Spring season 2025 is around the corner, and the latest forecasts show a La Niña influence over the jet stream pattern for North America. A high-pressure system in the Pacific will dictate the pressure anomalies and weather patterns over the United States, with a low-pressure zone over Canada keeping the cold nearby.
The meteorological Spring season lasts 3 months and covers the March-April-May period. As this is the transition period from Winter to Summer, we usually see a wide range of weather dynamics during this time.
An important factor this Spring will be the influence of the oceanic La Niña event, which had a burst of life in recent weeks. In this article we will take a quick look at Winter anomalies, the weather pattern for early March and the latest long-range forecasts for Spring 2025, shaped by the La Niña.
AS WINTER SEASON ENDS
The meteorological Winter season covers the December-January-February period. We are now in the final stages of this period, so we can look at the preliminary analysis of the Winter season 2024/2025.
Below is the pressure anomaly analysis for the meteorological winter period, or at least as much as it is currently available. You can see the dominant low-pressure area over the northeastern United States and southeastern Canada. Paired with a high-pressure zone over the West Coast, it creates a persistent northerly flow that has brought colder air into the United States.
The stronger the pressure difference is between the high and low-pressure systems, the stronger the northerly flow is. That also means a colder airmass, originating deeper from the polar regions.
You can see the temperature analysis below for the same period. Colder than normal winter was detected over much of the northern, central and eastern United States, and southwestern Canada. This is of course a 3-month average, so some weeks in this period were above normal. But this shows that there was more colder this winter.
Most of the northern and eastern Canada and the western United States have been warmer than normal this season, somewhat consistent with a La Niña pattern.
Looking at precipitation for the Winter so far, we only have high-resolution data for the United States. You can see more precipitation over the northwest and north, and over parts of the eastern and southern. But the southwestern U.S., the central plains, the southeastern U.S., and parts of the upper Midwest have had significantly less precipitation this season.
A large part of the southwestern United States has recieved less than 15% of normal precipitation amount in the past 3 months.
We can also look at total snowfall, but the data period starts on October 1st. That is because this period is considered the snowfall season or sometimes also the cold weather season. As you can see, this winter so far, a large part of the United States has seen snowfall, including the deep south coast.
Before going into the Spring forecast, we will also take a quick look at how the meteorological Spring will start, as it shows to continue the winter weather pattern over the United States.
THE WINTER FINALE
March will begin with a cold air drop into the eastern and northeastern United States. It will be driven by a deep low-pressure system over the eastern United States and Canada. At the same time, a large high-pressure ridge will rise over the northern United States and southern Canada, bringing along a warmer airmass.
You can see the resulting temperature pattern below. Colder air will drop into the eastern and northeastern United States, with expected to drop 15-25°F below normal over a large area of the northeast. But over the northwestern and southern United States, and over western Canada, the forecast calls for an early Spring wave, with above-average temperatures.
Looking at the snowfall forecast for the first days of March, you can see a belt of snowfall over southern Canada, into the upper Midwest and onwards into the northeastern United States. Some snowfall is also expected over the elevations of the western half of the United States and Canada.
The March and also Spring weather patterns overall, are expected to be under the influence of a large-scale ocean anomaly in the Pacific Ocean. In its current form, its called a La Niña, and has a known impact on the Spring weather patterns over the United States and Canada.
LA NINA INFLUENCE ON SPRING IN NORTH AMERICA
One of the important large-scale drivers of this winter season is the La Niña event in the tropical Pacific Ocean. It was getting stronger in the past two months, and is expected to affect the weather patterns over the United States and Canada going into meteorological Spring.
In the image below, you can see the recent ocean temperature anomalies across the Pacific. Notice the colder-than-normal surface waters in the tropical Pacific regions. That is a La Niña event, powered by the trade winds, spanning far across the central and western equatorial Pacific Ocean. The analysis below shows a strong ocean cooling in January.
La Niña is just a different name for cold ocean temperatures in the tropical Pacific Ocean. The actual ocean-atmosphere system is called ENSO (El Niño Southern Oscillation). This ocean area alternates between cold and warm phases, having a different global weather impact with each phase.
Below is the ENSO phase outlook from CPC. You can see that the La Niña is forecast to stay at least into early spring. But, the atmospheric impact of such large anomalies can last longer, especially over North America, which is close to the ENSO region.
Below is a video of the weekly ocean temperatures in January. You can see the development of a stronger cold anomaly, boosting the current La Niña phase and its weather impact in the upcoming weeks and perhaps months.
The image below shows the average position of the jet stream during La Niña seasons. This impacts the weather patterns over the United States and Canada, bringing colder air to the northern and central U.S. and warmer air to the southeast.
Jet stream changes also affect precipitation. In a La Niña season, we usually see more precipitation over the Pacific Northwest and the eastern United States. At the same time, a weaker subtropical jet means less precipitation for the southern United States.
This way, the jet stream divides the United States into two weather poles. In the northern part of the country, colder and wetter events are more frequent, as the jet stream directions the storm systems and cold weather there.
Because we have a weak La Niña this season, we will look at the snowfall patterns during a weak La Niña event. Below, you can see above-average snowfall across much of the northern United States and southern Canada. Peak snowfall is usually across the higher elevations of the Pacific Northwest.
The north-central U.S., including the Dakotas, Nebraska, and Minnesota, usually have a snowier winter during weak La Niña years. There is also more snowfall across the northeastern United States but less over the southern U.S.
The graphic covers the January-March period, but the La Niña influence does not change much from Winter to Spring, so this effect is similar for the whole season. But of course the overall snowfall amount gets lower significantly with each Spring month.
SPRING 2025 FINAL FORECAST FOR NORTH AMERICA
The latest pressure pattern forecast from ECMWF indicates a typical La Niña high-pressure system in the North Pacific. In response, we see a low-pressure zone over Canada. When a low-pressure system sits over Canada, that means the colder air over western Canada is ready to push into the United States on a northerly flow if the pattern allows it.
In Spring, the southern ridge starts to get stronger, so together with La Niña, we usually see an early onset of warmer temperatures over the southern United States.
Below is the temperature forecast for Spring, where the forecast hints at normal surface temperatures over the northwestern United States and upper Midwest and over most of Canda. Most of the western United States is forecast with much above normal temperatures, but the anomaly is decreasing towards the east.
Despite being shown warmer than normal, the central parts of the United States tend to get occasional colder weather and snow in early Spring during these jet stream patterns, as indicated by the pressure forecast. But mostly warmer-than-normal temperatures are forecast over the far south and the eastern United States.
The North American precipitation anomaly forecast below shows a typical La Niña-type pattern over Canada and the United States. As a result, the United States has wetter conditions in the Pacific Northwest and over the East, and less precipitation is forecast for the southwestern and southeastern United States.
In combination with colder temperatures, that also affects the snowfall potential in early Spring. Overall, the Spring seasonal patterns look very similar to a typical La Niña effect.
For the March-May period, less snowfall than normal is forecast over the western and northern United States. However, an above-normal snowfall amount is forecast for a large area from western and central Canada down into the northwestern United States. A lot of this snowfall likely comes from the March and early April weather patterns.
We will soon also produce an article with a more detailed breakdown of the snowfall potential in the Spring Season month by month.
UKMO SPRING SEASON FORECAST
In contrast to the ECMWF, we often use the UKMO model from the United Kingdom Met Office. This way, we can compare results, and if both models show a similar forecast, that raises confidence in the accuracy of the forecast.
The UKMO model agrees with the ECMWF over the North Pacific in forecasting a high-pressure system. No clear low-pressure anomalies are shown, but the pattern indicates a low-pressure zone over Canada, similar to the ECMWF, with a ridge also over the south-central United States.
The southern ridge returns each spring over the southern United States, but is usually stronger in a La Niña season.
The temperature forecast below shows a La Niña-like temperature pattern. Colder temperatures remain over western Canada and can also reach into the northwestern United States. No cold anomaly indications exist over the rest of the United States. But this is likely because the main low-pressure zone in this model is forecast further west over Canada.
Warmer-than-normal weather prevails over the southern parts of the United States. A potential gap in the warm anomaly is visible over the central parts of the United States, which indicates the occasional cold fronts from the northwest that move across the country.
The precipitation forecast shows drier-than-normal conditions over the southwestern United States and the south coast. Over the northern and eastern United States, you can see more precipitation than normal due to the La Niña influence.
We also have the UKMO snowfall data for the March-May period, which is very similar to the ECMWF. We see more snowfall over Canada, extending into the northwestern United States. But most of the United States shows less snowfall than normal in the Spring season, tho that does not mean no snowfall events can occur, as this is just a 3-month average.
Less snowfall than normal is forecast for the southern half of the United States and also over the northeastern U.S., but this may be due to less snowfall in April-May data. We will reveal this when we do a month-by-month snowfall breakdown in our next long-range article.
OFFICIAL SPRING OUTLOOK
Below is the latest official Spring temperature outlook for the United States from CPC. It shows the temperature probability, with colder to equal chances over the northern parts of the United States. The southern half of the country and the east show a higher probability of warmer-than-normal weather, similar to the models above.
You can also see an area of equal probability over the central United States. That indicates the likely path of cold air during cold fronts originating from the northwestern United States and western Canada.
The official precipitation forecast is also quite similar to the model forecast. We see an equal-to-higher probability for more precipitation in the eastern United States across the Ohio Valley and the Pacific Northwest. On the other hand, the southwestern United States is forecast to have a drier-than-normal spring season.
We will keep you updated on the developing weather trends in the coming seasons, so bookmark our page. Also, if you have seen this article in the Google App (Discover) feed, click the like button (♥) there to see more of our forecasts and our latest articles on weather and nature in general.
The main forecast images in this article are from Weatherbell maps using a commercial license.
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