Snow in late March is unusual
As a meteorologist, I hear the question “what’s up with this weird weather?” just about year-round. Most of the time, the weather isn’t so weird. In fact, it’s pretty typical of the season, but people have short memories and preconceived, Hollywood-influenced notions of normal when it comes to meteorology. That being said, if we see snow on Wednesday, well… that will be a little weird.
As of this writing (Monday afternoon), Wednesday’s chance for snow is not set in stone. One computer model keeps the temperature above 40 degrees, which means we will only see a cold rain. One has an early morning mix of snow and rain switching over to all rain as the day progresses. One has more snow than rain through the day. Without agreement in the models, confidence in the forecast is relatively low for now.
One thing is for certain: if it snows, the effects will be short lived. With above freezing temperatures leading up to the event and expected the day after, accumulation is unlikely – unless we see heavy bursts of snow. Of course, bridges and overpasses always require extra caution when frozen precipitation is possible.
So, how unusual is snow this late in the season? I used the North Carolina Climate Office’s Winter Storm Database to search for winter storms that happened after March 15 as far back as 1959. I found seven. Seven storms in late March over the last 58 years make the event abnormal, but not unheard of. Of those seven in the Triangle, three resulted in a trace of snow (2014, 2011, and 1981), one resulted in up to a half inch (2005), and three had amounts ranging from two to over seven inches (1983, 1972, and 1971).
Another question I’m often asked is whether El Nino or La Nina is causing the strange weather, so I looked at the historical records for the seven years in question to see if there seemed to be a link. I found none. Those storms happened during El Nino, La Nina, and neutral events. While there may be a link to some other cyclical phenomenon that I have not checked, a late-March storm may be one of those things that just happens occasionally.