NOAA, National Weather ServiceMiddle Atlantic River Forecast Center

Briefing

4:30pm June 7, 2013

Key Messages• MARFC is forecasting moderate flooding at 1 pt in NJ and

minor flooding at 8 pts in NJ, Southeast PA & the Lower James River basin in Virginia. Many other points are forecast to rise above their caution stages in the Potomac, James, Appomattox, Passaic, Raritan and Lower Delaware River basins.

• None of the MARFC points are in flood at this time. However, the James River at Scottsville and at Bremo Bluff are above their action or caution stages now.

• Forecasts will be closely monitored and updated through this

event. Check http://water.weather.gov for the latest info.

Tropical Storm AndreaThis is the latest forecast for the path of the center of Andrea. Remember heavy rain and flooding can occur hundreds of miles from the path of the storm center.

Timing of Rain• Rain from

Andrea continues to fall today.

• Majority of the rain should move out of the Mid-Atlantic region by sunrise Saturday.

Snapshot of weather radar at 4pm June 7, 2013. Yellows and oranges indicate areas of heaviest rain.

• Rain during the past 6 hours has been heaviest in the purple & red areas seen here. Amounts in these areas have ranged from 2 to over 3”.

• Some heavy rainfall reports we’ve received between 7am and 1pm today were: 1.87” Prince George, VA1.51” Richmond, VA1.50” Newark, DE 1.35” Graterford, PA1.31” Blackwater, MD

• This is the total amount of rainfall we’ve received over the past 48 hours.

• The reds indicate areas where 3 to over 4” of rain has occurred.

Additional Rain• This is the 72 hour

rainfall forecast from 2pm today through the entire remainder of the event for Andrea.

• The purples and reds are where we are expecting the heaviest rainfall this afternoon and tonight. Rainfall amounts are expected to be between 2 and 3 inches here.

River Forecasts• NOTE – WFOs are issuing forecasts and

warnings for some quick responding rivers. See http://water.weather.gov for all the details.

• Moderate flooding is forecast on the

Millstone River at Blackwells Mills, NJ• Minor flooding is forecast on the:

– Saddle River at Lodi, NJ– Passaic River at Pine Brook, NJ– Pequannock River at Macopin, NJ– Raritan River at Bound Brook, NJ– Brandywine Creek at Chadds Ford, PA– North Branch Rancocas Creek at Pemberton, NJ– Neshaminy Creek at Langhorne, PA– James River at Richmond-Westham, VASeveral points in the Passaic, Raritan,

Delaware, Lower Potomac, James and Appomattox River basins are expected to rise above their caution or action stages.

Purple indicates Major Flooding, Red Moderate Flooding, Orange Minor Flooding. Yellow is above caution or action stage.

Timing of Flooding

• Most crests will occur Saturday, with flooding lingering into Sunday.

• The lower Appomattox River and portions of the Passaic River will not crest until Monday.

Flood Impacts

• A listing of flood impacts at different forecast river stages can be found at http://water.weather.gov Click on the point you are interested in to get to the main hydrograph page. Scroll down below the forecast hydrograph to see the impacts.

• For example, today we are forecasting a crest above the moderate flood level on the Millstone River at Blackwells Mills, NJ. At that level, the impacts listed are: – The D&R Canal is flooded along River Road in Blackwells Mills and

South River Street in Millstone. – The base of Rt 533 bridge floods. – The Griggstown and several other causways may be closed for

flooding.

Flood Outlook• The Flood Outlook looks at

the possibility for significant flooding. Although our official forecasts are only calling for isolated minor & moderate flooding, there is enough uncertainty that you should prepare for the possibility of significant flooding in this region today through Sunday.

• Headwaters and smaller streams are especially vulnerable to these larger rises.

MARFC Status

• MARFC has been on 24 hour operations since 6am Thursday.

• Delaware, Passaic, Raritan, Potomac, Rappahannock & James River forecasts were updated this afternoon.

• All river forecasts continue to be monitored and updated as needed through the end of this event.

• MARFC is actively coordinating with our NWS Weather Forecast Offices and partners.

Flood Inundation Maps• Excellent resource to understand your flood risk.

Can be used to plan evacuation routes & travel.• Available at http://water.weather.gov for these

points:– Saddle River at Lodi, NJ – West Branch Susquehanna River at Jersey Shore, PA– Delaware River at:

• Matamoras/Port Jervis• Belvidere• Easton• Frenchtown• New Hope/Lambertville• Riegelsville• Stockton• Trenton

• NEW - USGS has just posted the Saddle River at Upper Saddle River flood inundation maps at: http://wim.usgs.gov/FIMI/FloodInundationMapper.html?siteno=01390450#.

Others are available at http://maps.srbc.net/simv/

MARFC graphics & info do not contain the entire flood threat. See your local NWS Weather Forecast Office for info on watches & warnings, flash flooding, storm surge, etc..

• Local NWS Weather Forecast Offices– Binghamton, NY http://weather.gov/bgm– Blacksburg, VA http://weather.gov/rnk– Mt Holly, NJ http://weather.gov/phi– State College, PA http://weather.gov/ctp– New York City, NY http://weather.gov/okx– Sterling, VA http://weather.gov/lwx– Wakefield, VA http://weather.gov/akq

Next MARFC BriefingThe next MARFC briefing for Andrea will be sent Saturday morning between 10am and 11am. Find us online at: http://weather.gov/marfc

https://www.facebook.com/US.NationalWeatherService.MARFC.gov

Twitter @NWSMARFC