Definite Cracks In That "Never Ending Summer" Regime

Weather patterns nationally and locally
are finally beginning to transition to
one more typical of autumn

Here in Vermont and across most of the nation, summer has continued unabated well into September, with no sign that the season is transitioning to autumn.  

Until now.

The pillars of summer's dominance are falling like dominoes, as rain and chilly air begin to make real inroads. And did somebody say snow?

Relax. There's no snow is in the Vermont forecast just yet. I'm talking about the western mountains. 

Normally, as we go into autumn, the jet stream gets more energetic and begins to slip south.  This allows larger storm systems to form and create widespread rains. It also increasingly lets cold air trapped in Canada loose,  sending it down on the United States.

During the first two weeks of September, t seemed like this transition was not showing the usual signs of starting.  Now, it has.

One welcome aspect of that shift happened in drought and wildfire stricken British Columbia, and Washington and Oregon in the United States.

As that jet stream sank south, it allowed an atmospheric river of moisture from the Pacific Ocean to smack into these areas. Some areas have seen up to four inches of rain. This will end or at least seriously reduce the risk of wildfires in these areas.

Some of the rain is brushing far northern California, but unfortunately most of that state will remain in drought and wildfire risk for some time yet.

It'll be cold enough behind that western storm to unleash a little snow by Monday in the high elevations of Idaho, Wyoming and Montana.  That's normal for this time of year, but still a sign of the season.

The first frost advisories of the season were up this morning in northern Minnesota, too. Again, normal, but still.

Here in Vermont, long range forecasts for summer warmth through the end of the month have fallen by the wayside.  Warm weather will not last as long as previous forecasts suggested. That's not to say we, or other parts of the nation won't have spells of warm weather between now and October.  It's just that it won't be consistently warm anymore. 

There's no sign of extreme cold coming up, but you will feel autumn's onset, especially toward the end of next week.

Before then, a brief intrusion of cooler air will drop temperatures into the mid and upper 30s Sunday night in the coldest hollows and the 40s elsewhere.  Once again, that's nothing unusual, but will still be the coldest weather since the end of May or very early June.

But at least it will be sunny and VERY pleasant Sunday and Monday, too.  But a big dip in the jet stream is coming, though there's a lot of argument about when later in the week that will happen.

When it does, you'll notice a transition to serious fall weather. Again, nothing wild for Vermont in September, but it sure won't be beach weather!