Weather5280 Insider
Transitioning from El Niño to La Niña and what that could mean for spring
We've been locked into El Niño conditions since last spring. Sea surface temperature anomalies have been much above average in the equatorial Pacific Ocean, but have recently really started to cool off. The El Niño peaked in late December and early January, and continues to weaken. Here is the equatorial sea surface temperature anomaly animation, during the past 90 days. This graphic represents the depth (0-450 meters) and east (120 degrees E) to west ( 80 degrees west) across the equatorial P
Weather5280 Insider
With La Niña 'officially' over, a look at where we are headed
Good morning, La Niña is done! Now onto a neutral pattern before El Niño likely establishes itself. This may come with cheers or jeers depending on your perspective and how each affects your operations. Let's walk through some brief details about where we are and where we are headed. La Niña is gone in the sea surface conditions – the ENSO region has warmed quite a lot. Right now, the westernmost region (4) is the coolest and the easternmost region, (1.2) is warmest. Moments of La Niña contin
Weather5280 Insider
La Niña rapidly weakens, what that means for our weather as we move through February and into spring
As I write this update, I remain most interested in what happens to La Niña this month. During January we saw a rapid warming of the sea surface temperatures, especially in the 1.2 ENSO region and I anticipate further warming with another MJO wave to move into that region this month. Let's begin with this topic before turning to the month's outlook for precipitation and temperatures. Here are the sea surface temperatures averaged from January 20th through February 4th, 2023. Colder than normal
Weather5280 Insider
January update: Death to La Niña?
It's increasingly likely that La Niña is very near the end of this latest phase as the likelihood of La Niña conditions this spring falls to 14% in the latest CPC forecast released this week. Here is that forecast, shown as the probability of ENSO phase going forward through three-month seasons. For March-April-May we have an 82% probability of neutral conditions. That forecast is based on multiple model and statistical projections for sea surface temperatures (SSTs) within the ENSO 3.4 regio
La Niña
La Niña update: Weakest SOI in over two years
La Niña is now the weakest it has been in over two years, using the SOI (Southern Oscillation Index) index for monthly values since 1950. The SOI is one measurement tool for calculating the strength of La Niña atmospherically, in this case using sea level pressure values. How does this change the winter outlook, or does it? I discuss that in this video and will present a research image below. Here's the latest monthly SOI data including November to show you the strength relative to all other p
Weather5280 Insider
La Niña's latest forecast and most likely weather pattern for the winter
I should begin by saying, forecasts made in November struggle. Largely this is due to the atmosphere which is working to change itself from its summer (~5 wave pattern) to winter pattern (~3 wave pattern), and during that change, there are some chaotic moments, especially during November. When we deal with this, projections can suffer from this "outside noise," and the relative stability of winter helps improve skill scores for forecasts. The same can be said for April when we flip-back. With t
La Niña
La Niña and Winter Outlook: A video update on the status of La Niña and early implications on snow season
La Niña remains in record territory as one of the strongest on record. The third-consecutive La Niña winter is headed our way, only the 3rd time this has happened since 1950. This in and of itself will have a strong influence on the winter outlook across North America.  There are factors in the Northeastern Pacific Ocean that need consideration, too, when looking at the snow forecast ahead. This video update begins with the latest La Niña data and how other ocean areas are shaping and will sh
La Niña
Video Update: The latest with La Niña and the outlook for winter
La Niña continues and appears very set on being with us for a third winter in a row, which is rare as it has only happened twice before. This has implications across the American West for water issues along the Colorado River (Lake Mead will continue to make headlines) due to La Niña's propensity for drought in the Southwest.
Weather5280 Insider
La Niña update and early fall/winter outlook
La Niña is still alive and well. The sea surface temperature anomaly animation for the past 90 days not only shows La Niña being maintained, but it is actually getting a bit stronger. While the North Pacific has warmed from late this spring, the central/equatorial Pacific has remained quite cool. The animation below shows what is happening beneath the surface across the equatorial Pacific: Simply put, the graphic shows ocean depth down to 450 meters across the equatorial Pacific Ocean. Those
La Niña
July La Niña and monsoon update
Plenty to sort through with this update, and based on what I'm seeing we have a lot riding on it too. First, let's look at what La Niña and rest of the global sea surface temperature anomalies have been doing, for the past 90 days. 1. Despite La Niña being very much alive, it has been weakening a bit recently. Notice less blue shading along the equatorial Pacific. 2. The colder than average water that was in the Gulf of Alaska and along the West Coast of the US has also been warming
Wind
Oh, so much wind! A historical perspective for Denver and the U.S.
Yes, it has been windy. And, it is safe to say it has been windier than normal around Denver and the Front Range in the past couple of months. It's important to keep things in perspective, so let's look at this from a top down approach, if you will. Wind events are common along the leeside of the Rocky Mountains, but what makes this recent pattern unusual is the scope of the winds across the U.S. as well as the frequency of strong wind events here in the city. To begin, let's take a look at A
Weather5280 Insider
February, 2022 La Niña update and what that may mean for precipitation patterns as we head toward spring and summer
We are midway through the winter, and with that it's time drop you a note about what La Niña is up to. First, a look at SST (sea surface temperature) anomalies across the equatorial Pacific: The above animation runs from early November through late January. Notice the blue shading really shrinking across the central and eastern Pacific Ocean. This is occurring at the surface of the ocean, and shows those anomalies not only becoming smaller, but also of less magnitude. The animation below sho
Weather5280 Insider
What a weakening La Niña could mean for spring and summer temperature and precipitation patterns across the Plains
In recent weeks, we have seen some changes take place with the ongoing La Niña episode, primarily in that it has weakened by quite a bit. The series of graphics below shows that trend. Sea Surface Temperature Anomaly Change Sub Sea Surface Temperature Anomaly Change Two very noticeable things are occurring. 1) the pronounced cold pool at the surface has warmed and almost disappeared and 2) the colder than average water that existed down to about 150 meters in the Central/Western Pacific has
Climate
Is there precedent for a wetter than average March in Colorado during a La Niña?
Our March/April/May outlook we released a few weeks ago was for a bias toward near average temperatures and below average precipitation for Northeast Colorado, and drier than average conditions across the region on the whole. This is largely based on the continued La Niña, and a host of other teleconnections and considerations which went into our analog package for the coming three months. While we've been discussing how this La Niña
Weather5280 Insider
La Niña update and potential analog year as we look ahead to fall
We will continue to update you on the progress of La Niña, because we think it is the single most important thing in our long range forecast. Granted, we still have a ways to go before the active hurricane season comes to an end, but the development of La Niña will likely have some pretty big ramifications. At the time of this article, here is a look at the sea surface temperature anomalies: cYou can see the “blue and green” shading off the west coast of South America, indicating cooler than
Weather5280 Insider
La Niña development update
A couple months ago, we were telling you that there was potential for a La Niña episode, before the year was done . While we were pretty sure about some of the signals, ENSO forecasting this time of year is always tough. Models struggle in the spring, and this is affectionately called the "spring predictability barrier". We've seen ENSO events show up in the modeling only to disappear as we enter into summer. Howe
El Niño
As La Niña Fades, is El Niño on Deck?
The recent weak La Niña episode that prevailed since last fall, has been all but erased. The animation below shows the sea surface temperature anomaly trend during the past several weeks. Blue colors mean colder than average sea surface temperature anomalies, while orange/red means warmer than average sea surface temperature anomalies. Notice how all of the blue color in the ENSO regions has pretty much disappeared. At the same time, we have seen some much warmer than average water build off
El Niño
A Return of the Monsoon for August? La Niña Check, Winter Analogs, and That Pesky PDO
In a good year, August can be one of the wetter months of the year for many of us in Colorado. Right on schedule, we've had a recent surge of monsoon moisture. This is always a good thing, especially when the amount of flash flooding we've seen of late has been relatively low. Below is a look at rainfall totals for the past three weeks. Overall, a pretty good look for the state. Northwest Colorado is hurting the most, with those of us living along the northern I-25 urban corridor also missing o
La Niña
La Niña Transition & The Monsoon
La Niña Transition Let's see how our transition from El Niño to La Niña is going. We've talked about this a lot during the past several months , and here is a look at the current sea surface temperature anomalies: The blue shading that you see extending off the west coast of South America represents cooling taking place in that part of the Pacific Ocean. However, while that is happening the rest of the Pacific Ocean is still quite warm. This is especia
Colorado Weather
El Niño Death and La Niña Birth: What It Could Mean for Colorado
If you frequent Weather5280 this the title of this post is not breaking news. In fact, we've been talking about this transition for several months. Today I wanted to provide an update for those that are interested, and show what history and various computer models are suggesting. First, let's look at the recent sea surface temperature anomaly changes over the tropical Pacific Ocean: The animation above shows the changes that have taken place at the surface since early February. Notice th
Long-range forecast
Long-Range Forecast Update: Quiet Pattern Sets in; Wet Spring Ahead?
Let the great meltdown begin! After a great snowstorm this past week, many folks are wanting some warmer weather. Well, if you are one of those people that wants warmer weather, this is certainly going to be the weather pattern for you. In fact, it is likely going to be one of those weather patterns that produces some of the nicest weather we've seen in a while. Why do I think this? Let's take a look... GEFS Ensemble Mean 500mb Maps: Tuesday: Thursday: Saturday: Monday: Wednesday: Fri
JAMSTEC
Updated JAMSTEC Model and Beyond El Niño
JAMSTEC Update It has been a while since we have chatted about the JAMSTEC model and its forecast for the next several months. There is a reason for this. During the past several months, it has been forecasting colder than normal temperatures for Eastern Colorado. We've lamented in the past about why we didn't think this would happen (current strong El Niño and positive PDO), but figure the model was worth a look again. Why? Because some of what the model has been spitting out may be spot on...
El Niño
Why Has it Been so Windy?
Winds up to 100mph recently, and the windy weather to continue La Niña patterns are great wind producers, especially for Colorado and the plains states. The recent wind resulted in tree damage and wildfires from the Pacific Northwest to Oklahoma. Peak wind gusts were recorded at 100 mph near Frisco, Colorado Saturday morning and 102mph at Gold Hill in Boulder County Monday night. We have had wind gusts well over 100 mph earlier this winter, and even last winter. The strongest ever recorded in t