Snow Squalls Threaten Vermont This Evening

A snow squall last winter reduces visibility to a few hundred feet
last winter in St. Albans, Vermont. Similar conditions might
happen in northern Vermont this evening as there is a risk of
snow squalls.  These will make the roads dangerous 

Just a quick Wednesday evening alert: Snow squalls are bearing down on Vermont, especially the north.

Things are aligning pretty well for snow squalls this evening, any of which can produce brief whiteout conditions, and rapidly icing roads.  Which of course is a perfect recipe for pileups and crashes on Vermont roads later on.

As of 4:20 p.m., a snow squall warning was already in effect for the northwestern Adirondacks, as a dangerous snow squall moved into that region.

The National Weather Service in South Burlington warned of potentially life threatening travel in the path of the snow squall.

Here's what's going on:  West to southwest winds have been producing narrow bands of lake effect snow off of lakes Ontario and Erie.  A cold front is moving into this mess, and picking up the moisture and the snow from these bands.

The cold front is providing lift in the atmosphere, which helps produce and maintain precipitation.  With this situation, you end up with relatively narrow lines of intense snow. These are the kinds of things that are especially dangerous on the roads.

In one second, everything's fine: Visibility is good and the road is clear. The next minute, you can't see anything through your windshield and everything is iced up.  This is a great recipe for car crashes.

Those bands of snow that are producing the New York snow squall warnings are heading east, and I wouldn't be surprised at all if we get some snow squall warnings in northern Vermont.

Snow squall warnings are much like severe thunderstorm warnings in the summer. They cover a few counties at a time at most, and warn of a short period, usually lasting under an hour, of severe weather conditions.

If you hear a snow squall warning for your area, postpone travel until well after it has gone by. Also, if you are still at work, wait until well after it goes by and the state salt shakers and plows can get out there and clear the roads.

It usually doesn't snow much after a snow squall has passed, so visibility will greatly improve too one the squall goes by.

The snow squalls that were in New York last this afternoon might become a bit more disorganized when the come into Vermont. That means they will probably be hit and miss, again, much like summer thunderstorms.

None of the squalls will dump much snow, an inch or two at most, but they will be dangerous as they pass through.  The biggest threat for these snow squalls will be between 5 and 9 p.m. this evening, with the earlier times in northwestern Vermont and the later times toward the Northeast Kingdom.