Western U.S. Weekly Weather Outlook – April 16-22

Week 1 Outlook: April 16-22

The next few days will feature two relatively weak troughs moving across the Western U.S., bringing rain and snow to the Rocky Mountains and Intermountain West and dry and windy conditions with elevated fire danger east of the Continental Divide and across the adjacent plains.  However, a strong and potentially wet and snowy storm system is projected for the end of the week across the Front Range and Eastern Colorado, which could bring some much-needed moisture to this region.  The main threat of precipitation across the Denver region at the end of the week will be on Friday and through the first half of the day Saturday.  Below is an image of NOAA’s projected precipitation amounts over the next 7 days.  Not a bad outlook for Eastern Colorado!


The track of the storm system will have to be monitored throughout the week, as this will impact where and how much precipitation falls across the I-25 corridor and Eastern Colorado.  In addition, this system will be highly temperature and elevation dependent with regards to snowfall potential.  Although confidence is increasing that portions of Eastern Colorado will see good moisture, how much of this falls as snow will be the primary question.  Areas above 6,000′ will stand the highest chance of seeing respectable snowfall amounts, while Denver itself may be more in question and will depend on how quickly rain can change to snow.  The best chance for the Mile High City to get some snow will be from Friday night through Saturday morning.

Outside of Colorado, this system is also expected to bring some beneficial moisture to the drought-plagued Southern Plains, including Oklahoma and Texas – areas that really need the moisture!  The caveat of course is that this storm system will likely also result in a severe thunderstorm threat across these areas on Saturday.  Overall, the late week system is looking very interesting for the eastern slopes of the Rockies and the adjacent plains, but plenty of uncertainties remain on the details this far in advance.


Week 2 Outlook:

High pressure will be taking control across the far Western U.S. early next week, resulting in drier than normal conditions across the Pacific states.  However, longer range models hint that another trough could drop in from the northwest, which would bring an additional shot of precipitation to the Central Rockies, and perhaps the Front Range and Eastern Plains of Colorado during the early to middle part of next week.  Beyond mid-next week, longer range models project more high pressure and drier than normal conditions across a good portion of the West, but there may be some weak systems that break through the ridge and bring additional precipitation chances to portions of the Rockies as well.

Impressive spring storm brings snow, wind, blizzard conditions to High Plains

A strong mid-latitude cyclone moved across the Central/Northern Rockies and into the High Plains on Thursday and Friday, bringing a variety of high impact weather to the region.  Ahead of the storm system, strong southwesterly winds and warm temperatures resulted in several wildfires starting in the Southern Plains, most notably a large fire in Western Oklahoma, as well as a large fire east of Pueblo in Colorado, which fortunately was contained rather quickly.  

As the low pressure system moved east of the Rockies early Friday, a strong cold front brought much colder temperatures (30-40 degree difference in high temperatures) across the Front Range of the Rockies and high plains along with strong winds, and for some areas snow.  The Denver Metro area largely missed out on the snow as the center of the low tracked too far north of the area, and as a result most of the snow fell east and north of the area.  There was a quick burst of snow at the leading edge of the system late Thursday night, however.  Also, the Palmer Divide south of Denver received a band of snow on the back edge of the system Friday evening with respectable snowfall amounts.  The highest impacts with this system occurred over far Eastern Colorado, Western Nebraska, and Western South Dakota.  Below is an image of the GOES 16 Visible Satellite Image from Friday afternoon, showing the mid-latitude cyclone nicely.


Image Source: College of DuPage


Snowfall amounts of a foot or more were recorded in Western South Dakota in the Black Hills area.  Strong winds resulted in blizzard conditions for Western South Dakota, Western Nebraska, and Eastern Colorado, where winds gusted to 60mph or more in some areas.  For instance, there was a NWS local storm report in Akron, CO on Friday afternoon reporting 8″ of snow on the ground with visibility of less than 500 feet.  Many areas in Eastern Colorado also reported numerous power outages due to wind, and around Limon there were reports of trees uprooted.  Although the major metropolitan areas of Colorado missed out on the highest impacts, this was quite a storm system for the high plains!

Extreme Fire Danger for Eastern Colorado

Warm and dry conditions have taken hold over Eastern Colorado this week, and increasing winds ahead of an approaching upper level trough will result in significant fire danger over the next couple of days.  The downslope flow is resulting in unseasonably warm temperatures across the plains of Colorado this afternoon, with some areas possibly approaching daily record highs.  Breezy west winds along with relative humidity values dipping into the single digits for some areas have resulted in high fire danger this afternoon.  On Thursday, winds will become even stronger from the southwest, with gusts to 50mph or higher possible for many areas, especially south of the Palmer Divide.  These strong winds along with dry fuels and low relative humidity will result in extreme fire danger.  NOAA’s Storm Prediction Center has outlined Thursday’s fire danger in the map below.



On Friday, a cold front will sweep across Eastern Colorado, resulting in sharply colder temperatures (highs about 30 degrees colder than Thursday!).  There may be some snow shower activity across the plains on Friday, but in general moisture will be limited.  Despite the cooler temperatures, winds are going to be very strong again out of the northwest.  If any fires begin prior to Friday, then the wind shift from southwest to northwest late Thursday night is something that will be of concern for fire behavior.

Western U.S. Weekly Weather Outlook – April 9-15

Week 1 Outlook – April 9-15:

The weather pattern for the upcoming week will result in the rich getting richer and the poor getting poorer with regards to moisture.  Much of the Intermountain West will see a drying trend over the first couple of days this week as high pressure builds over the Rockies, but over the second half of the week the next trough of low pressure will move into the Western U.S.  However, this trough will have a distinct bias for precipitation over the northern states, with the Pacific Northwest and Northern Rockies capitalizing on more rain and snow, while the Desert Southwest and Southern Rockies remain much drier.  Areas east of the Continental Divide, including Denver Metro, are likely to see minimal if any precipitation in this pattern, while mountain areas farther north in Montana and Wyoming will continue to add to an already above average snowpack.  Below is a projection from the NWS of precipitation over the next week.  Much of the precipitation over Eastern Colorado in this image was likely the result of some rain/snow showers that occurred earlier this morning.



The mountains of Utah and Western Colorado will likely experience some snowfall late this week, but the heavier amounts are projected to stay farther north.  The bigger story over the Southern Plains and Desert Southwest will be increasing wildland fire danger during the Wednesday through Friday timeframe.  As an upper level trough of low pressure moves into the Great Basin, strong downslope southwesterly winds will develop over the Southern Plains, which along with warmer than average temperatures (approaching 80 in Denver on Wednesday!) and low relative humidity values will result in critical fire danger over Eastern Colorado, a large portion of New Mexico, and the Texas Panhandle.  Wednesday and Thursday will likely feature the highest fire risk.  On Friday, a strong cold front will lead to cooler temperatures, but a Bora type wind event will be possible with strong northwest winds on the plains, and thus a continued elevated fire risk.  


Week 2 Outlook and Beyond:

For next week and beyond, the longer range signals continue to favor above average precipitation across the Pacific Northwest and Northern Rockies and below average precipitation across the Southern Rockies, Desert Southwest, and Southern Plains.  If these projections verify, then we will experience worsening drought conditions across the southern tier states, including much of Colorado, Utah, Arizona, New Mexico, and Western Texas.  While we will still see occasionally storm systems and precipitation chances across these areas through the end of the month, it does look to be less active than usual.  Without any periods of significant precipitation following what has already been a drier than average winter, we could be looking at a bad fire season across the Southern Rockies.

Thundersnow for parts of Metro Denver and Douglas County

A convective thundersnow shower developed south of I-70 along I-25 this afternoon producing hail, graupel and heavy snow for portions of the Denver Metro area southward into Douglas County.  This storm was fast moving but was able to produce heavy enough precipitation to overcome pavement with some slick/slushy roadways.  Temperatures were at or just above freezing as the storm moved through and snow/hail/graupel will melt off roadways now that intensity has decreased.  Welcome to spring in the Rockies!!!  A radar picture is featured above showing the intensity of the cell.

Colorado Snow Totals – March 26-27, 2018

A spring storm system brought snow to much of the Front Range of Colorado Monday night March 26, with the heaviest amounts occurring across southern and western portions of the Denver metro area (just like the last storm!).  Up to 8″ of snow fell over portions of Douglas County, while the Front Range foothills saw isolated amounts of up to a foot in Jefferson County.  Accumulating snowfall extended farther south into the Colorado Springs area as well, and the Wet Mountains south and west of Pueblo also saw respectable snowfall with several 6″ reports.  Below are some of the preliminary snowfall totals for the event ending Tuesday morning March 27.



Preliminary Colorado Snow Totals – March 26-27:

  • 13.0″ – Brookvale
  • 9.3″ – Pinecliffe
  • 8.0″ – Conifer
  • 8.0″ – Ponderosa Park
  • 7.0″ – Roxborough Park
  • 6.7″ – Lakewood
  • 6.5″ – Castle Rock
  • 6.5″ – Beulah
  • 6.0″ – Palmer Lake
  • 5.5″ – Estes Park
  • 5.0″ – Smoky Hill
  • 4.5″ – Louisville
  • 3.5″ – Downtown Denver
  • 2.7″ – Boulder
  • 1.5″ – DIA
  • 1.4″ – Colorado Springs

Fire Between Palmer Lake and Larkspur

Strong winds on Friday helped to fan flames of a fire south of Larkspur and north of Palmer Lake yesterday in Douglas County.  The fire consumed mainly grass, scrub oak and a few pine trees and is now fully contained.  Around 170 acres is thought to have burned.  Above is a picture of the fire scar.  This fire is a reminder of how dry conditions are across eastern Colorado, with particularly dry conditions areas south of I70 and east of the foothills.  A large fire occurred just a few weeks ago in the Kiowa area.  Stage 1 fire restrictions are in place across unincorporated portions of Douglas County.  

Red Flag Fire Weather Warnings have been issued for Saturday, March 24 from from El Paso County to the NM state line along and east of I25 from noon through 7pm, account dry conditions, mild temperatures, relatively low rh values, and gusty winds.

Western and Central U.S. Long Range Weather Forecast – March 20, 2018


Week 1 Outlook:  March 20-26

Miracle March will continue in California as another slow-moving trough of low pressure brings significant precipitation to the West Coast, including more heavy snow for Lake Tahoe and the Sierra Nevada Mountains.  By later in the week, moisture will also spread inland bringing snow to the Northern and Central Rockies including Montana, Wyoming, Utah, and Western Colorado.  Snow levels are likely going to start out quite high in all of these areas before colder air arrives later in the weekend. 

For Eastern Colorado and Denver Metro, we finally saw some good moisture and snowfall for some areas, but conditions will dry out again this week and temperatures will be very warm by the end of the week.  The recent moisture should curb fire danger in Northeast Colorado, but in Southeast Colorado where minimal precipitation has occurred, the fire danger will increase again later this week with warm, dry, and breezy conditions expected.  By early next week (Monday March 26), we may see a system slip into Eastern Colorado, bringing colder temperatures and snow chances to the Front Range, with lesser chances across southern Colorado.



Week 2 Outlook:  March 27 – April 2

High pressure will begin to take control across the West Coast of the U.S. by early next week, which will put an end to what has been a very wet/snowy month across California.  This ridge of high pressure will gradually progress inland next week, and will result in a drying trend for many areas.  However, northwest flow will likely result in below average temperatures for much of the week across the Rocky Mountains and Continental Divide Region, with additional shots of snow possible for the Northern Rockies as well as Colorado, including the Front Range and Eastern Colorado.


Extended Outlook:  Early April

Long range models are in generally poor agreement heading into early April so take this with a grain of salt for now, but there are more signs pointing toward high pressure being the more dominant feature across the Western U.S. during the early part of the month, which would favor a shift toward warmer than average temperatures and below average precipitation for most areas through the first week or so. 

Colorado Snow Totals – March 18-19, 2018

A short-duration but intense spring storm system brought heavy snow to portions of Northeast Colorado on Sunday evening March 18th.  As the storm approached, there were actually some thunderstorms that developed across the Boulder County foothills and portions of the Denver metro, before precipitation filled and changed over to snow early Sunday evening.  A few hours of intense snowfall rates occurred across the Denver area, especially south and west of the city with some of the highest totals in Douglas County around Castle Rock and Parker.  Below are some of the preliminary snow totals from NWS local storm reports as of Monday morning, March 19th.  The image below is a GOES 16 Visible Satellite capture of Colorado this morning, showing the new snow cover across the area.


GOES 16 Visible Satellite Image, Monday morning March 19, 2018


March 18-19 Preliminary Snowfall Totals for Colorado:

  • 12.5″ – Franktown
  • 12.1″ – Parker
  • 11.2″ – Jamestown
  • 10.5″ – Castle Rock
  • 10.2″ – The Pinery
  • 10.0″ – Elizabeth
  • 9.0″ – Parker
  • 7.5″ – Lone Tree
  • 6.8″ – SE Aurora
  • 6.8″ – Evergreen
  • 5.8″ – Northglenn
  • 4.9″ – Cherry Hills
  • 4.2″ – Black Forest
  • 4.0″ – Denver ESE
  • 4.0″ – Broomfield
  • 4.0″ – Lakewood
  • 3.1″ – Air Force Academy
  • 1.1″ – Boulder


Mixed bag of Colorado weather today as spring system arrives

A spring storm system moving across Colorado today is resulting in a wide variety of weather conditions across the state, with some areas expected to receive respectable snow, other areas mostly rain, and yet other areas staying mostly dry.  The fast-moving low pressure system will be favoring the Western Slope and High Country for precipitation today, as well as portions of the northeast plains, while southeast Colorado experiences drier conditions and high fire danger.  Here is a look at the GOES-16 satellite image below as moisture spreads into western and central Colorado.



Snow for the Colorado Mountains

Snow will fall in the high country, mainly above 9,000′, this afternoon and evening as the system moves through.  The National Weather Service is forecasting 4-8″ of snow for most of the western and central mountains of Colorado through about 9pm this evening, while the Continental Divide Region along the crest of the Front Range mountains could see 5-10″ of snow.


Rain showers and isolated thunderstorms for portions of the Northeast Plains

As the low pressure system moves into Eastern Colorado later this afternoon and evening, rain showers will develop over northern and eastern portions of the state, with some areas potentially receiving respectable amounts of moisture.  The Denver metro area may get in on some of this rain shower activity as well.  Temperatures are going to remain mild with this event, so most of the lower elevation areas will likely remain snow free, other than perhaps some wet flakes mixing in.  There is also a chance that some areas could experience their first thunderstorm of the year this afternoon with a relatively unstable airmass in place.


Critical Fire Danger for Southeast Colorado

The southern I-25 corridor, including Pueblo, and southeast and east central plains will be on the dry side of this system, but strong westerly winds and relative humidity values of 5-15% this afternoon will result in elevated fire concerns.  This region has already experienced a distinct lack of moisture this winter season and fuels are now critically dry.


High Winds for the Front Range Foothills

On the backside of this low pressure system, strong west/northwest winds are expected to develop along the eastern slopes of the Front Range, for places such as Estes Park and Nederland, extending south to Pikes Peak, with sustained winds of 30-40mph from late tonight through Friday morning, with gusts to 70mph possible.