Monday Night’s Ice: Are Our Priorities Straight?

with No Comments

The big push in the business of weather communication is impact-based forecasting.

Icy Glaze
Icy Glaze

In today’s fiercely competitive weather forecast environment, where “zip code” apps and websites are popular, this was a chance to stand out. An opportunity for real meteorologists and their forecasts to shine. An opportunity that doesn’t come around as frequently as it did in the 80s, or even 90s.

Model data has come great lengths since just the last decade. As meteorologists, we need to be sure we’re using that data in an effective way. Looking at my saved data from Sunday morning, the freezing drizzle signal was apparent.

GFS Model Sounding for 10pm Monday at KBDL (Generated 7am Sunday)
GFS Model Sounding for 10pm Monday at KBDL (Generated 7am Sunday)
NAM Model Sounding for 10pm Monday at KBDL (Generated 7am Sunday)
NAM Model Sounding for 10pm Monday at KBDL (Generated 7am Sunday)

Shallow moisture, flow off the ocean, with clouds not cold enough for heterogeneous ice nucleation (which you need for snow). The lowest temperature in the clouds at 10pm Monday was only -4.3º C. With the surface well below freezing, the only real forecast outcome was freezing drizzle. A dangerous glaze. See this National Weather Service paper on freezing drizzle from Corpus Christi, Texas.

Monday night, something went wrong.

Freezing drizzle glazed over roadways, sidewalks and driveways across the region. People fell down. Semi-trucks went off the highways. Not just 1 or a few, but many accidents. Traffic was backed up in Hartford…before 4am, on a Tuesday. It looked like many roads weren’t pretreated.  I understand rain will wash away pretreatment, but this was a light freezing drizzle.


As the event was ongoing, several meteorologists emphasized the danger. I did, too. But that didn’t help the people already in trouble. The focus was never on the freezing drizzle before the event started. No doubt, the size of the incoming storm on Tuesday overshadowed the freezing drizzle streaming in off the Atlantic from the east, on Monday evening. It’s too bad. Nearly all forecasts called for the storm to start as a wintry mix, but the freezing drizzle was pre-storm “junk.” It was distinct from the storm itself.

Here’s the text of the Winter Weather Advisory, from its issuance at 3:21pm Monday.

NWS Boston Winter Weather Advisory (3:21pm Issuance)
NWS Boston Winter Weather Advisory (3:21pm Issuance)

By 10:25pm Monday evening, it was clear things weren’t going well across the region. So here’s the update that was put out. No more mention of snow or sleet!

NWS Boston Winter Weather Advisory (10pm Update)
NWS Boston Winter Weather Advisory (10:25pm Update)

As Ryan Hanrahan tweeted Monday morning, long before the ice event started, a quick and dirty glance at Bufkit revealed an alarming potential for freezing drizzle. I retweeted it and took note for future situations.


Most people could care less if 1” or 2” or 3” of rain was going to fall on Tuesday. What’s the difference? If you’re in agriculture, sure, I understand. But the vast majority of people would’ve been far better off knowing about the glaze that would occur late Monday evening, before the storm. A “screaming message” of dangerous freezing drizzle may have prevented totaling the family car, jackknifing of tractor-trailers, or substantially reduced the potential for personal injury.

Part of the issue is the lack of understanding in regards to freezing rain. In theory, I would argue many understand that rain can freeze on contact with a surface below freezing (we’ve all seen pictures!) – but, many also don’t remember that process once it’s actually occurring. I haven’t done the research, but that’s my theory.

It’s easy to overlook a little drizzle, I suppose. But this is a reminder of how dangerous it can and often turns out to be, when it’s freezing. Perhaps a Freezing Rain Advisory would’ve worked better in this situation? The bottom line, forecasts need to be more clear and concise with the important impacts.

Personally, I’m all about improving.

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.