Update: Flood advisory issued for Boulder and Broomfield counties Friday night due to substantial rainfall

Published Jul 12, 2025

The National Weather Service released an updated flood advisory at 7:59 p.m. on Friday in effect until 10 p.m. for Boulder and Broomfield counties.

The NWS states to be ready for, “Flooding caused by excessive rainfall continues.”

“Minor flooding in low-lying and poor drainage areas,” explains the NWS. “Be aware of your surroundings and do not drive on flooded roads. Excessive runoff from heavy rainfall will cause minor flooding of small creeks and streams, highways, streets, underpasses, drainage areas and other low lying spots.”

Understanding the differences between advisories, watches, and warnings

• Flash flood warning: Take action!

A flash flood warning is issued when a flash flood is either imminent or already occurring. In flood-prone areas, it’s crucial to move immediately to higher ground. A flash flood is a sudden and violent inundation that can develop within minutes to hours, and it can even happen in areas not currently experiencing rainfall.

• Flood warning: Take action!

A flood warning is issued when flooding is imminent or occurring.

• Flood advisory: Be aware:

A flood advisory is issued when flooding is not expected to be bad enough to issue a warning. However, it may cause significant inconvenience, and if caution is not exercised, it could lead to situations that may threaten life and/or property.

• Flood watch: Be prepared:

A flood watch is issued when conditions are favorable for flooding. It does not mean flooding will occur, but it is possible.

Be flood-ready: Expert guidance from the NWS for your safety

In flood-prone regions or while camping in low-lying areas, understanding and following the NWS flood safety guidelines can be a lifesaver:

Move to higher ground:

If you reside in a flood-prone region or are camping in low-lying terrain, the first step to safety is relocating to higher ground.

Follow evacuation orders:

If local authorities issue an evacuation order, heed it promptly. Prior to leaving, secure your home by locking it.

Disconnect utilities and appliances:

If time permits, disconnect your utilities and appliances. This precaution minimizes electrical hazards during flooding.

Avoid basements and submerged areas:

Steer clear of basements or rooms where water has submerged electrical outlets or cords. This helps prevent electrical accidents.

Swift evacuation for your safety:

If you notice sparks or hear buzzing, crackling, snapping, or popping noises, evacuate immediately. Avoid any water that may be charged with electricity.

Refrain from walking in floodwaters:

Never attempt to walk through floodwaters. Even just 6 inches of swiftly moving water can forcefully knock you off your feet.

Seek higher ground when trapped:

In the event you become trapped by moving water, make your way to the highest point available and contact emergency services by calling 911.

During heavy rainfall, the risk of flooding is heightened, especially in low-lying and flood-prone regions. Always remember never to drive through water on the road, no matter how shallow it appears. According to the NWS, as little as 12 inches of rapidly flowing water can carry away most vehicles. Prioritize your safety by staying informed and prepared.

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 swollen waterways:

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:

Adhere to the two-second rule for maintaining a safe following distance behind the vehicle in front of you. In heavy rain, allow an additional two seconds of distance to compensate for reduced traction and braking effectiveness.

Reduce speed and drive cautiously:

If it is raining and the roads are wet, slow down. Take your foot off the accelerator and let your speed drop gradually. Never use the brakes suddenly because this may cause the car to skid.

Choose your lane wisely:

Stick to the middle lanes to minimize the risk of hydroplaning. Outer lanes are more prone to accumulating water.

Visibility matters:

Turn on your headlights and be careful of other vehicles to the rear and in blind spot areas as they are especially difficult to see through rain-spattered windows.

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:

Large trucks and buses can reduce your visibility with tire spray. Avoid tailgating and pass them swiftly and safely.

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.

• If the roadside is your only option, pull off as far as possible, preferably past the end of a guard rail, and wait until the storm passes. Keep your headlights on and turn on emergency flashers to alert other drivers of your position.

By following these safety measures, you can significantly reduce risks and ensure your well-being when heavy rain pours down. Stay informed about weather conditions and heed advice from local authorities to make your journey safe and sound.

Source: The National Weather Service