July 14, 2024

Another round of dangerous heat arrives during a dangerously hot summer

An excessively hot summer across the U.S. rolls on this week as another stretch of dangerously hot temperatures spreads from I-5 to I-95.

Temperatures could easily crest the century mark for many locations over the next couple of days as broad ridges of high pressure rule the roost to start the week.

Tuesday will feature the worst temperatures, with 100-degree readings expected in Oklahoma City, Nashville, Washington, and Philadelphia. The high heat will stretch all the way into New England, where daytime highs in the 90s will reach into Maine.

Humidity will make the heat exceptionally dangerous in many of these locations, with heat indices exceeding 105 for many communities. 

The National Weather Service's new HeatRisk product shows widespread "major" to "extreme" impacts from this latest bout of high heat.

Folks living with chronic health conditions, working outside, or living without air conditioning will feel the greatest impacts from this latest heat wave. Heat exhaustion or heat stroke can develop in under an hour with these conditions.

Very warm and humid nights won't provide much relief from the blazing daytime temperatures. The compounding effects of hot days and steamy nights will make this especially tough for folks without adequate cooling at home. Fans alone won't be enough to combat this heat.

This is the latest volley of blistering temperatures during an already-hot summer across almost all of the United States.

Source: IEM

Data collected by the Iowa Environmental Mesonet shows that just about everyone save for the northern Plains and Upper Midwest has dealt with above-average temperatures so far this season. Much of the excessive heat has been driven by warmer-than-normal nighttime low temperatures, a side effect of the increased humidity we've seen this season.

Source: IEM

Folks across the Southwest have taken the brunt of the extreme heat this year, with week after week of brutally hot temperatures roasting the region. Phoenix has seen above-average temperatures on 163 of the 195 days we've trudged through so far in 2024. The last time they saw a below-average day was at the beginning of May.

Source: IEM

It's not just the Southwest dealing with the heat. It's a similar story back east. Washington, D.C., has seen above-average temperatures for 78 percent of the year through Saturday, July 13, and we're about to add another week of excessive heat to those grim statistics.

The relentless heat we've seen so far this year is exactly what you'd expect to see in a changing climate. Temperatures have steadily risen each decade across just about the entire United States—and we're even outpacing the new climate standards that run from 1991 to 2020. 

Source: Climate Central

Climate change sets a new baseline for extreme heat throughout the United States and around the world. As the entire frame of reference moves toward a hotter climate, warm temperature extremes are far more likely that cold temperature extremes. Excessive heat will come in hotter than what we grew used to just one or two generations ago.

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July 1, 2024

Hurricane Beryl's explosive intensification is a grim warning for future storms

Hurricane Beryl rapidly strengthened into a category four storm this weekend with maximum sustained winds of 130 mph. The storm became the earliest category four hurricane ever observed in the Atlantic Ocean, beating the previous record by a full week.

This was far from the first record this relatively young storm broke early in its life.

Beryl was the earliest hurricane we've ever seen so far east in the tropical Atlantic. It was the first major hurricane in this part of the world during the months of June or July. It's going to be the strongest hurricane to hit the Windward Islands this early in the season.

The storm's rate of intensification places it among a very small group of any Atlantic hurricane observed since modern records began in 1851. Meteorologist Sam Lillo crunched the numbers and posted Sunday that the storm's rapid intensification is unheard of this early in the season, matched only by a handful of historical storms that formed at the peak of the season in August and September.

What gives?

Experts have been worried that we're in for a very active hurricane season this year. Seasonal outlooks from NOAA and Colorado State University both called for a tremendous number of storms—so many, in fact, that we may exhaust the list of names for only the third time since the 1950s.

The ingredients behind an active season aren't just about the raw number of storms that form. After all, we had Tropical Storm Chris in the Gulf of Mexico on Sunday. The storm lasted for less than a day as it formed while making landfall on Mexico's east coast.

SOURCE: Tropical Tidbits

While we'll probably have plenty of short-lived and forgettable storms, the ingredients present across the Atlantic are favorable for creating storms like Beryl.

Warmer-than-normal sea surface temperatures are running as hot now as they should at the peak of the season. Combine that with favorable atmospheric conditions expected as La Niña develops and the ingredients are there for explosive development of any healthy tropical disturbance that can take root and take advantage of its environment.

We (hopefully) won't see more record-breaking storms this year. But Beryl makes it clear that the environment is more than capable of supporting very intense storms this hurricane season. This early-season storm is a warning shot to prepare emergency kits and emergency plans now rather than waiting until the peak of the season. It could be a long summer.

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June 26, 2024

July may start with tropical systems brewing in the Caribbean

Forecasters are watching several tropical disturbances over the Atlantic Ocean for potential development over the next week.

It's something worth watching (oh I love that cliche, don't you?), as well as a glaring reminder that we're diving deeper into what's expected to be a very active hurricane season.  

Two Disturbances On The Map

Wednesday afternoon's forecast from the National Hurricane Center paints two areas on the map for potential tropical development over the next seven days.

The first area has a 20 percent chance of development as it heads toward the Yucatan Peninsula through the weekend. This area is relatively disorganized, and weather models aren't pumping it up much before it reaches land in a couple of days. Regardless, the disturbance is likely to produce heavy rain across Central America as it pushes inland.

It's that disturbance far out in the tropical Atlantic Ocean that's raising some eyebrows.

This area has a 40 percent (medium) chance of development by next week as it steadily makes its way toward the Caribbean Sea. This area has plenty of warm water and gradually more favorable conditions to get its act together as it approaches the region.

Between the two areas, that disturbance far out in the Atlantic has the best chance of growing into Beryl by this time next week.

What happens after that is a little iffy because it's more than a week out. It's likely that a strong center of high pressure over the central Atlantic would keep any systems far enough south to avoid the U.S. East Coast, but folks across the Gulf always have to monitor anything entering the Caribbean...just in case.

Sea surface temperatures across the tropical Atlantic are more than 2 degrees Celsius warmer than normal. The Atlantic has been running a fever for over a year now, and it's this relatively hot water that's fueling deep concern as we head deeper into this hurricane season.

Last year, forecasters expected El Niño in the eastern Pacific to keep a lid on the Atlantic hurricane season by increasing destructive wind shear across the ocean basin. However, those warm sea surface temperatures overpowered any effects of El Niño to drive 2023 to see one of the most active seasons on record.

This year, we're officially in ENSO-neutral territory, meaning neither El Niño nor La Niña are present. There are better-than-even odds that we'll tilt into La Niña by this fall, which lessens wind shear and makes conditions more favorable for tropical systems to take root over the Atlantic.

Between those warmer-than-normal waters and an expected La Niña, expert seasonal outlooks are calling for one of the most active Atlantic hurricane seasons on record.

Take advantage of the relative quietness of the early season to make plans in case a storm threatens your area. Build an emergency supply kit now so you don't have to scramble for supplies later. Make preparations to deal with and avoid flooding even if you're hundreds of miles inland.

[Satellite image courtesy of NOAA]

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June 22, 2024

Stay alert: Tornado risk builds for parts of New England on Sunday

A risk for tornadoes will build over parts of New England on Sunday as a strong low-pressure system moves just north of the region. Keep a close eye on the radar through the day and make sure you have a way to get warnings the moment they're issued.

Forecasters are watching a low-pressure system moving through Ontario and Quebec this weekend. This system will spark thunderstorms throughout the northeastern U.S. on Sunday, bringing a risk for all modes of severe weather as they feed on ample warmth, humidity, and wind shear across the region.

A forecast surface analysis for 2:00 p.m. EDT on Sunday. (WPC)

The Storm Prediction Center has issued a slight risk for severe weather covering most of New England, New York, and Pennsylvania through the day Sunday. Damaging winds and large hail will be the primary threats in the strongest storms that develop.

Dynamics are favorable for an increased risk for tornadoes in storms that form closer to the center of low pressure, along and just behind the warm front as it scooches near the international border. The Storm Prediction Center outlined Vermont, New Hampshire, western Massachusetts, and eastern New York as the most favorable area for tornadoes through Sunday afternoon.

An enhanced risk for severe weather covers southern sections of Vermont and New Hampshire where a higher risk for tornadoes will exist on Sunday.

Tornadoes aren't uncommon in New England, but a threat like this only comes around every couple of years.

Folks here always aren't dialed into the threat for severe weather—especially if they're outdoors enjoying the steamy summer weather. 

If you live in the region, or know anyone who's in the region this weekend, get the word out that severe thunderstorms are possible on Sunday. Make sure you have a way to get severe weather warnings the moment they're issued.

Look at your smartphone and ensure that emergency alerts are turned on for tornado warnings. These push alerts are geotargeted to your location—if you get one, you are in danger, and you need to take shelter immediately. Wireless emergency alerts are credited for saving countless lives since they were implemented last decade.

NOTE: I updated the article a few minutes after publication as the Storm Prediction Center released a new outlook upgrading some areas to an enhanced risk for severe weather.

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June 17, 2024

Extreme heat kills. It's no joke. Folks shouldn't treat it like one.

If a tornado outbreak killed a few hundred people, it would be remembered as a national tragedy. 

When a heat wave kills a few hundred people, it's the butt of countless jokes. 

People are wimps. Just turn on a fan.

Get used to it like we are down here. It's just called summer.

That kind of nonsense shows up every time there's a prolonged extreme heat event and it's never any less enraging.

Extreme heat is one of the deadliest weather events in the world.

It's not a made-for-television disaster, but it's there whether we see it or not—silently claiming parents and grandparents, striking down perfectly healthy kids at football games, exacting a horrible toll on lower income people already struggling to make ends meet.

Heat waves are responsible for nearly half of all disaster-related fatalities. Heat has claimed an average of 188 lives per year over the past decade, compared to 103 flood-related deaths and 48 tornado-related fatalities over the same period.

Hot temperatures are relative. A 90°F day with humidity requires a level of acclimatization to handle. Someone living in Orlando, Florida, will have an easier time slogging through a scorching day than someone up in Burlington, Vermont. But not even everyone in the south has access to air conditioning. Extreme heat still kills and injures vulnerable people in the humid southeast and the deserts of the southwest.

It's not just a matter of what you're used to.

Lots of homes in the northern United States and throughout Canada still don't have air conditioning—whether by design or simply for lack of affordability. These homes become unbearably hot when the outside temperature climbs above just 80°F. Throw higher readings and some heat-retaining humidity into the mix and you have a recipe for extreme physical stress just trying to exist.

Heat waves also compound on themselves. Humid heat doesn't allow for any relief at night. Hot days spilling into hot nights wrap around you like a wet blanket when you don't have air conditioning to stay cool. Fans don't help in that kind of setup.

You're left with a situation where hundreds of thousands of vulnerable neighbors, friends, and family members are left to their own devices, hoping they see relief at the end of a days-long nightmare. They're lucky if they can get to a cooling center or visit someone for some relief from the stifling air. Many of them are forced to grin and bear the suffering, hoping that they're able to stay hydrated enough to stave off heat exhaustion or heat stroke.

Extreme heat is no joke.

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June 16, 2024

Tropical disturbance, unusually hot ocean likely to fuel Gulf Coast flooding this week

A tropical disturbance slowly moving into the western Gulf of Mexico will bring copious amounts of rain over the next couple of days, leading to a threat for flash flooding across coastal portions of Texas and Louisiana.

Forecasters expect the heaviest precipitation to fall over coastal Texas, where 5-10 inches of rain is possible through the middle of the week. Locally higher totals are possible. The region has famously poor drainage—especially the Houston metro area—so the likelihood of flash flooding during heavy rain is almost a given.

Remember, never try to drive across a flooded roadway. It's impossible to tell how deep the water is until it's too late, and the road may be washed out beneath the floodwaters. It only takes a few inches of moving water to lift up a vehicle and carry it downstream.

The slug of moisture is arriving with a tropical disturbance moseying into the western Gulf of Mexico. The National Hurricane Center gives the area a 60 percent chance of developing into a tropical depression over the next few days as it moves into the region.

Heavy rain is coming whether or not this develops into a named system. Some of the worst heavy rain events are the result of unnamed tropical disturbances—just look at what happened in Florida last week.

A tropical disturbance sent a vast amount of tropical moisture streaming over southern Florida. Persistent thunderstorms developed over the region, wringing out that moisture in the form of drenching rains that fell at several inches per hour at times.

Some areas wound up with more than two feet of rain, with the National Weather Service's latest precipitation analysis showing even more than that over the past ten days.

This latest tropical disturbance is a reminder that the Atlantic Ocean is open for business—and this season could mean business.

All major hurricane forecasts are calling for an extremely active hurricane season with predictions rivalling the busiest seasons on record. We could see more than 20 named storms this year if the forecasts pan out.

Extremely warm sea surface temperatures are driving those forecasts—and they're also likely driving the persistent heavy rain we've seen (and will soon see) across the Gulf Coast.

Warmer waters raise air temperatures over the ocean, allowing the air to hold more moisture than it would otherwise. It's likely that warmer sea surface temperatures are increasing the amount of moisture we're seeing over the region, which is enhancing rainfall totals in turn.

How unusually warm is the ocean right now?

Sea surface temperature anomalies are running 1-2°C above normal throughout almost the entire tropical Atlantic basin. 

Compare that to this time last year, where the extent and intensity of anomalies were still ugly, but a little less intense than we're dealing with this year:

It's worth noting that last year's very warm temperatures were able to fuel one of the most active hurricane seasons on record, overpowering the influence of El Niño which tends to subdue tropical activity in the Atlantic. 

This year, though, we've got even warmer waters and a La Niña in the Pacific, which is favorable to tropical development in the Atlantic. It could be a long, rainy summer. Hold on.

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June 12, 2024

High-impact heat set to build over much of the U.S. through mid-June

The jet stream is moving to Canada—and you might also want to head north after seeing the temperatures on the way over the next week or longer.

A long-duration spell of warmer-than-normal temperatures will bathe the eastern half of the United States through the middle of the month as a ridge takes hold over the region.

Not only will this pattern crank up the heat, but it may finally shut off the Ferris wheel of severe thunderstorm outbreaks we've endured since early spring.

The Temperatures

It's already plenty hot across the Plains and the southeastern corner of the country, where temperatures on Wednesday easily climbed into the 90s for many locations.

We'll see that heat spread north and east as the ridge builds into place through the weekend, with daytime highs pushing into the upper 80s and lower to mid-90s by Sunday.

The warmth isn't going anywhere in a hurry, with highs in the 90s likely across the eastern seaboard all through next week and possibly into the following weekend.

Here's a look at the National Weather Service's forecast high temperatures on Monday, June 17...

...and here's a look at Tuesday's predicted high temperatures:

The Setup

A jet stream parked over the northern tier of the United States has driven the drumbeat of severe weather over the past couple of months. One low-pressure system after another cresting the Rockies and roaring through the central U.S. has fueled a healthy thunderstorm season.

We just experienced our second-most tornadic April on record, and the Storm Prediction Center announced Tuesday that last month was one of the most severe Mays on record.

Image: Tropical Tidbits

The jet stream tends to migrate north as summer settles in, which helps push severe weather farther to the north—while also letting the heat build to the south.

Models are consistently showing ridges of high pressure parked over the eastern half of the United States through the middle of the month. Air sinks beneath ridges, warming up as it descends toward the ground.

A persistent ridging pattern will keep temperatures much warmer than normal for a week or longer, which is no small thing considering average temperatures in the latter half of June are pretty warm to begin with.

Heat Impacts

This is the first large-scale test of the National Weather Service's new HeatRisk product, which measures the potential impact of high heat on certain regions. HeatRisk takes into consideration factors like:
  • The time of year
  • How far above normal temperatures are for that time of year
  • How long the unusual heat will stick around
  • Temperatures reaching thresholds known to cause heat-related illnesses
Urban areas are regions farther to the north are likely to experience higher risk from heat than communities down south. Access to cooling and your body's physical acclimation to heat plays a significant role in heat impacts. A 90°F and humid day is far different for folks living in Mobile, Alabama, than it is for a lifelong resident of Detroit, Michigan.

The potential for major to extreme heat impacts light up the board across the central and northern U.S. over the next week given the latest NWS temperature forecasts. The greatest risk focuses on the Midwest by the end of the weekend, pushing toward the Great Lakes by the beginning of next week.

The compounding effects of hot, humid days and stuffy, muggy nights will take a toll on vulnerable people—especially those without reliable access to air conditioning. Take care if hot temperatures are on the way to your area. It's easier to succumb to heat exhaustion or worse than you think, even for someone who's otherwise healthy.

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June 9, 2024

A deep dive into the powerful 2015 tornado that destroyed Fairdale, Illinois

A devastating EF-4 tornado carved a scar through 30 miles of farmland in north-central Illinois on a muggy afternoon in April 2015. Two people died and nearly a dozen more were injured as the storm levelled neighborhoods in Rochelle and Fairdale, about an hour's drive west of Chicago.

Estimated winds reached 200 mph as the tornado swept homes and businesses clean off their foundations. Falling just 1 mph shy of scale-topping EF-5 status, it stands in the records at the strongest tornado to hit Illinois that decade. 

Here's an in-depth look at how a modest rain shower grew into a killer supercell over the course of just two hours.

Note: This is an adaptation of an article I originally wrote for The Vane on April 14, 2015. Since neither Gawker nor The Vane exist anymore (outside of the Internet Archive), I'm reworking and publishing this article by popular request.

A Volatile Setup

We saw a classic springtime severe weather event unfold across the central U.S. during the second week of April 2015.

A strong trough diving over the Rockies spawned a low-pressure system over eastern Colorado on Wednesday, April 8, leading to a multi-day severe weather outbreak across the Plains and Midwest states.

This system was in its prime as it arrived in eastern Iowa during the day on Thursday, April 9. The air certainly had that stormy 'feel' to it on Thursday afternoon as southerly winds dragged warm, muggy air over Illinois—providing plenty of instability and moisture for thunderstorms to thrive.

A mile or two above the surface, southwesterly winds were racing along at highway speeds as air whipped around the strengthening low-pressure system. Even higher in the atmosphere—about five miles up—winds were blowing out of the west at nearly 100 mph. 

Wind shear is a critical factor in pushing ordinary thunderstorms beyond severe limits. This sharp change in wind speed and direction with height creates a horizontal rolling motion in the atmosphere. A thunderstorm's strong updraft can force this horizontal rotation to tilt vertically, allowing the updraft to 'absorb' the rotation (so to speak). 

A thunderstorm with a rotating updraft is called a supercell. Rotation makes a supercell's updraft stronger and more resilient than an ordinary thunderstorm, creating a storm that can last longer, travel farther, produce bigger hail, and spawn tornadoes.

Particularly intense supercells are capable of supporting the strongest tornadoes ever observed. These high-end twisters can grow more than a mile wide, packing winds close to 200 mph as they carve a path dozens and even hundreds of miles long.

The supercell that tore through north-central Illinois on April 9, 2015, was one of those storms.

5:34 p.m. CDT

Unstable air rapidly rising into the atmosphere about 70 miles southwest of Fairdale generated a vigorous batch of billowing cumulus clouds.

The weight of the water overpowered the strength of the updraft, falling to the ground as the first detectable batch of light rain just south of the town of Annawan.

5:48 p.m. CDT | Elapsed Time: 14 minutes

It took less than fifteen minutes for the shower to grow into a downpour as the thunderstorm kicks into gear. We can already see the storm taking on the vague outline of a supercell's classic shape.

Wind shear is tilting the storm's updraft toward the northeast, forcing the rain-cooled air in the downdraft to flow around the western side of the storm—a feature known as a rear-flank downdraft. This setup allows the storm to vent its rain-cooled air without interrupting the warm, unstable air feeding into the downdraft. 

5:59 p.m. CDT | Elapsed Time: 25 minutes

By the top of the hour, the storm is rapidly maturing into a full-blown supercell.

The warm, unstable air streaming into the updraft leaves a precipitation-free vault in the base of the storm known as an inflow notch. We can see the rear-flank downdraft wrapping around the western side of the storm. These two features help generate the classic hook echo that make supercells so ominously recognizable on radar imagery.

However, supercells really thrive when they're all alone. Another thunderstorm that bubbled up a few miles to the west is interfering with its development. The storm will struggle to reach its full potential until the neighboring storm dissipates or moves away.

6:08 p.m. CDT | Elapsed Time: 32 minutes

Eight minutes after the hour, the supercell's appearance is already improving as the neighboring storm starts to pull away. We can see the beginnings of a hook echo showing up on precipitation and velocity (wind) imagery.

The storm is starting to develop a "v-notch" as strong winds aloft deflect around the updraft like water around the bow of a boat, leaving something of a rain-shadow effect immediately downwind from the updraft. 

6:11 p.m. CDT | Elapsed Time: 34 minutes

Forecasters issue a severe thunderstorm warning for large hail and damaging winds.

6:27 p.m. CDT | Elapsed Time: 52 minutes

The leading edge of the supercell approaches Rochelle, Illinois, and its population of about 10,000 residents. A well-defined hook echo is present on radar now, a sign that rotation within the storm is rapidly tightening up as the supercell takes advantage of the favorable environment.

6:35 p.m. CDT | Elapsed Time: 1 hour, 1 minute

Forecasters at the National Weather Service in Joliet issue a tornado warning based on the strong rotation indicated by radar imagery.

A 3-D rendering of the supercell shows the powerful mesocyclone stretching from the base of the storm up beyond the cruising altitude of passenger jets—indicative of a very healthy and very hazardous supercell.

6:47 p.m. CDT | Elapsed Time: 1 hour, 12 minutes

One of the great benefits of modern weather radar is that we don't always have to wait for visual confirmation to know that a storm is producing a tornado.

Tornado debris reflects a significant amount of radiation back to the radar site. This return often shows up as a dark circle—called a debris ball—that coincides with the location of strong rotation within the storm.

A (then-recent) radar upgrade called dual polarization allows us to see the size and shape of the objects reflecting the radar beam, which is useful for telling rain, hail, and debris apart. A big mix of different sizes and shapes will show up with a low correlation coefficient. The data left no question that this is a significant amount of debris lofting into the atmosphere.

6:57 p.m. CDT | Elapsed Time: 1 hour, 22 minutes

This large, wedge tornado is now at its peak intensity as it spares Rochelle by tracking just west and north of the town center.

The most intense damage occurs along S Richard Road and E Kuehl Court, just northwest of Rochelle. Several homes on these roads were completely levelled, with wind-swept debris tossed a significant distance downwind from each residence. Surveyors used this damage to rate the tornado a high-end EF-4, just one tick below EF-5 strength.

Just north of Rochelle, though, a restaurant called Grubsteakers takes a direct hit from the tornado. Thanks to advanced warning—the tornado warning has been in effect for 23 minutes at this point—all 12 people in the building escaped injury by huddling in the restaurant's cellar.

Grubsteakers was a total loss, but it didn't take the full brunt of this powerful tornado.

Surveyors found EF-4 damage just a short walk north of Grubsteakers, where the tornado destroyed a home, scrubbed a barn down to its foundation, and debarked sturdy trees on the property.

7:00 p.m. CDT | Elapsed Time: 1 hour, 25 minutes

An exceptionally clear view of the tornado from the south allows multiple storm chasers and residents to capture crisp images of the storm as it passes through the area.

After hitting properties north of Rochelle, the tornado spent the next several minutes passing over farmland. Multiple homes and structures suffered damage, with surveyors finding EF-2 to EF-3 damage in a few spots.

Satellite imagery taken a few days after the storm revealed a remarkable pattern of cycloidal marks carved into the topsoil along the tornado's visible scar. Large tornadoes often contain multiple vortices swirling around the larger overall circulation. The vortices, as well as any debris caught in them, can gouge the ground in swirling patterns that are easily visible from the air after the storm.

7:13 p.m. CDT | Elapsed Time: 1 hour, 38 minutes

Fairdale takes a direct hit.

The tornado carved through the northwest corner of this 0.08-square-mile community, destroying more than a dozen homes and damaging just about every building in town.

Two people died and 22 more were injured in the few seconds it took for the tornado's intense winds to rip through Fairdale. One resident in the path of the storm filmed the tornado from a window as it approached the community; his wife died and he was injured when the storm destroyed their home. 

Ground surveys and satellite imagery reveal the extent of the damage. Extensive ground scouring, debarked trees, and near-complete destruction of all structures and vehicles left the northwestern corner of Fairdale unrecognizable. 

7:27 p.m. CDT | Elapsed Time: 1 hour, 52 minutes

Past its prime, the large supercell that produced the Fairdale tornado is in the waning stages of its life.

The supercell is beginning to merge into the squall line chugging through northern Illinois, which brought rough weather to the city of Rockford just a few minutes earlier. Rain-cooled air and the nearby thunderstorms are disrupting the supercell's structure, forcing it to break down.

7:50 p.m. CDT | Elapsed Time: 2 hours, 16 minutes

Just over two hours after a tiny shower in central Illinois grew into a supercell that dropped a violent tornado, the storm has fully absorbed into the squall line and is no longer its own, independent storm.


One of the most striking aspects of the storm was how the violent tornado itself developed.

If we animate the radar at the storm's peak strength, we can see that a tiny shower ingested into the inflow that fed the storm its supply of unstable air. There have been plenty of similar cases over the years where a nearby shower or thunderstorm brushes past or gets ingested into the hook of a supercell thunderstorm, enhancing the spinning and stretching motions needed to spawn a powerful tornado.

This tragic event provided a remarkable opportunity to watch the evolution of a destructive thunderstorm from infancy to dissipation. It's sometimes easy to forget that even the mightiest storm begins as a single puffy cloud. 

[Top image courtesy of the NWS. All radar images courtesy of Gibson Ridge and compiled/annotated using Canva.]

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