Storms In Hawaii Cause Widespread Flooding, Other Havoc. Worst In Years

Torrential rains in Hawaii made this house
slide down into a raging river as a 
long lasting, severe storm rakes the
islands. Photo via Facebook, 
Dillon Mitchell 

A week long storm is easing - but not quite done - as Hawaii once again reels from widespread flooding, wind damage and landslides. This storm was the worst in a series. 

As Forbes reports:

"Governor Josh Green declared a state of emergency as the week-long onslaught of rainfall, landslides and infrastructure damage continued into the weekend."

Forbes continued: 

"'Maui got it even worse and locals describe that the whole island feels like it is underwater,; wrote his Dodds in Surfer. He continued: 'The steep slopes around Haleakala turned into walls of mud, rock and debris moving at terrifying speed. Some are calling it the worst rainstorm in the island's modern history.'"

Rainfall amounts were incredible. A site in Maui recorded a five-day total of 44.37 inches of rain. Other sites on Maui had 25 to 35 inches of rain over those five days. 

On the big island of Hawaii, Mauna Loa had 25.45 inches of rain in five days with other sites on the Big Island coming in with over 20 inches. A few locations on Kauai and Oahu reported nearly 20 inches of rain over that five-day period. 

Those rainfall amounts were even greater than forecasts, which were themselves ominous. 

On Maui, roads became rivers, with vehicles floating in them like leaves in a stream. In one neighborhood, a large storage container joined the vehicles that had floated downstream. Tourists could not cross the rushing water on the streets to make it back to their condos. It was too dangerous. 

 Power outages have kept coming in recent days even as crews have worked in the storms to restore power. More than 120,000 Hawaiian homes and businesses were without power Friday. That number was at around 114,000 on Saturday. 

More than 100,000 Hawaiians were without power Saturday. 

The Hawaii Department of Transportation reported parts of numerous roads closed due to the heavy rain and flooding

In Waikiki, news video showed high winds and sheets of heavy rain, making the streets look like they were enduring an approaching hurricane. Streets and sidewalks were louder water. In a luxury shopping district, an enormous tree collapsed in the storm, blocking most lanes of a wide, busy avenue. 

Nearly an hours's drive from Waikiki on Oahu's North Shore, things were even worse. Major roads, fields,s, and even a major beach access were under muddy water because of the relentless rain 

Video from Maui showed a house collapsing into a swollen river. Sections of roads have collapsed, some taking cars and SUVs with them.  

On the Big Island, Kilauea volcano complicated things further. Just before the storm, an eruption created a rain of tephra (chunks of lightweight lava, debris and ash) on areas surround the volcano. That's the second time this winter such an event happened, and this one was more extensive than a tephra fall back in January.  In some places six inches of tephra accumulated.

Cleaning up that mess was complicated by the heavy rains. And I imagine the tephra clogged ditches and brooks somewhat, which would exacerbate flooding. 

If this post sounds kind of familiar, it's because we reported on another destructive storm back on  February 11.  It's been an incredibly rainy, windy winter in Hawaii

As I earlier noted, the storm over the past few days far outdid and out-damaged all the other previous storms this winter.   

Some of the storm's origins came from as far as the southwestern United States. The building heat wave and strong dry high pressure is causing a blockage in the atmosphere, allowing a train of storms to blast through the Hawaiian Islands. 

The principal storm was know as a Kona Low, which frequently occur in Hawaii during the winter. Usually winds in Hawaii blow from the east. A Kona Low forms when winds shift to the west or southwest, bringing much more humid air from the tropics. 

Because of the usual trade winds, the wettest parts of Hawaii are on the north and east side of the islands. South and west sides are actually pretty dry. The Kona storms, with their high humidity and southwest winds, can drown the the drier parts of the island. 

The storm is easing as to today. Instead of wet southwest winds, or the usual east to northeast trade winds, the breezes are slackening to near calm. That'll keep showers going all week across the islands. There's the risk of yet another Kona storm towar

 

Los Angeles Bracing For Scary Christmas Storm

The most severe Christmas storm since at least 1971
looms in the Los Angeles area as atmospheric 
rivers continue to batter the West Coast. 

Perhaps the scariest of the barrage of atmospheric rivers tormenting the West Coast is now targeting the Los Angeles area. 

The heavily populated, sprawling area around Los Angeles, the coast north and south, and the mountains to the east all face torrents of rain and strong, damaging winds. 

In their forecast discussion this morning, the National Weather Service wrote in all caps, that I'll avoid, "This is a very dangerous holiday storm. Anyone traveling on Christmas Eve or Christmas Day will need to exercise extreme caution. Make sure to take the proper action before the storm hits."

The rain is starting today, then turn more intense tonight, and peak tomorrow morning. Rainfall rates during the peak hours of the storm in and near Los Angeles will be somewhere around an inch per hour. 

Total rainfall between now and Christmas in southern California is forecast to be in the four to seven inch range, with locally higher amounts. 

NOAA's Weather Prediction Center has put parts of the L.A area under a rare high risk zone for a "significant  threat of flash flooding, landslides, rock falls and mud slides. The greater than normal travel during the Christmas holiday will likely expose a potentially larger number of people to these life-threatening hazards."

On Tuesday, as light rain began making inroads in Los Angeles County, residents were stacking sandbags and other barriers in Pacific Palisades, Altadena, Malibu and other areas where there were big fire last year. They're hoping debris flows won't outmatch these efforts. Crews were also installing Jersey barriers in hopes of diverting landslides away from vulnerable homes. 

Some debris-prone roads, like Topanga Canyon Boulevard, were closed even before the first drops of rain fell. 

Thousands of people have been told to pack "to go" bags and be ready to evacuate at a moment's notice.  

High winds will complicate this whole mess. In the L.A basin, winds could reach up to 55 mph, and in the foothills and mountains nearby, those winds could reach as high as 80 mph. 

As the soils get soggier and soggier, it'll be easier and easier for the wind to blow trees over. 

The intensity of the storms should wane somewhat by Christmas Day, but scattered downpours will continue to vex the L.A basin.

Further north in California, atmospheric river storms that caused serious flooding in the Sierra Nevada foothills have diminished somewhat. But more rain, sometimes heavy and mixed with thunderstorms, will continue the flood risk.  There's even a low risk of brief spin-up tornadoes with the thunderstorms. 

High winds warnings remain in effect until the afternoon of Christmas Day for a wide area of central and northern California. 

Meanwhile, in the Sierra Nevada, several more feet of snow are expected in the next few days. 

Pacific Northwest Braces For Atmospheric Rivers, Flooding Over Next Few Days

Atmospheric rivers could bring up to 10 inches
of rain in the next few days parts of the Pacific
Northwest, raising flooding fears. This map is
forecast rain for the next 7 days. 

The Pacific Northwest has a wet, dark reputation this time of year. The people are nice enough, the weather is not. Sufferers of seasonal affective disorder will do well to avoid places like Seattle and Portland this time of year. 

Usually, it's a grinding, boring day after day realm of drizzle, light rain, fog and chill. Sometimes, though, things can really get out of hand. 

The next few days look what one of those out of hand periods.

A strong atmospheric river is due to hit Washington and Oregon beginning tomorrow and lasting through much of the week. This long lasting deluge is sure to cause at least some flooding and landslides as inches and inches of rain bombard the western halves of Washington and Oregon. 

Some areas of Washington and Oregon could get four to as much as 10 or more inches of rain by Wednesday night.   The Willamette Valley, which runs roughly from Portland to Eugene, Oregon, is expecting three to five inches of rain. 

The Seattle metro area could get two to five inches of rain, which means clogged drains and street flooding, landslides on steep slopes and shallow-rooted trees toppling over as soil turns to loose mud. 

But the real problem looks like it will be in the Cascade Mountains east of Seattle and Portland, and the Olympic Mountains of northwest Washington. 

Five to ten inches of rain could pour down on these mountains, which would quickly race down steep slopes into populated valleys below.  

The atmospheric river - really a series of atmospheric rivers - are tapping into tropical moisture which of course involves warm air. That means snow levels will be high.  You'll probably have to get above 6,000 above sea level to hit snow. That leaves only the higher peaks and volcanoes in the wintry weather. . 

The higher the snow level, the more water will race down the slopes, which is why everybody is so worried about flooding. Flood watches are up for all of the western third of Washington and much of western Oregon. 

Officials in both states said people in flood prone areas should have spent Saturday and as much of the day Sunday as they could getting ready for high water. 

It's always hard to predict exactly how high rivers will get in these situations. But the flood-prone Snoqualmie River is forecast to reach near major flood stage Tuesday, then have a secondary major flood stage peak on Thursday. 

Some of the flooding could extend across the border to Vancouver Island and other areas of southwest British Columbia, Canada, but the worst effects still look like they'll hit south of the border. 

The Cascade Mountains will wring out some of the moisture, so eastern Washington won't get much rain. But the storms will then hit the mountains of Idaho and western Montana, where more rain and snow will fall.

The snow levels in Idaho will be oddly high because of the warm air. Elevations below 8,200 feet or so will probably see mostly rain.  

This type of weather pattern often brings incredibly strong winds to parts of Montana and Wyoming, so those two states will be looking out for that this week.  

Late this week, the super rainy weather in the Pacific Northwest will slow down or stop for about a week, give or take. Then the atmospheric rivers might resume again. 

 

Grim Day In Caribbean As Extreme Hurricane Melissa Nears Jamaica Landfall

Close up satellite view of Hurricane Melissa's eye
nearing southwestern Jamaica at dawn this morning. 

 UPDATE 9 a.m.

It's even worse now.

A recent update just in has maximum winds up to 180 mph, and central pressure down to 896 millibars.

This now tentatively makes this the fifth or sixth most intense hurricane in the Atlantic on record.

Landfall will be within just a few hours 

I'm dreading the news later today from Jamaica.

PREVIOUS DISCUSSION

Hurricane Melissa sank to ridiculous extremes overnight, with winds staying at 175 mph on its approach to Jamaica.  

That the storm has maintained that incredible intensity since at least early yesterday afternoon is really something to dreadfully behold.

 The central pressure this morning in the eye of Hurricane Melissa was 901 millibars, making it the seventh strongest hurricane on record anywhere in the Atlantic Ocean. 

The updates are now coming so fast and furiously now that it's hard to keep up. But we'll give you a good idea and summary of what's going on. 

THIS MORNING'S SITUATION

Winds of tropical storm strength were lashing Jamaica at dawn. Those will quickly go to hurricane force by mid to late morning ahead of an expected landfall early this afternoon.

It's going to be a brutal day in Jamaica to say the least. 

Winds of 175 mph at landfall would flatten pretty much everything. There's a chance Melissa could "weaken" slightly before landfall, but as a practical matter, it won't make a difference.  Winds of, say 165 mph would have pretty much the same effect as winds 10 mph higher.  

To give you an idea how bad it is in there, hurricane hunter planes reportedly detected a gust to 241 mph just 700 feet off the surface offshore of Jamaica last night. 

Once Melissa makes landfall, the effects of hills and mountains can make the hurricane winds locally gust to 1.5 times the overall wind speed. Meaning some pockets in the Jamaican mountains could see gusts to 250 mph. We'll never know for sure, as there are few wind gauges to measure and probably none of those gauges would survive such winds.  

A wider visible satellite image of extreme 
Hurricane Melissa shortly after dawn today. 

The only good news is the area of hurricane force winds only extend out 30 miles or so from the eye. That means eastern Jamaica will escape the worst of the winds, but not the worst of the flooding. The water and landslides will be catastrophic island-wide.

Melissa is still moving pretty slowly, with a forward speed of just 5 mph. Most hurricanes, on average move at 10 to 15 mph. 

The slow movement means the extreme rains from Melissa will linger over Jamaica, and neighboring Haiti and Dominican Republic, longer than usual for a hurricane. That would make the terrible flooding with the hurricane even worse.  

I've been watching live cams from Jamaica, at least until the power goes out there. One of them shows the Flat Bridge over the Rio Cobre River in Spanish Town, Jamaica. As of around dawn, the river was a torrent, very high, muddy, full of debris. This was before the intense part of Hurricane Melissa arrived.

Imagine how bad the flooding will be after another one to three feet of rain crashes down on Jamaica today. 

The advice to Jamaicans from the U.S. National Hurricane Center is still dire:

"Remain sheltered! Catastrophic flash flooding, landslides and destructive winds will continue through today, causing widespread infrastructure damage, power and communications outages, and isolated communities. Total structural failure is possible near the path of Melissa's center. Along the southern coast, life-threatening storm surge and damaging waves are expected through the day. Failure to act may result in serious injury or loss of of life."

On social media, hotel guests reported they are on lockdown. They've been advised to shove mattresses against the windows and huddle behind closed doors in the bathroom during the worst of the storm. 

The social media posts from Jamaica are already frightening. Virtuallywithdee on Threads, has been live posting her experiences with the storm. At 6:15 a.m. she posted:

"The updates are coming faster because I honestly can't believe what I'm seeing. The rain is pouring like someone's throwing buckets of water nonstop - the downpour is wild. Electricity is flickering in and out, and the mobile service is getting spotty. The wind is giving me chills... and she still hasn't even arrived yet."

HORRIBLE DAY AHEAD

Media reports and social media will probably go dark later this morning and stay that way for quite a while after as electricity and cell service collapses in the hardest hit areas. 

I'm worried sick about the fate of Jamaicans. CNN tells us the International Federation of the Red Cross says it expects 1.5 million people - more than half of Jamaica's population - to be directly affected by Hurricane Melissa. 

The worst effects will be across western Jamaica.  The Capitol, Kingston is in the eastern third of the island and expects peak wind gusts of 70 to 85 mph with up to 16 inches of rain. As of 7 a.m. wind was already gusting to 59 mph in Kingston. 

Montego Bay, in northwest Jamaica, should expect peak winds gusts of 100 to 140 mph and up to 20 inches of rain. Scary, indeed.

CUBA 

The worst conditions in eastern Cuba should hit later today and through tonight. 

In Santiago de Cuba, peak wind gusts are forecast to be in the 100 to 120 mph range, with about a foot of rain. Some nearby hillsides could see two feet of rain. 

Heavy rain is already falling in Cuba and that should get worse through the day. 

HAITI/DOMINICAN REPUBLIC

Hurricane Melissa is passing to the west of these two nations, but it's still having a catastrophic effect there, especially in Haiti. Extreme flash floods and landslides are likely there this week. Tropical storm force winds will also hit Haiti. 

Several deaths have already been reported in Haiti due to flooding and landslides. 

Hurricane Melissa is still forecast to smash through the southeastern Bahamas tomorrow and Thursday before heading into the open Atlantic. It could lash Bermuda with strong winds early Friday before it races into the cold northern Atlantic Ocean where it will finally die over the weekend.  

Hurricane Melissa Explodes In Caribbean; Is Dire Threat To Jamaica, Maybe Cuba

Forecast track and timing of Hurricane Melissa, which
is about to decimate the island of Jamaica. 

Jamaicans, and weather forecasters are waking up to a horror this morning. 

Hurricane Melissa is following the worst case scenario, having blown up from a tropical storm to a powerful hurricane packing 140 mph in a matter of less than 18 hours. 

Worse, the storm is still getting strong, still moving forward at a snails pace, and still locking in on Jamaica as a target.

Melissa is forecast to reach Category 5 intensity today, the strongest possible hurricane. It would be the third category 5 Atlantic hurricane this year, which is incredibly rare. Climate change doesn't seem to make hurricanes more frequent, but it does seem to make it more likely that some of them will reach intense Category 5 intensity. 

Fortunately, the other two Cat 5's of 2025, Erin and Humberto, did not hit land.

Our luck has run out with Melissa. 

As of this morning, Melissa was moving over water that is record hot, 88 or 89 degrees. This patch of water under Melissa is the warmest of anywhere in the Atlantic.  The hotter the water, the more fuel for a hurricane, and the stronger it will become. 

Whether it's still a category 5 or a "mere" category 4 when Melissa makes landfall in Jamaica, probably Tuesday morning, is besides the point. This is going to be a devastating, deadly blow to the island. 

It's already been raining for weeks in Jamaica.  The soil is saturated. There was flooding even before Melissa entered the picture. 

Hurricanes always dump incredible amounts of rain. You virtually always have inland flooding once they come ashore.  Most hurricanes come and go, with a forward speed of maybe 10 to 15 mph.

Melissa's forward speed was just 5 mph this morning. As a tropical storm and more recently a hurricane, it was just sitting over the Caribbean, dumping heavy rain on Haiti and Jamaica before it ever grew into the monster it is now. Melissa will only just begin to move faster over Jamaica, but it will be much too little, much too late. 

More than three feet of rain is expected on at least parts of the island, guaranteeing horrific landslides and catastrophic flooding. Jamaica is mountainous, so it's especially prone to flash flooding and heavy rains. That was the problem in western North Carolina last year with Hurricane Helene. The water just cataclysmically rushed down those slopes. Same will happen in Jamaica.

The wind will tear things apart for sure, but the flooding will be much worse.

How do you run away from flash flooding and mudslides when the wind is gusting well past 100 mph and debris is flying through the air like giant box cutters, slicing through everything?

I'm just sick about this. 

In the past, the United States would often swoop in with truly lifesaving aid when there's an extreme disaster like what is about to happen in Jamaica. But the Trump administration has turned its back on the rest of the world. So the suffering will be even worse due to the indifference of MAGA. We might send aid, but not the way we once did. 

Hurricane Melissa won't directly hit Haiti, but its torrential rains are blasting that impoverished nation on Hispaniola. This will be a nightmare for them too. We already have reports of three people killed by Melissa in Haiti and one in neighboring Dominican Republic.

We need to include Cuba in this mix. Once Melissa is done with Jamaica, it will move on to eastern Cuba. The storm might be slightly weaker than it will have been in Jamaica, but it still will be a powerhouse, with extreme flooding and seriously damaging winds in Cuba by late Tuesday and early Wednesday.

From there, Melissa will head northeastward, blasting through the Bahamas with more destruction before heading out into the open Atlantic Ocean. It might threaten Bermuda toward Friday. Then it should finally die out in the cold North Atlantic next weekend.  

Vermont Damage Reports Still Coming In From Weekend Storm. Will Wet Spring Lead To Another Summer Of Floods?

Via WCAX, flooding Saturday in White River 
Junction, Vermont. Severe storms over the weekend
punctuated a very wet May, leading to speculation
we might have more flash floods this summer.

 Vermonters are still tallying the damage from Saturday's storms that left damage scattered throughout the state.  

Hartford and White River Junction  were especially hard hit with destructive winds and flooding. Hartford officials said 31 homes received at least some damage from flooding and as of yesterday residents of five homes were still displaced.

The emergency room at the VA Hospital in White River Junction had to be temporarily moved due to flooding, though overall hospital operations are still going on as scheduled. 

Another home was severely damaged in Hartford when a large tree fell on it. In another spot, a garage was flattened by falling trees.

The National Weather Service said the microburst that hit the Hartford area packed winds of between 65 and 80 mph, depending on the neighborhood.

In Bristol, Vermont, a landslide threatened West Street, also known as Routes 116 and 17. Crews this week are working to shore up the road, meaning travelers that can expect delays and possible detours.  Heavy rains likely caused the slope failure.  

As noted in Sunday's post, other damage was reported across the state. Roads were temporarily closed in Waitsfield, Warren, Plainfield, East Montpelier and other towns. 

WET MAY, MORE FLOODIING?

This is turning out to be a wet, soggy May and more rain is on the way. So far this month, Montpelier has had 5.55 inches of rain;  St. Johnsbury 5.1 and Burlington 4.31 inches,  That's more than should fall in the entire month of May. 

We won't come close to breaking a May rainfall record. In Burlington that honor goes to May, 2013 with 8.74 inches. 

We probably won't receive an extraordinary amount of rain in the next week, just light stuff north with likely somewhat heavier rain south. 

This shouldn't  cause any new flooding. But the new precipitation coupled with a lack of sunshine will keep soils saturated for awhile yet. 

If we have a wet summer with plenty of downpours, the soggy May could set Vermont up for another season of damaging flash floods. We've had two years in a row of that, so we don't need a third.

There's no guarantees, of course. The weather pattern could change and we could end up having a rather dry summer.

For what it's worth, long range forecasts call for a warmer and wetter than normal summer, That hints at the kind of humid days that could produce torrential downpours and flash floods.  True, such long range forecasts aren't always accurate, but it's something to think about. 

Climate change isn't helping. A warmer atmosphere holds more water, which can be released in the form of intense storms. Rainfall in Vermont has increased as a result.  Summer downpours are often more torrential than ever, dropping immense amount of rain in a short period of time. 

That's what happened Saturday in parts of Vermont. A few areas received an inch of rain in less than half hour.  

Just to be on the safe side, if you live in a flood prone area, make sure now that your flood insurance is up to date. Have a plan to escape fast if water rises. It also wouldn't hurt to have a "to go" bag prepared with necessities ahead of time in case you need to make a hasty flood retreat.

Two Extreme And Dramatic Weather Events Prove Fatal In Alaska, Arizona

Extreme flash flooding in the Havasu Creek and Falls
area of the Grand Canyon last week killed one person
and forced helicopter rescues for dozens of others. 

 I've been a bit fascinated and horrified in the past week of two big local weather-related events in two very different, scenic spots. One was a landslide in Ketchikan, Alaska and the other an epic flash flood in northern Arizona. 

I often cite local disasters like this as evidence of the harm created by climate change. 

Both of these disasters might have been related to climate change, but I don't know for sure and can't prove it either way. But still, they're pretty intense. 

NORTHERN ARIZONA

Havasu Creek and Havasu Canyon in northern Arizona - part of the Grand Canyon are an incredibly scenic spot in northern Arizona, popular with hikers and vacationers. It features Havasu Falls, a gorgeous blue-green feature that attracts thousands of tourists annually and is a main attraction to the Grand Canyon 

Hundreds of hikers were in the canyon and along the creek last Thursday when disaster struck. It's monsoon season in Arizona, when moisture from both the Pacific Ocean and the Gulf of Mexico find their way to the Desert Southwest. 

The monsoons create intense thunderstorms, famous for creating abrupt flash floods in the deserts, low water crossings, creeks, canyons and back country of Arizona. 

Last Thursday, an especially intense monsoon struck in and around Havasu Canyon.  The resulting flash flood was epic, stranding at least 100 hikers and sweeping away a woman, who was later found dead. 

Reports News 12 in Arizona:

"Chenoa Nickerson, 33, was hiking with her husband near Havasu Creek on Thursday when the  couple was swept away by the flash flood. Her husband was able to be rescued by rafters, but Nickerson went missing in the Colorado River."

Her body was eventually found 20 miles downriver. Nickerson's family is raising money for the National Park Service Search and Rescue in her honor. Family members said the search and rescue team is historically underfunded, and they believe this is a great way to honor Nickerson's memory. 

I couldn't agree more. 

The death toll could well have been higher, but Havasupai tribal members who live in the area recognized the flash flood situation developing and warned hikers to seek high ground immediately.  

The Havasupai Tribe's reservation is perhaps the most remote in the nation. You can only get to it on foot, mule or via helicopter. 

Havasu Falls and surrounding trails are now off limits to visitors for the foreseeable future. The tribe is working with FEMA on coordinating repairs.  Although monsoon flash flooding is common in this area, the one that struck last week was much worse than usual.  

Dramatic video of the flash flood are here and here. 

KETCHIKAN, ALASKA

Ketchikan, Alaska, on the state's panhandle south of Juneau,  is normally very wet - one of the wettest cities on Earth. Its normal annual rainfall is about 150 inches. (That compares to roughly 40 inches a year here in Vermont).  

Aerial view of the big landslide
in Ketchikan, Alaska.

Recently, however, the tain was too much even for soggy Ketchikan. A tragic landslide last Sunday buried part of a city neighborhood, killing one person and injuring three others. Numerous homes were destroyed in a dense neighborhood not far from downtown, reports Alaska Public Media.

The person killed was Sean Griffin, a senior maintenance technician for Ketchikan who was off duty but volunteering to clear clogged storm drains when the landslide hit. 

A number of factors could have contributed to the slide. Around 2.5 inches of rain fell on Ketchikan that day That's unusually heavy for a single day there, but not record-breaking.  

 Fatal landslides have been increasing in southeast Alaska, with four such slides in the past decade. It's possible climate change has had a hand in this, as increases in temperature, precipitation and wind associated with climate change might be making the steep landscape less stable. 

Gabriel Woken of the Alaska Division of Geological and Geophysical Surveys said he suspect climate change might be playing a role, but the causes of the landslides are so complex that it's hard to know for sure.  

"Atmospheric River" Soaking Pacific Northwest

Satellite view from yesterdayof a long narrow band of clouds
stretching from the Philippines to the Pacific Northwest. 
That's the atmospheric river dumping torrential rains and
causing flooding and landslides today in 
Washington and Oregon 

 As many of us know, it's really rainy during the winter in the Pacific Northwest. 

The first half of this week, though, is a super soaker out there due to an atmospheric river off the Pacific.

An atmospheric river is a relatively narrow plume of deep moisture that crosses large sections of oceans, and dump heavy rainfall wherever they make landfall.  They're called atmospheric rivers because they act like real, land based rivers.

The amount of moisture in these atmospheric rivers is often equivalent to the water flow near the mouth of the Mississippi River.

These atmospheric rivers usually have their origins in the tropics. The one hitting the Pacific Northwest has its origins near the Philippines. 

The more intense atmospheric rivers can cause catastrophic flooding.  There was a nasty one that caused record rainfall and dangerous, fatal landslides in southeastern Alaska earlier this winter, for instance. 

The atmospheric river now hitting the Pacific Northwest seems pretty impressive, too, so it is or will cause I  plenty of problems with flooding. And landslides. 

Remember I said that atmospheric rivers have their origins in the tropics.  Which means these are often quite warm.  In this case, snow levels in the Cascade Mountains will rise to as high as 8,000 feet above sea level. This will create melting snow, which will feed runoff into already flooding rivers.

Higher elevations are also prone to avalanches, as rain or heavy wet snow falling on top of drier snow layers can start the snow sliding down steep mountainsides. 

Even more dangerous is the risk of landslides which is often a problem in the Pacific Northwest. It's already been a rather rainy winter up there, even by their standards. Soils are saturated and heavy, and the torrential rains with this atmospheric river will make things worse. 

Most of the moisture from the atmospheric river will get wrung out in the Cascade Mountains and in the Rocky Mountains of central and northern Idaho. 

 But the strong jet stream that organized this atmospheric river will continue eastward, contributing to expected high winds today and especially tomorrow in most of Montana, much of Wyoming and the western Dakotas.

Winds could gust to 70 mph or more in some of these areas. 

The jet stream will buckle over the eastern Pacific Ocean in the next couple of days, shutting off the atmospheric river and turning the rain much lighter and more showery in the Northwest starting tomorrow.