Supercells with large hail possible around Seattle, Portland on Wednesday

Supercell thunderstorms with very large hail could develop across parts of the Pacific Northwest on Wednesday afternoon. While severe thunderstorms usually happen in Washington and Oregon every year, the severity of the storms expected on Wednesday could rival the upper bounds of what folks in this area are used to seeing.

Warm temperatures at the surface, combined with a strong upper-level trough swooping ashore, will lead to widespread instability across much of Washington and Oregon by Wednesday afternoon.

Thunderstorms bubbling up amid the instability will find enough wind shear throughout the atmosphere to turn severe. Some of these thunderstorms could develop into supercells, which are storms with rotating updrafts that allow the storm to grow stronger and last longer than a 'regular' thunderstorms.

Damaging winds, large hail, and an isolated tornado or two are possible in the strongest storms that develop on Wednesday. While all modes of severe weather are possible, the greatest threat by far will be the potential for large hail, especially along the I-5 corridor between Seattle and Eugene.

Forecasters with the Storm Prediction Center painted a 15% risk for significant hail across the region. Hail is considered "significant" when it's about the size of a hen egg (2.00 inches in diameter) or larger.

The SPC says that supercells here could produce hailstones 2.00 to 2.50 inches in diameter. This is more than enough to cause serious injury, smash up cars, and do serious damage to homes.

Hail this large is exceptionally rare in the Pacific Northwest.

Since 2003, we've seen 16,642 reports of hail 2.00+ inches in diameter across the United States. Just 15 of those reports came from Oregon, and only 5 of those instances were reported in Washington.

Including reports of golf ball size hail (1.75 inches in diameter) brings the total number of significant hail reports in Oregon up to 94, and raises that number up to 24 in Washington. Despite the jump in numbers, all of those significant hail reports came in east of the Cascades—none within the I-5 corridor itself.

Please take this threat seriously if you're under a risk for severe thunderstorms on Wednesday.

Falling hail can seriously injure or kill you. Hailstones the size of golf balls and hen eggs typically fall at 70 mph—and they often travel faster if there are high winds involved.

Try to avoid getting caught in a vehicle during a severe thunderstorm. If you're in a vehicle when hail starts to fall, cover up with anything available—coats, blankets, sunshades, anything that may protect you from shattered glass, flying debris, and the hail itself.

If you're at home when a severe thunderstorm arrives, stay away from doors and windows no matter how tempting it may be to watch the storm. Hailstones blowing in the wind and bouncing around can easily shatter windows, send debris into the air, and even hit you.

---

Follow me on Facebook | Bluesky | Instagram

Get in touch! Send me an email.

Please consider subscribing to my Patreon. Your support helps me write engaging, hype-free weather coverage—no fretting over ad revenue, no chasing viral clicks. Just the weather.
  

Deadly severe weather outbreak lived up to its potential

A multi-day severe weather outbreak that unfolded across the central and southern United States over the past couple of days certainly lived up to its deadly potential.

There's a chorus of naysayers after every high-risk severe weather event who say the forecast was a bust and the event didn't live up to the "hype."

National Weather Service (NWS) meteorologists will spend the next couple of days surveying the damage left behind by Friday's and Saturday's storms. It's safe to say that it was an impactful and memorable severe weather event.

The New York Times reported on Sunday morning that at least 36 people died in the storms as they ripped through the region, and the vast majority of those fatalities occurred in tornadoes. 

Friday's event saw hundreds of damaging wind reports throughout the Midwest as squall lines shoved strong winds down to the surface. Multiple tornadoes touched down from Arkansas to Indiana, and it's likely that several of those tornadoes were significant EF-2s or stronger.

The bulk of Friday's severe weather occurred within the Storm Prediction Center's (SPC) moderate risk area, which is a level four out of five on the categorical scale used to measure the risk for severe thunderstorms. 

Saturday saw a high risk for severe weather—a level five out of five—across portions of Alabama and Mississippi, with a level four moderate risk radiating out from Louisiana to Georgia.

While Saturday's severe weather wasn't as prolific as what we saw on Friday, there were still multiple destructive tornadoes in and around the high-risk area. It's likely that we'll see more confirmed tornadoes than what appears in the storm reports map above once the NWS finishes its storm surveys this week.

The SPC issues severe weather risks based on storm coverage, storm intensity, and forecaster confidence. High risk days are very rare. Saturday was only the 66th day since Jan. 1, 2000, that we've seen a high risk issued. All the dynamics were in place Saturday for significant tornadoes to develop in any thunderstorms that took full advantage of the environment. 

Much like the internet has warped our senses of time, space, and each other, the constant reliving of previous outbreaks seems to color our view of predicted severe weather events. 

More bluntly, as one meteorologist said on Bluesky: "Just because you didn’t get your disaster porn in a heavily populated area doesn’t mean the forecast was a bust. Some of y’all need therapy."

No two events are ever alike. Generational outbreaks are called generational outbreaks for a reason. All the warning lights were blinking red for Friday's and Saturday's events—and, sadly, the setup delivered.

---

Follow me on Facebook | Bluesky | Instagram

Get in touch! Send me an email.

Please consider subscribing to my Patreon. Your support helps me write engaging, hype-free weather coverage—no fretting over ad revenue, no chasing viral clicks. Just the weather.
  

High-risk tornado outbreak expected in the Deep South on Saturday

A rare 'high risk' for severe weather—a level five out of five—is in effect for a swath of the Deep South on Saturday as a dangerous thunderstorm setup sweeps across the region.

The Storm Prediction Center (SPC) only issues one or two high risk areas every year. This means that forecasters are confident in the likelihood of a tornado outbreak across the affected areas.

URGENT: The National Weather Service is a lifesaving public resource. We must save it.

The Setup and Risk

A powerful low-pressure system rolling across the center of the country unleashed deadly severe thunderstorms Friday and through the overnight hours. Multiple tornadoes and widespread wind damage were reported from Texas to Minnesota.

That setup is pushing east to start the weekend, with a second and even more intense round of severe thunderstorms expected through the day Saturday.

Strong instability and ample wind shear should give rise to widespread severe thunderstorms by Saturday afternoon. Conditions are favorable for these storms to quickly turn into supercells capable of producing intense, long-track tornadoes, as well as destructive wind gusts and hail the size of golf balls or larger. 

While all modes of severe weather are possible, the greatest concern remains the tornado threat. If today's risk lives up to its potential, this could be a high-end outbreak with multiple intense tornadoes in and around the moderate and high risk areas.

Potential Hiccups

Tornado outbreaks are relatively rare for a reason. These devastating events require all the ingredients aligning just right to spawn significant severe weather. It appears that all those ingredients are in place in the right sequence today.

But sometimes things don't work out as expected. What are the potential modes of failure today?

Forecasters expect multiple dangerous supercells to roll across the moderate and high risk areas, bringing with them a threat for significant tornadoes. However, it's not out of the realm of possibility that we could see thunderstorms quickly align into one or more squall lines, in which case the predominant threat would transition to widespread damaging winds with the potential for embedded tornadoes.

Existing cloud cover across the region could rob the atmosphere of some of the instability it needs to allow thunderstorms to flourish across areas under the highest risk for severe weather. This appears less likely given the storms already bubbling up at the time of this post's publication.

That said—all the warning lights are blinking red. This is a serious threat and folks in the region should pay close attention to the weather and ensure they've got a way to stay safe if dangerous conditions threaten.

Severe Weather Safety

Make a plan in advance where to go in the event a tornado warning is issued for your location. Mentally map out the safest part of your home, as well as where you'd duck for cover in commonly visited places like school, work, grocery stores, and while you're in your vehicle.

Ensure you have a way to receive severe weather warnings the moment they're issued. Please remember that tornado sirens are not reliable and they're not meant to be heard indoors.

Check your phone now and ensure that emergency alerts are enabled for tornado warnings. These free push alerts are a lifesaving defense against dangerous thunderstorms. The system triangulates your location based on your cell signal to determine if you're in a tornado warning. It works, and it's saved countless lives over the past decade.

Always have a backup when it comes to receiving severe weather alerts. NOAA Weather Radios are like smoke detectors for the weather. You can program these devices to sound a loud alarm the moment your county is included in a watch or warning—even when the power's out and they're running on batteries.

The NWS Is At Risk

The forecasts referenced in this article were issued by the National Weather Service, a critical federal agency that's likely responsible for directly saving more lives than just about any other office in the government. The National Weather Service costs $3 per year per taxpayer.

Free and instant lifesaving warnings, Doppler radar data, satellite imagery, computer models, and realtime observations would likely vanish if this agency were gutted. Please contact your representatives to urge lawmakers to save NOAA and the National Weather Service from irreparable damage.

---

Follow me on Facebook | Bluesky | Instagram

Get in touch! Send me an email.

Please consider subscribing to my Patreon. Your support helps me write engaging, hype-free weather coverage—no fretting over ad revenue, no chasing viral clicks. Just the weather.
  

Significant severe thunderstorm outbreaks expected Friday and Saturday

Two significant rounds of severe thunderstorms are likely over the next couple of days as a powerful low-pressure system develops across the center of the country.

I covered the basics of the setup yesterday. All the dynamics are present for a multi-day severe thunderstorm outbreak heading into the weekend.

A rapidly intensifying Colorado low will drag ample instability over the center of the U.S. Strong wind shear throughout the atmosphere will enable any thunderstorms that form to quickly turn severe, threatening damaging winds, large hail, and tornadoes.

Friday

A moderate risk for severe weather—a level four out of five—is in effect Friday from southeastern Iowa through northwestern Tennessee. This includes St. Louis, Springfield, and Paducah. A broader threat for severe weather exists from southern Wisconsin all the way south to the Gulf of Mexico.

Forecasters expect a robust squall line to develop and race east across the region, posing a threat for widespread damaging wind gusts in excess of 60 mph.

Significant wind gusts of 75+ mph are possible in and around communities under the moderate risk. Embedded tornadoes could form within the squall line. 

If you live in this area, please plan to avoid parts of your home where large trees or tree limbs loom overhead. If you're in a vehicle when storms arrive, park away from trees and power lines. Most injuries and fatalities in severe thunderstorms are the result of trees falling into homes and vehicles during high winds.

Conditions will also be favorable for supercell thunderstorms to develop ahead of or within the squall line itself. These supercells could produce strong tornadoes, hail the size of golf balls or larger, and very strong wind gusts.

The threat will continue after dark across communities on the eastern side of the risk zones.

Saturday

Saturday could be a rough day for tornadoes across the Deep South.

If the lingering thunderstorm activity from Friday doesn't stabilize the atmosphere, conditions on Saturday will be favorable for widespread intense supercells to develop across the Deep South from eastern Louisiana through eastern Tennessee.

A moderate risk for severe weather includes New Orleans, Mobile, Jackson, Montgomery, Tuscaloosa, and Birmingham, for the risk for intense, long-track tornadoes in any supercells that form across the region. This could be one of those days we get "particularly dangerous situation (PDS)" tornado watches.

While the bulk of Saturday's risk will remain to the south, lines of severe thunderstorms are possible as far north as Cleveland and Erie. These storms could produce damaging wind gusts of 60 mph or stronger, which could lead to tree damage and power outages.

Severe Weather Safety

Make a plan in advance where to go in the event a tornado warning is issued for your location. Mentally map out the safest part of your home, as well as where you'd duck for cover in commonly visited places like school, work, grocery stores, and while you're in your vehicle.

Ensure you have a way to receive severe weather warnings the moment they're issued. Please remember that tornado sirens are not reliable and they're not meant to be heard indoors.

Check your phone now and ensure that emergency alerts are enabled for tornado warnings. These free push alerts are a lifesaving defense against dangerous thunderstorms. The system triangulates your location based on your cell signal to determine if you're in a tornado warning. It works, and it's saved countless lives over the past decade.

Always have a backup when it comes to receiving severe weather alerts. NOAA Weather Radios are like smoke detectors for the weather. You can program these devices to sound a loud alarm the moment your county is included in a watch or warning—even when the power's out and they're running on batteries.

The NWS Is At Risk

The forecasts referenced in this article were issued by the National Weather Service, a critical federal agency that's likely responsible for directly saving more lives than just about any other office in the government. The National Weather Service costs $3 per year per taxpayer.

Free and instant lifesaving warnings, Doppler radar data, satellite imagery, computer models, and realtime observations would likely vanish if this agency were gutted. Please contact your representatives to urge lawmakers to save NOAA and the National Weather Service from irreparable damage.

---

Follow me on Facebook | Bluesky | Instagram

Get in touch! Send me an email.

Please consider subscribing to my Patreon. Your support helps me write engaging, hype-free weather coverage—no fretting over ad revenue, no chasing viral clicks. Just the weather.
  

Severe weather risk builds as another powerful spring storm develops

The risk for severe thunderstorms will build heading into this weekend as yet another significant low-pressure system roars to life across the center of the country. 

Widespread severe thunderstorms are likely on Friday and Saturday, an event the Storm Prediction Center described on Wednesday as a potential "outbreak."

URGENT: The National Weather Service is a lifesaving public resource. We must save it.

The Setup

A model snapshot of the trough that'll give rise to our powerful low-pressure system on Friday (Tropical Tidbits)

A powerful trough swinging over the West Coast will cross the Rockies to end the week. The lift from this trough, combined with a powerful jet stream over the southern U.S., will give rise to a rapidly developing low-pressure system over eastern Colorado early on Friday.

This Colorado low will deepen in a hurry as it traverses the Plains toward the Upper Midwest. Much like the storm we saw last week, this system's rapid intensification could threaten some monthly air pressure records from Nebraska to Minnesota.

High Winds

A rapidly deepening low-pressure system is a recipe for widespread powerful winds. Expect wind advisories and high wind warnings to eventually blanket much of the central and southern U.S. as this storm builds over the region. Wind gusts in excess of 40 mph, with much higher gusts, will be possible Friday and Saturday.

The combination of high winds and dry air wrapping around the backside of the system will create a multi-day wildfire risk across large chunks of New Mexico, Texas, and Oklahoma. Any wildfires that spark through the weekend could quickly grow out of control and threaten nearby communities.

Severe Thunderstorms—FRIDAY

Warm, unstable air surging inland on southerly winds will create ample instability throughout the middle of the country on Friday. Intense wind shear associated with the developing storm will give the storms the kick they need to quickly turn severe. 

Forecasters expect severe thunderstorms to spread from west to east through the day. All modes of severe weather—damaging winds, large hail, and tornadoes—will be possible on Friday. 

The Storm Prediction Center (SPC) has issued an enhanced risk, a level three out of five, for much of the Mississippi Valley from northern Mississippi into north-central Illinois, including the cities of Memphis and St. Louis.

"Not only will extreme wind field favor damaging winds, but profiles will also favor supercells capable of fast-moving tornadoes, whether a broken line or in QLCS fashion along surging outflows," the SPC said in its forecast on Wednesday. A QLCS—quasi-linear convective system—is a squall line.

Severe Thunderstorms—SATURDAY

The greatest risk for severe thunderstorms will develop on Saturday as the focus of the threat moves into the Deep South. All the dynamics are in place for a potential severe weather outbreak across the region. 

The SPC doesn't issue categorical outlooks four days in advance, so we have a more generic risk map (shown above) to highlight the threat for severe weather on Saturday. An orange 30% risk is roughly the same as a level three enhanced risk for severe weather.

All modes of severe weather will be possible on Saturday. The concern will grow if Friday's leftover thunderstorm activity doesn't stabilize the atmosphere, which would allow for more favorable dynamics for severe weather on Saturday.

"If this scenario unfolds, a concerning severe weather setup supporting all-hazard severe could unfold across portions of LA/MS/AL through the day and into evening, and eventually spreading east into GA overnight," the SPC said on Wednesday.

Severe Thunderstorms—SUNDAY

No matter what happens on Saturday, it's likely that we'll see thunderstorms continue east overnight and approach the eastern seaboard heading into the day Sunday. 

The SPC highlighted a slight risk for severe weather from northern Florida through northeastern Pennsylvania ahead of these storms. It's likely that damaging winds would be the predominant threat from these storms, but dynamics may be favorable for a tornado or two.

Severe Weather Safety

Make a plan in advance where to go in the event a tornado warning is issued for your location. Mentally map out the safest part of your home, as well as where you'd duck for cover in commonly visited places like school, work, grocery stores, and while you're in your vehicle.

Ensure you have a way to receive severe weather warnings the moment they're issued. Please remember that tornado sirens are not reliable and they're not meant to be heard indoors.

Check your phone now and ensure that emergency alerts are enabled for tornado warnings. These free push alerts are a lifesaving defense against dangerous thunderstorms. The system triangulates your location based on your cell signal to determine if you're in a tornado warning. It works, and it's saved countless lives over the past decade.

Always have a backup when it comes to receiving severe weather alerts. NOAA Weather Radios are like smoke detectors for the weather. You can program these devices to sound a loud alarm the moment your county is included in a watch or warning—even when the power's out and they're running on batteries.

The NWS Is At Risk

The forecasts referenced in this article were issued by the National Weather Service, a critical federal agency that's likely responsible for directly saving more lives than just about any other office in the government. The National Weather Service costs $3 per year per taxpayer.

Free and instant lifesaving warnings, Doppler radar data, satellite imagery, computer models, and realtime observations would likely vanish if this agency were gutted. Please contact your representatives to urge lawmakers to save NOAA and the National Weather Service from irreparable damage.

---

Follow me on Facebook | Bluesky | Instagram

Get in touch! Send me an email.

Please consider subscribing to my Patreon. Your support helps me write engaging, hype-free weather coverage—no fretting over ad revenue, no chasing viral clicks. Just the weather.
  

Powerful spring storm threatens tornadoes, damaging winds this week

Widespread severe thunderstorms, winter weather, and damaging winds are likely over the next couple of days as a powerful low-pressure system develops across the center of the country. 

This storm could come close to breaking some monthly pressure records across the Midwest. Even if it falls just short, this intense Colorado low will run the table with just about every type of active weather through midweek. 

URGENT: The National Weather Service is a lifesaving public resource. We must save it.

The Setup

SOURCE: Weather Prediction Center

A strong jet stream snaking across the middle of the United States is giving rise to a powerful low-pressure system over eastern Colorado. This system will steadily intensify as it makes its way toward the Great Lakes through Wednesday, dragging the entire spectrum of active weather along its path. 

This system's minimum central pressure could drop to around 980 mb by Wednesday, which is within a few millibars of the all-time March low air pressure records in places like Chicago. This is going to be a formidable storm—and its strength will reflect in the thunderstorms, winds, and wintry weather it produces.

Wind advisories and high wind warnings span much of the southern United States as this storm roars to life. These will be pressure gradient winds—simply winds kicked up by the low-pressure system's rapid intensification, independent of the thunderstorms expected across the region. 

Cold air on the northern side of the system will drop heavy snowfall across the Plains and Upper Midwest, with blizzard conditions expected through parts of eastern Colorado and western Nebraska.

The most pressing concern, though, is a dayslong risk for severe thunderstorms.

Monday's Severe Weather

An enhanced—level 3 out of 5—risk for severe weather exists across parts of the southern Plains on Monday night into early Tuesday morning.

Forecasters expect severe thunderstorms to develop across northern Texas and southern/central Oklahoma during the overnight hours. Storms may initially form as supercells before quickly congealing into a squall line. Tornadoes, damaging winds in excess of 60 mph, and large hail are all possible in these nocturnal thunderstorms.

Tuesday's Severe Weather

The risk for severe thunderstorms will peak on Tuesday as strong wind shear meets up with ample instability over the Deep South. 

Monday night's squall line will likely continue moving east toward the Mississippi River through the morning and afternoon hours on Tuesday, bringing the risk for damaging winds with embedded tornadoes.

Additional thunderstorms are possible ahead of that squall line. Any discrete thunderstorms that develop in this environment will be capable of producing strong tornadoes. The severe threat will continue as the squall line pushes through the region with the risk for damaging winds in excess of 70 mph. 

Wednesday's Severe Weather

Our squall line will keep on trucking toward the East Coast overnight Tuesday into early Wednesday, shoving the risk for severe weather east.

Thunderstorms may produce damaging wind gusts as far north as Buffalo, New York, and as far south as Orlando, Florida. The greatest risk for damaging winds—and possibly an embedded tornado or two—will exist from the D.C./Baltimore area south through the Carolinas and into eastern Georgia. 

NOTE: The forecasts referenced in this article were issued by the National Weather Service, a critical federal agency that's likely responsible for directly saving more lives than just about any other office in the government. The National Weather Service costs $3 per year per taxpayer.

Free and instant lifesaving warnings, Doppler radar data, satellite imagery, computer models, and realtime observations would likely vanish if this agency were gutted. Please contact your representatives to urge lawmakers to save NOAA and the National Weather Service from irreparable damage.

---

Follow me on Facebook | Bluesky | Instagram

Get in touch! Send me an email.

Please consider subscribing to my Patreon. Your support helps me write engaging, hype-free weather coverage—no fretting over ad revenue, no chasing viral clicks. Just the weather.