Welcome back to winter. I don't think anyone is excited to see sub-freezing temperatures on a daily basis throughout all of March...not to mention four nor'easters. Meteorology professor Steve Seman can confirm the remarkable temperature trend that's happening so late in the winter season.
#StateCollege just snapped a remarkable 26-day stretch with minimum temperatures < 32º. I can only find 3 longer streaks that ended this late in the season:— Steve Seman (@SteveSeman) March 28, 2018
33 days in 1989 (2/23-3/27)
38 days in 1984 (2/26-4/3)
46 days in 1960 (2/12-3/28)#pawx
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| Graphic showing how much warmer March should be than February. Credit: Weather World & Dr. Nese |
Having a March that's colder than the preceding February is fairly uncommon for most of the northeastern United States. First, let's take a look at the numbers and the maps. March, on average, is between eight to ten degrees warmer than February usually is for most of Pennsylvania and New England. This temperature difference decreases as you move south, with places like Florida only seeing a two to four-degree increase from average February temperatures to average March temperatures. Most years this temperature difference is positive - that is, March is warmer than February. However, you occasionally get the years with an unseasonably mild February followed by an unseasonably cool March causing these temperature differences to be negative.
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| Temperature departures for the month of February in the northeast. Credit: High Plains Regional Climate Center |
For the northeastern United States, the entire month of February was between four and eight degrees above what it should have been for the month of February. This can be seen by the reds and oranges in the above graphic of departure from normal temperatures.
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| Temperature departures for the month of March so far for the Northeast. Credit: High Plains Regional Climate Center |
When you flip the calendar over to March, however, temperatures have been between two and eight degrees below average for a normal March, with especially colder temperatures in the Mid-Atlantic states. This can be seen with the darker greens, blues, and purples in the above graphic of departure from normal temperatures.
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| Temperature differences from February to March for the state of PA for 2018. Credit: Weather World & Dr. Nese |
When the temperature differences from February to March are placed throughout Pennsylvania, it's clear to see that instead of an eight to ten-degree positive increase in temperatures from February to March, we have had a three to a six-degree decrease in average temperatures from February to March. Places south of Pennsylvania, such as North Carolina, South Carolina, and Florida, have seen even more negative temperature differences. Some locations experienced a March that was seven or eight degrees colder than February was, which is pretty incredible.
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| Eastern U.S. temperature differences from February to March for 2018. Credit: Weather World & Dr. Nese |
Even though this has happened the past two years - March was colder than February in 2017 for Pennsylvania as well - this is not a very common trend. It's only happened six times since 1900 for Pennsylvania: 1915, 1932, 1960, 1984, 2017, and now 2018. When you move further south, to Flordia for example, a colder March than February has happened eleven different years since 1900, making it less uncommon due to the lower temperature difference from February to March that usually happens down there.
Why did this happen in two consecutive years for the first time since 1900? We don't really know. My first guess would be something to do with La Niña, which we've been under "mild" versions of for the past couple of years. La Niña winters are usually wetter and warmer for the eastern United States, which would have made a lot of sense for February - above normal temperatures and much more precipitation than usual. However, March 2018 broke this rule and the rule to be warmer than February.
So, what should our high temperature be for this time of year? Right around 52 degrees here in State College for the end of March. We'll see temperatures around 52 degrees on Thursday through Saturday to end this week, which will feel like a heat wave compared to what we've been experiencing.
But I've got bad news. The warmth will not stick around. Back to the mid-to-lower 40's for highs at the end of next week and possibly continuing throughout the first half of April. Spring is unfortunately still on the back burner, giving us a few teases but not sticking around for good yet.
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| Looking like April will start off colder than average. Credit: AccuWeather |
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