Update: Brace for penny-sized hail with thunderstorms in Northern Colorado Sunday – gusts up to 40 mph

Published May 18, 2026

An updated weather alert was issued by the National Weather Service on Sunday at 7:50 p.m. for strong thunderstorms until 8:15 p.m. for Larimer and Boulder counties between 6,000 and 9,000 Feet, Larimer County below 6,000 feet/Northwest Weld County, Boulder/Jefferson counties below 6,000 feet/West Broomfield County and Central and South Weld County.

Prepare for penny-sized hail (0.75 inches) and wind gusts of up to 40 mph.

“At 7:50 p.m., Doppler radar tracked a strong thunderstorm 5 miles south of Lyons, or 30 miles south of Fort Collins, moving east at 35 mph,” describes the NWS. “Gusty winds could knock down tree limbs and blow around unsecured objects. Minor damage to outdoor objects is possible.”

Locations impacted by the alert include Northern Boulder, Longmont, Firestone, Frederick, Berthoud, Mead, Lyons, Niwot, Hygiene and Campion.

According to the NWS, “Monitor the weather situation closely and be alert for threatening weather conditions.”

Lightning on the horizon: Expert safety measures for thunderstorms

Each year, lightning strikes the United States approximately 25 million times, mostly during the summer. It claims the lives of about 20 people annually, according to the NWS. The threat of lightning becomes more pronounced as thunderstorms draw nearer, peaking when the storm is directly overhead and gradually waning as it moves away.

To guarantee your safety in the midst of a thunderstorm, take into account the following recommendations:

Lightning safety plan:

• When venturing outdoors, it’s crucial to have a lightning safety plan in place.

• Monitor the sky for threatening signs and listen for the sound of thunder. If thunder is audible, it’s an indication that lightning is nearby.

• Seek a safe place to shelter, preferably indoors.

Indoors safety measures:

• Once you’ve found shelter indoors, abstain from using corded phones, electrical appliances, or plumbing fixtures, and refrain from approaching windows and doors.

• Lightning can follow conductive pathways, and these precautions reduce the risk of electrical surges.

Wait for the all-clear:

• After the last lightning strike or thunderclap, wait at least 30 minutes before resuming outdoor activities.

• Lightning can strike even when a storm has seemingly passed, so exercise caution.

When indoor shelter isn’t available:

If you find yourself outdoors with no access to indoor shelter during a thunderstorm, take these steps to maximize your safety:

• Avoid open fields, hilltops, or ridge crests, which expose you to greater lightning risk.

• Steer clear of tall, isolated trees and other prominent objects. In forested areas, stay close to lower stands of trees.

• If you’re with a group, ensure individuals are spread out to prevent lightning current from transferring between people.

• Camping in an open setting during a thunderstorm is strongly discouraged. If you have no alternative, set up camp in a valley, ravine, or other low-lying areas. It’s crucial to note that a tent provides no protection against lightning.

• Do not approach water bodies, wet objects, or metal items. While water and metal don’t attract lightning, they conduct electricity effectively and can pose significant risks.

In summary, when facing the threat of lightning, preparedness and vigilance are your best allies. By following these guidelines, you can significantly reduce the likelihood of lightning-related incidents and prioritize your safety.

Driving through downpours: Safety guidelines for wet roads

Rain can turn roads into hazards. Stay informed and follow these tips from the NWS to ensure safety during heavy rainfall:

Beware of rapid water flow:

During heavy rain, avoid parking or walking near culverts or drainage ditches, where swift-moving water can pose a serious risk.

Maintain safe driving distances:

The two-second rule for following distance is your ally in heavy rain. Extend it to four seconds to ensure safe spacing in adverse conditions.

Slow down and drive with care:

On wet roads, reducing your speed is crucial. Ease off the accelerator gradually and avoid abrupt braking to prevent skidding.

Choose your lane wisely:

Stay toward the middle lanes – water tends to pool in the outside lanes.

Prioritize visibility

Enhance your visibility in heavy rain by turning on your headlights. Watch out for vehicles in blind spots, as rain-smeared windows can obscure them.

Watch out for slippery roads:

The first half-hour of rain is when roads are slickest due to a mix of rain, grime, and oil. Exercise heightened caution during this period.

Keep a safe distance from large vehicles:

Don’t follow large trucks or buses too closely. The spray created by their large tires reduces your vision. Take care when passing them as well; if you must pass, do so with caution.

Mind your windshield wipers:

Overloaded wiper blades can hinder visibility. If rain severely impairs your vision, pull over and wait for conditions to improve. Seek refuge at rest areas or sheltered spots.

When stopping by the roadside is your only option, position your vehicle as far off the road as possible, ideally beyond guardrails. Keep your headlights on and activate emergency flashers to alert other drivers of your position.

In the face of heavy rain, these precautions can make a significant difference in ensuring your safety on the road. Remember to stay informed about weather conditions and heed guidance from local authorities for a secure journey.

Source: The National Weather Service