March Madness: Severe Weather and Record Breaking Heat

After a week of record contending highs, Mother Nature has decided to revert back to normal or near normal temperatures. Highs for Monday and Tuesday will be some 20-30 degrees cooler than those of just a week ago.

Why the Heat?

Two weeks prior to the June-like warmth, a broad ridge of high pressure had anchored itself across the contiguous U.S. Areas of high pressure move slower than low pressure. High pressure also acts as a giant lid, capping the atmosphere aloft and trapping air at the surface. With little or no wind, the atmosphere can become stagnant for days if not weeks on end.

March saw a blocking pattern that typically develops across the southeast states during the mid to late summer. This type of pattern- known as the "Ring of Fire", occurs when a portion of the Bermuda-Azores high becomes affixed in the same general area for days. The longevity of the event is attributed to a lack-of Canadian cool fronts, which aid in eroding the cap and breaking down the high pressure ridge.

"Summer in March"

Record smashing high temperatures numbered in the thousands- the most for any spring since record keeping began in the late 1800s. Perhaps nowhere was the record breaking heat most noticeable than International Falls, Minnesota. The city known as the "Nation's Icebox" set their first and second consecutive hottest temperatures for the month of March at 78° and 79° (42-43 degrees above average). Coincidentally, their low temperature of 60°F tied the previous record high for that date.

Map illustrating global temperature anomalies (departure from normal) for the month of March. Note the orange and red shading for the eastern two-thirds of the contiguous U.S. denoting warmer than average temperatures.  This area represents about 10% of global temperatures.  Source: Poclimate/ http://policlimate.com/climate/ncep_cfsr_t2m_anom.png

Return to Seasonable

While much of the eastern two-thirds of the U.S. was experiencing above average temperatures, the west was locked under a low level trough that brought persistent rain and snow to the Pacific Northwest.  The trough eventually became too extreme and unstable, breaking off from the jet stream and forming a "cut-off low" that would bring severe weather and cooler temperatures to much of the lower 48.

The return of near seasonable readings means highs in the 40s Monday and Tuesday.  As a result of high pressure, overnight lows Monday night are forecast to drop well below freezing for much of the Great Lakes and Midwest.  Unfortunately, Mother Nature's revert to winter comes at a time when many fruit trees are in full bloom.  The combination of clear skies and calm winds has prompted Freeze Warnings, which could come at a cost for Lake Erie vineyards and orchards.

Unlike its predecessor, this weather regime will be short lived.  Highs are forecast to be in the 60s by mid week.

'Like' us on Facebook for breaking weather, streaming video and customizable severe weather content!