Wicked Fast Jet Stream Over Pacific Contributing To Our Changeable Weather

Jet stream forecaast for the Pacific Ocean between Asia and
North America for this coming Saturday The fast flow (in pink and orange)
denotes a fast west to east flow that is influencing the weather
across the United States, pushing repeated storms
into the West Coast, which turn into fast moving
disturbances racing generally west to east across the
United States. 

Lately, there's been a hugely fast west-to-east jet stream over the Pacific Ocean from Asia all the way to the North American west coast, and that's been influencing our weather here in Vermont.

This state of affairs began before Christmas and will continue at least into the middle of this month, if not beyond.

I'll get into how this affects Vermont in a bit. -

This jet stream has been sending a series of fast-moving storms into the West Coast from central California north into British Columbia, Canada.

These storms have been, and will continue to dump bursts of heavy rain and blinding mountain snow in these region

These have also brought damaging winds to California, Oregon, Washington and especially British Columbia over the past couple of weeks. Just over the weekend, Seattle had a gust to 60 mph, it's highest gust in 12 years. About 300,000 people were without power because of the storm.

The good news with this pattern is rain has been falling off and on through most of California, and a decent snowpack is building up in the Sierra Nevada Mountains.  That's great for the parched state's water supply.

Of course, a lot of those occasionally heavy rains are falling on massive areas scarred by last year's wildfires. Mudslides in one of these burn areas over the weekend closed the Pacific Coast Highway near Malibu. This is an area that was hit by a large wildfire late last year.

Several motorists, including rapper Soulja Boy, were trapped in the mud and debris on that highway. Everyone was rescued, nobody was hurt, but many of the cars were badly damaged or destroyed.

A couple video clips of the rough West Coast weather are at the bottom of this post.

THE OVERALL PATTERN

These storms have been zipping eastward across the United States, seemingly just on momentum alone. Most of the moisture from these storms get stripped off by the mountains in the West, so they become somewhat moisture-starved.

Some, but not all of the storms manage to pick up replacement moisture from the Gulf of Mexico, which helps explain why the Southeast has been so wet lately.

All this energy from had been those strong storms on the West Coast is still mixed up with all this. Pressure gradients between the storms and brief high pressure systems have caused frequent bouts of windy weather coast to coast, including here in New England and Vermont.

I noticed winds gusted to 40 mph in Burlington Sunday. The next system Tuesday morning will bring gusts of 45 mph to the Champlain Valley. More gusty winds are in the forecast for Thursday.

This seemingly endless parade of storms running east to west across the nation have been blocking any long-lasting cold waves from invading the country. Behind each storm, a bit of Arctic air does get stripped off and sucked southward from Canada, giving brief cold snaps to the northern tier of states, especially here in New England.

Notice that temperatures were in the single digits either side of zero here in Vermont this morning with subzero wind chills.

Then the next storm comes along, scooping a bit of mild air up from the south to give us a quick warm spell. Then the cycle repeats, over and over again. This is why the weather has been so changeable here in Vermont since Christmas: Warm to cold back to warm again.

The relatively flat east to west jet stream means most of the storms don't get a chance to become super strong. The last really substantial storm we had was on December 21 and 22, which caused flooding across Vermont. We've had six quickie storms since then, all of them pretty minor.

It's January, so it's not too hard for some pretty cold air to briefly bleed in between storms.

BOTTOM LINE FORECAST IN VERMONT

The first round of snow this week, late tonight and Tuesday
morning, will only amount to an inch or two for most
of us, with possibly even less than that in the Champlain Valley.

Here's how the next few days look The next one coming along tonight and Tuesday morning will bring some more relatively light snow, with patchy valley rain.

The strong winds, those 45 mph gusts in the Champlain Valley and 35 mph gusts elsewhere in Vermont, will peak late tonight and during the early and mid-morning hours on Tuesday.

Total snow accumulations with this initial burst will be one to three inches, with locally less than that in parts of the Champlain Valley.

There will be a lull in the action Tuesday afternoon and evening. No cold air will be able to sneak in during this time, so it will remain mild, with highs in the 30s to near 40 Tuesday and temperatures staying in the low 30s for most of us Tuesday night.

Another disturbance in this quick jet stream flow will come in late Tuesday and Wednesday. This one looks like it might be good enough to dump several inches of snow, perhaps two to six inches of powder, by Wednesday afternoon in much of Vermont.

The Champlain Valley might miss out again: It will be mild, so there, some of the precipitation, especially earlier on Wednesday might come down as a cold rain, which would minimize accumulations.

Overall, these frequent snows are great for winter sports prospects this month in the Green and White Mountains, and the Adirondacks.

After this relatively snowy period, the door will open for a piece of an Arctic high pressure system will break off and head south into New England, giving us the strongest, or nearly the strongest cold snap we've had all winter. This will hit next weekend, but don't worry too much about it.

Snow showers, mostly in the mountains, will continue amid the strong northwest wind gusts and falling temperatures Thursday, introducing a good three-day long cold snap.

It will be a run of the mill January cold snap, nothing we haven't seen before. We'll gethighs in the single numbers to near 10 and lows mostly in the 5 to 15 below range over the upcoming weekend. However, the west-to east race of storms will continue, though, so the cold snap won't last long.

It's possible, but not definite, that the next weather disturbance that originated in the Pacific Ocean could create a coastal storm that could dump some snow on us toward next Monday. That is highly uncertain but something to watch. One computer model gives us a substantial snowstorm, most of the others forecast not much of a storm and little or no snow for the region. We'll see.

Beyond that, the fast air flow across the nation will probably continue and our changeable, back and forth Vermont January weather will continue as it has since the start of the month.

Here are some of those weather video clips from the stormy West Coast.

First, a news clip about the mud slide along the Pacific Coast Highway:



Here's some footage of wind storm damage in Washington State from Saturday night and early Sunday morning: