another Quick Note: Snow in Summertime!

Many areas above 9,500 to 10,000 feet in elevation will see decent snow accumulation over the next 48 hours. Keep this in mind if you’re planning on camping or driving up in that area. It will be cold and wet and travel over some mountain passes may be slightly impacted.

I’ll have another post up late Friday talking about the weekend, the active pattern will continue followed by a big shift next week. Phew… lots to cover, stay tuned!

 

Severe Weather Possible Today – 5/26/2019

Palmer Divide Specific Severe Weather Discussion

For the Palmer Divide region we don’t expect widespread severe weather this afternoon but any thunderstorms that develop will have the potential to become strong or severe. A slight risk exists for the Palmer Divide East of Interstate 25 with the primary threat being large damaging hail and strong winds. There is also a small potential for tornadoes with some of these severe storms but the main risk for those is further Southeast of our area.

Remember, a slight risk means severe storms will be widely scattered, so most folks won’t see an impact but if you find yourself under a storm… keep an eye as it could quickly grow strong or severe.

Timing

  • Storms are expected to fire around 12-2PM
  • Severe weather may be possible after 1PM

Preparedness Actions

  • As hail and wind are the primary threats so take actions to protect property
    • Move things that you don’t want hail damaged into a building or under a structure
    • Be sure to secure any lightweight objects that could blow around in high winds
  • Keep a close eye on local weather sources for weather watches and warnings and have access to that information easily in the afternoon

Please Note: NWS has requested that Storm Spotter Activation may be required after 1PM today.

If you are a NOAA/NWS Certified SkyWarn Weather Spotter in Douglas or Elbert County, please be prepared to report severe weather with intensity, description and location this afternoon.

Southeastern Colorado Specific Severe Weather Discussion

The main threat for severe weather exists over extreme Southeastern Colorado today. In these locations a significant hail and wind threat exists along with a substantial threat for tornadoes. If you live in or around these areas please take proper precautions and make preparations this morning. Don’t wait until storms fire this afternoon, things will begin to move very quickly!

Of most concerns are the areas outlined in the hatch above. This product is for Significant Tornado risk areas. If you live in areas from roughly east of Eads, south into Lamar and just East of Springfield you need to be especially aware this afternoon.

Summary – My Thoughts

We will have to keep a close eye on this setup. Models don’t show a whole lot going on along the Palmer Divide and I-25 corridor today, but given the atmosphere is relatively primed today for severe weather in the area we still need to take that into consideration.

So today’s message is that most of us won’t see severe weather (it won’t be particularly widespread along the Palmer Divide) but there is a decent change some of us will. Primary things to watch out for will be hail and wind but give our terrain around here, you know that tornadoes will be a slight possibility with any severe storms.

I’ll be away from the computer this afternoon but will try to pass along any updates as needed.

Stay safe out there and keep your eyes to the sky!

 

 

Memorial Day Weekend Weather Outlook – 2019

The long 3 day weekend is upon us and I have some great news… it’s going to be a nice one in the weather department. We will see a return of spring-like weather with temperatures generally in the 60’s and 70’s during the day across the Palmer Divide (depending on your elevation.)

Saturday and Sunday will feature blue sky days with little to no chance for storms and rain, a nice change and a great warm up and dry out from what we’ve had!

By Monday things begin to change a little bit, but not until later in the day. The first part of memorial day will start out mostly sunny with clouds beginning to build in the afternoon. Models show a cold front moving in later in the day, but not a ton of agreement on exactly when.

Suffice to say, expect scattered storms on Monday afternoon with windy conditions likely picking up by the evening hours. The good news is as of right now the storm chance looks relatively small so most areas won’t see an issue, but definitely keep an eye out if you have outdoor plans in the afternoon and evening!

Widely scattered storms will be possible Monday afternoon.

I hope everyone has a happy and safe holiday weekend!

Let us never forget the men and women who died while serving to protect our freedoms and this great country. Happy Memorial Day.

Powerful Spring Storm May Throw Curve-balls! – Here’s the Latest – 5/20/2019

This storm is going to surprise a lot of folks… a powerful spring storm system is moving through Colorado and the central and southern plains. Colorado will see ample amounts of moisture and for some areas that may mean decent snow accumulation, while the SE corner will see heavy rain and potentially severe storms.

 

^^ My video update at 2PM on May 20, 2019 ^^

Weather Watches/Warnings/Advisories

Here’s the latest winter weather highlights as of 3PM on May 20, 2019

Winter Weather Advisory – Palmer Divide Region

URGENT - WINTER WEATHER MESSAGE
National Weather Service Denver CO
1221 PM MDT Mon May 20 2019

...STRONG LATE SEASON SPRING STORM TO AFFECT COLORADO...

.A strong storm system will move into Colorado today and continue
to affect the area through Tuesday night. This system will bring
heavy, wet snow to elevations above 6000 feet, impacting travel
with snow covered and slushy roads.

COZ041-210400-
/O.EXB.KBOU.WW.Y.0025.190521T0000Z-190521T1800Z/
Castle Rock-
Including the cities of Castle Rock, Elbert, Fondis, Kiowa,
and Larkspur
1221 PM MDT Mon May 20 2019

...WINTER WEATHER ADVISORY IN EFFECT FROM 6 PM THIS EVENING TO
NOON MDT TUESDAY...

* WHAT...Wet snow expected. Total snow accumulations of 5 to 10
  inches expected, with the heaviest amounts above 7000 feet.

* WHERE...Castle Rock.

* WHEN...From 6 PM this evening to noon MDT Tuesday.

* ADDITIONAL DETAILS...Travel could be very difficult. The
  hazardous conditions could impact the morning or evening
  commute.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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.

Winter Storm Warning

COZ031-033-034-210400-
/O.CON.KBOU.WS.W.0012.000000T0000Z-190522T0600Z/
Rabbit Ears Pass-
Rocky Mountain National Park and the Medicine Bow Range-
The Mountains of Summit County, the Mosquito Range, and the
Indian Peaks-
Including the cities of East Slopes Park and Northern Gore
Ranges, Gore Pass, Rabbit Ears Pass, Cameron Pass,
Laramie and Medicine Bow Mountains, Rabbit Ears Range,
Rocky Mountain National Park, Willow Creek Pass, Berthoud Pass,
Breckenridge, East Slopes Mosquito Range,
East Slopes Southern Gore Range, Eisenhower Tunnel, Indian Peaks,
Kenosha Mountains, Mount Evans, Williams Fork Mountains,
and Winter Park
1221 PM MDT Mon May 20 2019

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL MIDNIGHT MDT
TUESDAY NIGHT...

* WHAT...Heavy snow expected. Total snow accumulations of 8 to
  18 inches expected. Winds gusting as high as 35 mph.

* WHERE...Rabbit Ears Pass, Rocky Mountain National Park and the
  Medicine Bow Range and The Mountains of Summit County, the
  Mosquito Range, and the Indian Peaks.

* WHEN...From noon Monday to midnight MDT Tuesday night.

* ADDITIONAL DETAILS...Travel will be hazardous with snow
  covered roads. Secondary roads may see more difficult travel
  conditions due to more significant accumulation of heavy, wet
  snow.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Warning for snow means severe winter weather
conditions will make travel very hazardous or impossible. If you
must travel, keep an extra flashlight, food and water in your
vehicle in case of an emergency.

Updated Forecast

If you saw my video this afternoon (it’s posted above) you know that I’m not 100% sold on what the models are saying. Since this storm is a bit of a different animal I’ve kept snowfall totals somewhere in between ultra conservative and what the models are saying. As I mentioned; this is a fluid forecast and it’s very likely these numbers will change in the next few hours. Stay tuned for updates!

Expected Snowfall (through Thursday 6PM)

*These are our forecast numbers and may not always match the NWS official forecast numbers*
  • Castle Rock and surrounding areas
    • 3-6 inches
  • Parker, Lone Tree, Highlands Ranch areas
    • 2-5 inches
  • Elbert, Elizabeth, Kiowa
    • 4-8 inches
  • Larkspur, Monument,Black Forest, Palmer Lake,
    • 3-6 or 4-8 inches — Depends largely on elevation!
  • Woodland Park, W. Colorado Springs Foothills
    • 5-10 inches (especially higher elevation foothills areas West of Colorado Springs)

Timing

  • Monday PM: snow showers had begun in most areas along the Palmer Divide. We expect accumulation during the day to be light
  • Monday Night: Heavier snow showers will establish overnight and into early Tuesday morning
  • Tuesday AM: Snow showers will continue through the rush hour, most accumulation will be confined to areas above 6,500-7,000 feet
  • Tuesday PM: will be watching for continued wet and unsettled weather throughout the day. Most areas will see rain rather than snow Tuesday afternoon.

Potential Impacts

  • We expect minor to moderate travel impacts along the Palmer Divide; roads may become slick and slushy, especially in areas above 6,500 feet
  • Freezing temperatures will be possible; sensitive vegetation should be covered  Monday and possibly Tuesday night. We will keep an eye on this!

 

As I said in my video and discussion above, the models are jumping all over snow totals but I’m not sold just yet. Models often struggle with snow accumulation this time of year due to temperatures and sun angle (melting) which is why I generally lean conservative on snowfall this time of year.

That being said, we can’t ignore that this storm is highly unusually in its setup and mechanics for this time of year. With that, the forecast is still very much fluid and will change a few more times over the next 24 hours.  Stay tuned and I’ll be sure to pass along updates!

 

The Week Ahead – Remaining Cool and Unsettled – 5/19/2019

Another strong spring storm is moving into the area starting late in the day Sunday and will bring cool, wet and unsettled conditions to the front range over the next several days. Here’s the latest details and look at what the rest of the week holds!

Weather Watches/Warnings/Advisories

 

The mountains will be under again in the latest storm; many areas will see between 8-16 inches of snow with some higher peaks seeing upwards of 20 inches. Moderately strong winds are possible in the high country and that with the combination of falling snow could make travel dangerous.

Here’s some detailed information, if you have travel plans in the high country later Monday through Tuesday  you’ll want to pay special attention to the hazards and timing:

...WINTER STORM WATCH REMAINS IN EFFECT FROM MONDAY AFTERNOON
THROUGH TUESDAY AFTERNOON...

* WHAT...Heavy snow possible. Total snow accumulations of 8 to
  16 inches possible with up to 20 inches in some mountain
  areas. Winds could gust as high as 35 mph.

* WHERE...Rabbit Ears Pass, Rocky Mountain National Park and the
  Medicine Bow Range, The Mountains of Summit County, the
  Mosquito Range, and the Indian Peaks and The Northern Front
  Range Foothills.

* WHEN...From Monday afternoon through Tuesday afternoon.

* ADDITIONAL DETAILS...Travel will be hazardous with snow covered
  and slushy roads. Secondary roads may see more difficult travel
  conditions due to more significant accumulations of heavy, wet
  snow.

Closer to Home… Our Palmer Divide Forecast

Snow is back in the forecast… this should come as no surprise folks! Colorado is no stranger to snow all the way through late May… and if you’ve been paying attention we’ve been entrenched in a particularly cool and unsettled pattern for quite awhile now.

Expected Snowfall (through Thursday 6PM)

*These are our forecast numbers and may not always match the NWS official forecast numbers*
  • Castle Rock and surrounding areas
    • 0-2 inches
  • Parker, Lone Tree, Highlands Ranch areas
    • 0-2 inches
  • Elbert, Elizabeth, Kiowa
    • 0-3 inches
  • Larkspur, Monument,Black Forest, Palmer Lake,
    • 0-3 inches — Black Forest totals may be lesser in lower elevations
  • Woodland Park, W. Colorado Springs Foothills
    • 0-3 inches (especially higher elevation foothills areas West of Colorado Springs)

While areas along the Palmer Divide may see snow, not much is expected to accumulate on more than grassy or dirt surfaces. Ground temperatures are warm and temperatures will be marginal at best for snowfall sticking. Most areas will see very little to no accumulation.

If models verify on this; expect bands of heavy wet snow across the Palmer Divide. Keep in mind though, due to warm temperatures and ground;  snow accumulations won’t be impressive…

Timing

  • Sunday PM- showers and thunderstorms will be possible. Precipitation will mainly be rain
  • Monday late morning/early afternoon – spotty showers in the earlier morning hours will give way to stronger showers and thunderstorms by late morning to early afternoon. Precipitation will mainly be rain at this point.
  • Monday afternoon/evening – heavier showers and thunderstorms likely, rain may transition to snow along the Palmer Divide sometime between 5-9PM depending on temperatures.
  • Monday overnight – Snow showers will continue overnight, some snow may be heavy at times but only minor accumulation expected
  • Tuesday Morning – Snow and rain showers continue depending on your elevation. Should see precipitation taper off by early Tuesday afternoon
  • Tuesday afternoon/evening – continued unsettled conditions but precipitation should be lighter. Spotty rain and snow showers could be possible into Tuesday afternoon and evening

Potential Impacts

  • We expect minor travel impacts along the Palmer Divide; roads will remain mostly wet with spotty slush
  • Freezing temperatures will be possible; sensitive vegetation should be covered Sunday, Monday and possibly Tuesday night. We will keep an eye on this!

 

Synopsis

Fascinating storm system we have shaping up here. I posted a video below of the Nam3K model we’ve been looking at throughout this post with precipitation type and 500mb contours turned on. You can see the low pressure trough establish and swing through California, Arizona and into Utah.

The trough weakens a bit as it crosses the mountains (as they often do thanks to the terrain) but pay special attention what happens as it regenerates on the plains of Colorado. If this looks familiar it should! We’ve seen this a couple of times this year… remember the blizzard we had in March and the weaker snow storm we had in April?

People love to call this a “bomb cyclone” these days and while I’m not in love with that term (hype, hype, hype!) I’ll use it since it’s familiar to most people.

This rapid intensification will mean a few things weather-wise depending on where you live.

  • Colorado Mountains
    • Heavy snow as the low transitions across the higher terrain. Expect mountain areas to pick up ample amounts of snow with strong winds possible Monday Afternoon – Tuesday Afternoon
  • Colorado Front Range
    • Temperatures will be too warm to see a “blizzard” type event out of this. That being said, there’s a lot of energy and a ton of moisture. Expect moderate to heavy rain and some snow accumulation in the higher terrain. Strong winds will also be possible in some areas.
  • Further East (ahead of the low on the plains)
    • Classic severe weather setup here. Energy and instability ahead of the low will means some areas in the central and southern plains will be primed for significant severe weather.
    • If you have friends or family in Oklahoma, Texas or Kansas… make sure they are following their local weather sources. Significant tornado threats exist with this storm in the plains.

Summary

I’ll have some more posts up here and there over the next few days. The weather pattern looks to remain active for at least the next couple of weeks.

I may have a livestream up regarding some of this late Sunday night so stay tuned for that if you stay up!

 

Snow and Cold Blast on the Way! – 05/08/2019

We look to have ourselves another powerful spring storm on the way to Colorado. As of this morning, many areas along the front range had already seen a healthy dose of rain and that doesn’t look to change through the day today. What will change is the rain will transition to snow by sometime this evening and once it does and the sun goes down, we should see snow begin to accumulate in higher elevation areas. (Thinking the best shot is areas over 5500 feet at this time.

Here’s the latest on this storm!

Weather Watches/Warnings/Advisories

Updated watches, warnings and advisories in Colorado as of 1PM on May 8, 2019

Winter Weather Advisory is in effect for the front range foothills and Western sections of Douglas County only. Locations include: 

Cameron Pass,
Laramie and Medicine Bow Mountains, Rabbit Ears Range,
Rocky Mountain National Park, Willow Creek Pass, Estes Park,
Glendevey, Nederland, Red Feather Lakes, Bailey, Central City,
Evergreen, Georgetown, Idaho Springs, and Westcreek

More details with this advisory:

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 6 PM MDT
THURSDAY...

* WHAT...Snow expected. Total snow accumulations of 6 to 12
  inches expected.

* WHERE...Southern Front Range Foothills.

* WHEN...From noon Wednesday to 6 PM MDT Thursday.

* ADDITIONAL DETAILS...Travel could be hazardous with slushy and
  snow covered roads at times.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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.

A Winter Storm Warning is in effect for mountain areas and will feature between 8-16 inches of snow. Combined with high winds especially over the passes, we expect mountain travel to become very difficult if not hazardous by later Wednesday.

Here’s the details on that warning:

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 6 PM MDT
THURSDAY...

* WHAT...Heavy snow expected. Total snow accumulations of 8 to
  16 inches expected.

* WHERE...The Mountains of Summit County, the Mosquito Range,
  and the Indian Peaks.

* WHEN...From noon today to 6 PM MDT Thursday.

* ADDITIONAL DETAILS...Travel could be very difficult. The
  hazardous conditions could impact the morning or evening
  commute.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Warning for snow means severe winter weather
conditions will make travel very hazardous or impossible. If you
must travel, keep an extra flashlight, food and water in your
vehicle in case of an emergency.

Closer to Home… Our Palmer Divide Forecast

Expected Snowfall (through Thursday 8AM)

*These are our forecast numbers and may not always match the NWS official forecast numbers*
  • Castle Rock and surrounding areas
    • 2-5 inches
  • Parker, Lone Tree, Highlands Ranch areas
    • 2-5 inches
  • Elbert, Elizabeth, Kiowa
    • 3-6 inches (will be watching higher elevations!)
  • Larkspur, Monument,Black Forest, Palmer Lake,
    • 3-6 inches — Black Forest totals may be lesser in lower elevations
  • Woodland Park, W. Colorado Springs Foothills
    • 5-10 inches (especially higher elevation foothills areas West of Colorado Springs)

WPC snowfall at 25th percentile. I like to use this number more in the spring as it can help account for melting and compacting. Still relatively respectable snowfall amounts it’s indicating!

Timing

  • Precipitation has already started as rain this morning across the Palmer Divide
  • Models show rain turning to snow sometime between 5-8PM. Expecting little accumulation during daylight hours but as the sun goes down accumulation becomes more likely.
  • Highest chance for accumulating snowfall for the Palmer Divide looks to be the late evening hours Wednesday through early Thursday morning
  • There’s a lot of moisture with this storm, snow may be moderate to heavy at times in very specific spots

Potential Impacts

  • We don’t expect major travel impacts with this storm at this time
  • Roads under sustained heavier snow may become slushy, this is most likely at higher elevations. Some minor to moderate travel impacts may be experienced.

Summary

This storm looks a bit more promising than our last “snow” storm. A combination of a  low pressure system spinning moisture into Colorado from the South and a strong low pressure system funneling cold air in from the North means this is a better setup for snow overall.

But just keep in mind, with this storm as with many spring setups; the exact positioning of where these features set up as well as when they make it in to the state (timing) makes all the difference.

We will keep an eye on things and pass along any updates!

Quick note: more snow is possible Thursday night into Friday morning. We’ll have updates on that probably later Wednesday night or Thursday morning… let’s take this one storm at a time!

Spring Weather Roller Coaster Ramping Up! – 05/06/2019

Monday – Severe Weather Threat

The marginal risk for severe weather is mainly East of the I-25 corridor with main threat being hail and wind. Can’t rule out a widely scattered brief tornado though!

A marginal risk for severe weather exists for a corridor extending from East of Denver and the Douglas County Line out into Elbert County, Eastern El Paso County and towards Eastern Colorado. Thunderstorms are expected to form after 2PM today and anything forming in or around these areas could be strong or become severe.

Primary Threats

  • Large hail
  • Strong winds
  • A slight tornado risk exists (see graphic below)

 

Just because you’re not in the exact threat area is not reason to let your guard down. Anywhere along the Palmer Divide could see a spin up or two where storms form on Monday. Keep your eyes up!

The tornado risk today is small (about 2% probability) and mainly covers the area in Southeastern Elbert County and Eastern El Paso count extending towards Southeastern Colorado. Shear, instability and lift enhanced by terrain means tornado formation will be possible in this area. We are not expecting widespread tornadoes along the Palmer Divide or in Colorado today though.

Tuesday – Thursday – Cold with Rain and Snow Chances

A complex and rather slow moving storm system will begin to affect the region on Tuesday and looks to last through Thursday. As with a most of our storm systems this time of year; the whole gambit is possible. Everything from severe weather to moderate rain to accumulating snow is a potential outcome from this storm.

This storm system features a nice double whammy of cold air moving in from the North and moisture moving in from the South. As many of you know, where exactly these features set up will mean all the difference between rain vs. snow and how much moisture we see in general. The good news is, models have consistently favored the Palmer Divide region with a healthy dose of terrain induced upslope meaning we would see a healthy dose of moisture.

That being said, the big question still remains around the snow. Will we see any and how much (if any) will accumulate. Here’s a couple of model thougts:

WPC outlook like the last storm shows pretty low accumulation amounts overall. Generally in the 1-3 inch range for most areas along the Palmer Divide with slightly heavier amounts to the West in the higher elevations of the foothills.

The EURO is a bit more bullish on snow, considering it’s accuracy when it has slightly higher amounts it’s definitely something to take note of. We will be watching this model closely over the next 24-48 hours to see if there are any up or downtrends on snow accumulation.

The biggest story with this storm may not be the snow, but the temperatures!

Wednesday night through Thursday morning 6 HR Low temps

Thursday night through Friday morning 6 HR low temperatures

Keep in mind, the images above come from the Euro; it’s a low resolution model so doesn’t take into consideration small local microclimates and terrain. It is possible some areas could end up colder than shown above.

Summary

All in all, a very active weather week ahead… but as we all like to say- we need the moisture. Doing some of the data in April; it actually ended up drier than average along most areas of the Palmer Divide. We will need to continue getting periodic wet storms to keep things from getting too crispy! The good news is there is a pretty pronounced wet pattern for the next several weeks and possibly even extending well into summer.

We’ll keep an eye on the storms this afternoon and the bigger colder one later this week and be sure to pass along any updates!

 

Powerful Spring Storm Moving In – Latest Updates – 04/29/2019

There is no doubt the storm moving in this afternoon is a powerful one, there are two areas identified as higher impact areas that will see significant precipitation and even significant snowfall accumulations. The bad news is that models are coming into agreement (and as we suspected) that the Palmer Divide doesn’t look likely to be in one of those high impact areas.

Here’s the latest updates as of noon today:

Weather Watches/Warnings/Advisories

The only Palmer Divide areas in winter weather highlights today are extreme Western Douglas County and areas in the Western foothills West of I-25 and West of Colorado Springs.

The only winter weather highlights issued around the Palmer Divide region are shown above. Winter Storm Warning areas may see over a foot of snow, while Winter Weather Advisory areas will see a slushy/snow mix that may cause travel difficulties. With the data we are seeing and the latest NWS forecast discussion, we have no reason these warnings/advisories will be expanded to other areas along the Palmer Divide at this time. We will continue to watch that for changes though…

Expected Snowfall (through Tuesday 12PM)

*These are our forecast numbers and may not always match the NWS official forecast numbers*
  • Castle Rock and surrounding areas
    • 0-3 inches
  • Parker, Lone Tree, Highlands Ranch areas
    • 0-3 inches
  • Elbert, Elizabeth, Kiowa
    • 0-3 inches (will be watching higher elevation areas for slightly higher totals)
  • Larkspur, Monument,Black Forest, Palmer Lake,
    • 1-4 inches
  • Woodland Park, W. Colorado Springs Foothills
    • 5-10 inches (especially higher elevation foothills areas West of Colorado Springs)

Expected snow accumulation totals through Tuesday 12PM – have been decreased slightly across the board for areas outside the foothills. Foothills and mountain locations; no changes made to expected snowfall from yesterday.

Timing

  • Precipitation will likely as we move late into the afternoon and evening hours
  • Any snow that falls earlier Monday may not accumulate much
  • Highest chance for accumulating snowfall for the Palmer Divide looks to be the time-frame around 6PM Monday evening to Midnight.
  • Snow may be heavy at times under convective snowfall bands Monday night

Potential Impacts

  • Models have backed off for the potential for heavy snowfall bands, but they are still there.
  • Will be watching the Monday evening and Tuesday morning commute closely for potential travel impacts
  • Roads parked under convective snow or snowfall bands could see slushy and slick conditions

 

Summary

As with all these spring storms, they don’t look too impressive on paper but still are worth watching closely. The major wildcard here is the temperatures, a shift of a couple degrees colder can drastically change how much snow we expect to see. Any shift to warmer temperatures means less than expected snow.

Another thing that doesn’t impress me too much is the wind profiles with this storm, especially at the surface.

In a situation like this we see Southeasterly winds bringing moisture around the storm system and transporting it into Colorado. As the air moves up the Southern part of the Palmer Divide it create upslope conditions, but on the other side it can create downslope. This doesn’t help with efficient snowfall and in some cases it can actually dry out the atmosphere as the air rushes down the other side.

In a scenario like this I’d expect heavier snow along the foothills and mountains.  I’d especially watch the areas directly west of Colorado Springs, Denver and Boulder. If you’re travelling to the mountains or foothills tonight into Tuesday morning, that’s where you’ll see the highest travel impact.

We will keep watching for any changes, as you all know by know these spring storms can often throw a curve ball at the last minute!

 

Early Week Spring Storm Update – 04/28/2019

A bit of a lengthy post ahead as we’ve got a lot to cover.

An unsettled weather pattern will set up over Colorado starting on Sunday and continuing possibly through Wednesday. With it will come a chance for storms in Eastern Colorado and heavy snow for some mountain areas. Additionally, some areas along the front range could see signifianct accumulating snow (mainly foothills locations and areas Northwest of Denver) with some areas along the Palmer Divide seeing accumulating snow but lesser amounts with the data we are seeing.

Without further ado; here’s the details for the next couple of days. Keep in mind, this forecast is fluid so continue to expect changes and tweaks as we get more data in.

Sunday 4/28/2019 – Thunderstorms and Strong Cold Front

SPC severe thunderstorm risk for 4/28/2019

Sunday will start off relatively nice with breezy conditions under partly cloudy skies. With a storm system moving into the western and northwestern part of the state the atmosphere will destabilize and allow the potential for thunderstorms. While a general thunderstorm risk will exist closer to the front range, the Storm Prediction Center has eastern Colorado in a “Marginal Risk” area today for wind and hail threats from severe thunderstorms. Marginal means severe thunderstorms will be possible in those areas but storms will be very isolated, so no “widespread” severe thunderstorm risk exists in Colorado today.

Highs Sunday will generally be in the mid to low 70’s across the Palmer Divide. Be sure to keep an eye out for a stray thunderstorm in the afternoon hours.

By late Sunday night, a strong cold front moves in from the North and will begin to drop temperatures substantially into Monday morning.

By Monday morning, temperature should be in the upper 20’s to low 30’s across the Palmer Divide. Many areas will struggle to hit 40 degrees for a high on Monday.

Note: some models have this cold front pushing through sooner (8-10PM timeframe) so don’t be surprised if it gets here a bit early!

Monday – Tuesday Spring Storm Details

As we continue later into spring, storms with snow tend to get harder to nail down. There are a lot of things working against significant accumulating snowfall such as temperatures at different elevations and the higher angle of the sun. We find that for any strong storms with lots of snow to manifest, we have to see a lot of variables set up perfectly and the odds are often against everything setting up exactly.

SPC 72 hour likely snowfall forecast is pretty well in line with what we are thinking for snow accumulation. Again this product tends to be a bit higher with snowfall accumulation than we’d like but it’s well within our range.

Expected Snowfall (through Thuesday 12PM)

*These are our forecast numbers and may not always match the NWS official forecast numbers*
  • Castle Rock and surrounding areas
    • 1-3 inches
  • Parker, Lone Tree, Highlands Ranch areas
    • 1-4 inches
  • Elbert, Elizabeth, Kiowa
    • 1-4 inches (will be watching higher elevation areas for slightly higher totals)
  • Larkspur, Monument,Black Forest
    • 2-4 inches
  • Woodland Park, Palmer Lake, W. Colorado Springs Foothills
    • 5-10 inches (especially higher elevation foothills areas West of Colorado Springs)

Timing

  • Precipitation will be possible on and off Monday, mainly as rain throughout the day
  • Any snow that falls Monday may not accumulate much
  • Highest chance for accumulating snowfall for the Palmer Divide is evening and overnight hours from late Monday into Tuesday morning
  • Snow may be heavy at times along the Palmer Divide Monday night

Potential Impacts

  • Models are showing evidence for convective and banded snowfall… as you know this means some areas could see quick, intense bursts of snowfall in a short period of time
  • Will be watching the Monday evening and Tuesday morning commute closely for potential travel impacts
  • Roads parked under convective snow or snowfall bands could see slushy and slick conditions

 

Synopsis

A very tricky forecast for this storm as we know these spring storms have a lot more moving parts than earlier season storms do. The temperatures, moisture, upslope, etc… all need to play ball for us to see a significant snow accumulation event. In most cases they don’t set up because one or more of those variables doesn’t set up quite right.

With this storm we are seeing models struggle to agree on snowfall. This is because some have moisture falling during the day more (warmer temps less snow accum.) while others have the heaviest overnight Monday (colder temps more snow accum.)

The Nam3k is relatively excited about this storm mainly along the foothills. As you get into lower elevations of Douglas and Elbert counties you see a pretty marked drop-off on snow accumulation. Note that Denver looks to have higher accumulation than the central and eastern sections of the Palmer Divide with this particular model.

The Euro is even less excited about accumulating snowfall outside of the mountains and foothills. Keep in mind, this model does particularly well with snowfall forecasts so it is worth watching closely.

Euro ensembles don’t seem to excited either… this snapshot for Centennial Airport (KAPA) shows the mean of these models run is just a bit shy of 2 inches. Given all that I’ve seen this looks right in the ball park with what I’d expect at this point in time.

Summary

So while this doesn’t look like a major storm at this point for the Palmer Divide, we can’t ignore the signs of convective snow and banded snowfall. As we’ve discussed, where these set up is very difficult to predict and all we can see on models is that the potential is there.

If you find yourself under a convective burst of snow or a snow band, your location may very well exceed some of these forecasted totals… while areas just a few miles North or South may see much lower totals.

Chalk this up as a spring storm that has the potential to cause minor to moderate travel impacts and just be ready for it. I’m away from the computer the rest of today but will pass along updates as I can from my cell phone. If anything changes one way or another I’ll be sure to post updates!