Big changes have been made to the March temperature outlook due to an unexpected pattern change, according to the latest outlook from The Weather Company, an IBM Business.
Previously, most of the Lower 48 was expected to experience a warm start to spring, but the latest information suggests that may not be the case.
Temperatures are expected to be below average from parts of the Dakotas to the upper-Mississippi Valley into the Tennessee Valley and north Georgia. A widespread area from Montana eastward into the Great Lakes and into the South is likely to see near or slightly below average temperatures in March.
Most of the Northeast, as well as areas west of the Rockies, can expect temperatures near or slightly warmer average. The most above average conditions will be found in Central and Southern California into southwestern Nevada and southwestern Arizona.
The adjustments in the March forecast take into account the expected changes in the upper level pattern.
"The historically-strong polar vortex will likely persist well into March (via historical correlations and dynamical model forecast) but there has been enough upstream ridging to drive periodic cold shots into the central and eastern U.S. This may continue well into March, similar to what occurred with very strong positive Arctic Oscillation last March," noted Dr. Todd Crawford, chief meteorologist at The Weather Company.
A strong polar vortex correlates with warmer than average temperatures in much of the U.S. However, the jet stream is expected to shift heading into March, with an upper level ridge (northward bulge of the jet stream) developing near Alaska and a trough (southward dip of the jet stream) over portions of the Lower 48. This setup allows colder air to flow into the contiguous United States.
As mentioned, the latest computer models suggest that this March could be similar to last year.
March 2019 saw below-average temperatures in parts of the Northwest, Plains and portions of the Mississippi and Ohio Valleys. Several low pressure systems also impacted the U.S. during the month, including a powerful bomb cyclone, dubbed Winter Storm Ulmer.
Crawford also comments that there is relatively low confidence in the March forecast, especially in the East.
Average March Temperatures
Meteorological spring begins March 1 when milder temperatures begin to become more common and widespread.
Above average temperatures in the Southwest could mean fairly warm temperatures, with highs topping out in the 70s and 80s.
It is still chilly across the northern tier in March, so below average temperatures in the Northern Plains and upper Midwest would make it feel more like winter than spring.
Average Highs in March
Colder than average temperatures in the South could also make for chilly mornings, which could be a concern for vegetation.
Near or slightly above average temperatures are likely in the Northeast which suggests temperatures still dipping below freezing in the mornings.
Average Lows in March
The Weather Company’s primary journalistic mission is to report on breaking weather news, the environment and the importance of science to our lives. This story does not necessarily represent the position of our parent company, IBM.
The Weather Company’s primary journalistic mission is to report on breaking weather news, the environment and the importance of science to our lives. This story does not necessarily represent the position of our parent company, IBM.
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