Napa County is the focus of an updated flash flood warning issued at 3:11 p.m. on Monday by the National Weather Service. The warning is in effect until 4:15 p.m.

"Life threatening flash flooding of areas in and around the Pickett Burn Area," the NWS San Francisco CA said. "Move away from recently burned areas. Life-threatening flooding of creeks, and roads is likely. The heavy rains will likely trigger rockslides, mudslides, and debris flows in steep terrain. Impacted areas include Pickett Road, Dutch Henry Canyon Road, Swartz Creek Bridge at Athena Springs Road areas near Trib to Swartz Creek, Pond Outlet near Pope Valley Road, and the Duvall Lake Outlet. Move away from recently burned areas. Life-threatening flooding of creeks, roads and normally dry arroyos is likely. The heavy rains will likely trigger rockslides, mudslides and debris flows in steep terrain, especially in and around these areas. Please report observed flooding to local emergency services or law enforcement and request they pass this information to the National Weather Service when you can do so safely."

Follow these instructions on how to use sandbags and other flood preparation tips to protect your home, and click on the links below to get sandbags in your county:

All enabled mobile phones in the area will receive emergency alerts for "considerable or catastrophic" hazards. To monitor other local risk, residents are advised to sign up for county alert systems and to monitor agencies' social media. Follow these instructions to enable your phone to receive Wireless Emergency Alerts (WEAs). To receive local alerts in the Bay Area, visit each county's website:

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.

A flood warning is declared when flooding is on the verge of happening or is already underway.

A flood advisory is released when flooding is not expected to reach a severity level necessitating a warning. Nonetheless, it can still cause considerable inconvenience and, without exercising caution, potentially lead to situations that threaten life and/or property.

A flood watch is issued when conditions are favorable for flooding. It doesn't guarantee that flooding will occur, but it signifies that the possibility exists.

Floods can pose a significant threat, especially if you live in a flood-prone area or find yourself camping in a low-lying region. To ensure your safety, the NWS offers essential flood safety guidelines:

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.

Adhere to 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.

Steer clear of flooded basements and submerged areas:

Avoid basements or rooms submerged in water with electrical outlets or cords. Preventing electrical accidents is crucial.

Swift evacuation for your safety:

If you notice sparks or hear buzzing, crackling, snapping, or popping sounds, evacuate without delay. Do not enter water that may carry an electrical charge.

Stay away from floodwaters:

Never attempt to walk through floodwaters, even if they appear shallow. Just 6 inches of fast-moving water can forcefully sweep 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 rain, flooding is possible, especially in low-lying and flood-prone areas. Never drive through water on the road, even if it does not appear to be deep. It takes just 12 inches of rushing water to carry away most cars, according to the NWS. Stay safe by being prepared and informed.

When heavy rain sets in, the risk of flooding and hazardous driving conditions rises. Whether it's prolonged rainfall or rapid runoff, being prepared is essential. Here are some valuable safety tips from the NWS to ensure you stay safe in heavy rain:

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.

Slow down and stay cautious:

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.

Prioritize visibility:

Enhance your visibility in heavy rain by activating your headlights. Be particularly vigilant 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:

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.

Update: Flash flood warning active for Napa County early Monday evening -- significant threat, act now