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Hurricane Florence Update — What to Know in Advance of the Storm

Flood watch versus flood warning

Posted at 11:45 a.m.

Hurricane Florence continues its path toward the Atlantic coast. As with all hurricanes 1,000 miles away, forecasts can change, but as of this morning here’s the latest for Fairfax County:

  • 4-8 inches of rain beginning late Thursday into early Friday (though this prediction could increase or decrease); major winds should not be an issue.
  • Potential flooding over the weekend, especially as Florence is likely to stall over land and due to all the recent rain we’ve already received.
  • Rain and flooding impacts could last into early next week as flood waters from areas north and west of the county will move our way even after Florence passes. This is a potentially long-term flooding event for Fairfax County, so please pay attention to trusted sources for information.
    Hurricane Florence path (Sept 11, 2018)


One question we’ve heard quite a bit so far is “does Fairfax County provide sandbags?” Unfortunately, with over a million residents and thousands of businesses, Fairfax County simply cannot provide sandbags. We encourage residents to visit their local hardware store.

Here’s a tip from our public works staff: A simple sandbag can be made from those plastic grocery/store bags you already have at home. Simply fill them with sand or soil and you have a pretty effective sandbag.

Preparedness Actions

  • If possible to do so safely, clear loose and clogged rain gutters and downspouts before the storm arrives.
  • Trim trees and shrubbery. Rain-saturated ground increases risk for falling trees. Consult a certified arborist if you need help.
  • If you have a sump pump, make sure it is working and that the outlet pipe is not blocked. If possible, install a battery-operated backup in case of a power failure.
  • Move important indoor items to the highest possible floor.
  • Check in on elderly neighbors or those with access and functional needs to see if they need any assistance to prepare for the storm.
  • See yesterday’s blog article with more preparedness steps.

Flood watch versus flood warningStorm Drains

With all this rain, storm drains may be affected. To report blocked drains during regular business hours (Monday-Friday, 7:30 a.m. to 4 p.m.), call 703-877-2800, TTY 711. For after-hours storm flooding emergencies that are not life threatening, call 703-323-1211, TTY 703-239-8498, and state that you are reporting a storm sewer emergency; this number is staffed 24 hours a day.

Stay Weather Aware and Know the Terms

  • A Flood Watch means that a flood is possible in the area.
  • A Flood Warning means flooding is already occurring or will occur soon.
  • Get the most current forecast from the National Weather Service (NWS).
  • Find updates on Hurricane Florence from the National Hurricane Center, as well as the hurricane center’s Facebook and Twitter.
  • Sign up for severe weather alerts from Fairfax Alerts; Receive alerts by email and text.

Prepare Now for Impacts from Hurricane Florence

Posted at 1:15 p.m.

According to the National Hurricane Center, Hurricane Florence may impact our area later in the week. The storm is currently a category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale. Further strengthening is anticipated, and Florence is expected to be an extremely dangerous major hurricane through Thursday.

On the forecast track, the center of Florence will move over the southwestern Atlantic Ocean between Bermuda and the Bahamas Tuesday and Wednesday, and approach the coast of South Carolina or North Carolina on Thursday.

Hurricane Florence

Preparedness Action To Take Today

We don’t know yet what impact Florence will have on our region, but we are likely to continue to see a lot more rain. Here’s a few things you can do now to prepare.

  • Make sure your gutters and downspouts are clear of debris and that water flows away from your home.
  • If you live in an area prone to flooding or have had flooding in the past, take precautions to move valuables from the basement; at least move items off the floor onto higher shelves if possible.
  • Check your emergency supply kit and replenish any items missing or in short supply, especially medications or other medical supplies. Be sure to you have extra batteries and flashlights in case you lose electricity.
  • Purchase a battery-powered or hand-crank NOAA weather radio. Find an online NOAA radio station or download the NOAA radio app for your smartphone (Apple Store | Google Play).
  • Review your family’s emergency plan. Does your family know what to do or where to go in case of an emergency or localized flooding? And be sure you know what to do with pets.
  • Fill plastic bottles with clean water for drinking.
  • Fill your car’s gas tank in case you need to evacuate your home or seek shelter elsewhere.
  • Sign up for severe weather alerts from Fairfax Alerts. You can receive these alerts by email and text.

And finally, local creeks and streams are already rising and many reaching capacity. Do not let children play in or near streams or creeks do to the potentially rapidly rising waters.

Hazardous Weather This Week

The National Weather Service has issued a Hazardous Weather Outlook for the potential of severe thunderstorms this afternoon and evening that could lead to locally heavy rainfall with the potential of flash flooding. This hazardous weather outlook continues Tuesday through Sunday with minor to perhaps moderate flooding expected along the Potomac River Basin on Tuesday.

A Flood Warning also has been issued for the Potomac River at Little Falls, from overnight tonight until Wednesday afternoon. The forecast predicts a rise above flood stage by overnight tonight and crest near 11.0 feet by early tomorrow evening. The river is expected to fall below flood stage by late Wednesday morning.

Never Drive Through Flooded Roadways

Flooding is one of the leading causes of weather related fatalities in the U.S. On average, flooding claims nearly 90 lives each year.  More than half of these deaths occur in motor vehicles when people attempt to drive through flooded roadways. This happens because people underestimate the force and power of water, especially when it is moving.

Just six inches of fast-moving water can knock over and carry off an adult. Twelve inches of water can float a small car. If that water is moving, it can carry that car away. Eighteen to 24 inches of flowing water can carry away most vehicles, including large SUVs.

It is impossible to tell the exact depth of water covering a roadway or the condition of the road below the water. This is especially true at night when your vision is more limited.  It is never safe to drive or walk through flood waters.

Any time you come to a flooded road, walkway, or path, follow this simple rule: Turn Around Don’t Drown.

Flash Flood Watch in Effect Today

Posted at 9 a.m.

The National Weather Service has issued a Flash Flood Watch, in effect from 9 a.m. through this evening.

A Flash Flood Watch means that conditions may develop that lead to flash flooding. Flash flooding is a very dangerous situation.

Multiple rounds of showers and thunderstorms are expected today with localized heavy rainfall rates of 1 to 2 inches per hour possible.

Runoff from excessive rainfall may cause rapid rises of water in low-lying and poor drainage areas as well as streams and creeks, resulting in flash flooding. Urban areas will be most susceptible.

You should monitor later forecasts and be prepared to take action should flash flood warnings be issued.

Live Weather Radar

More on the weather forecast is online. Also, register for free severe weather alerts from Fairfax Alerts.

Flash Flood Warning Issued Until 2:30 p.m. Today

Posted at 10:45 a.m.

The National Weather Service has issued a Flash Flood Warning for the cities of Fairfax, Alexandria and Falls Church, as well as central Fairfax County until 2:30 p.m. today.

A Flash Flood Warning means that flooding is imminent or occurring. If you are in the warned area move to higher ground immediately. Residents living along streams and creeks should take immediate precautions to protect life and property.

The weather service reports that at 10:24 a.m., Doppler radar indicated thunderstorms producing heavy rain across the area. Over two inches of rain have already fallen near Merrifield, with over one inch in much of the remainder of the area. Additional rainfall amounts of one to two inches are possible. Flash flooding is expected to begin shortly.

Precautions / Preparedness Actions

  • Keep children away from creeks and their potentially rapidly rising waters.
  • Turn around, don’t drown when encountering flooded roads. Most flood deaths occur in vehicles. Never drive your vehicle into areas where the water covers the roadway. Flood waters are usually deeper than they appear. Just one foot of flowing water is powerful enough to sweep vehicles off the road.

Get more on the forecast and sign up for severe weather alerts from Fairfax Alerts.

You may also receive a WEA alert on your phone. Wireless Emergency Alerts (WEA) are free informational text messages sent to WEA-enabled phones within range of an imminent and dangerous local situation, severe weather event or AMBER alert. The National Weather Service and Fairfax County are among the select entities that can send these messages to your phone regardless if you signed up.

Flash Flood Watch Issued for Friday and Saturday; 3 Inches of Rain Possible

Posted at 3:30 p.m.

Flood Watch

The National Weather Service (NWS) has issued a flash flood watch, in effect from tomorrow (Friday) afternoon through Saturday afternoon, July 29. A flash flood watch means that conditions may develop that lead to flash flooding. Flash flooding is a very dangerous situation.

NWS reports that low pressure is going to develop over the Mid Atlantic Friday and remain nearly stationary this weekend. This will have the potential to bring 3 inches or more of rain to the region through Saturday afternoon. Thunderstorms could cause locally higher rainfall amounts.

Heavy rainfall may result in rapid rises in streams and creeks. This could quickly result in flooding, especially in low lying and poor drainage areas.

You should monitor weather forecasts and be prepared to take action should flash flood warnings be issued.