The Storm Was in the Forecast: U.S. Winter Dispatch, Chain Law and TONU Decisions for 2026-27

It is 3 p.m. on a Thursday in January. A reefer load of produce picks up in the Rio Grande Valley tomorrow morning for a Nashville grocery DC on Monday. The National Weather Service has had an ice storm watch posted across north Texas and the mid-South since Tuesday. The carrier wants to know whether you will pay a truck-ordered-not-used if the shipper closes, the shipper wants to know whether you can guarantee the appointment, and your dispatcher wants to know whether the driver can use the two-hour adverse conditions extension if I-40 turns to glass. The honest answer to the last question is probably no, because the storm was in the forecast. The answers to the first two depend entirely on what you wrote down before anyone needed them.

Most of winter's cost is not the storm. It is the argument afterward about who owns the delay.

This winter's risk sits further south than your playbook

The federal Climate Prediction Center's October 8, 2026 ENSO discussion put the odds of a strong-to-very-strong El Nino lasting through January to March 2027 above 83%, with a real chance of the strongest event on record. NOAA's winter outlook, released October 15, 2026, says that pattern likely shifts the jet stream south and east, favoring wetter-than-average conditions across the southern tier from California to Florida and up the Eastern Seaboard, with warmer-than-average temperatures across the northern U.S. The agency's own framing was that the odds tilt toward stormier weather across the South.

Warmer on average does not rule out arctic outbreaks. Winter Storm Fern moved through in late January 2026, pushing arctic air to the Gulf Coast and laying snow and ice from New Mexico to New England. A national tender rejection index jumped from 9.75% on January 21 to 12.19% on January 28, according to a trade-press market analysis published January 31, 2026, against an average of 5.35% from February through October 2025. A national spot rate index rose nearly 3% in the same week. The same analysis called it the third consecutive winter of storm-driven, large-scale service disruption.

FMCSA issued Regional Emergency Declaration No. 2026-001 on January 23, 2026, and a separate heating-fuel declaration first issued December 12, 2025 was extended four times through March 14, 2026. Read them before counting on them. The heating-fuel relief covered only the driving-time limits in 49 CFR 395.3, only for carriers directly hauling propane, natural gas or heating oil to the emergency, and it excluded routine deliveries and mixed loads with a token amount of relief cargo. An emergency declaration is not a general winter exemption.

NOAA also said the National Weather Service will use "Particularly Dangerous Situation" wording this season in select blizzard and ice storm warnings, reserved for high-confidence events of historic severity. That is a clean, public, timestamped trigger to build policy around.

"Adverse driving conditions" ends where the forecast begins

The federal adverse driving exception in 49 CFR 395.1(b)(1) lets a driver who cannot safely complete a run because of adverse conditions drive up to two additional hours beyond the normal limits, to finish the run or reach a safe place for the truck and cargo. Since the 2020 hours-of-service changes, that extension applies to both the 11-hour driving limit and the 14-hour window.

The catch is the definition in 49 CFR 395.2. Adverse driving conditions are snow, ice, sleet, fog or other adverse weather, or unusual road or traffic conditions, that were not known, or could not reasonably be known, to the driver immediately before beginning the duty day (or before driving after a qualifying break or sleeper period), or to the motor carrier immediately before dispatching the driver.

That last clause is the one dispatch forgets. If an ice storm warning was posted when you dispatched, the carrier knew or reasonably could have known. The extension is unlikely to hold up, and the plan has to work inside normal hours. Two other rules sit on top:

• 49 CFR 392.14 requires extreme caution and reduced speed when snow, ice, sleet or fog affect visibility or traction, and says that if conditions become sufficiently dangerous, operation shall be discontinued until the vehicle can be operated safely. That is a federal instruction to stop, not a suggestion.

• 49 CFR 390.6 bars a motor carrier, shipper, receiver or transportation intermediary, including their agents, from coercing a driver to operate in violation of the safety regulations. Brokers and shippers are named. Threatening to pull freight unless a driver keeps rolling into conditions 392.14 says to stop for invites a coercion complaint.

So treat the forecast at the moment of dispatch as a recorded fact. If you cannot show what was posted at dispatch, you cannot show the extension was legitimate.

Chain law is a routing input, not a driver problem

Chain rules differ sharply by state, and the differences decide which lanes a tractor can legally run.

California has no carry season. When chain controls are posted, every heavy-duty vehicle over 6,500 pounds gross must have chains mounted to proceed, snow tires on a heavy truck earn no exemption, and a trailer with brakes needs at least one axle chained, according to Caltrans guidance. Trucks screened without chains are turned back to lower elevation. Controls are most common on I-5 north of Redding, I-80 over Donner Pass and US-50 over Echo Summit, but also hit SR-58 near Tehachapi, I-15 over Cajon Pass and I-5 over Tejon Pass. A wet California winter puts the southern passes in play more often.

Colorado requires vehicles over 16,000 pounds to carry chains or approved alternative traction devices from September 1 to May 31 on I-70 west of Morrison and on designated stretches of US-40, US-50, US-160, US-285, US-550 and Highway 9, whatever the weather. A state freight fact sheet dated August 2026 lists $100 plus a $32 surcharge for not carrying, $500 plus surcharge for not chaining when the law is in effect, and $1,000 plus surcharge for blocking the road. The town of Vail adds its own local penalties of $1,500 for operating without chains when conditions warrant and $2,650 for blocking Vail Pass, according to local reporting on September 11, 2026. Enforcement is rising: the state patrol reported that troopers issued 586 chain citations and port of entry officers 2,405 last winter, up from 641 and 902 in the law's first winter, despite a mild, low-snow season.

Washington requires vehicles over 10,000 pounds to carry chains from November 1 to April 1 on I-90 between North Bend and Ellensburg and on a list of other passes, regardless of conditions, plus at least two extra chains, according to WSDOT. That season started two days ago.

The operational decision is not whether drivers know these rules. It is whether your load planning knows them. Booking an I-70 or I-90 load without confirming chains are on the truck is a compliance decision made on someone else's behalf. Colorado estimates, per the same September reporting, that every hour I-70 is closed by a crash costs its economy about $2 million.

Writing weather into the rate confirmation

No federal rule sets TONU, layover or weather-delay pay. It is contract, and on most spot loads the contract is a one-page rate con written for a sunny day. Federal cargo liability under 49 U.S.C. 14706 addresses loss of or injury to the property, not missed appointments, so if a weather delay costs anyone money, the rate con and the master agreement decide who absorbs it. Decide these before December:

• Define the trigger with a public source. Tie a "weather event" to something timestamped and outside both parties' control: an NWS winter storm, blizzard or ice storm warning for the origin, destination or route, posted chain controls, or a DOT road closure. The new "Particularly Dangerous Situation" wording is a natural threshold for automatic holds with no penalty to either side.

• Separate the cancellations. A load cancelled before dispatch because a warning is posted is not a TONU. A truck that arrives and finds the shipper closed for weather is. A truck that cannot reach the shipper because the road is closed is a third case. Price each.

• Write the force majeure clause to match. Shipper master agreements often carry broad force majeure language that excuses the shipper's volume commitments in a storm but says nothing about the carrier's detention or layover. Decide whether it also suspends service-failure penalties and tender scoring for the same window.

• Layover and rebooking. State when layover begins after a weather-missed appointment, the daily rate, who rebooks, and that a weather reschedule is not a carrier service failure.

• Freeze protection. Freight that cannot freeze moves as protect-from-freeze on reefer equipment at a reefer rate, or the shipper accepts the risk in writing. "Keep from freezing" scribbled on a dry van BOL invites a claim nobody priced.

• Driver safety language. Mirror 392.14 and 390.6: nothing in the agreement requires a driver to operate in conditions that make operation unsafe, and stopping under 392.14 is not a breach.

Asset, broker and hybrid: different exposures

Asset carriers own the safety call and the hours. The decisions are when to stop dispatching into a forecast, how to pay drivers who sit, and which lanes to decline. Mileage pay plans leave a driver parked at a closure with no income and every reason to push. A flat delay rate on weather holds removes that pressure.

Brokers own neither the truck nor the driver, so their exposure is contractual and reputational. If the shipper agreement promises appointment compliance and the carrier rate con is silent on weather, the broker has written itself a weather insurance policy. Pressure from a broker rep to keep a truck moving also lands on the broker under the coercion rule.

Hybrids face a fairness test. The instinct in a storm is to protect asset trucks and push brokered carriers through. Set one weather standard per lane regardless of who hauls it.

Encoding the policy so it holds up

Every operation has its own lanes, customers, equipment and pay plans, so there is no standard winter policy to copy. What separates the shops that come out of a storm with clean margins is that the policy lives in the system they dispatch from rather than in a memo. A weather-hold status that pauses service-failure scoring and stamps the warning or closure that triggered it. A record of the forecast at the time of dispatch on every load into a warned area. Required chain confirmation on designated mountain lanes during the carry season. Permissions that limit who can waive a TONU, approve layover or override a dispatch cutoff, with a reason. Billing rules that generate the accessorial when the status changes. Built that way, a February dispute over a January storm is a lookup, not a fight.

FAQ

Can a driver use the adverse driving conditions extension for a forecast snowstorm?

Usually not, because the federal definition only covers conditions that were not known, and could not reasonably have been known, before the duty day began or before the carrier dispatched the driver.

Does an FMCSA emergency declaration suspend hours of service for all freight in a winter storm?

No, declarations apply only to carriers giving direct assistance to the emergency, and only for the regulations they list. The 2025-26 heating-fuel declaration relieved only 49 CFR 395.3 driving-time limits for propane, natural gas and heating oil, and excluded routine deliveries.

Which states require trucks to carry chains in winter?

Colorado and Washington have carry seasons, and California requires chains whenever controls are posted. Colorado's season runs September 1 to May 31 for vehicles over 16,000 pounds, and Washington's runs November 1 to April 1 for vehicles over 10,000 pounds on designated passes.

Who pays TONU when weather closes the shipper?

Whoever the rate confirmation or master agreement says pays it, because no federal rule sets TONU. Tie the weather trigger to an official warning or closure.

Can a broker or shipper be penalized for pressuring a driver to keep driving in bad weather?

Yes, because 49 CFR 390.6 bars motor carriers, shippers, receivers and transportation intermediaries from coercing drivers to violate the safety regulations.