(looks like Canada doesn't catch a break this summer, and US central plains gonna be tornado alley again)
Summer 2024 Forecast Update: Under the Atmospheric impact of the shift from El Niño to La Niña
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The precipitation forecast for North America also shows less rainfall over the southwestern and western parts of the United States and parts of western Canada. More rainfall is expected across the Midwest, East Coast, and over the deep south.
summer-2024-forecast-update-ecmwf-united-states-canada-seasonal-precipitation-anomaly
We also saw a temperature anomaly over the Midwest, so this is an interesting signal. But if we know how the pressure pattern looks, we know that the Midwest will be under a more southerly to southwesterly flow. That brings heat but also moisture, which is supportive of thunderstorm formation.
So when we have an overlap of increased rainfall and increased temperatures, like over the Midwest, it can be seen as an increased thunderstorm activity.
However, we are looking at the early summer trends, so the precipitation picture will become more defined with new runs. But overall, the summer weather pattern over North America does look to have a visible La Niña signature in the weather patterns.
It makes sense, as North America is much closer to the source region in the Pacific, so it is expected to feel the early changes of the new La Niña emerging.
UKMO SUMMER FORECAST
The second model of choice is from the United Kingdom Met Office, hence the forecasting system’s name, UKMO.
Below is the pressure anomaly forecast, and it shows a similar pattern to the ECMWF above. It shows a high-pressure area over a larger part of Canada and the northern United States, extending over the whole Atlantic.
(more)
https://www.severe-weather.eu/long-range-2/summer-2024-forecast-update-atmospheric-impact-enso-shift-united-states-canada-europe-fa/
