One New England Blizzard…Two New England Blizzards… (H. Michael Mogil, CCM, CBM, NWA-DS*)
The storm responsible for the blizzard (Fig. 1 – left) was a “meteorological bomb,” a storm that undergoes rapid pressure falls (or “explosive deepening”) of at least 24 millibars (0.71 inches of mercury) in 24 hours. Bombs typically contain some “thundersnow,” which often means locally heavier snowfall. This bomb was no exception.
First, it’s important to reiterate what a blizzard actually is. According to the NWS, a blizzard involves falling and/or blowing snow, sustained or frequent wind gusts of 35 miles per hour or more and visibilities frequently reduced to less than a quarter of a mile. All of these conditions must last for three hours or more.
For purposes of this summary, the NWS meteorologists used only official airport reporting stations (since all of the above weather conditions are routinely reported at these). For visibilities, they decided to use reported values of one-quarter mile or less since, “…that is quite low for an automated sensor to detect.” Obviously, blizzard conditions occurred elsewhere across the area.
- Providence, RI wins the competition with 5 hours and 18 minutes of blizzard conditions (10:51 a.m. to 4:09 p.m.).
- Hyannis, MA was a close second with 5 hours and 4 minutes (12:56 p.m. to 6:00 p.m.).
- Boston, MA netted blizzard conditions for 4 hours and 34 minutes (12:20 p.m. to 4:54 p.m.).
Other locations reporting blizzard conditions (in decreasing length of time of blizzard conditions) included Martha’s Vineyard, MA; Block Island, RI; Beverly, MA; Marshfield, MA; New Bedford, MA; and Westerly, RI.
As the region digs out, another storm system looms on the western horizon. This one, much like its predecessor, promises to involve “explosive deepening” as it passes by the region from late Sunday into late Monday (Fig. 1 – right). However, its movement will be significantly slower, allowing heavy snowfall and blizzard conditions to last longer. Already, local snowfall forecasts are pegged at approaching two feet.
This will be a “hunker down” storm. So stay home, dress in layers if you venture out, and, unless you have a snowblower, consider letting a local teenager shovel your driveway.
© 2017 H. Michael Mogil
Originally posted 2/11/17
* The National Weather Association Digital Seal (NWA-DS) is awarded to individuals who pass stringent meteorological testing and evaluation of written weather content. H. Michael Mogil was awarded the second such seal and is a strong advocate for its use by weather bloggers.