Philadelphia/Mount Holly Weather Forecast Office Presentation Created

2/11/2018 4:18 AM @NWS_MountHolly NWSMountHolly

Flooding

potential

today and

this evening

What Has Changed?

No significant changes.

Total rainfall may seem lower on map,

but that does not include rain that

already fell.

Decision Support Briefing #3

As of: 5 am Sunday, February 11,

2018

Philadelphia/Mount Holly Weather Forecast Office Presentation Created

2/11/2018 4:18 AM @NWS_MountHolly NWSMountHolly

Main Points

Hazard Impacts Location Timing

Areal Flooding

Smaller streams may rise and

overflow their banks. Roadways

may quickly become flooded and

impassable.

Greatest risk along NJ

Turnpike/I-95 corridor

from around

Wilmington, DE to New

York City.

The potential for flooding

lasts through this evening.

River Flooding

Some of the larger rivers may

rise to their banks or experience

minor flooding.

Rivers in southeast PA,

including the lower

Schuylkill; rivers in

northern and central NJ,

including the Raritan

and Passaic. If the

Raritan basin sees the

brunt of the rainfall, the

Millstone River could

experience moderate

flooding.

The potential for river

flooding begins this morning

and continues through

tonight.

Philadelphia/Mount Holly Weather Forecast Office Presentation Created

2/11/2018 4:18 AM @NWS_MountHolly NWSMountHolly

River Flooding: N MD/DE, SE PA, most of NJ

Areal Flooding: N MD/DE, SE PA, most of NJ

None Limited Elevated Significant Extreme

Summary of Greatest Impacts

None Limited Elevated Significant Extreme

Philadelphia/Mount Holly Weather Forecast Office Presentation Created

2/11/2018 4:18 AM @NWS_MountHolly NWSMountHolly

Storm Total Rainfall

Forecast details:

Between 1 and 2 inches

of rain has already fallen

across MD, DE, and

southern NJ. An

additional 1 to 2 inches

of rain with locally higher

amounts is expected.

Heaviest rain through

this afternoon.

Flood Watch may have

to be extended based on

how much rain falls and

how rivers respond.

Philadelphia/Mount Holly Weather Forecast Office Presentation Created

2/11/2018 4:18 AM @NWS_MountHolly NWSMountHolly

Flood Watch remains in effect for most of the region.

The heaviest rain will fall through this afternoon.

Low-lying flooding is likely where the heaviest rain occurs.

Minor flooding is possible for most rivers, streams, and creeks today and tonight.

Moderate river flooding cannot be ruled out, especially for the Millstone River.

To see where our concerns specifically lie, visit our AHPS site and click, “River

Forecasts” tab at: https://water.weather.gov/ahps2/index.php?wfo=phi

Event Summary