Tag Archive | National Weather Service

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.


Video: Heat Advisory Issued Today and Heat Safety Tips

Posted at 1:15 p.m.

The National Weather Service has issued a heat advisory today, in effect until 8 p.m. tonight.

Heat index values will be up to 107 degrees with maximum temperatures in the mid to upper 90s. The heat and humidity may cause heat stress during outdoor exertion or extended exposure.

Staff from our Office of Emergency Management, Health Department and Office to Prevent and End Homelessness joined us to discuss today’s heat advisory, what you can do to stay cool and safe in the summer heat, as well as what you should be aware of and can do to assist our vulnerable population.

For more information on extreme heat, visit www.fairfaxcounty.gov/emergency/hazards/extreme-heat.htm. For the current weather forecast, visit www.fairfaxcounty.gov/emergency/weather-forecast.htm.

Heat Advisory

Posted at 10:30 a.m.

Heat Advisory issued for July 20, 2017

The National Weather Service has issued a Heat Advisory, in effect from noon to 7 p.m. today, Thursday, July 20. A Heat Advisory means that a period of high temperatures is expected.

Heat index values of up to around 105 degrees are expected.

The combination of high temperatures and high humidity will create a situation in which heat illnesses are possible during outdoor exertion or extended exposure.

Extended excessive heat is expected across the region through the weekend; severe thunderstorms also are possible tonight through the weekend.

Heat Advisory Issued for July 20m, 2017


Precautionary / Preparedness Actions

  • Never leave children or pets alone in a closed vehicle.
  • Take extra precautions if you work or spend time outside.
  • When possible, reschedule strenuous activities to early morning or evening.
  • Wear light weight and loose fitting clothing when possible and drink plenty of water.
  • Drink plenty of fluids: Drink two to four glasses of cool fluids each hour. Your body needs water to keep cool. Drink water even if you don’t feel thirsty. Do not drink caffeinated or alcoholic beverages because they dehydrate the body.

To reduce risk during outdoor work, take frequent rest breaks in shaded or air conditioned environments such as shopping malls, etc. Resting for just two hours in air conditioning can significantly reduce heat-related illnesses. Consider spending the warmest part of the day in public buildings such as movie theaters, shopping malls and other community facilities. You can also visit one of Fairfax County’s Cooling Centers.

Anyone overcome by heat should be moved to a cool and shaded location. Heat stroke is an emergency — call or text 9-1-1 immediately.

Air Quality Alert

The Metropolitan Washington Council of Governments has issued a Code Orange Air Quality Alert today for the D.C. metro area.

A Code Orange Air Quality Alert means that air pollution concentrations within the region may become unhealthy for sensitive groups. Sensitive groups include children, people suffering from asthma, heart disease or other lung diseases and the elderly. The effects of air pollution can be minimized by avoiding strenuous activity or exercise outdoors.

Fairfax Alerts