A Derecho Pet Safety Plan: Which Alert Reaches Your Phone, and the Wind Speed at Which It Does Not

A derecho is a warned storm, but the weather service’s phone alert does not track the wind speed that defines it. NOAA’s Storm Prediction Center (SPC) puts it plainly: “Derechos rarely occur without warning, although warning lead times may be comparatively limited during the early stages of storm development.” The warning arrives as a Severe Thunderstorm Warning.

The gap is in the phone alert. Since August 2, 2021, only the top tier of that warning, the “destructive” tag at 80 mph, sends a Wireless Emergency Alert from the weather service. NOAA defines a derecho at gusts of at least 58 mph. So a household can be inside a genuine derecho, under a valid warning, in a wind that takes down trees, and get no weather-service alert on its phone. Your county can still send one, and other alert paths exist.

For animals, that means two things. Do not wait for a buzz to bring them in: the watch is the last stage reliably ahead of a system moving at highway speed. And plan for the outage behind the storm, which in 2012 killed more people than the wind did. The watch advice is our reasoning from the storm’s speed, not a published pet rule, and we mark it as ours where it appears.

What to do, and when

Before storm season, on an ordinary afternoon:

• Call your county or parish emergency management agency. Ask what triggers your outdoor sirens and what the county’s own opt-in alert system is. Cherokee County, Georgia says it plainly: “Warning siren policies vary from county to county.”
• Set up an alert path that works indoors and while you sleep. Dane County, Wisconsin says an outdoor siren will probably not wake you.
• Do not let the phone be your only path. All Severe Thunderstorm Warnings also go out through weather.gov, NOAA Weather Radio, the Emergency Alert System, and emergency managers. A weather radio with a tone alarm does not care what tag the warning carries.
• If you live in a manufactured or mobile home, settle your destination now, not a room. The National Weather Service (NWS) says to get out of mobile homes that can blow over in high winds.
• Choose your shelter room and stage a carrier or crate for every animal that will be in it. The crate-versus-loose decision is on crate or loose during the storm; it turns on whether the room can take on water.
• Learn to read an SPC convective outlook, especially black hatching (explained below).
• Put current ID on every animal and confirm the microchip registration reaches a phone number you answer.
• Size your outage plan to days and to a whole region, not a block.

When a watch is issued (our decision point):

• Bring animals indoors and get the cat into the carrier now, while you can still find the cat. The State of Michigan says to bring pets indoors at the first sign or warning of a storm.
• Clear the yard of anything that can become a projectile. Move a parked vehicle out from under limbs if you can.
• Put the carrier in the same secure room you will shelter in, with water in it. A carrier closed at the watch stays closed through the wind and into the outage behind it, so treat that confinement as a heat decision as well as a wind decision. This is our reasoning, not a published instruction.
• Charge what needs charging, fill water containers, and start thinking of the outage as days long.
• If you live in a manufactured or mobile home, this is when you leave, not when the warning arrives.

When the warning arrives:

• Go to your shelter location. The NWS says to take shelter in a substantial building and, for pets, “Take your pets with you if time allows.” Your own life ranks above the retrieval.
• Stay away from windows.
• If you are in a vehicle, the NWS says to drive to the closest secure shelter if there is sufficient time, not to stop and wait.
• If you are caught outside with no building, SPC’s advice for a person is to lie flat and face-down on low ground, protect the back of your head with your arms, and avoid trees. That is written for people, and no source extends it to handling an animal.
• Do not treat a siren going quiet as an all clear.

After the line passes:

• Walk the yard yourself, in daylight, before any animal goes into it. SPC warns of broken glass, nails, partly fallen limbs and other debris.
• Treat every downed line as live, especially in wet areas, and keep animals away from them.
• Check the fence line before trusting it. Keep dogs leashed until you have.
• Report your outage. SPC says not to assume the utility knows.
• Switch from the storm plan to the long-outage plan (see the last section).

What NOAA calls a derecho

SPC’s Derecho Facts page says a wind-damage swath at least 250 miles long, with gusts of at least 58 mph along its length and several well-separated gusts of 75 mph or more, from a storm system that moves faster than the mean wind, may be classified as a derecho. The page says the definition was revised in 2016 and 2025. It also says the rest of the page and a derecho archive are still being updated to match, so treat its figures as the current public statement, not settled science.

Four points matter to a household:

• 250 miles. A derecho is a regional event. The damage, the outage and the closed gas stations spread across the same 250-plus miles.
• 58 mph is the floor for the whole length. Keep that number in mind for the alert section.
• The strongest winds come in patches. SPC says derecho winds vary along the path, sometimes at or below 57 mph and sometimes from 75 mph to more than 100 mph, because they come from clusters of downbursts. Being inside the derecho tells you little about the wind at your fence line. SPC’s FAQ puts the ceiling at 130 mph gusts, which it compares to a strong EF2 tornado.
• The system outruns the air around it. That drives the timing section below.

NOAA’s published wordings differ slightly. The Facts page says the 58 mph gusts run along the swath’s length; the FAQ says along most of its length, and only the FAQ adds that the parent system must have a line-width of at least 60 miles. A journal paper the SPC cites proposes a stricter definition: paths of at least 400 km, and at least five reports of gusts of 33 m/s or more, 80 km apart, with at least three measured rather than estimated. That is a research proposal, not an SPC product; SPC’s own page is the working definition.

Which alert reaches your phone

Since August 2, 2021, the NWS has tagged Severe Thunderstorm Warnings by damage threat. Its news item names derechos in the first paragraph as one of the hazards these warnings cover. The tiers, from the NWS graphic:

Damage threat tag	Wind	Hail diameter	Phone alert (WEA)?
Base (no tag; default)	58 mph (60 mph appears in the warning)	1.00 inch (quarter)	No
Considerable	70 mph	1.75 inch (golfball)	No
Destructive	80 mph	2.75 inch (baseball)	Yes

The graphic says the highest category applies from either a qualifying wind or hail value, so a storm can reach the destructive tier on hail alone. It says phone alerts are activated whenever a warning with the destructive tag is issued or updated. The NWS also reports that, on average, only 10 percent of severe thunderstorms nationwide reach the destructive category each year, and that most of those are damaging wind events such as derechos and some large supercells.

What the alert says

The NWS published proposed wording for these alerts in a feedback request in 2021. These are samples, not a transcript of a live alert, and the times in them are placeholders. The 90-character version reads: “NWS:DESTRUCTIVE WIND STORM in this area til 1215PM TZDT. Take shelter now. Check media.” The longer version tells you to take shelter in a sturdy building, away from windows, and warns that flying debris may be deadly. The Spanish 90-character version reads “SNM:TORMENTA DE VIENTO DESTRUCTIVA en esta area hasta las 1215PM TZDT. Tome refugio ahora.” If someone in your household relies on Spanish-language alerts, see bilingual pet emergency care instructions.

The same statement notes that on phones limited to 90 characters the message will not contain the wind speed or hail size. A shorter alert is a phone limit, not a smaller storm.

The gap

Here is what we conclude, and it is our reasoning, not a NOAA finding. The wind speed that makes an event a derecho (58 mph along its length) is lower than the wind speed that fires the weather service’s phone alert (80 mph). The wind varies along the path, and the tag is set per warning polygon. So a household can sit in a genuine derecho, under a valid warning, in a wind that will take down a tree, and get no NWS alert on its handset because that stretch was warned at the considerable or base tier.

Treat the phone alert as a floor, not a trigger. Waiting for the buzz means choosing a threshold higher than the one that defines the hazard.

This is a limit on the weather service’s own warnings, not on your phone. The NWS’s Wireless Emergency Alerts page says these alerts are sent by authorized government alerting authorities, including local and state public safety agencies, FEMA, the FCC, the Department of Homeland Security and the NWS. Among the types you may receive, it lists local emergencies requiring evacuation or immediate action. So your county can push an alert the destructive tag would not. Whether it will for a 70 mph stretch of a derecho is a local decision, not a published threshold.

A second path helps. The NWS says all Severe Thunderstorm Warnings continue to go out via weather.gov, NOAA Weather Radio, the Emergency Alert System and to emergency managers. County opt-in alert systems are a separate sign-up from Wireless Emergency Alerts; wildfire evacuation alert apps for pet owners covers them, and inland hurricane pet preparedness covers NOAA Weather Radio.

Sirens are a county question, and an outdoor one

“A derecho arrives with no siren” is not a safe general statement, and neither is “sirens will sound.” As of August 15, 2026, three county agencies published their triggers, and all three tie sirens to severe thunderstorm warnings with 80 mph winds, worded differently:

Agency	Trigger	Indoor audibility	Coverage
Dane County, Wisconsin Emergency Management	Warnings carrying the destructive tag (baseball-sized hail and/or 80 mph winds)	Sirens should not be relied on to be heard inside a structure; a sleeping person will probably not be woken	144 sirens, in the most densely populated areas
Knox County, Indiana Emergency Management Agency	Destructive damage threat tag: 80 mph winds and/or hail of 2.75 inches or greater	Never rely on sirens indoors, even if one is nearby and easily heard	Sounded all at once, by zone, or individually, following the warning polygon
Cherokee County, Georgia Emergency Management Agency	Warning text forecasts winds greater than 80 mph	Buildings are designed to keep sound out; sirens are most useful for people outside	58 siren sites; they do not cover the entire county

Three counties are a demonstration, not a national rule. The action item is to call your own agency.

Two points matter more to a pet household than the trigger:

• Sirens are an outdoor system. All three agencies say so. Dane County states that the siren system is not designed to alert people indoors. If your plan depends on being woken to bring animals in, that is disqualifying on its own.
• Silence is not an all clear. Cherokee County says there is one tone and no all-clear signal, and that when the sirens stop the danger is not over. Knox County says a siren turning off does not indicate that a threat is over. (Dane County’s once-only, no-all-clear statement is written about tornado warnings, so we do not extend it to thunderstorm warnings.) If you planned to let animals back into the yard when the noise stops, those statements should stop you.

Knox County also explains the geometry: warnings are not issued for whole counties. The forecaster draws a polygon around the affected area, and if you are inside it, you should go to a safe location. Your county being in the warning and your address being inside the polygon are different questions, and the second decides whether an alert reaches your phone.

Why the watch is the decision point

Hours of system, minutes at your address

SPC says derecho-producing systems typically move at 50 mph or faster, and a few have been clocked at 70 mph. NOAA’s assessment of June 29, 2012 says that system moved east-southeast at 60 mph from Indiana in the early afternoon to the Mid-Atlantic around midnight, traveled 700 miles, and affected 10 states and Washington, D.C.

At one address the wind lasts far less time. On August 10, 2020 at Des Moines International Airport, the NWS recorded a 75 mph gust with gusts over 50 mph for over 20 minutes. That is the pattern: hours of system, tens of minutes of wind, one pass at highway speed.

The join

The NWS describes a watch area as typically large, covering numerous counties or even states, and a warning area as around the size of a city or small county. NOAA’s 2012 assessment recorded warning lead times over 30 minutes for that event. The FDA says to bring pets indoors as soon as local authorities say a storm is coming, and to keep animals in their carriers or crates, though that page is scoped to hurricanes and floods. Michigan’s page is broader: “Always bring pets indoors at the first sign or warning of a storm or disaster.”

None of these is a derecho-specific animal rule. Our conclusion: a system moving at 50 to 70 mph shortens the interval between a warning polygon reaching your address and the wind reaching it, and that interval does not lengthen as the event nears. The watch is the last stage reliably ahead of the line. So animals come in and go into carriers at the watch, and the difference is between doing it calmly and doing it with a bow echo thirty miles out.

Three exceptions travel with that advice:

• Manufactured and mobile homes. Leave, do not settle animals into a room. The NWS says to get out of mobile homes that can blow over in high winds, and SPC says mobile homes may be overturned or destroyed in a derecho. Tornado warning in a mobile home with pets covers what that costs and how to make it work.
• Already in a vehicle. The NWS says a vehicle is safer than being outside, but to drive to the closest secure shelter if there is sufficient time. SPC says occupants of cars and trucks are vulnerable to falling trees and utility poles, and that trucks, buses and SUVs may be blown over. Choose the closest secure shelter before you need it, not a long drive.
• The confinement outlasts the storm. This one is ours. A carrier closed at the watch is still closed when the outage arrives. NOAA’s assessment records 34 heat-related deaths after the 2012 derecho in areas where the power was out. Keep the carrier in your shelter room, keep water in it, and read heat emergency with no air conditioning for the heat half of the problem.

Crate versus loose is not this page’s decision; crate or loose during the storm decides it. For mechanics, see getting a large dog into a basement storm shelter, what to stock in a tornado safe room for pets and a dog home alone during a warning. The derecho contribution to all of it is one word: earlier.

No hurricane calendar, but a map exists

A hurricane plan is a calendar: the T-minus storm countdown card counts backward from a forecast landfall. The SPC product descriptions describe probabilistic and categorical area forecasts, not a track-and-cone graphic for an individual storm complex. There is no pre-drawn evacuation zone for this hazard (evacuation levels decoded covers the ladders that exist for others), and so no boarding deadline to compute.

What does exist is the SPC convective outlook. Days 1 to 3 carry categorical and probabilistic graphics. Probabilities mean the chance of severe weather within 25 miles of any point. A black hatched area means a 10% or higher probability of significant severe events within 25 miles, where significant includes thunderstorm wind gusts of hurricane force (74 mph) or higher. Hatching over your county on a wind day is the closest thing this hazard has to a cone. A Day 4 to 8 outlook covers 72 to 192 hours out, drawn at 15% and 30% probability thresholds. SPC defines its top risk category to include a long-lived derecho with hurricane-force gusts and widespread damage.

Where the map failed in 2012, and where warnings worked

NOAA’s assessment of June 29, 2012 records that the event was not forecast well in advance. Warm-season derechos are often difficult to forecast more than 12 to 24 hours ahead, and forecast models gave little help beyond 24 hours. SPC’s outlooks did not extend the severe risk to the Mid-Atlantic coast until the afternoon of June 29. A household in Maryland or Virginia planning from a Day 2 outlook on June 28 was not in the risk area; by the next afternoon they were, and the line arrived that night. That finding covers that event. It does not show that SPC outlooks generally fail on derechos.

The warnings performed. The assessment says offices generally did an excellent job issuing warnings, with lead times over 30 minutes, and that all deaths occurred within severe thunderstorm warning polygons. That undercuts the no-warning story more than any definition does. The problem is what a household does with the thirty minutes.

A date fence: damage threat tags and the phone alerts they trigger began August 2, 2021. Nothing here says phones alerted during the 2012 or 2020 events. The NWS itself says the destructive tag would have activated a phone alert for many high-impact events, including the August 2020 derecho.

Outside the house: kennels, runs, fences and the car

SPC says people outdoors are at greatest risk in a derecho. It adds that even indoors, mobile homes may be overturned, barns and similar buildings can collapse, and people inside homes, businesses and schools are sometimes hit by falling trees that crash through walls and roofs, or injured by flying glass. The NWS instruction for someone outside is to go inside a sturdy building immediately, and it states: “Sheds and storage facilities are not safe.” It adds that sheltering under a tree can be deadly.

None of those passages is about animals, and we know of no agency guidance for outdoor animals in a derecho. What follows is our reasoning from them.

• Kennel buildings, covered runs, carports and sheds fall inside the category the NWS calls not safe. There is no reason a structure that will not protect a person from a falling limb will protect a dog from one. If your derecho plan has an animal staying in an outdoor enclosure, change the plan.
• A shade tree over a run is the specific hazard. SPC says derecho impacts have increased in recent years in part because shade trees planted in suburban areas in the 1950s and 1960s have matured, and it calls older suburbs with overhead utility lines especially vulnerable.
• A fence that holds a dog on a calm day is not the same fence after a panel goes down. An animal loose in a neighborhood after a derecho is among downed lines, broken glass and debris. Current ID on the collar and a microchip registered to a phone number you answer are what turn a lost animal into a returned one. See microchip registration audit and what to put on a pet ID tag for a disaster.
• The car is not storage. SPC’s vehicle warnings apply whether or not anyone is in the seat. Leaving an animal in a parked car has its own dangers; see leaving a pet in the car at an evacuation stop.

Two documented derechos

Both are used here for duration, damage and aftermath, not for anything about phone alerts.

June 29, 2012, Ohio Valley to Mid-Atlantic. NOAA’s assessment reports winds commonly above 60 mph, numerous reports above 80 mph, and isolated pockets above 100 mph. Thirteen people were killed, mainly by falling trees. About 4 million customers lost power for up to a week, some for longer. The region was in a heat wave, and there were 34 heat-related deaths after the derecho in areas where the power was out.

August 10, 2020, Iowa and eastward. The Des Moines forecast office reports the highest official gust as 99 mph at the Marshalltown Airport, with an unofficial 106 mph gust at Le Grand, and a path across the region of over 750 miles. Its preliminary estimated-wind map shows two distinct locations of 100+ mph winds, with the area near Cedar Rapids estimated at 120+ mph. The office labels that map preliminary and subject to change, and that caution applies to the figure.

After the line passes

The wind at your address is minutes. The consequences run for days across a region.

• The outage is regional. SPC says derecho damage to overhead lines can cause massive, long-lasting outages affecting hundreds of thousands of people, and in the worst events power may not be restored for many days. It adds that repairs take longer than after a tornado because damage is widespread and supplies run short.
• Your fallback places are inside the damage path too. SPC’s FAQ warns that hotels and motels may be affected and gasoline availability may be limited over a broad area. A boarding kennel two towns over, a relative across the county, and the fuel to reach either are all assumptions to test against a 250-mile swath.
• Heat is the documented killer after the wind. NOAA’s assessment says most of the 2012 heat victims were elderly and could not easily reach air-conditioned places, and many residents in remote areas had no water and could not refrigerate medication.

None of that is written about animals. The join is ours: the outage that took the air conditioning also took the aquarium heater, the oxygen concentrator, the well pump and the refrigerator holding medication, across a region. Backup power measured in hours does not fit an outage measured in days. See the weeks-long outage pet plan, pets and power outages and heat emergency with no air conditioning.

Clean-up has its own casualties. SPC’s FAQ says a sizable number of derecho injuries and deaths occur during clean-up, long after the storm has passed. It tells people to avoid downed power lines, especially in wet areas, because the wires could still be live, and not to assume the utility knows about your outage. Our reasoning for pets: the yard an animal walks into the next morning is the same debris field that hurts adults wearing gloves, and a dog’s feet and nose are closer to it. Walk it yourself in daylight first, keep dogs on a leash on pavement you can see, and do not assume the fence line survived. Ice storm pet safety covers downed lines and paw hazards in more depth.

Limits of the guidance

• No derecho-specific animal guidance. The agency pages cited here are storm-generic: the FDA’s hurricane-and-flood page, Michigan’s broader storm-or-disaster line, and the NWS’s take-your-pets-if-time-allows clause. If your state extension service or emergency management agency publishes derecho guidance for animals, it outranks the reasoning on this page.
• One SPC sentence is easy to misread. The Derecho Facts page says the advance notice given by a derecho often is not sufficient for one to take protective action. Read alone, that sounds like derechos are unwarned. In context it is about a person outdoors reading the sky, where darkening skies and gust-front clouds appear on very short notice because the system moves so fast. Visual cues are late. Warnings are not.
• The definitions are in motion. SPC says its definition was revised and its archive is being rebuilt, and the journal paper it cites is a proposal. To check a figure later, open SPC’s page rather than this one.

Where to go next

This page is one hazard spoke of the pet emergency playbooks hub.

• The animal itself: crate or loose during the storm, getting a large dog into a basement storm shelter, what to stock in a tornado safe room for pets.
• Manufactured or mobile home: tornado warning in a mobile home with pets.
• The aftermath: the weeks-long outage plan, pets and power outages, heat emergency with no air conditioning.
• Alerting: inland hurricane pet preparedness, evacuation levels decoded for pet owners.

Then do the single highest-value thing on this page, which takes one phone call. Ask your county emergency management agency what triggers your sirens and what its own alert system is, and set up an alert path that works while you sleep.