Our First “Spring” Snowstorm!
2019-03-21 09:19:06.000 – Thomas Padham, Weather Observer/Education Specialist
Our first “spring” storm of the season is set to begin across the White Mountains this evening, lasting through most of Saturday. Although we’re officially into astronomical spring as of yesterday, we’ll be observing plenty of wintry weather from this system over the next 48 hours. This will be an interesting system in terms of strength and also the complicated features that are already coming together to make the storm.
Two weak areas of low pressure already merged overnight across the Carolinas, with one moving from the Ohio River Valley helping to begin the strengthening process of the coastal storm. Widespread heavy rainfall is moving north through the Mid-Atlantic as of this writing, with a few embedded thunderstorms. A third system tracking through Ontario and Quebec overnight Thursday will begin merging with the coastal low, leading to a period of more rapid strengthening as the storm moves into New England. The track of the storm will be critical in terms of determining how much warmer air changes over our precipitation to rain or a mix, but as of right now the storm should stay just east of the region and we’ll remain just cold enough for almost all snow.
GFS model mean sea level pressure (MSLP) anomaly showing two distinct areas of low pressure (dark blue shading) Thursday evening before the systems merge into a more powerful storm Friday into Saturday centered over Maine.
The storm is then expected to stall and churn its way slowly across Maine for much of Saturday, leading to a prolonged period of snowfall that will substantially add to our totals here in the White Mountains and across the higher terrain of the greater Northeast. With the central pressure expected to reach near 980 mb or even a little lower, this will be a pretty powerful storm especially for late in the season. The pressure gradient between building high pressure to our west and the storm will lead to winds in excess of 100 mph for much of Saturday and even into Sunday. Whiteout conditions are also likely from the fresh snow being kicked up.
So how much snow are we potentially going to see? This will likely be one of the bigger snow storms of the year for the summit. March is actually our second snowiest month, and so we’re no stranger to major snowstorms during this time of the year. Taking a look at many of the models, this storm will likely yield anywhere from 10-20” of snow for the summit through Saturday night. The range for this storm is high due to the potential for still some mixed precipitation (possibly even briefly plain rain) to reach all the way up to 6,000 feet. Snowfall will also initially be heavy and wet, but by Saturday will become much more light and fluffy as temperature fall through the teens above.
NAM-3KM model snowfall roughly 1-2 feet of snow for the higher terrain of New York, Vermont, and the White Mountains of New Hampshire. Images courtesy of Tropical Tidbits.
It’ll be very interesting to see how this storm plays out across the Northeast. Parts of far northern New York, including the northern Adirondacks, could be the big winners with this storm with nearly 2 feet. This could be the last major (snow in excess of a foot) snowstorm for us this season on the summit, although there’s always the potential for a big storm lasting even into May as I’ve witnessed in my time here. It’s already been an incredible winter season, with 171 mph winds and about 260 inches of snow. Despite this, I’m always looking forward to more snow and high winds on the summit!
Thomas Padham, Weather Observer/Education Specialist