Today: Some Severe Risk New England; Ominous Tornado Threat Southern Plains

Areas in dark green have a chance of a
few isolated severe thunderstorms today.
Area in yellow has a somewhat greater
chance of severe storms, but this won't
be nearly as widespread as the dangerous
weather in the southern Plains today. 

1:15 p.m. Update

Maybe it's because I'm from rather tornado-free Vermont, but I'd be scared right now if I lived in Oklahoma.

As of this writing the National Weather Service was just about to issue a rare "Particularly Dangerous Situation" tornado watch for western and central Oklahoma.

Supercells are expected to explosive develop there in the next couple of hours in an atmosphere that has a rare combination of extreme factors that can form violent and long lasting tornadoes.

This kind of thing happens only once every few years, so forecasters are right that this is a very dangerous situation. Everyone in this region should be on high alert for the rest of this afternoon and evening. 

Here in the Northeast, things still aren't too bad as of 1 p.m. There are a couple of broken lines of storms forming, the most well developed one so far in east central New York and starting to run into southwestern Vermont.

This line will continue to develop and might cause some severe storms later this afternoon.  Other storms will develop, and some might still become severe, especially from the Green Mountains east.

Some storms were already developing near Burlington and near the Canadian border as of 1 p.m. Keep a watchful eye to the skies this afternoon for scattered strong to locally severe storms. We're still in line to get this.

At least it's not remotely comparable to the situation in Oklahoma.

UPDATE 10:15 a.m. Monday:

The first hints of a line of storms looks like they are about to form in the northwestern Adirondacks and then head east. There's still a chance of some scattered severe thunderstorms in Vermont and the rest of New England, starting in the northwest in about an hour or two.

The storms should be through Vermont by late afternoon, with the greatest but still uncertain risk of strong to severe storms in the eastern half of Vermont.

I'm thinking the Champlain Valley should be through the brief window of severe thunderstorm risk by about 3 p.m. or so.

Meanwhile, that high risk zone of potentially dangerous tornadoes today has been expanded slightly east to encompass the Oklahoma City metro area.

Earlier, Oklahoma City was still in a serious, but ever so slightly less dire Moderate Risk. People in Oklahoma and Texas should be ready to seek shelter at a moment's notice today. It's still a dangerous situation out there today.

PREVIOUS DISCUSSION:

The chances of some very, very dangerous tornadoes is high in the southern Plains today as the atmospheric conditions are almost off the charts to create such an ominous hazard.

That, of course, is the big weather headline of the day, and I'll get into the major threats in Oklahoma and Texas in a bit. But since we're in New England, I'll talk about a lesser, but still real threat of severe thunderstorms in our neck of the woods today.

I was surprised by the amount of severe weather in New York and Pennsylvania yesterday.  There were quite a few tornado warnings, though I don't know yet if any touched down in those states.

The severe weather made a run at southwestern Vermont, but the storms weakened a little just before reaching the Green Mountain State.

But it was a close call. There are no reports of significant damage in Vermont, but just over the western border into Fort Edward, New York and the Glens Falls area, it was something! Tornado warning went up west of Glens Falls, a roof blew off a house in South Glens Falls, and there was a ot of damage in Fort Edward.

Some of the storms in Vermont overnight produced torrential downpours, with up to three inches of rain reported near Worcester. That caused minor flooding and some areas of road washouts.

It's possible some of today's storms, if they're persistent, could cause some local flash flooding, but that problem won't be widespread.

We're still in a severe thunderstorm threat today in Vermont and the rest of New England. As always, only a few people will receive any severe storms, but stay weather alert.

A cold front will be intruding on warm, humid air in place right now. There was a round of thunderstorms early this morning, which often tends to stabilize the air and reduce the chances of severe weather.

But there will be some sun during the rest of this morning, and that will destabilize the air again enough to raise the threat of storms.

While anyplace in Vermont and the rest of New England could get a strong storm today, the best chances seem to be in the southeastern third of Vermont, most of New Hampshire, and western Massachusetts and Connecticut. 

The biggest threat from today's storms would be strong straight line winds. There is actually a very minimal but still real threat of a brief tornado in southeastern Vermont, western Massachusetts and New Hampshire. But nothing like what the southern Plains will experience today.

Conditions in Vermont will quickly calm down this evening and in the early part of tonight further east into New England.

So just go about your business, and if you hear a severe thunderstorm warning, just get into a sturdy house or building and wait it out. It won't last long.

SOUTHERN PLAINS DANGER

A rare high risk zone (in pink) today for potentially strong,
violent, long-lived tornadoes. Areas in red, including
Oklahoma City are at nearly as high of risk as the pink zone.

I can certain understand why a lot of people are worried about the weather today in northern Texas and Oklahoma. NOAA's Storm Prediction Center has declared a pretty rare high risk zone for significant and very dangerous tornadoes in much of that region, including the cities of Lawton, Altus and El Reno, Oklahoma.

This is the first high risk alert the Storm Prediction Center has issued for anywhere in the nation since May 18, 2017.

The much larger metro area of Oklahoma City is just outside the edge of the high risk zone, but still in a moderate risk zone for big tornadoes, which is something to take super seriously.

A lot of schools are closed in the Oklahoma City metro area today so that kids are not stuck in potentially unsafe schools, or worse, out on the road in school buses when dangerous weather hits.

Tornado outbreaks often peak around the time of the evening rush hour, so I imagine a lot of people in that region are calling in "sick" to work today, so they're not caught out on jam packed roads if dangerous weather hits.

Nobody knows for sure whether Oklahoma City and its populous suburbs wil get nailed today, but somebody will probably see a very bad tornado. Everyone hopes, of course, the worst tornadoes stay out in open country.

The wording on the Storm Prediction Center's advisory this morning isn't pretty: "This event should result in a significant threat to life and property," says the advisory. It adds that conditions are favorable for "long-track strong tornadoes and possibly violent tornadoes."

There will be at least two rounds of bad storms with this unusually strong storm system. The first is already creating severe thunderstorms in western Texas and those should grow and sweep across northern Texas and Oklahoma this morning and early afternoon. These storms will carry the risk of some tornadoes and large hail.

There have already been reports of baseball sized hail early this morning in northwestern Texas. Usually, you don't see hailstones that big with early morning thunderstorm. That gives you an idea of how volatile this situation is.

Then the second, most serious round gets going this afternoon into the evening. That's when the region I described is under the gun for violent tornadoes, hail up to the size of softballs and straight line winds of 80 mph or even more.

Not everybody in this area will get some extreme weather, but a few places probably will. This will be in the news headlines tonight and tomorrow.

Tornadoes obviously capture attention, but another big threat is looming with these storms, especially up in Oklahoma and in particular the Oklahoma City area.

It's been wet there, and extreme amounts of rain will accompany these dangerous, tornadic thunderstorms. There's a high risk of flash flooding in central Oklahoma today, says NOAA's Weather Prediction Center.

It's only somewhat more common to have a high risk zone for flash floods than a high risk zone for tornadoes. Whatever the case, Oklahoma and some surrounding areas are in for a very, very rough day.

Severe Storm Threat Definitely On Today In Vermont, Surrounding Areas

We here in Vermont are in the middle of a severe
thunderstorm risk today. Strong straight line winds are
the big

When I got up this morning and looks up at the clouds, they were screaming by, north to south. If Vermont State Police could catch them, they would issue speeding tickets for sure.

Those speeding clouds are a sign that we are in for severe weather. I was looking up at something called a low level jet. It's essentially a package or river of fast moving air just a few thousand feet overhead.

Under the right conditions, thunderstorms can "grab" this high speed air and bringing to the surface in the form of very damaging wind gusts.

We have most of those right conditions today.

A cold front is approaching from the west. If you've been outside, you noticed it has turned humid again. And we have that low level jet.

The only thing missing is a lot of sunshine. That would destabilize the air even more, making severe thunderstorms more likely. Watch the skies between 9 a.m. and 1 p.m. today: If there's a lot of sun, the severe thunderstorms goes up.

The main risk in today's storms is those strong, damaging wind gusts. Of course, not everybody will get that, but a few to several places probably will. The current thinking is the  thunderstorms coming in today will probably in the form of a broken line heading east.

Watch out in particular for sections of this line of storms that form something that looks like  a backwards "C" on radar. Those are called bowing echoes. The apex of the backwards "C" is an area that will be especially dangerous for destructive winds.

While not a high threat, there is a slight chance of a tornado or two. A tornado would be most likely if a storm forms ahead of the main line of rough weather and starts to rotate. We could get a supercell or two out of this, anywhere in eastern New York, Vermont, New Hampshire and perhaps points south.

NOAA's Storm Prediction Center is giving us a
very slight, but non-zero chance of a couple
tornadoes today. 

Of course the chances of seeing a twister are low. Vermont and New Hampshire are in a 5 percent chance zone for a tornado. That means if you are in these two states, there's a 5 percent chance a tornado will touch down within 25 miles of you.

You see, a slim chance, but not a zero chance. Already, there were brief tornado warnings earlier this morning in western New York and western Pennsylvania.

By the way, southern Quebec, including Montreal is under the gun for all this potential severe weather, too. The Ottawa area, which saw devastating tornadoes last Friday, is under a much lesser threat today.

The biggest threat for severe storms today will be between 1 p.m. and 7 p.m.

The National Weather Service in South Burlington,  ermont is thinking the main line of storms will form in northern New York between 1 and 3 p.m this afternoon, then reach the Champlain Valley around 4 p.m., give or take, then be out of Vermont and into New Hampshire by 8 p.m. or so.

If you've got lawn furniture and loose objects outside, I'd bring them inside or tie them down this morning in case strong thunderstorm winds hit.

If you have plans to go boating or hiking today, cancel those plans. Go tomorrow instead. The weather will be gorgeous by then. Trust me.

Also, today's the wrong day to park your car under an old, rotting tree.

There is a decent chance National Weather Service will issue a severe thunderstorm watch or even, possibly, a tornado watch later this morning or early this afternoon. That would be a signal to go about your business as usual, but keep your ear perked up for potential warnings.

If you get a severe thunderstorm warning, get inside a sturdy building and stay away from windows. (In a worse case scenario, flying debris in strong winds could break the glass.)  In the off chance you get a tornado warning, just go to the basement in a sturdy building. If there's no basement, get into an a room with no windows closest to the middle of the building.

Some of these storms will also have torrential, blinding rain. The storms will move fast and not linger over any one place for a long time. That means that there will be no substantial flooding. But the rain will be so intense that street flooding can occur in an instant. Drainage ditches and small streams could turn pretty wild pretty fast, too.

It all clears out this evening, and it's back to delightfully crisp, sunny fall weather Thursday.

Quick Update: Brief New England Chill; Big Florence Menace

Deep blue skies over St. Albans, Vermont this morning, a hallmark of
a chilly September morning. 

As expected, it got cold early this Sunday morning in the North Country.

Saranac Lake, New York, as usual, seemed to be the cold spot with a low of 26 degrees. Several spots in northern Vermont dropped below freezing, and this wasn't just limited to the Northeast Kingdom frost hollows.

For instance, Morrisville got down to 31 degrees. ropped to or below freezing, so it was frosty in some places. Montpelier came close to freezing with a low of 35 degrees.

The 42 degrees at Burlington, Vermont this morning was the chilliest reading since May 21. All this isn't too unusual for second week of September. The record low for Burlington this morning was 37 degrees, so we weren't too far off. But this kind of thing happens from time to time.

We have two more days of cool weather to go, but no more frost pockets. Today will get into the 60s - similar to yesterday. You'll notice high clouds increasing during the day, too as a storm system that contains the remains of Tropical Storm Gordon moves towards us.

Monday will be breezy and raw, but it will be worth it as rains from that storm move in. High temperatures will only be in the 58 to 65 degree range for most of us. Again, not all that odd for September, but we're still not used to it.

That storm looks like it will drop perhaps 0,75 to 1.50 inches of rain on most of us. That rain is badly needed and we'll take what we can get. There will be a few locations that will lose out and get less rain, and other areas that will be big winners, with two or more inches of rain.

Starting Tuesday, we're in for a long period of warmer than normal temperatures, but it won't be the 0 degree heat and terrible humidity we had last week.

FLORENCE A BIG MENACE

Satellite image of Tropical Storm Florence early this morning
show a much better organized storm with a developing eye.
This photo likely represents the beginning stage of
a rapid intensification. 

Once a tropical storm gets into an environment where it can develop quickly, it often takes a day or so to get its act together.

Tropical Storm Florence, weakened and disorganized by strong upper level winds late last week, has spent the past 24 hours getting its act together before it could strengthen much.

Since yesterday, the storm has gotten more symmetrical, with dense clouds concentrated more toward its center. 

Which means it's now ready to explode into a monster. Satellite photos of the storm taken during Sunday morning indicate Florence is now beginning that rapid intensification.

The National Hurricane Center will very likely upgrade Florence back to a hurricane by late this morning.

Florence still appears to be a terrible threat to the southeastern United States by Friday. It looks like it will make landfall, possibly around North Carolina late Thursday or early Friday. This forecast could change, as hurricanes are unpredictable and Florence has been particularly so.

Current projects for the path of Florence. It's important to note this
is NOT a final forecast and its path could change

Of course, the strong winds of a major hurricane like Florence is expected to be are extremely destructive.  But the worst of such winds cover a relatively small area, perhaps a stripe that's 50 to 100 miles wide that goes inland for a few dozen miles.

Awful, yes. But this might not be the worst aspect of Florence.

Some computer models suggest might stall around North Carolina or Virginia for several days.

That scenario would dump a few FEET of rain on the area, and lead to the catastrophic flooding. This idea of Florence stalling is comparable to Hurricane Harvey last year, which stalled in Texas and giving that area some of its worst flooding in history.

This stall might or might not happen, but it's certainly something to watch.

Meanwhile, Tropical Storm Helene way out in the eastern Atlantic looks destined to stay well out to sea. Tropical Storm Isaac, however, is a potentially scary hurricane threat to the Caribbean.

Dangerous "Atmospheric River" To Cause Mid-Atlantic, Northeast Flooding

Three to seven inches of rain, and locally higher amounts, are
likely, especially in the red areas of this map during the next seven days.

An atmospheric river is set to dump tremendous amounts of rain on a broad strip running north and  northwestward off the Atlantic Ocean through areas around North Carolina and Virginia, northward through Pennsylvania and central New York. 

That means these areas need to be really, really on guard for serious flooding over the next few days.

First, we need to define for us all what an atmospheric river is. I'll let NOAA do it:

"Atmospheric rivers are relatively long, narrow regions in the atmosphere - like rivers in the sky - that transport most of the water vapor outside the tropics. These columns of vapor move with the weather, carrying an amount of water vapor roughly equivalent to the average flow of water at the mouth of the Mississippi River.

When the atmospheric rivers make landfall, they often release this water vapor in the form of rain or snow."

The problem is, atmospheric rivers often release extreme amounts of rain, causing extreme floods.

Atmospheric rivers are to blame for extreme floods around Nashville, Tennessee in 2010; and another extreme, deadly flood around South Carolina in October, 2015 that dumped up to two feet of rain in that state.

Not all atmospheric rivers are bad. They're common in California in the winter, and help replenish reservoirs and add to the snowpack in the Sierra Nevada mountains. Melting snow in the summer then keeps reservoirs and drinking water supplies at reasonable levels.

Like anything in weather, atmospheric rivers vary in intensity. Some aren't too tough to take, dropping a few inches of rain on a drought-stricken area, for example.

But often, they are terrible. And they can unload their tremendous rainfall well inland from wherer they come ashore -- like in the 2010 Tennessee flood I just mentioned.

The atmospheric river slated to hit parts of the East Coast this week is being created by a really wonky weather pattern now in place.

Usually this time of year, the jet stream, which controls the paths of storms and fair weather systems, sputters in a general west to east course near the United States/Canada border. In July, there's rarely much in the way of big southward dips or huge northward bulges in the jet stream.

There's an exception going on now and the weather pattern is really off the rails.  There's a big dip in the jet stream centered over the Great Lakes. This dip is causing unusually chilly weather for this time of year near the Great Lakes, and strangely severe storms in the South. Those storms created hail as big as tennis balls in Georgia and some other southern states.

Meanwhile, the Bermuda high is pushing a big heat ridge northward in the western Atlantic Ocean. Part of the Bermuda High has pushed as far north as Nova Scotia.

This is setting up the atmospheric river flowing northward from the tropics between the big Bermuda High to the east and the dip in the jet stream to the west.

This pattern is kind of stuck until later Thursday and Friday, when things will start moving. So the heavy rains will keep going over the same places from North Carolina  to New York through then. This could extend into southwestern Quebec as well.  Remember, this is tropical moisture, so any showers and thunderstorms can create one to two inch per hour rainfall rates.

This can cause life-threatening flash flooding. There was already destructive flooding and water rescues in Pennsylvania this morning.  That flooding will likely worsen this afternoon in parts of Maryland, Pennsylvania and the southern tier of New York.

We here in Vermont are on the eastern edge of this atmospheric river pattern. That means we are subject to the torrential downpours, but not the constant fire hose of rain. I noticed during a batch of rain that moved northward through Vermont this morning, an inch of rain fell on Rutland in just an hour.

We desperately need the rain here in Vermont, so precipitation this week is a good thing. We still have to watch out, especially Wednesday night and Thursday, when the axis of heaviest rain will probably shift to near or over the Green Mountain State.

Despite the dry conditions, an excessive downpour, or a series of downpours going repeatedly over the same spot, can cause dangerous flash flooding. It's impossible at this point to determine if, or even whether Vermont will see any flash flooding from this system.

The National Weather Service is eyeing the possibility of that happening, so stay tuned.

Starting To Worry About Irma A Little

Hurricane Irma looking ominous on satellite photos
this morning

Lots of places now need to watch out for massive Hurricane Irma. 

Forecast tracks for Irma are still not set in stone, of course, but we are starting to get some clues as to where it's headed, and the news is not great.

First in line are the northern Leeward Islands, basically the eastern entrance to the Caribbean, where hurricane watches are up.

And the National Hurricane Center has this to say:

"Interests in the remainder of the Leeward Islands, the British and U.S. Virgin Islands, Puerto Rico, and the Dominican Republic should monitor the progress of Irma."

While you're at it, you might start throwing in the Bahamas and Cuba for places that should watch Irma.

Irma still had maximum sustained winds of 115 mph early this morning, and the storm looked healthy on satellite images. Irma is now moving into even warmer ocean water, which could easily favor more strengthening.

A lot of forecasters are pretty confident Irma will rise up to Category 4 strength soon.

Overnight, the forecast models shifted the expected path of Irma a bit south and west in the long term, which puts the United States more at risk.

It's still possible the models could shift back away from the U.S. Any threats to the United States mainland are a week away, so huge changes in forecasts are still likely.

For now, the threat is anywhere on the East Coast, with an area from Florida to the Carolinas most at risk. Again, this is NOT definite. It's just something for people in these areas to keep an eye on for now.

Already, though, I see reports of store shelves in Florida cleared of bottled water and other supplies.

It is probably smart to get ready now, so you don't have to do a rush job amid a panic. If the storm ultimately misses, people in Florida and elsewhere will have supplies, and practice for the next time there's a hurricane threat.

California Rains Are Wonderful! California Rains Are Horrible!

Car stuck in floods n Sepulveda Basin in southern California's
 San Fernando Valley on Tuesday. Photo from KTLA. 

Talk about double-edged swords: A series of storms that might last two weeks or more began in California last night.

The storms promise to drop inches and inches of rain onto the parched landscape, definitely eroding a multi-year drought, perhaps the severest in memory.

Many feet of snow will accumulate in the Sierra Nevada mountains. That's also great news: If it keeps accumulating like crazy, there will be plenty of melt water flowing from the mountains into the state's nearly empty reservoirs.

Who can complain about that?

Well, everybody. California's landscape is not good at big rainstorms. There's steep slopes that can become saturated and turn into deadly mudslides.

There's been a lot of wildfires in California in the past few years because of the drought. In areas where vegetation has burned away, there's nothing to hold the soil in place. That increases the risk of mudslides and debris flows.

Flash flooding is also common when it rains hard in California.

Ideally, the way to break the California drought is to have daily light rain and drizzle all winter to soak into the ground and restore the aquifers after such a horrible drought.

However, that's not how California winter storms work, especially in years when there's a strong El Nino, like this one.

In the short term, the first storm so far has created some local floods and mudslides and debris flows in California, but nothing hugely destructive so far.

There was flooding on the 101 Freeway, and boulders fell on the Pacific Coast Highway in Malibu Canyon, the Los Angeles Times reported. 

More flash flooding is possible Wednesday, but it looks like there might be a break in the rain over the weekend and early next week, which is a good thing.

Beyond that, the parade of storms coming off the Pacific Ocean could feature bursts of heavy rain that makes flash flooding more likely, despite the drought.

This problem could keep getting worse if the storms keep coming through the rest of January, February and into March. The steep hills will get more and more saturated, and will become more likely to give way, sending walls of mud into densely populated neighborhoods.

The damage from floods could get pretty nasty too. Everybody is especially worried about the area around Sacramento.

It's widely believed that Sacramento has the second biggest flood risk of any metro area in the nation, behind New Orleans. And we all know what happened to New Orleans when Hurricane Katrina hit in 2005.

As the Sacramento Bee put it:

"A levee breach in Sacramento could cause many deaths and cripple the economy for 1.4 million people in the metro area who depend to some degree on the city of Sacramento staying dry."

As I noted El Nino storms tend to have a lot of juice, a lot more moisture and energy than storms that happen when there's not an El Nino. You could also get a series of so-called "Pineapple Express" storms, which are basically huge atmospheric rivers that tap deep tropical moisture and spray it like a fire hose onto sections of the West Coast.

Plus, climate change has, in general, made rain storms more intense, since warmer air can hold more moisture than cooler air.

Indeed, there have been more frequent extreme floods in recent years and decades. Ask anybody in Missouri, or South Carolina, or Texas, or where I live in Vermont.

I am being all gloom and doom here, I realize. If we're lucky, if California is lucky, the floodig and mudslides won't be too bad. Maybe there will be frequent dry breaks between storms allowing the water to soak into the ground. That would help end the drought without causing too many flash floods or mudslides.

If we're lucky, California will have a gloriously wet winter without anything too extreme.

If we're lucky.

Hawaii Braces For Rare Hurricane, Another One Will Then Harrass State

Hurricane Iselle spinning toward Hawaii yesterday.  

Hurricane Iselle was still making a beeline for the Big Island of Hawaii Thursday morning, and it could become the first hurricane on record to hit that particular island in the Hawaiian chain.

Hurricane Julio is coming right behind Iselle, but it looks like Julio will curve north of the islands, but will probably come close enough to cause some more wind and more flooding

That two tropical systems would threaten Hawaii in one week is unprecedented, notes Mashable.

Hurricanes thrive on warm ocean water, and die when the water gets cooler.

Hawaii is normally sort of protected by normal ocean currents that keep the water surrounding the island kind of on the cool side. So hurricanes usually, but not always,  die before they reach Hawaii.

Ocean temperatures in much of the Pacific Ocean, including in areas near Hawaii, are warmer than average, which gives tropical storms a kick in the pants to stay alive.

In fact, the forecast with Iselle kept getting worse over the past few days.  As Iselle headed toward colder water, it was expected to weaken into a tropical storm. But shifting winds in the upper atmosphere that usually tear hurricanes apart didn't materialize yesterday, so Iselle actually strengthened a bit.

Now, it's entering cooler water and those upper level winds, called shear, are starting to affect Iselle. It may or may not be a hurricane by the time it reaches the Big Island, but whether it is a hurricane or just close to it is just a matter of semantics.

Since Hawaii doesn't usually get such strong winds, trees and structures aren't able to withstand winds of 50, 60, 70, or 80 mph like in some other areas of the United States. So wind damage might be worse than if it hit, say, Florida, where there are somewhat stronger building codes.

Or, buildings that were up to code in Hawaii might have issues nobody knows about because there hasn't been strong winds in such a long time.

The rain is going to cause flooding too. Water will rush down the steep slopes of the islands. They're expecting 5 to 8 inches of rain in many areas, with some spots reaching a foot. The flash flooding and landslides might be terrible.

As I said, this might end up being the first time the Big Island of Hawaii, the easternmost one, is hit directly by a hurricane.

More western islands in Hawaii, where the water temperature is a little warmer, have been hit by hurricanes before.

The most noteworthy was Iniki in 1992, which hit the island of Kauai with 140 mph winds. It killed six people and caused widespread damage.

Here's a video of Iniki lashing Kauai Island in Hawaii in 1992. It's from a Discovery Channel show called "Destroyed in Seconds." After the narrator sets up the scenario, things get scary 45 seconds into the video:

Don't Let The Showers Fool You: Fire Danger Is High

We just endured a flood last week. The soil out there is still damp and wet. It rained in much of of the Northeast the past couple of days. There was even hail and thunderstorms on Cape Cod Wednesday.  

A firefighter works to extinguish a forest fire
near Bristol, Vermont last spring. The fire
danger is high again in the Northeast today.  

No need to worry about brush and wildfires here fire, right?

Wrong, wrong WRONG! Very wrong.

This time of year, there's lots of dry, dead stuff from last summer. Things haven't really greened up yet, so that dry, dead stuff can fuel dangerous brush and forest fires.

And never mind that it rained yesterday or the day before. This stuff dries out quickly in the April sun. (There's no leaves on the trees yet to shade this dry dead material in the fields and on forest floors. )

All it takes is weather like that forecast today and you can get big fires quickly.  Those fires can spread to houses and other buildings pretty fast.  We had days last spring when forest and brush fires damaged a couple buildings in Vermont, and threatened many more.

Across the Northeast, it's going to be sunny and windy today. The humidity is going to be very low.  Sometimes, in April, humidity here can drop to desert-like levels because there is no foliage to add moisture to the air.

The result is, there is a very high fire danger across most spots from Maine, New Hampshire and Vermont all the way down into the Mid-Atlantic states.  Red flag warnings and special weather statements are up across the region warning of the fire danger.

Today is NOT the day to burn your brush pile. Or carelessly throw cigarette butts out your car window. Or for children to play with matches.

These fires can get surprisingly big and fast. Just the other day near St. Johnsbury, Vermont, despite rain a few days earlier, a nine-acre brush fire threatened electric transmission lines and a neighborhood. 

So, don't be careless with fire. And let that brush pile sit until it rains again. Which will probably be this weekend.

Severe Weather Threat To Last Three Days In Vermont

UPDATE 1 p.m. TUESDAY:  

I think the chances of severe thunderstorms this afternoon and evening have diminished somewhat. the National Severe Storms Center says so, as does the National Weather Service in South Burlington.

Their logic is too much warm air is moving in aloft, that would "cap" the development of storms. By that I mean it will be harder for the towering clouds of thunderstorms to form today than first thought.

Also there's quite a bit of cloudiness lingering behind this morning's rain. The clouds will block sunshine, which would otherwise heat the atmosphere and encourage thunderstorms to form.

Still, there might be a few pop up severe storms here and there across northern New York and New England today and this evening. I just don't think there will be a huge number of such storms.

PREVIOUS DISCUSSION:

I don't think I've ever seen anything like this: There's a chance of severe thunderstorms in Vermont for three days in a row, starting today.

A severe thunderstorm over St. Albans Bay, Vermont
in July. Similar scenes are quite possible in Vermont
and surrounding states today, Wednesday and Thursday.  

Severe weather is fairly rare in September. Three days in a row is pretty wild for this time of year.

Let's break it down: First, today: 

A cluster of showers and thunderstorms was moving through northern New York, Vermont and into New Hampshire Tuesday morning. While there are some downpours and lightning strikes with this, none of the weather is severe.

Once the cluster of storms goes by noon, you'll notice it abruptly turning humid. That will be one ingredient for possible severe storms later this afternoon.

The other ingredients are rising pockets of air, high upper level winds and something called shear. That's when winds change directions as you rise up through the atmosphere.

Those ingredients combined can set off lines of severe storms or supercells, the long lasting, giant thunderstorms that can produce tornadoes in some instances.

Working against the chances of severe storms today is this morning's rain. It tends to stabilize the atmosphere somewhat. Plus, a layer of warm air way up above us could put a "cap" on rising air currents, and that might discourage thunderstorms.

Still, I, and most other forecasters,  think some storms will get going in northern New York and northern New England today, and some of those might get severe, with strong winds, hail, and maybe even a brief, isolated tornado somwhere in this region.

Not everyone will get hit, but keep an eye to the skies later this afternoon and this evening. Things could get nasty.

Then we get into Wednesday.

On Wednesday it's going to be strangely hot and humid for mid-September. Temperatures could get up to 90 degrees in cities like Burlington, Vermont and Albany, New York. (The record high Wednesday in Burlington is 95 degrees. I don't think it will get that hot)

It'll be oppressively humid, on par with some of the most humid weather we've had all summer.

All that heat and humidity, along with an atmosphere that will continue to favor strong updrafts and changing wind directions, could set off more severe thunderstorms in a zone from northern New York through the northern half of Vermont,  northern New Hampshire, and into western Maine

The threat will be roughly the same as today: Not everyone will get hit, but some areas could get damaging winds, big hail, and maybe even a brief tornado. The risk of bad storms is greatest in the afternoon and evening.

One more day, Thursday.

We'll wake up Thursday morning to another oppressively humid morning. A cold front will be coming at us from the west.

The timing of the cold front will determine who has the biggest risk of severe storms. If it's a little fast, New York and Vermont could just get heavy rain with thunderstorms while the high winds, hail and slight tornado risk are more to the south and east.

If the front is slower, then New York and Vermont fall under the risk.

The front goes by later Thursday, and it's back to autumn and no severe storms by Friday.

This three day run of potentially hazardous weather in the Northeast is really odd for this time of year, as I've said. But severe weather isn't unheard of in the fall.

Way back in 1845, an incredibly large, long lasting tornado formed near Lake Ontario and traveled 200 miles across the Adirondacks, holding together despite the mountains, finally dissipating near South Burlington, Vermont.

In September, 1821, several damaging tornadoes hit Vermont and New Hampshire. 

More recently, a large tornado killed three people and caused major damage in 1979 around Windsor Locks, Connecticut. 

And last year, on September 8, all of Vermont was under a tornado watch, though no tornadoes are known to have developed in that outbreak of severe weather.  Here's a video of the storm I took last September 8 in Charlotte, Vermont. No tornado, but pretty stormy: