Another Big Interruption To Spring For Us Suffering Vermonters (And Many Others)

The sky looked summery and the trees were greening up in the warm
sunshine in St. Albans, Vermont on Sunday, but spring is about
to go into another chilly stall. 

It seemed like spring really, finally hit its stride the past few days in Vermont.

Sunshine and warmth over the weekend had the trees racing to green up. Flowers bloomed, lawns got their first mowing and people ventured out in shorts and t-shirts.

It made it all the way up to 76 degrees in Burlington on Sunday, making it the warmest day since last September 23.

There was even lightning visible to the north last night, a sign that summer would like to approach. And yet......    

Vermont weather always finds a way to disappoint, and the upcoming trends do look kind of bleak. Let's just say I hope you didn't get too overenthusiastic getting your garden plants in.

As has happened frequently since mid-April, the forces of winter want to make another push.  Hopefully, this will be winter's last stand.

It'll certainly be cooler this week, startind today.  This week's temperatures will be five to 10 degrees below average, which means highs in the 50s for the most part and lows in the 30s, with risks of frosts on a couple nights between now and Thursday.

Then it manages to get worse, as forecasts now indicate. An odd mass of Arctic air will plunge south, putting the northeastern third of the United States at least into some really cold temperatures.

We can blame something call cross-polar flow. The weather pattern is orienting itself so that a batch of cold air from northern Siberia is going and over the North Pole, then southward across eastern Canada into the United States.

Spring blooms enjoy some warm evening sunshine Sundau im
St. Albans, Vermont.  These same flowers will be shivering
in the cold over the next 10 days or so. 

This type of thing happens occasionally in the winter, giving us some of our deepest cold spells. But cross-polar flow is almost unheard of for May, so this is something.

On forecast maps, this looks like a giant blue and purple bowling ball of cold air hitting a strike on the Northeast.

As dire as that sounds, this probably won't be the worst May cold snap on record. But it will be uncomfortably chilly.

If you're a gardeners, you'll want to be on frost alert for the next ten days or so. Not every night will bring a freeze, but pay attention to forecasts daily, and protect those early plants.

It wont be just us that's affected.

With spring well under way, there's a widespread risk of damaging frost and freezes across the Great Lakes states and across the Northeast and all the way down into the South. I anticipate a lot of crop and fruit orchard damage in these areas by this time next week.

Since the worst of this is a good five days away, teasing out precisely how this will play out. We know it's going to be awfully cold for this time of year. But how cold? And will it snow?

Here in Vermont, we might have quite a few clouds, some wind and showers of rain and snow through most of this upcoming cold wave.  In a way, that would be good. If we get a night during the cold snap that's clear and calm, temperatures would really bottom out and the freeze would be all the more damaging.

That might happen during this, but the trends in the forecast so far favor clouds and wind.

There's the risk of late season snows, too, but at this point, it's not looking like much. (But that could change if a coastal storm really gets going. That's possible early next week, but no likely.

This will be a long lasting cold wave, too.  It won't start to warm up until the middle or end of next week.

Another concern I have is how dry it is out there, especially in the Champlain Valley. Drier conditions make it easier for temperatures to really bottom out at night.  Wet ground adds humidity to the air, and that helps keep temperatures up a little bit.

You don't want to put hoses, sprinklers and irrigation out yet, either. Freezing temperatures could damage all that. So watering gardens is difficult for the time being.

Even without the cold in the forecast, we could use some rain.  Deep soil moisture is still OK, but the surface is dusty as hell. No soaking rains are in the forecast for the next week or so.  Just scattered light rain and snow showers that won't amount to much.

As much as we all like spring sunshine, it would be nice if we got into a wetter and warmer pattern during the second half of this month. We have no way of knowing whether it will do that just yet, so for now, ugh, bundle up.