Sunny spring weather to give way to thunderstorms this weekend in Texas

High pressure will strengthen across the Lone Star State this week, resulting in beautiful spring weather.  Temperatures are running about 5 degrees below average so far this March across the Dallas-Ft. Worth area, but the middle part of the week will feature near perfect conditions.  For Dallas, look for sunny skies Wednesday through Friday with highs in the low to mid 70s and lows in the upper 40s.

The nice weather this weekend will give way to more unsettled weather this weekend, however, including a good chance of thunderstorms.  Friday night/Saturday morning, a trough of low pressure can be seen moving into the Texas Panhandle (image source: pivotalweather.com).  

 

Southerly low level winds will help to draw in moisture from the Gulf of Mexico, with overnight showers/thunderstorms developing across western and northern Texas Friday night.  The threat for showers and thunderstorms will then persist across Northern Texas throughout the day Saturday, including the Dallas-Ft. Worth area.  The best chance of storms will be in the afternoon when daytime instability is at its peak, but morning thunderstorms will be a possibility as well.  

The threat for severe thunderstorms on Saturday appears to be low at this time, but if you have outdoor plans on Saturday, then you’ll need to be on alert for the threat of lightning.

On Sunday, low level moisture will further increase from the Gulf of Mexico while at the same time a dryline is projected to set up across West Texas (image source: pivotalweather.com).

 

 

The increase in low level moisture combined with favorable upper level winds projected will result in a greater potential for severe weather across the Dallas-Ft. Worth area and North Texas on Sunday.  Also, cooler temperatures in the upper 60s on Saturday will give way to warmer temperatures in the upper 70s on Sunday.  This additional heating at the surface will increase the threat for severe thunderstorms as well.

While we are still several days out, the take-home points initially for the weekend across the greater Dallas area are as follows.  Saturday will have a higher chance of showers and thunderstorms throughout the day with a minimal threat of severe weather.  Sunday will likely have drier conditions through the first half of the day, but a greater chance of strong to severe thunderstorms during the afternoon.

With an active weekend expected, it would be wise to monitor outdoor plans and events accordingly, and to have a safety plan for both lightning and severe weather.  

By Monday, the threat of thunderstorms should shift east of the area with cooler and drier conditions arriving behind the passage of a cold front.

Blizzard Warnings issued for Denver Metro and Northeast Colorado

A very powerful storm system will move into Eastern Colorado on Wednesday, bringing heavy snow and very strong winds across the northeast plains.  Blizzard warnings have been posted along the I-25 corridor from Denver to Colorado Springs and east to the Kansas border.  Winter Storm Warnings are in effect for the remainder of the Front Range. 

Check out the map below, which shows NWS Watches and Warnings across the Southern Rockies and Southern Plains (image source: pivotalweather.com).  Not all areas will get snow, but most areas will experience very strong winds!

 

 

The sea level pressure with this system is projected to be near record levels for Colorado on Wednesday.  The next image shows the forecasted surface low strength and position for Wednesday afternoon, with a projected sea level pressure of 974 millibars (image source: College of DuPage).

 

 

Sea level pressure values this low typically only happen with coastal systems, such as hurricanes/tropical storms or nor’easters, and are very rare in continental areas.  In other words, this storm is going to be extremely powerful, especially with regards to wind!

This is going to be a high impact storm for all of Eastern Colorado in terms of wind, and hence the Blizzard Warnings.  Snowfall amounts are tricky across the I-25 corridor, but even just a couple of inches of snow with wind gusts in excess of 50-60mph will cause major problems.  And it’s likely many areas will see snowfall in excess of 6″.  Travel is not recommended across Eastern Colorado Wednesday afternoon and evening.

Timing-wise, precipitation will start as rain late tonight outside of the mountains, with a change-over to snow across the Denver urban corridor by mid to late morning Wednesday.  Snow will then fall heavily at times through Wednesday afternoon and into the evening, before tapering off overnight.  This is a fast-moving system, but given the strength we expect snow rates to be heavy and could add up quickly over a short period of time.  Combined with the wind, significant travel impacts are expected.

In our morning forecast, Skyview Weather predicted 4-8″ of snow across Metro Denver with higher amounts south and east of the city, and lower amounts west and north of the city (due to downsloping northerly winds west of I-25).  These amounts may or may not need to be adjusted depending on model trends.

Keep in mind that with an anomalously strong system such as this one, models may not be accurately projecting the impacts, and it’s possible that snowfall amounts could be higher than what is currently forecast for parts of the metro area.  We saw a similar scenario in March of 2016 when 2 feet of snow fell across parts of Denver metro in a relatively short period of time, and was higher than most forecasts predicted.  There is certainly the potential for some areas to pick up 10″ or more of snow in tomorrow’s, especially across southern and eastern portions of the metro area and certainly across the Palmer Divide. 

On the flip side, if the system exits too quickly to the east or the changeover from rain to snow is delayed, then snowfall amounts would be reduced.  Regardless, preparation should be made to consider this a high impact event given the high winds (which is a near-certainty) and the upper-limit potential for heavy snow, which could cause serious problems on the roads.

Even More Snow for the Colorado High Country

Colorado’s High Country can’t seem to get a good break from snow this year as round after round of snow has impacted the region, which in turn has helped Colorado’s snow pack tremendously, but also caused very dangerous avalanche conditions.  Multiple rounds of heavy snow tends to lead to layering of snow, with different densities, which increases the risk for avalanches.  In addition to all the snow that has already fallen in the Colorado High Country, another powerful round of snow is poised to impact the High Country over the next few days.  Most mountain areas will see snow totals between 4-8″ with isolated higher amounts especially towards southwest Colorado where this next system looks to impact the most.  Here is the NWS snow prediction over the next two days:

Generally most areas are between 3-6″, with higher elevations in the 8-12″ range, with southwestern Colorado receiving the brunt of this system with totals up to 24″ in some areas.  This will hinder any travel plans over the next couple of days with treacherous driving conditions as strong winds and heavy snow can cause white out conditions, favoring higher elevations and mountain passes. 

As for probabilities,  NWS chance of 2″ or more can be seen here:

As you can see, most areas will receive at least 2″ of snow for the Colorado High Country.  Here is the probability of receiving 6″ or more:

Most areas in higher elevations have better than a 50% chance of receiving 6 or more inches of snow over the next two days, with Vail and southwest Colorado at 77% and 82% respectively.  As for more snow?  Here is 12″ or greater per NWS probabilities:

Here we finally see most areas in Colorado’s high country not receiving a foot of snow over the next couple of days, although still a 50% chance for southwest Colorado and a 30% chance Vail.  As for 18″ or greater:

Still a slight chance southwest Colorado could see over 18″ of snow in the next couple of days on an already large amount of accumulated snow.  

What has all this snow resulted in?  A very strong Colorado snow pack this year as Colorado’s statewide SWE (Snow Water Equivalent) has reached 129%, with southwest Colorado all the way up now to 131%, 138% respectively.  Very good snow fall in 2019 has helped tremendously in getting Colorado’s SWE above 100% and more snow is on its way!  Here is a look at Colorado’s SWE as of March 8th 2019:

With additional snow in the forecast, we could see Colorado’s statewide SWE climb to 150% which will be great for spring run off and hopefully decrease the drought conditions that have persisted over the last few years!

 

 

Overnight Severe Thunderstorms Possible Across North Texas Tonight

A powerful trough of low pressure will move across Texas late tonight, triggering 1-2 rounds of overnight thunderstorms across the Dallas-Ft. Worth metro area.  Warm, moist air will be in place today ahead of the system, but cloud cover should largely limit thunderstorm development.  However, strong upper level support from the approaching system tonight will allow for thunderstorms to develop across North Texas (image source: pivotalweather.com).

 

 

The prime time for thunderstorms will be while most people are sleeping, between about midnight and 7am Saturday.  Strong upper level dynamics along with an unstable atmosphere will also result in a severe weather threat overnight, with large hail being the primary threat.  Although the tornado threat will be low, it can’t entirely be ruled out so it would be wise to keep a weather alarm handy overnight.

The next image below shows the projected radar reflectivity from HRRR-model at 1am Saturday, when it projects the first round of storms to be moving across the Dallas-Ft. Worth area (image source: weathermodels.com).

 

 

A second round of thunderstorms is also likely to arrive closer to daybreak Saturday as a cold front arrives, with the threat of severe weather existing with this second round as well.  After about 7am we should see the threat of storms quickly come to an end with dry and breezy conditions developing during the day.

Cool and showery conditions are expected across the Dallas area on Sunday and Monday, but the thunderstorm threat looks low to none both days.

Attention then turns to a powerful low pressure system approaching by the middle of next week, which will bring a risk for both severe weather and flooding on Tuesday and/or Wednesday across the Dallas-Ft. Worth region.

Utah Long Range Weather Forecast for Spring 2019

Following an exceptionally dry 2017-2018 winter season, snowfall has rebounded across the state of Utah this winter.  This was especially true in February, when snowfall was well above average across most of the state.  As it stands now, the snowpack in the Colorado mountains is decidedly above average state-wide (image source: NRCS).

 

 

Across the Salt Lake City Metro Area and Wasatch Front, snowfall has actually been a little below average this winter, at least along the I-15 corridor.  Through the end of February, the Salt Lake City Airport had received 35.4″ of snow for the season, compared to a season-to-date average of 42.4″. 

However, across the eastern benches snowfall has been a little above average.  The climate reporting station near the mouth of Big Cottonwood Canyon had received 84.0″ of snow for the season through the end of February, compared to a season-to-date average of 69.5″.

Now that March has arrived, it’s time to start taking a look at the spring season, which historically is the wettest season in Northern Utah.  Meteorological spring is defined as the period from March through May.

Currently, we are in a weak El Nino phase.  This is something that has been advertised since last fall, but only in recent weeks have ocean temperature anomalies in eastern El Nino Pacific started to take on a true El Nino signature.  Weak El Nino conditions are expected to persist into the spring and possibly linger into the summer as well (image source: NOAA). 

 

For Northern Utah, El Nino does not have a particularly strong signal one way or another during the winter months, but during the spring it tends to exhibit a bias towards wetter than normal conditions.  Southern Utah has a stronger wet signal during El Nino phases, both during the winter and spring months.

An interesting twist to the outlook this year is the cooler than average waters of the North Pacific off the west coast of Canada and the U.S.  This has been indicative of a negative Pacific Decadal Oscillation phase (or -PDO), and has created a favorable environment for colder than average temperatures across the Western U.S. recently along with frequent low pressure troughs pushing into the west coast.  See below (image source: NOAA).

 

 

Given the favorable pattern outlined above for an active pattern across the Western U.S., this raises the odds for a wet spring across all of Utah, and a snowy spring across the higher elevations.

Another factor we look at in the spring forecast is western U.S. snowpack and current drought conditions.  Moisture (or a lack of) at the surface tends to play a feedback role in the atmosphere, especially later in the spring when convective rains/thunderstorms become more common.  Surface moisture is also a sign of recent weather patterns, which can be tough to break without a large scale change in the upper atmospheric flow pattern.

Currently, drought conditions still remain over much of Utah and portions of the Great Basin (image source: NOAA).  However, compared to last summer and fall, the drought situation has substantially improved thanks to a wet and snowy winter.

 

 

The next image shows current snowpack percent of average, in terms of snow water equivalent, across the Western U.S. (image source: NRCS).  This is a great look for the Western U.S. with widespread above average snowpack for all but the far northwest.  Places that previously were experiencing serious drought last year, such as Utah and California, have received well above average snowfall this winter.  This means more moisture available later this spring as low pressure systems track across the West.

 

 

Looking at past years with similar El Nino and PDO regimes that also had above average winter snowpack, we came up with four analog years:  1995, 1993, 1978, and 1969.  We also came up with two other weaker analog years (1953 and 1979) that were factored into our outlook to a lesser degree than the four stronger analog years.

Here are the average precipitation and temperature anomalies for the above mentioned years.

Precipitation:

 

Temperature:

 

While there are always factors that will occur that cannot be predicted in advance, most signals point toward an active spring season across Utah.

As a result, we are anticipating a bias toward above average precipitation and colder than average temperatures across Utah this spring. 

Snowfall across the Salt Lake City area in March and April is tricky, since much of it depends on whether or not cold enough air arrives with individual storms for precipitation to fall as snow rather than rain.  March and April tend to see less snowfall in SLC compared to December through February, with an average of 13″ during the two months combined.  This year, we anticipate several more snow events in SLC with near to perhaps slightly above average snowfall during the March-April period.

By later in the spring, we’re expecting above normal thunderstorm activity to go along with above average precipitation.  Salt Lake City averages 2 thunderstorm days in April, increasing to 6 thunderstorm days in May.  We think SLC will end up with more thunderstorm days than usual in May.

Flooding due to snowmelt, along with increased odds of above average spring precipitation, could become a concern later this spring as well.  Canyon country in Southern Utah in particular is likely to see an elevated flooding risk this spring due to above average higher elevation snowpack and expected wetter than average conditions this spring.

There is always a degree of uncertainty with long range forecasts, but we believe based on past evidence that the odds favor an active spring.

Here are our precipitation and temperature odds for March through May:

Precipitation Odds:

Above Average:  40%
Near Average:  30%
Below Average:  30%

 

Temperature Odds:

Above Average:  20%
Near Average:  30%
Below Average:  50%

 

As for the summer season, it’s a bit too early to say how that will play out, but we will see how things progress this spring and will release a summer outlook down the road.

Colorado Long Range Weather Forecast for Spring 2019

Following an exceptionally dry 2017-2018 winter season, snowfall has rebounded across the state of Colorado this winter.  This was especially true in February, when snowfall was well above average across most of the state.  As it stands now, the snowpack in the Colorado mountains is decidedly above average state-wide (image source: NRCS).

 

 

 

Across Eastern Colorado, season-to-date snowfall is close to average across most Denver metro area locations.  This has been quite an improvement compared to the past two winters, and after a dry start to this winter as well.

Now that March has arrived, it’s time to start taking a look at the spring season, which historically is the wettest season in Colorado.  Meteorological spring is defined as the period from March through May.

The first few days of March came in like a lion this year, with widespread snowfall statewide (very heavy amounts in the high country) and record cold temperatures across the Front Range.

For the long range forecasts, we have taken a look at past years with similar climate variables to what we are currently experiencing, and came up with several “analog” years to give us some direction.

Currently, we are in a weak El Nino phase.  This is something that has been advertised since last fall, but only in recent weeks have ocean temperature anomalies in eastern El Nino Pacific started to take on a true El Nino signature.  Weak El Nino conditions are expected to persist into the spring and possibly linger into the summer as well (image source: NOAA).  In past years, El Nino springs have often resulted in an active storm track across the west central and southwest U.S. with wetter and snowier than average conditions for the Front Range.

 

An interesting twist to the outlook this year is the cooler than average waters of the North Pacific off the west coast of Canada and the U.S.  This has been indicative of a negative Pacific Decadal Oscillation phase (or -PDO), and has created a favorable environment for colder than average temperatures across the Western U.S. recently along with frequent low pressure troughs pushing into the west coast.  See below (image source: NOAA).

 

 

 

Given the favorable pattern outlined above for an active pattern across the Western U.S., this raises the odds for a snowy spring across Colorado’s Front Range, including Denver.

Another factor we look at in the spring forecast is western U.S. snowpack and current drought conditions.  Moisture (or a lack of) at the surface tends to play a feedback role in the atmosphere, especially later in the spring when convective rains/thunderstorms become more common.  Surface moisture is also a sign of recent weather patterns, which can be tough to break without a large scale change in the upper atmospheric flow pattern.

Currently, drought conditions still remain over portions of the Southwest U.S. (image source: NOAA).  However, compared to last summer and fall, the drought situation has substantially improved thanks to a snowy winter.

The next image shows current snowpack percent of average, in terms of snow water equivalent, across the Western U.S. (image source: NRCS).  This is a great look for the Western U.S. with widespread above average snowpack for all but the far northwest.  Places that previously were experiencing serious drought, such as the southwest and California, have received well above average snowfall this winter.  This means more moisture available later this spring as low pressure systems track across the West.

 

 

Looking at past years with similar El Nino and PDO regimes that also had above average winter snowpack, we came up with four analog years:  1995, 1993, 1978, and 1969.  We also came up with two other weaker analog years (1953 and 1979) that were factored into our outlook to a lesser degree than the four stronger analog years.

Here are the average precipitation and temperature anomalies for the above mentioned years.

Precipitation:

 

 

Temperature:

 

While there are always factors that will occur that cannot be predicted in advance, these are fairly strong signals toward an active spring season across Colorado.

As a result, we are anticipating above average precipitation, above average snowfall, and colder than average temperatures across Colorado this spring.  The odds for a big snowfall event or two will be elevated across Denver and the Colorado Front Range in March and April this year, compared to recent winters.

Later this spring, if the active pattern persists then we could see elevated thunderstorm potential and elevated severe weather potential over the second half of May and into June.  Also, flooding could become a concern in May for creeks and streams along the eastern slopes of the Front Range and adjacent plains, due to snowmelt from an above average mountain snowpack, and perhaps from heavy spring precipitation events as well. 

There is always a degree of uncertainty with long range forecasts, but we believe based on past evidence that the odds favor an active spring.

Here are our precipitation and temperature odds for March through May:

Precipitation (including snowfall) Odds:

Above Average:  50%
Near Average:  30%
Below Average:  20%

 

Temperature Odds:

Above Average:  20%
Near Average:  30%
Below Average:  50%

 

As for the summer season, it’s a bit too early to say how that will play out, but we will see how things progress this spring and will release a summer outlook down the road.

More Snow for the Colorado High Country

Lots of snow impacted the Colorado High Country over the weekend causing avalanches along I-70 which closed portions of the highways.  Unfortunately, the Colorado High Country will only get a small break as another round of snow is poised to hit bringing additional snowfall on already deep, unsteady snow pack.  Expect to see additional avalanche alerts over the next couple of days as new snow, up to 20″ in isolated areas, falls from now through this week and into the weekend.  Moderate to heavy snow combined with gusty winds will cause white out conditions for most mountain passes, which will create hazardous driving conditions for most of the Colorado High Country.  Remember to be prepared, if you do have to travel into the mountains, for road closures and dangerous driving conditions.  Here is a look at National Weather Service’s two day expected snow:

Although most areas look to receive little to no accumulations, there are pockets of isolated higher amounts up to two feet of new snow over the next two days!  For percentage chances of snow, here is NWS two inch or more percentage probability:

Most areas have a high chance of at least seeing two inches of snow.  As for seeing above 12″ inches of snow, here is a breakdown of percent chance per NWS:

Areas around Aspen appear to have the best chance for seeing over a foot of snow, with the best chance between Glenwood Springs and Gunnison.  Expect to see higher amounts in elevated areas and mountain passes where moderate to heavy snow, with gusty winds will cause white out conditions. 

 

Colorado High Country Snow

March will start off with a bang for the Colorado High Country as a strong storm system will produce heavy snow for most of the Colorado Rockies this weekend favoring the Central Rockies and Northern Rockies.  Strong westerly flow aloft, combined with an atmospheric river of moisture will push into western Colorado today and through most of the weekend.  Snowfall will be heavy and create treacherous driving conditions in the Colorado High Country, especially on mountain passes where white out conditions will be possible due to heavy snow and gusty winds.  The national weather service has predicted upwards of a foot of snow in Vail and Frasier over the next two days with Aspen, Fairplay, Kremmling, Walden, Estes Park and Boulder receiving between 6-9″ through 5pm Sunday.  Any areas above Vail in elevation, and western facing slopes could see much higher isolated amounts from this storm system with areas getting up to two feet of snow!  Here is the probability forecast for 4″ or more:

Not only is there a very good chance for more than 4″ for most of the Colorado High Country, Ft. Collins has a 100% chance of seeing 4″ by 5pm Sunday, Boulder 94%, Denver 79%, Castle Rock 66% and Colorado Springs at 48%.  Based on this probability map, there is a clear visual that this storm system will favor northern Colorado as opposed to a usual Palmer Divide, upslope driven storm that we have experienced most often here in Denver.  As for the probability of seeing a foot of snow, here is NWS 12″ or greater outlook through Sunday at 5pm:

Vail is by far the big winner for chances of seeing a foot of snow at 76% with the Central Rockies and western facing slopes to the north and southwest having a decent chance of seeing at least a foot of snow.  

If traveling this weekend into the Colorado High Country, be prepared for hazardous driving conditions! 

Cold and Snowy March Expected for Central and Western U.S.

February has been quite a month across the Central and Western U.S., with locations from Seattle to Jackson Hole, Wyoming to Minneapolis-St. Paul all setting monthly snowfall records.  Denver and Salt Lake City have seen good snowfall this month as well, with the entire region experiencing below average temperatures.

Medium to long range models are in agreement that spring is not coming anytime soon either as the calendar flips to March.  Significant troughing across the Central and Western U.S. will likely result in below average temperatures over the first two weeks of the month, with frequent storm systems likely to bring additional snowfall.

Check out NOAA’s 6-10 day and 8-14 day temperature outlooks, showing the strong bias toward colder than normal temperatures.

 

 

 

The storm track will remain active over the first couple of weeks of March as well, with meaningful snow events a strong possibility for cities such as Denver, Salt Lake City, Minneapolis, and Chicago.  The cold pattern will likely relax somewhat over the middle to second half of the month, partly due to the fact that sustained cold is harder to come by that late in the year. 

However, signs do point toward near/below average temperatures over the second half of the month with above average precipitation projected across much of the country.  It does not look like winter will be going away quietly this year.

Colorado’s Snow Pack Well Above Average

Plentiful snow for the high country over the past month, especially in the San Miguel, Dolores, Animas, San Juan and Upper Rio Grande areas have helped Colorado’s statewide snow pack tremendously.  Currently statewide, Colorado is at 114% of average snow water equivalent (SWE), up 5% from just over two weeks ago statewide and 21-22% over the southwest region of the state as seen below for February 10, 2019:

Here is the current Colorado SNOTEL Snow Water Equivalent (SWE) map:

A much needed increase of snow in Colorado’s southwestern mountains over the past couple of weeks has really improved the amount of available water, which should relieve at least a portion of Colorado’s drought to the southwestern region. Here are the latest drought monitor conditions provided by Brad Rippey of the U.S. Department of Agriculture:

Per the U.S. Department of Agriculture, Colorado is still suffering significantly with drought conditions nearly throughout the state.  The worst areas of drought for Colorado are currently in the southwest region, where several areas are experiencing extreme drought, with portions of the central and southern mountains in a severe drought situation.  However, this map does not indicate the impacts of the most recent snow to Colorado’s southwest which saw an uptick of 21-22% in SWE.  Hopefully that increase in snow over the past few weeks improves the severe to extreme drought conditions.  

A look ahead to what we can expect over the next couple of weeks indicates below-average temperatures for most of Colorado and northeast towards the high plains.  There will be a good chance March starts off a bit cooler than average for Colorado as seen below:

As for precipitation, Colorado should start of March with a chance for slightly above-average precipitation between 40-50% for most the state with 50-60% above average precipitation for the far western portion of the state as seen below:

With below average temperatures and above average precipitation chances, expect to see additional improvement to Colorado’s drought going into spring as March can be a very snowy month for our state!