Winter Storm Snowfall Totals and Recap

The latest storm to impact the front range of Colorado behaved pretty much as we predicted. We expected to end up in the 3-6 inch range for the Castle Rock area and most locations around town received between 3-4 inches of snow. The storm moved through with some intense bursts of snow early Friday morning, snow showers lingered into the afternoon and eventually the storm moved out on Friday afternoon.

Generally, we liked the forecast on this one. The NWS upgraded our Winter Weather Advisory to a Winter Storm Warning, predicting the heavy snow bands would drop 5-10 inches of snow for us and I briefly considered upping my own forecast. After a look outside at our accumulation as of the morning and a look at some model guidance and the speed and track of the storm, I decided against upping my own snowfall forecast.

Now, a quick look at officially reported snowfall totals.

Reported Snowfall Totals

Saturday will be chilly with a few additional bands of snow moving in, overall accumulation will be very light. Sunday and Monday, look for warming temperatures, sunny skies and lots of melting snow!

I’ll have an update early next week regarding our next storm system, slated to move through on Wednesday and a look at the unsettled weather pattern that may begin to affect us for the next couple of weeks. Stay tuned!

 

Winter Weather Advisory and Snow on The Way!

The Winter Storm we have been tracking all week has gone from looking monstrous last week, to less an impressive early this week to pretty decent by this morning. This time of the year, models really seem to struggle with storm setups and this one is no exception.

The National Weather Service has issued a Winter Weather Advisory for most of the front range of Colorado. This includes the cities of Castle Rock, Parker, Elizabeth, Highlands Ranch, etc… The advisory begins Thursday night at 6pm and lasts until Friday 6pm. This advisory mentions periods of heavier snowfall and cold temperatures making for tough travel conditions especially on Friday morning.

See Also: Current Weather Watches/Warnings/Advisories

What to Expect

This latest storm is beginning to move into the area this morning, the low pressure system is currently meandering through Denver and to the South. If you are in Castle Rock and look to the North, you’ll notice the clouds beginning to move in.

This afternoon expect precipitation to fall as rain at first but quickly chance over to snow at some point in the late evening to nighttime hours.

8PM radar forecast

8PM radar forecast

Depending on the timing of this, the rush on Thursday evening could be a bit tricky, should it slow down or stay as rain expect just we roads, but should things move a bit quicker you can probably expect some slushy roadways.

Friday morning’s commute looks to be the main impact. Snowfall is projected to continue overnight and into Friday morning. Snow should be ongoing through mid-day Friday and with cold temperatures building in and moderate snowfall rate the roads will most likely be icy and snow packed.

Storm Total Accumulation: 3-6 inches for Castle Rock **Some areas may see up to 8 inches in the immediate area with areas East of town most likely.

Impacts: Road conditions will deteriorate Thursday night. Travel on Friday morning will be tough and with snow expected through the day, road conditions could remain tricky through the afternoon.

Time frame: Expect to see rain by Thursday afternoon changing to snow in the late afternoon to evening hours. Snowfall will continue overnight through Friday morning and into Friday afternoon.

Synopsis

A low pressure system is dipping to the South over Colorado. Originally when we looked at this earlier in the week it was predicted it would move to the South further west, not allowing good up slope moisture to establish and meaning a light to no snow event for most across the front range. This morning’s model runs show the low in a more favorable position:

Predicted position of the Low as of this morning

Predicted position of the Low as of this morning

Model guidance has adjusted snowfall accordingly this morning and while this is still not the best position for a high snowfall event, the track of the low coupled with the storm system slowing a bit will mean we should see decent snowfall accumulation.

Models I’ve targeted in on are the GFS and NAM:

GFS 24 hour snowfall totals

GFS 24 hour snowfall totals

NAM 24 hour snowfall totals

NAM 24 hour snowfall totals

The biggest difference I see between the two is the NAM brings the snow in earlier and keeps it around a bit longer, thusly it is predicting slightly higher snowfall numbers. One of these two will be relatively correct, a quicker moving storm and later change to snow means the GFS looks more accurate. A quicker change to snow Thursday afternoon and a slowing of the storm would suggest the NAM would be closer. As a weather nerd, this will be interesting to watch.

Meanwhile, the SREF ensembles show this for snowfall totals:

SREF_03182106

The mean of all the models run showed right around 5-6 inches for Centennial Airport and similar for Monument. Since there is no model run specifically for Castle Rock and I have to take into account our higher altitude and more favorable terrain for up slope I usually take the average between the two. In this case, since they are almost spot on with each other this would make me lean towards the NAM and say we could see somewhere in the 5-7 inch range when it’s all said and done.

The other thing is when you see things not agree this close to the time the storm arrives it throws a bit of red flag up for uncertainty. I’m highly confident we will see accumulating snow in the Castle Rock area tonight and Friday. The big question is will we stay on track for 3-6 inches, do I need to bump the forecast up to 4-8 or does it fall apart at the last minute. Spring snowfall events along Colorado’s front range are notoriously tricky.

Should be interesting to watch, in the meantime stay tuned here at MountainWave Weather and I’ll pass along any changes to the forecast this afternoon.

Happy Saint Patrick’s Day, cheers!

 

Cooler Weather and Snow Return to Colorado Front Range

A strong cold front moved through the area on Monday and caused very strong winds and a noticeable temperature drop for many of us along the front range. This is the beginning of a short period of unsettled weather that will last throughout the week.

The Setup This Week

The upper level jet stream has oriented into an West/East fashion and will mainly stay between that and a Northwesterly orientation throughout the week.

300mbconus

This means different things for different areas of Colorado:

  • This is a favorable storm track for snowfall in the mountains, we saw the beginning of this last night as many mountain areas (mainly North of I-70) picked up a foot of snow or more. Mountain areas will continue to see on and off snow showers through the week.
  • The front range will see cooler temperatures but overall dry conditions. A setup like this does not allow the warm air we have been seeing to establish itself over the Eastern half of the state.

The proof is in the temperature modeling for the next few days:

Tuesday March 16 forecast temperatures by 11AM

Tuesday March 15 forecast temperatures by 2PM

Wednesday March 16 forecast temperatures by 2PM

Wednesday March 16 forecast temperatures by 2PM

Thursday March 17 forecast temperatures by 2PM

Thursday March 17 forecast temperatures by 2PM

Friday March 18 forecast temperatures by 2PM

Friday March 18 forecast temperatures by 2PM

Notice the cooler temperatures, generally 40’s and 50’s across the front range. While I wouldn’t consider these “cold” temperatures for this time of year, it is certainly cooler than what we have seen over the better part of the past month or two.

What About the Snow?

At this time there looks to be enough energy to squeeze out some moisture for some of us along the front range in the late Thursday into Friday time frame. Honestly, that this point the storm system does not look that impressive, the orientation of the jet stream (as I discussed above) and the positioning of the storm center (too far South) will not be conducive to a major snow storm.

I will continue to track the modeling for changes as sometimes these storms can fool us, but as of right now it looks like 0-3 inches is the most likely snow total amount for Castle Rock and areas South of Denver through Friday afternoon.

gfssnowfall_fri03182016c

The GFS shows about 1-1.5 inches of snow for us South of Denver and this is the highest any model is predicting. Most models have total accumulation under an inch, so we may see little to no snowfall accumulation overall.

 Cooler and Wetter Period Establishing or Short Lived?

300mbconus

I’ve put this image up again, the jet stream position as of Friday March 18. I talked earlier about the Northwest flow establishing over the state but another interesting feature to note is the ridge building once again off to our West. This to me signals that this cooler and slightly wetter period will be short lived, a ridge re-establishing to our West will allow that warm and dry air to filter back into Colorado by the end of the weekend.

To verify this I took a look at the projected temperatures next week and saw a lot of 60’s and 70’s again so this seems to be in line with my thinking.

Additionally, I’m beginning to be a bit concerned about our prospect of a wet March. The CPC’s outlook for the next 6-10 and 8-14 days shows this:

CPC's 6-10 day Precipitation probability outlook

CPC’s 6-10 day Precipitation probability outlook

CPC's 8-14 day Precipitation probability outlook

CPC’s 8-14 day Precipitation probability outlook

Again, a dry March does not break the entire spring season for us but it does create a bigger hole we need to dig out of. We will continue to watch this pattern closely for any changes but I’ll end this post with an interesting fact:

Aprx. Date of Last Significant Snowfall: February 2, 2016

Total Snowfall Recorded for March 2016: 0.5 in.

Average Snowfall for March: 14.7 in.

For March 2016 we are 14.2 inches below normal for snowfall as of right now!

 

 

John Braddock Visits Cimarron Middle School

Special thanks to my storm chase partner: Chris Moccio, for this photo.

Special thanks to my storm chase partner: Chris Moccio, for this photo.

I had the great privilege of visiting Cimarron Middle School in Parker Colorado this past Thursday. Presenting to a class that was beginning a weather unit, I presented on the tools and trade of meteorology, how weather works including fronts, pressure and maps.

Additionally I talked about what it takes to become a storm chaser, how learning about weather and forecasting is important and even showed some pictures from this past month’s Storm Chaser Convention in Norman Oklahoma. I think the highlight for the class was the showcase of storm chase vehicle and tornado pictures that I put up and spoke about. A lot of schools are beginning to take a closer look at weather as it is now spring in Colorado and one of the most exciting times of year to observe and learn about weather in the state.

I had an absolute blast doing it and although I was cut a bit short due to a fire drill… ugh. I still enjoyed it quite a bit and it seems like the class enjoyed it as well.

 

Being my first public speaking engagement on meteorology I was joined by two good friends, my storm chase partner Chris Moccio (left) and very good friend Tom Santana (right.) Thanks for accompanying me guys!

10152515_10102672429741363_3496074653618464828_n

 

Weekend Weather Planner March 11- 13

WinterWxWeekendOutlook_Mar11-13-2016CR

So far, our snowiest month in Colorado is turning out to be extremely dry and warm for almost the entire state. The good news is that we still have quite a few days left in the month so it’s not time to get worried just yet. Many models have been predicting the second half of the month to be cooler and wetter and as of right now there is nothing signaling the contrary.

March has been extremely dry:

PRISM_ppt_early_4kmD2_MTD_20160310

You can see a lot of white, oranges and reds across Colorado. Many areas east of the continental divide have seen 0-.1 inches of precipitation so far; this amounts to 0-1 inches of snow. Quite a surprise considering we average well over a foot of snow for the month. As a side note; many areas South of Denver (Castle Rock, Parker, Elizabeth, etc…) average between 14-16 inches of snow for the month of March. I emphasize again, there is still a lot of days left in the month but we are beginning to dig a hole and the further we get behind the more difficult it will be to catch up.

The mountains have done slightly better, most areas have seen between 2-8 inches of snow, which sounds like quite a bit but these areas are still well below average. Snow pack in the state has been falling:

swetimepeakark16

The snow pack statewide is down into the 80% range which is getting a bit low. Many areas saw extreme dryness in February and that trend has continued into March.

The good news is the storm track looks to get more active shortly for the mountains, as soon as this weekend their snow pack situation should be helped by a series of storms moving in. The same can’t be said for Denver as it still looks to remain dry, minus one storm we are watching late in the week. This storm unfortunately, looked very promising with earlier model runs is looking less impressive every day.

In the meantime, enjoy the wonderful weather this weekend and I’ll have another update and look at the weather next week on Monday night. Cheers!

March is Still Snow Season in Colorado!

With the unusually warm temperatures and abnormally dry conditions we have experienced for well over a month now, it is easy to forget that we are still in the heart of snow season for Colorado. March is, on average our snowiest month of the year statewide and while the first half of the month hasn’t lived up to that title, there are signs from some of the medium range and long range models that we may still have a shot at a decent sized winter storm.

The Weather Pattern Has Shifted in the Last Week

For the entire month of February we have seen a very pronounced ridge to our West steering many storms away from Colorado and keeping us under sunny skies and dry air. Due to the positioning of the high pressure ridge and some of the associated features East of Colorado we have also saw very windy days throughout the past month as well.

See Also: Western U.S. Ridge Keeps Colorado Very Warm and Dry

02182016_wxtrgraphic

The above image is what we’ve seen a lot of lately, a high pressure over Colorado or just to our West. There are signs however things are changing and we saw the first glimpse of this with the wild weather that arrived in Colorado on Monday.

Euro model shows breakdown of high pressure ridge over Western U.S.

Euro model shows breakdown of high pressure ridge over Western U.S.

As I pull up an updated version of our weather pattern at the moment I see a few interesting changes to our upper air pattern that we haven’t seen in some time:

  • Notice the high pressure ridge has retreated further West, this will allow more storm systems to hit the Western U.S. (See the big low over Mexico!)
  • The fact that we are seeing more Low Pressure systems moving into the Western U.S. shows our storm track may be getting more active in Colorado
  • It has been well over a month since we have seen activity like this

 

 

 

Models Are Picking Up on “Something”

Modeling has been somewhat flaky this year, I believe they are simply having issues trying to understand a complex El Nino setup that has not behaved like a typical El Nino. Basically I have been taking any model predictions more than 5-7 days out with a grain of salt and while they have struggled with details further out they are good general look at what the atmosphere “may” be doing over coming days and weeks.

GFS/EURO

Both of these models are showing some interesting features into next week:

Euro model showing a strong closed low over SE Colorado next week

Euro model showing a strong closed low over SE Colorado next week

GFS model showing a closed low in nearly the same spot next week

GFS model showing a closed low in nearly the same spot next week

 

 

 

 

 

 

 

 

 

 

 

This is the exact setup of a low pressure system we would expect to see for a large snowstorm for the front range of Colorado. The reason I’m not hyping this particular storm system up is that there are a lot of things working against it. As it is further out, there is no guarantee this will be the positioning of the low, there doesn’t seem to be a ton of moisture with it and the system as a whole is projected to move very quickly.

So why am I even talking about it? Just the fact that we are seeing things like this suggests that eventually we are going to transition back to a cooler wetter pattern across the state. When you have storm tracks like this, moving in the way the are, you always have the potential of something surprising us. I don’t see anything impressive for these storm systems at the moment, but the potential is there for one of these to sneak up on us. I’d be keeping an eye on late next weekend and into the middle and later half of next week.

Does a Big Snowstorm Look Possible in the Next Couple of Weeks?

We’ll look again at the CPC prediction maps as they will give us a good look at the odds of being colder or warmer, wetter or drier over the next 2 weeks.

6-10 Days Out (Next week into the following)

CPC temperature probabilities

CPC temperature probabilities

CPC precip probabilities

CPC precip probabilities

 

 

 

 

 

 

 

 

 

 

 

 

 

The CPC predicts a higher than average chance that temperatures will remain above normal through the next 6-10 days, but they also predict a higher probability of being wetter than average. So we should expect to be warm and relatively wet through the next 10 days. I see the bulk of any precipitation coming after this weekend, it looks dry and warm through that period.

8-14 Days Out (Late next week into 2 weeks out)

CPC 8-14 day temperature probabilities

CPC 8-14 day temperature probabilities

CPC 8-14 day precip probabalities

CPC 8-14 day precip probabalities

 

 

 

 

 

 

 

 

 

 

 

 

 

Again with the look at the 8-14 day we see a higher than normal chance of wetter conditions but notice on the temperatures how the big blue blob of below normal temperatures rest right over the Western U.S. This matches up quite well with what some of the modeling shows. Very interesting indeed…

Summary

To sum this all up; we will be keeping a close eye on how this all plays out in the next 2 weeks. A big snow storm is POSSIBLE in the next 2 weeks given the information I’ve seen but I won’t go so far as to call it LIKELY.

The fact is that El Nino years tend to be warmer than average and as we get later in March the angle of the sun and temperatures begins to work against us. The main takeaway here is don’t put away your snow shovel yet and don’t get those snow tires removed just yet. There are several opportunities starting next week for something to come out of left field and surprise us and the weather lately has a tendency to lull people into a false sense of spring.

In the near term, should anything begin to look interesting I’ll be sure to post details on it and give as much of heads up as possible. Thanks for reading and stay tuned!

 

Snow! Monday Re-cap and Tuesday Outlook

Monday’s Snow Expected but Location and Intensity Was a Surprise

Monday’s weather was highlighted by the arrival of a front and surface low pressure system Monday morning and into the afternoon. This caused a couple of things to happen along the front range of Colorado:

  • Moisture increased as the surface low moved into Colorado
  • A shift in winds caused up-slope, because of the warmer temperatures on the ground and the colder temperatures aloft, we saw convection initiate along the front range foothills and plains.
  • Due to the intense lift (from combined convection and up-slope) some areas saw intense areas of rain, others intense areas of snow and others thunderstorms.
  • Keep in mind, spring in Colorado is a roller coaster. One may see snow, hail, rain and tornadoes all in the same day.

Convective Snowstorms

To understand how our weather turned out yesterday we’ll cover a coupe of weather basics. Convection of air is caused when warm moist air rises into a cooler, drier layer of air aloft. Yesterday we had an excellent set up for this as it was quite warm in the morning. A surface low and associated cold front enhanced moisture and lift available along the front range.

thunder

Due to this process most areas saw thunderstorms yesterday, thunder was heard from Fort Morgan to Highlands Ranch at one point or another. South of Denver, temperatures dropped due to the cold front, this allowed snow to fall from these thunderstorms.

If one of these bands of convection sets up over an area and is producing snowfall, it can result in a period of quick, intense snowfall.

3-8-2016 9-54-48 AM

Models have a hard time predicting stuff like this. In fact, none of the models except for one had any snowfall accumulating South of Denver. These types of setups can catch meteorologists off guard, we can generally tell if there will be convective snow in a forecast, but it is very difficult to predict where it will be or how intense it becomes.

More Snow Expected Tuesday

3-8-2016 10-00-16 AM

There is still quite a bit of moisture in the air today along the front range. The energy left over from yesterday’s front and storm systems could combine later this afternoon and into the evening to produce up-slope again along the front range. It is looking likely that a shift in the winds this evening will mean another shot of snow and rain for areas along the front range. Denver and points North should mainly see rain but higher altitudes South of Denver (Palmer Divide, Castle Rock, Parker, etc…) will likely see snow.

Just like yesterday, some areas may see heavier bursts of snow for a short period of time but overall accumulation (if any) look light. After Tuesday we should see a return to warmer, drier and spring-like weather. I’ll have a post up about that on Wednesday most likely.

One note: with all the spring-like weather it is easy to say winter is over. I’ve seen some media outlets and online blogs already declaring winter over for Colorado. Don’t be so sure! A lot of models are hinting at “something” coming later this month, so don’t be fooled!

Castle Rock Weekend Outlook Mar 4-6, 2016

At the risk of sounding like a broken record… This weekend will feature more above average temperatures and wind.

WinterWxWeekendOutlook_Mar4-6-2016CR

The weather hasn’t been too terribly exciting along the front of Colorado for the past few weeks, not since the beginning of February have we seen significant snowfall or storms. Expect warm days and nights over the weekend with daytime and nighttime temperatures well above average. The wind will stick around too, the worst wind conditions will most likely come later in the day on Sunday in advance of a storm system. If you are out and about this weekend remember the sunscreen!

Monday Looks Like Best Chance for Moisture

3-4-2016 12-20-49 PM

GFS total Moisture through 11pm Monday. QPF (qualitative precipitation forecast)

A small storm system moving through on Monday into Tuesday gives us the best chance for moisture along the front range. The GFS predicts about .5 inches of precip. for Denver which given how temperatures along the front range will reach the 50’s I imagine most of this will fall as rain.

The bad news is when I fast forward the model out another 7 days, I see no more significant moisture east of the divide. The mountains look to get some decent shots of snow over the next 7 days but the front range will be lacking in that department.

When’s the Next Big Snow Storm?

That’s the big question right now, at the current time I don’t see anything significant on the horizon as far as a major storm system. That’s not to say that things couldn’t change very quickly though and I’ve discussed before how long and medium range models are good for a “general” look at the weather but, they can change quickly and are sometimes not terribly accurate.

Looking at the next 7-10 days I see a lot of this:

jet_mar2016

This flat orientation is going to be great for California’s drought as it will bring a ton of moisture to that area. For Colorado it is mediocre at best for our mountains and not good for the Eastern half of our state. Any moisture gets wrung out in California, leaving only a bit left of our mountains and by the time it makes it to Denver, the air is very dry.

The later we go into March, the less our chance of a major snowstorm is. The longer days and higher sun angles make it more difficult with each day to accumulate large amounts of snow.

Not time to panic yet (if you’re waiting for the big blizzard this spring) but there are some causes of concern here.

I’ll have another update early next week with a more detailed longer term outlook.

Have a great weekend!

 

Red Flag Warning Issued for Wednesday March 2

red_flag_warning

Gusty winds and low humidity coupled with the serious lack of moisture the past few weeks will make for critical fire weather conditions on Wednesday. Any fires that start could grow out of control quickly, so any planned burning should be put off until conditions improve.

In addition, keep those cigarette butts in the car. Many fires start this way from careless tossing of these out the windows on roadways and highways.

.

day1otlk_fire

See More: National Weather Service Red Flag Warning

The storm prediction center has the critical fire conditions outlined in their Fire Weather Outlook today. In addition, the National Weather Service has issued a Red Flag Warning for those critical areas of Colorado. At this time the warning includes all of the eastern plains of Colorado including the city of Denver and the Palmer Divide area.

 

_cowxwarnings3-2-2016 8-26-43 AM

See More: Colorado Weather Watches and Warnings

Have a great Wednesday everyone and be safe!

 

March 1: First Day of Meteorological Spring and Severe Weather Season

Many of us are familiar with the astronomical seasons, this year spring starts on March 20, Meteorological spring starts today however. The main difference between these is the astronomical seasons are marked by position of the Earth relative to the sun. Meteorological seasons are marked more by temperature and weather fluctuations on the planet for certain times of the year.

Meteorological Spring and Colorado

As we transition into the spring season in Colorado it usually means big changes in our weather. Spring (both astronomical and meteorological) is a time of transition for our state. I often reference roller coaster to explain weather in Colorado during meteorological spring (march-may.)  because this period features wild fluctuations in temperatures and weather conditions. We may see several days of 70’s and near 80’s followed by a strong cold front and blizzard that drops feet of snow and features temperatures in the 20’s and 30’s. If you have lived in Colorado for any decent amount of time, you are not surprised when we get dumped on with inches if not feet of snow in May.

The Climate Prediction Center has issued an outlook for Meteorological spring and it can give us a glimpse of what we expect overall this year for spring in Colorado:

cpc_MAM2016_tempoutlookcpc_MAM2016_precipoutlook

The setup we see here is pretty typical of what we would expect for an “El Nino’ type spring, warmer than average temperatures and above average precipitation. The CPC really says there are equal chances of being above or below average for temperature for most of Colorado minus the far Southern and Southeastern areas. I tend to agree with this thinking given the data I’ve seen so far, I think March will start off very warm and dry but transition into a cooler wetter period in the mid to second half of the month.

See Also: Western Ridge Over U.S. to Keep Colorado Warm and Dry for First Half of March

April and May are less clear, but if we go with what we would expect in an El Nino year, we should see some big temperature swings and above average precipitation. There are some concerns about how quickly the El Nino breaks down as that could drastically alter what we see for weather in Colorado this year, breaking down too slowly or quickly could alter our weather pattern for the spring quite drastically. This is a topic I’ll cover another day, but one to keep in mind.

Start of Severe Weather Season

In Colorado we don’t often see much severe weather early in Meteorological spring, but we do get quite a bit more active towards April and May. The rest of the U.S. however, the changing position of the jet stream, combined with greater daytime heating and a colder atmosphere aloft begins to kick of some nasty weather in areas of the country.

March U.S. Tornado Risk

Credit: The Weather Channel

March severe weather generally occurs in the Southeastern part of the country (commonly referred to as Dixie Alley.) By later in the month with better heating and moisture return, states like Texas, Kansas and Missouri begin to see greater risk of severe weather.

Colorado doesn’t see too much severe weather in March as we tend to still be transitioning out of winter, however we do get the occasional front and energy combination for severe weather.

 

April U.S. Tornado Risk

Credit: The Weather Channel

 

As we reach April, the severe threat tends to shift to the Northwest a bit. States such as Oklahoma and Texas tend to see a much greater threat with a lingering threat of severe weather over Louisiana and the deep south.

Again, for Colorado we tend to see more thunderstorms but usually the heating is not quite enough to get severe storms on a large scale basis. That being said, we still have a bit of a risk through most of April.

 

 

May U.S. Tornado Risk

Credit: The Weather Channel

May, the final month in Meteorological spring is when things begin to get interesting across the great plains and Colorado. This is the first month where we typically have a good combination of heating and energy available in Colorado to sustain decent severe storms.

Typically, Colorado sees most of its severe weather (relating to tornadoes and hail) in the months of May, June and in some cases July.

 

 

Colorado Severe Weather Signs to Look For

There are a few signs the atmosphere will give us that could foretell whether or not we have an active severe weather season in Colorado and all these signs pertain to specific ingredients that severe weather needs:

  • Heating/ Instability
    • Severe storms need warm air and lots of it as energy
    • If we have a colder April and May, we can expect a lot of severe weather to struggle to form. In years like this we can have a more active late severe weather season if it warms up quickly into May
    • Strong heating allows warm air to rise at the surface into the cooler environment above, creating thunderstorms.
  • Moisture
    • This is a big one for Colorado as we are usually quite dry
    • The storm systems and fronts that move through Colorado need to set up in such a way that moisture is pushed into the state. This generally means a low sitting to our Southeast moving moisture into the state with a cold front behind it for lift and energy
  • Upper Level Winds/ Lift
    • This is a topic I can spend an entire article on (and I will soon) as Colorado has some unique features that allow us to get severe weather when most states wouldn’t
    • Generally we want the jet stream either overhead or slightly to our West. A surface low to our Southeast meaning winds near the ground are coming from the Southeast or East and winds aloft are out of the West. This would create wind shear that allows our storms to begin to rotate and sustain severe levels
    • We can also get instability and life behind cold fronts that move though. If the winds and energy come together in the right positions, we get a nice severe weather day

 

As we ramp up into Colorado’s severe weather season over the next few weeks, I will have quite a few articles about the mechanisms and processes that contribute to our severe weather in Colorado. So if you find that stuff at all interesting, stay tuned!