Overview
Spring has officially sprung and there is some quite mild weather expected during the next couple of days in much of the eastern half of the nation. There are signs, however, that point to additional cold air outbreaks into at least the first week of April from the Northern Plains to the Mid-Atlantic/Northeast US. The overall weather pattern across North America still features some high-latitude blocking over northern Canada and Greenland and this, in turn, is allowing for the transport of colder-than-normal air masses on occasion into the northern US from Canada. In fact, this pattern of normal to below-normal temperatures has been pretty commonplace in the last ten years during the months of March and April from the Northern Plains to the Mid-Atlantic/Northeast US.
Details
The month of February featured a stratospheric warming event in the polar region of the Northern Hemisphere and the tropospheric response has been high-latitude blocking across northern Canada and Greenland during the month of March. In response to the high-latitude blocking, the main jet stream aloft has been shunted to the south and this has allowed for the successful transport of cold air masses into the northern US from Canada in recent weeks. Signs point to this same kind of pattern continuing for at least another couple of weeks which will take us into the first week of April. While there will certainly be occasional days of warmer-than-normal weather, any given 5-day period over the next couple of weeks will likely average out to be colder-than-normal for this time of year from the Northern Plains to the Mid-Atlantic/Northeast US.
In addition to the persistent cold, there can be additional snow events for some of the same areas that have been hit hard in recent storms…namely, parts of the Upper Midwest and interior higher-elevations of the Mid-Atlantic and Northeast US. This weekend, for example, could feature accumulating snow across parts of the Upper Midwest and then ultimately across the interior Northeast US. Low pressure will push into the Upper Midwest on Saturday likely bringing some accumulating snow to portions of Wisconsin and Michigan and then ultimately a second system will form off the New England coastline likely resulting in accumulating snow across upstate New York and interior northern New England.
The MLB season gets underway on Thursday, March 30th and there certainly can be some cold air around for the first week of the season as we head into the month of April. The colder-than-normal weather conditions are especially likely in that zone from the Northern Plains to the Mid-Atlantic/Northeast US. With the potential cold weather conditions, the Home Run Forecast Index (HRFI) can start the season on the low side in many stadiums indicating unfavorable weather for balls to carry.
Meteorologist Paul Dorian