“Stratospheric warming” near the North Pole at mid-month suggests cold air outbreaks can continue in the US well into the early stages of the 2025 baseball season
The current stratospheric temperature pattern across the Northern Hemisphere features a rather typical looking (cold) polar vortex centered right near the North Pole with some “stretching” into the eastern part of Canada. There are reasons to believe that a major “disruption” in the stratospheric polar vortex will take place during the next couple of weeks leading to a “split” vortex by the second half of March and significant warming right near the North Pole where temperatures can climb from around -60°C to -25°C.
While not a guarantee, this kind of “disruption” in the location and magnitude of the stratospheric polar vortex often results in the movement of cold air masses from the polar region into the middle latitudes such as across the central and eastern US. In fact, a stratospheric warming event of this magnitude can have an impact on temperature patterns in the middle latitudes for several weeks to follow which would take us not only through the latter part of March, but into April as well. In recent history, there have been several stratospheric warming events during the month of March (1984, 1993, 2014, 2015, 2018) and they were typically followed by colder-than-normal stretches of weather.
Additional cold air outbreaks from late March into April would ensure that there will be plenty of early season baseball games featuring low Home Run Forecast Index (HRFI) values. The HRFI is displayed on a scale of 1-10 where the lower numbers indicate weather conditions are not favorable for hitting home runs and that is likely to be the case in many stadiums as the season gets underway thanks in large part to this developing stratospheric warming event.
Meteorologist Paul Dorian