Cold Air Bring Signs Of Spring, But Winter To Win Out For Now

Shower clouds billowed upward Sunday as warm March
sun caused updrafts into chilly air aloft, forming
numerous, but scattered showers of rain, snow and graupel.

 It was subtle, but it was there. 

The sky on Sunday bore signs of spring, even as temperatures began to drop as wintry air approached New England.  

It was in the clouds. Cold air had moved in aloft.  At the same time, as we head toward spring, the sun is getting stronger and stronger.  That sun was able to heat up what is snow-free ground in many areas of Vermont. 

This, in turn caused updrafts that hit the chilly air a few thousand feet overhead. That forced the updraft to condense into sort of those billowy clouds you see in the summer. 

It wasn't pure spring. Some of those billowy clouds yielded snow and graupel mixed with the rain, so they weren't exactly pleasant summertime showers.  

Still, Sunday was a welcome change of sorts. During the heart of winter, the sun is usually too weak to cause much in the way of updrafts, so clouds more often than not have that bland, flat overcast look. In the spring and summer the sky begins to look more interesting, as it did Sunday. 

So, spring!

Maybe not so fast. On top of the wintry showers these clouds produced, their gust fronts caused by the downdrafts in these tall clouds, would chill the air abruptly. Sunshine and relative warmth would disappear into instant chill whenever and wherever these showers showers arrived Sunday.  

OUTLOOK

The forecast still calls for more winter than spring for the next week or so. Spring, despite the signs we saw Sunday, is on hold.

Today, we'll probably see similar weather to Sunday, with those convective clouds and scattered rain, snow and graupel showers. They might be fewer and further between than Sunday. Between now and Tuesday morning, a few inches of snow might pile up in the central and northern Green Mountains. 

The next little system coming in Wednesday looks like it will have a little more oomph that previous forecasts told us. It will by no means be a big storm, but it'll be responsible for yet another few inches of snow in the mountains, and a dusting to a couple inches down in the valleys. 

It'll stay cold through the weekend, with the chilliest days being Thursday and Sunday.  Many of us won't make it above freezing those two days. 

Meanwhile, we a look forward to the prettier skies of later spring and summer. 

As we go further into spring and into summer, the contrast between the heated air near the ground and colder air aloft will grow. On some days, anyway. 

By summer, the mini-billowy, vertical clouds you saw Sunday will grow into those tall thunderstorms that occasionally create torrential downpours, lightning strikes and strong wind gusts. In contrast to the mini-me showers we had Sunday. 

Thunderstorms are perversely my favorite kind of weather. Sunday's clouds happily told me the season of lightning is coming soon.  I'll just have to bundle up and wait, at least during this week.  

A Sign Of Spring: "Leaf Out" Starting In Extreme Southern U.S.

Sugar maple leaves opening up for the spring on a rainy
day last May in St. Albans, Vermont.  In a sign of spring,
experts who watch spring blooms say leaf out is beginning
in extreme southern parts of Florida,
Texas and California. 

 If you're looking for signs of spring already, here's a good one. Spring leaf out has started in far southern Florida and California, and in the southern tip of Texas. 

According to the National Phenology Network, the leaf out is a few days to a week earlier than average in these locations. 

As always, there's a bit of bad news if you're into signs of spring. There was a freeze and a bit of frozen precipitation late last week in southern Texas will surely be a setback for this burgeoning spring. 

Phenology is the study of cyclic and seasonal natural phenomena, especially related to climate and its interaction with plant and animal life. 

I don't think any area of the country has bottomed out with the lowest temperatures of the season and started heading uphill toward spring. But the days are starting to get longer, so that's encouraging the the early leaves in these far southern locales. Plus, it's been warmer than normal lately in those places, too.

These hints if spring will start to spread north as we head into February as the southern United States begins to recover from the depths of winter. 

The National Phenology Network measures the onset of spring in any given locale by two measures. The first leaf out is when the hardiest plants begin to show signs of buds opening into leaves.

First bloom, which comes later, is when people first notice flowers on plants like lilacs and honeysuckle.  It's too early for first blooms just yet.