Remember All That Snow In California Mountains? Now Causing Flooding

Spring has finally arrived in the snowbound high elevations of California's Sierra Nevada mountains.

The feet upon feet of snow is starting to melt amid above normal temperatures. As a result, flood warnings are up for many of the rivers in that region.

In many respects, this is good news: As we all know, a lot of this water is flowing into reservoirs for use in the summer and early fall, when it doesn't rain much at all in California.

Too much melting too fast can be a real problem though.

The National Weather Service says that campers and hikers and such should stay away from trails near rivers, and not set up camp anywhere near them. Peak flows and creek crests usually peak in the late evening and overnight.

Near Yosemite National Park, a flooding river fed by snowmelt stranded cattle on a newly formed island, forcing officials to airdrop food and hay for the 30 cattle there for two nights in a row.

A river in Nevada had been predicted to reach near record levels, which could have causes seriously flooding in some towns. However, flood projections have been scaled back somewhat.

There's still plenty of snow up in the Sierra, so heat waves going into June could really cause some serious problems. They're hoping for near-normal temperatures out in the western United States over the next few weeks.

The Nice Thing About Summer Storms Is Cool Clouds

Massive storm moving into Washington DC, last week. 

One thing I like about late spring and summer, when we're more likely to get thunderstorms, are the gorgeous cloud formations these storms form.

An example came Thursday in northern Virginia and the Washington DC area, when an immense, severe supercell thunderstorm moved over the region, as Capital Weather Gang noted. 

Like some of these supercells in the Midwest, this one looked like an alien mothership as it moved over DC.

When the storm moved on, people got a great sunset look at mammatus clouds on the real flank of the anvil at the top of the storm, too.

Wild mammatus clouds over Landsdowne, Virginia last week.

These clouds can be pretty creepy, but they're probably the least dangerous part of a supercell thunderstorm.

Usually, when you see them, the storm has already passed you by, so you're probably safe.

So go out and take a photo of those.  

Late last week, I flew from Vermont to Omaha, Nebraska via Atlanta. (Don't ask).

Our plane bound for Omaha zigagged around some strong thunderstorms that were producing flash flooding in parts of the Midwest.

It was probahly pretty nasty under those storms, but from the air they looked majestic, as you can see in this next photo I took from the plane.

Ah, summer. Some like the sunshine. Others, like me, like clouds.

Thunderstorms over the Midwest as seen from air somewhere
over the Midwest last Friday.

A Review: Heat And Storms Were Pretty Extreme In Vermont, New England This Week

Microburst winds of up to 100 mph shredded this camp
in West Addison, Vermont during severe storms Thursday
Image from television station WCAX in Burlington.

(Editor's Note:) I'm travelling this week, so blog posts might on occasion be a little spottier, and at times a little less frequent than normal, but keep checking, as I will be making every attempt to post frequently.)

Anyway, back to the weather.

And what a weather week! Record heat, and more important, the heat was broken by some exceptionally powerful, if brief thunderstorms.

 And yet, over eastern sectons of Vermont and New England, the heat returned Friday, even as it became chilly from the Champlain Valley westward.

Here are the details to recap:

We got going on Wednesday, with record warmth across all of Vermont and much of the Northeast, as noted in the previous post Thursday morning.

Then Thursday came. In Burlington, Vermont the temperature reached 93 degrees, tying the all time high temperature for any day in May since records got going in the 1880s.

This makes two of the five first months of the year tying or breaking monthly record highs in Burlington. (The previous February all time maximum of 63 degrees was shattered by a reading of 72 degrees this year.)

By the way, the low temperature in Burlington Thursday was 70 degrees. That set a record for the highest low tempeature for that date. (May 18.)  The old record was 63 degrees.

Elsewhere, record highs were broken by several degrees. Boston reached 95 degrees, beating the old record by five degrees. Hartford, Connecticut got to 96 degrees, beating the old record of 90.

Way up in the northern tip of Maine, Caribou got up to 90 degrees, the first time it's reached that level there since July, 2014.

As I was preparing to leave my St. Albans home for a trip
amid hot Thursday evening weather, I spotted this
strong storm abruptly take shape northeast of town. 

The even bigger story was the brief, but violent thunderstorms that erupted late Thursday afternoon. At that time, a cold front was still well to our west, but what's known as a pre'frontal trough came in.

These pre-frontal troughs are fairly common well ahead of a cold front during hot spells, and, if timed to come through in the afternoon or evening, often create severe thunderstorms. That's because these troughs add lift to the atmosphere already made volatile by heat.

Almost always, pre-frontal trough severe thunderstorms are hit and miss.  Some places get nailed, others stay in the sunshine.

But the people that get nailed really get hammered. In West Addison, a National Weather Storm survey team on Friday looked at the damage from Thursday's storm to see whether it was a tornado or straight line winds.

No tornado, it turns out, but it was as bad as one. A microburst, which is a blast of air from a severe thunderstorm that plunges to the ground that blows violently in a narrow path once it hits the ground, caused the havoc in West Addison.

In West Addison, the microburst landed just offshore in Lake Champlain and zoomed eastward onshore. It cut down a bunch of trees and hit a house, partially lifting off its roof and largely collapsing the structure. The house was destroyed, the National Weather Service said, by micoburst winds of up to 100 mph.

An occupant inside the house was slightly injured.  WCAX-TV reported the situation could have been even worse. The television station said the hosue was actually a camp that had been blown off its foundation and flipped upside down.  Linda Taft, 75,  and her dog were inside at the time.

As the house flipped over the couch she had been sitting on with the dog got tossed around, and she grabbed a pillow to cover her face as she tried to protect the dog.

Neighbors who rushed to help found the woman on the ceiling with the dog, and luckily both were n good spirits.

According to WCAX, one of the neighbors who rescued Taft quoted her as saying as she was being rescued, "I only had two glasses of wine tonight and I never got my third."

Taft was taken to the hospital to be checked out, but she's fine. Just bruised. She said she plans to rebuild the camp.

In Addison and elsewhere, large, wind driven hail blew out windows and dented cars. In Barton, fallen trees blocked the path of a train, and a tractor trailer was blown over. Statewide, 15,000 people or so lost electricity.

Measured wind gusts included 68 mph in Wells, Vermont and 58 mph at the National Weather Service offices in South Burlington.

By mid morning Friday, the cold front had moved into the Champlain Valley, but not yet further east. At mid-morning it was down to 50 degrees in Highgate. Meanwhile, eastern and southern areas got hot again quickly.

St. Johnsbury in eastern Vermont reached 91 degrees Friday for a new record high. On Friday, Boston and Hartford reached 90 degrees for the third day in a row.

In Atlantic Canada, places like Prince Edward Island and New Brunswick, which are coming off an unusually harsh winter, had record highs that got as far as 90 degrees on Friday.

Now, the weather has reversed again, and I really, really hope you didn't think the hot spell made it safe to put your tomatoes and peppers out.

There's areas of frost this morning. Tonight, frost advisories have been posted for the Adirondacks, north-central and northeast Vermont, and parts of New Hampshire and Maine. A section of far northern New Hampshire and western Maine are under more dire freeeze warnings. 

After tonight, the weather is certainly going to remain changeable for the foreseeable future, but not nearly as wild as it has been this week.

Here's a video from Roger Hill of one of the storms rolling into North Montpelier, Vermont

Northeast Heat Overperforms; Wild Weather Everywhere Today

A busy weather day for much of the nation today. Areas in
yellow have a slight risk of severe storms. Dark green
is a marginal risk. That hot pink area in the middle of
the country is a risk for strong tornadoes today. 

Every once in awhile, you get a day where there's lots of wild weather everywhere.

One of those is today. Including here in Vermont and the rest of the Northeast, though it's not nearly as heart-pounding here as it is in a few other parts of the country.  

First, I owe you a bit of a mea culpa. I said in yesterday's post that record high temperatures would not be broken Wednesday in Vermont, as the peak of the odd early season heat blast would hit today, Thursday instead.

Well, that heat really overperformed on Wednesday. Burlington set a record high of 91 degrees Wednesday, besting the previous record of 90, set in 1977.

Montpelier made it to 87, beating the record of 85 degrees back in 1977. And St. Johnsbury reached 89, edging out the 88 in 1991.

The heat is on today, as you may have noticed with the stuffy night we had last night.

More record highs might be set today, depending on clouds and wind speeds, but a few records probably will fall. The record high today in Burlington is 89 set in 1989, and that mark is definitely in danger.

You'll notice it's windier today than yesterday, so at least there's a breeze. But it's more humid, too, so there's that.

The wind will be especially strong in New York's St. Lawrence Valley, were gusts could reach 50 mph. And that doesn't even include the thunderstorms that might develop later.

NOAA's Storm Prediction Center has northern New York and the northwest tip of Vermont in the slight risk zone for severe thunderstorms.

A little disturbance ahead of a cold front might create a few isolated severe thunderstorms late this afternoon across the North Country. There won't be a lot of thunderstorms, but they'll be working with hot, gusty air, so a couple of those could get really strong.

Another line of storms ahead of a cold front will probably get into northern New York later this evening. Some of those will be severe, with high winds being the biggest threat. There's also the risk of big hail, and and even a teensy, tiny little chance of a brief tornado spin up, too. Heavy rains could accompany the storms.

This line of storms will likely start to weaken as they get into Vermont, but some might still be severe tonight, especially in western Vermont. So we'll watch that.

Yet another dramatic turnaround in the weather comes Friday, with much, much cooler weather. Highs will only be around 60 to 65 degrees, which is only a tad cooler than normal for this time of year, but it will feel dramatically different compared today.

I mentioned that this busy weather in Vermont is not as extreme as other areas of the country and that's surely true.

You'll probably hear on the news tonight and tomorrow of a very nasty tornado outbreak, especially in Kansas and Oklahoma. Conditions there are ripe today for strong, long lasting tornadoes, so that's certain a big danger. Hope the big tornadoes stay out in open country, and not blast through cities like Topeka, Wichita and Oklahoma City.

Meanwhile, in Wyoming and Colorado, a HUGE late season snowstorm was getting underway this morning.  Up to three feet of snow is forecast in the high elevations of Wyoming by Saturday. Areas around Laramie, Wyoming could see 20 inches of snow out of this, which is really something.

In Denver, a few inches of wet snow might accumulate tonight on fully leafed out trees. The weight of that snow would break quite a few branches and power lines.

So far at least, I haven't heard of any forecasts of maurading locusts.

Brief Blast Of Summer Heat, Today And Tomorrow, Then Maybe Summer Storms?

Winds blowing across the cool waters of Lake Champlain
will temper an early season hot spell today and tomorrow
along the immediate shores of the lake. 

This will be a shock to the system.

The heat blast we've been anticipating arrives today and peaks tomorrow with temperatures in a few towns reaching 90 or better in much of the Northeast, including Vermont.

We're not acclimatized to the heat, so if you have to work outdoors, like I do, try to do it early in the morning or in the evening, when it's a bit cooler.

Or do stuff right near Lake Champlain, especially along west and south facing shores.

Water temperatures are only in the 40s, and gusty southwest winds today and tomorrow will pick up that coolness and drive it onshore. I bet a few places along the southern tip of Grand Isle, for example, might not make it out of the 70s.

On the other hand, be careful about getting out on the lake. If you fall in, hypothermia can set in quickly. With expected gusty winds on the lake during this warm spell, you can capsize your boat. The water is too cold to stay in for any length of time with risk of death. Sorry to be so glum there, but that's the way it is.

By the way, us New Englanders don't do all that well with hot weather anyway, although that's probably true in a lot of places.

A recent study shows that in New England, hospital visits increase by 7.5 percent when the heat index is 95 degrees, as compared to days when the heat index is just 75 degrees.

Today's record high of 90 degrees in Burlington, Vermont looks safe, as temperatures should "only" get to the mid-80s there.

Tomorrow's record high of 89 is in jeopardy, though, as temperatures should get to 90 or so, unless the wind has a more westerly component and that cool wind off Lake Champlain reaches the Burlington International Airport, where they keep track of the temperatures at the National Weather Service office.

As noted, this is going to be a windy hot spell, with gusts to 30 mph or more in many areas. Some areas, like New York's St. Lawrence Valley, could get gusts of 45 mph today and tomorrow, which could lead to some minor tree damage.

A cold front will end the heat Thursday night, but that could lead to more trouble: Scattered severe storms in a few spots;

STORMS

Yesterday was, in fact, a bad day for severe storms and tornadoes across the nation, and that trend will continue the rest of the week.

At least one person died when a tornado hit a Wisconsin mobile home park. There were at least 26 reports of tornadoes, with the most damaging ones in Wisconsin, and around Elk City, Oklahoma.

Today should be a rough day, too, especially around Iowa and Wisconsin, where there is a threat of more tornadoes.

Tornado damage near Elk City, Oklahoma Tuesday. While
things won't get nearly this bad locally, a few severe thunderstorms
are possible Thursday evening in northern New York and
northwestern Vermont. Photo by Lacie Lowry. 

Thursday will probably be even worse, with an even higher chance of tornadoes and severe storms, especially in and around Kansas and Oklahoma.

And oh yes, as mentioned, our area could get a couple severe storms Thursday evening, too. That cold front I mentioned will be approaching, and some big thunderstorms will probably get going in Ontario late Thursday evening.

They'll then march across northern New York and into the Champlain Valley in the evening, but start weakening, especially from the Champlain Valley eastward.

Not everyone will get a thunderstorm Thursday evening. They'll be scattered. And only a few areas will get severe storms. This won't be a widespread severe event. But a few towns will have damaging winds, large hail, dangerous lightning and torrential downpours

If  you're out and about in the North Country Thursday evening and enjoying the summer weather, it's best to get inside if a storm comes in.

Mid-May Weather Pattern Created Extremes Around Northern Half Of World

Wildfires in Greece this week amid record early season heat
Photo by Aris Messinis, AFP/Getty Images

An especially wavy jet stream in the Northern Hemisphere is causing some pretty extreme weather in some areas of the world this week.

The jet stream - that upper atmospheric river of fast moving air that controls weather patterns, is experiencing wild bulges to the north in some areas, and deep plunges southward in others.

Depending on where these ridges and dips are and move the weather can change quite a bit.

As noted yesterday, this is affecting us here in Vermont: It snowed in some high elevations Sunday. By Thursday, a few towns in the warmer valleys of the Green Mountain State will be around 90 degrees.

As noted in Weather Undergrounds Category 6 blog, the weather elsewhere has taken some strange turns as well. Greece and parts of northern Africa are having some of their hottest May weather on record. It was as high as 105 degrees in one town in Greece, and Athens reached 92 degrees, its hottest day for so early in the season.

Brush fires broke out in Greece, killing one person.

Meanwhile, in parts of northern Europe, winter hangs on. Norway had its snowiest May since the 1960s. Parts of eastern Finland received six to 10 inches of snow on Mother's Day. In  Russia, bursts of heavy snow hit Moscow on May 11.

A snowy scene in Moscow on May 11

Meanwhile, back in the United States, parts of the Rocky Mountains, especially in areas of Idaho and Montana, a winter storm watch is in effect through Thursday because of expected heavy snow.

Part of the reason for the wild weather extremes and the wavy jet stream is something called a "negative NAO."  

NAO stands for "North Atlantic Oscillation."  Sometimes it's positive, sometimes it's negative, and there's a complicated index that tells you how positive and how negative it is. If it's really positive or really negative, weather can go off the rails.

A negative NAO can mean less than normal low atmospheric pressure near Iceland and less than normal high pressure in the subtropics. The weak pressure gradient helps give the jet stream more room to meander more to the north or south.

In the first part of May it the "NAO" was really  negative. That meant weather patterns that favored colder weather in the Northeastern United States and in northern Europe and hot weather in soutern Europe.

The NAO is trending toward zero, neither negative nor positive, so the weather is calming down somewhat. (By the way, when the NAO is positive, it tends to get stormy in western Europe, warm in the United States and frigid up in northern Canada.)

Yep, That Was Snow Higher Up On Mother's Day. Next Up: A Heat Blast

This photo was taken from inside a New Hampshire DOT truck
that was salting snow-covered roads in Plymouth, NH. Sunday. 

On Sunday, some higher elevation towns in parts of the Berkshires of Massachusetts, the Green Mountains of Vermont and especially mid and high elevations of northern and western New Hampshire got an unwelcome Mother's Day treat: Snow.

A few towns in New Hampshire were surprised by  four inches of it.  Along with power outages caused by wet, heavy snow weighing down foliating trees.

The summit of aptly named Mount Snow in southern Vermont got at least six inches.

This isn't the first Mother's Day with snow in New England and it probably won't be the last. I do remember a more widespread snow on Mother's Day, I think in 1996.

New Hampshire in particular had the snow because they were in the core of the weekend nor'easter's  heavy precipitation. The heavier precipitation cooled the atmosphere to the point where it was able to snow. It helped that the bulk of the precipitation came through New Hampshire at night, when it would have been cooler anyway.

You can see the results on a WMUR news clip on the bottom of this post.

The snow quickly turned to a light rain Sunday and the snow on the ground melted away.

New England is still under the influence of this nor'easter today, but luckily, no snow, except maybe in places like the tippy top of Mount Washington.

The problem today will be wind as there's a squeeze play going on between the departing nor'easter and high pressure coming in from the northwest.

Winds could gust to 40 mph throughout New England today, which, with trees now leafed out, ould bring down some branches and cause some local power failures. Leaves on trees act as little sails on trees on windy days, bending branches more than they otherwise would.

After that, we get another dramatic change. That high pressure in Quebec will drop down to a spot off the United States East Coast and strengthen. Southwesterly winds will pump summer air into New England by mid-week.

Quite a few 80s will pop up Wednesday, and if there's enough sunshine, a few spots could hit 90 degrees Thursday.

By then, a cold front will be approaching and thunderstorms could erupt by late afternoon, especially in northwestern New England, New York, southwestern Quebec and Ontario. A few storms could end up being strong. That'll be something to watch.

At the end of the week and next weekend, the weather will turn just about normal for this time of year, which will be nice after such a topsy-turvy weather week.

Here's that snow video from New Hampshire: