Alert archive / New Jersey / Coastal Flood Advisories in 2021

Coastal Flood Advisory 13, NWS Philadelphia/Mount Holly

October 12, 2021Kent County, Sussex County, Delaware; Atlantic County, Cape May County, Cumberland County, New Jersey

NWS Philadelphia/Mount Holly issued this coastal flood advisory at Oct 12, 2021, 4:07 AM EDT for Kent County, Sussex County, Delaware; Atlantic County, Cape May County, Cumberland County, New Jersey. It took effect at Oct 12, 2021, 12:00 PM EDT. It was in force for 5 hr.

The area

The counties it named.

The facts

Issued
Oct 12, 2021, 4:07 AM EDT (08:07 UTC)
In effect from
Oct 12, 2021, 12:00 PM EDT
Expired
Oct 12, 2021, 5:00 PM EDT
In force
5 hr
Issued by
NWS Philadelphia/Mount Holly

Counties Kent County, DE, Sussex County, DE, Atlantic County, NJ, Cape May County, NJ, Cumberland County, NJ

The radar

The Dover AFB radar (KDOX), 46 km from the middle of the area, began a volume at 08:09 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 00:00Z, 8.1 hours before the alert went out and 136 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Wallops Is Stn, VA at 00:00Z on 2021-10-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Wallops Is Stn, VA at 00:00Z on 2021-10-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 28 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
524 m above ground
0-6 km bulk shear
9 kt
0-1 km storm-relative helicity
28 m²/s²
0-3 km storm-relative helicity
136 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

488 
WHUS41 KPHI 120807
CFWPHI

Coastal Hazard Message
National Weather Service Mount Holly NJ
407 AM EDT Tue Oct 12 2021

DEZ003-004-122100-
/O.CAN.KPHI.CF.S.0007.000000T0000Z-211012T1000Z/
/O.NEW.KPHI.CF.Y.0013.211012T1600Z-211012T2100Z/
Inland Sussex-Delaware Beaches-
407 AM EDT Tue Oct 12 2021

...COASTAL FLOOD ADVISORY IN EFFECT FROM NOON TODAY TO 5 PM EDT
THIS AFTERNOON...

* WHAT...Up to one foot of inundation above ground level 
  expected in low-lying areas near shorelines and tidal 
  waterways.

* WHERE...Inland Sussex and Delaware Beaches.

* WHEN...From noon today to 5 PM EDT this afternoon.

* IMPACTS...At this level, flooding begins on the most 
  vulnerable roads in coastal and bayside communities, and along 
  inland tidal waterways. Some partial or full road closures are 
  possible.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Coastal Flood Advisory means that minor tidal flooding is
expected. Minor tidal flooding often results in some road
closures. Usually, the most vulnerable roadways will flood. 

Do not leave your vehicle at a location that is prone to tidal
flooding. Do not drive your vehicle through flood waters. The
water may be deeper than you think it is. You will be putting
yourself in danger and your vehicle may be damaged, leading to
costly repairs. 

Visit the Advanced Hydrologic Prediction Service at
water.weather.gov/ahps for additional water level and flood
impact information for your local tide gauge.

&&

Time of high total tides are approximate to the nearest hour.

Delaware Bay at Lewes
MLLW Categories - Minor 6.0 ft, Moderate 7.0 ft, Major 8.0 ft
MHHW Categories - Minor 1.3 ft, Moderate 2.3 ft, Major 3.3 ft

             Total      Total    Departure          
 Day/Time    Tide       Tide     from Norm   Flood  
            ft MLLW    ft MHHW       ft      Impact 
 --------  ---------  ---------  ---------  --------
 12/02 AM     5.4        0.8       1.6       None    
 12/02 PM     6.6        2.0       1.6      Minor    
 13/03 AM     5.1        0.5       1.4       None    
 13/03 PM     6.2        1.5       1.3      Minor    
 14/04 AM     4.9        0.2       1.2       None    
 14/05 PM     6.0        1.3       1.2      Minor

&&

$$

DEZ002-NJZ021>025-122100-
/O.NEW.KPHI.CF.Y.0013.211012T1600Z-211012T2100Z/
Kent-Cumberland-Atlantic-Cape May-Atlantic Coastal Cape May-
Coastal Atlantic-
407 AM EDT Tue Oct 12 2021

...COASTAL FLOOD ADVISORY IN EFFECT FROM NOON TODAY TO 5 PM EDT
THIS AFTERNOON...

* WHAT...Up to one foot of inundation above ground level 
  expected in low-lying areas near shorelines and tidal 
  waterways.

* WHERE...In New Jersey, Cumberland, Atlantic, Cape May, 
  Atlantic Coastal Cape May and Coastal Atlantic. In Delaware, 
  Kent.

* WHEN...From noon today to 5 PM EDT this afternoon.

* IMPACTS...At this level, flooding begins on the most 
  vulnerable roads in coastal and bayside communities, and along 
  inland tidal waterways. Some partial or full road closures are 
  possible.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Coastal Flood Advisory means that minor tidal flooding is
expected. Minor tidal flooding often results in some road
closures. Usually, the most vulnerable roadways will flood. 

Do not leave your vehicle at a location that is prone to tidal
flooding. Do not drive your vehicle through flood waters. The
water may be deeper than you think it is. You will be putting
yourself in danger and your vehicle may be damaged, leading to
costly repairs. 

Visit the Advanced Hydrologic Prediction Service at
water.weather.gov/ahps for additional water level and flood
impact information for your local tide gauge.

&&

Time of high total tides are approximate to the nearest hour.

Murderkill River at Bowers Beach
MLLW Categories - Minor 6.1 ft, Moderate 7.1 ft, Major 8.1 ft
MHHW Categories - Minor 0.9 ft, Moderate 1.9 ft, Major 2.9 ft

             Total      Total    Departure          
 Day/Time    Tide       Tide     from Norm   Flood  
            ft MLLW    ft MHHW       ft      Impact 
 --------  ---------  ---------  ---------  --------
 12/03 AM     5.5        0.3       1.1       None    
 12/03 PM     6.6        1.4       0.7      Minor    
 13/04 AM     4.9       -0.3       0.6       None    
 13/04 PM     6.2        1.0       0.5      Minor    
 14/04 AM     4.7       -0.5       0.5       None    
 14/05 PM     6.0        0.8       0.4       None

Maurice River at Bivalve
MLLW Categories - Minor 7.6 ft, Moderate 8.6 ft, Major 9.6 ft
MHHW Categories - Minor 1.3 ft, Moderate 2.3 ft, Major 3.3 ft

             Total      Total    Departure          
 Day/Time    Tide       Tide     from Norm   Flood  
            ft MLLW    ft MHHW       ft      Impact 
 --------  ---------  ---------  ---------  --------
 12/02 AM     6.7        0.4       1.3       None    
 12/03 PM     8.0        1.7       1.5      Minor    
 13/03 AM     6.4        0.1       1.2       None    
 13/04 PM     7.5        1.2       1.2       None    
 14/04 AM     6.2       -0.1       1.2       None    
 14/05 PM     7.3        1.0       1.2       None

Atlantic Ocean at Atlantic City
MLLW Categories - Minor 6.0 ft, Moderate 7.0 ft, Major 8.0 ft
MHHW Categories - Minor 1.4 ft, Moderate 2.4 ft, Major 3.4 ft

             Total      Total    Departure          
 Day/Time    Tide       Tide     from Norm   Flood  
            ft MLLW    ft MHHW       ft      Impact 
 --------  ---------  ---------  ---------  --------
 12/02 AM     4.6        0.0       1.2       None    
 12/01 PM     6.3        1.7       1.5      Minor    
 13/02 AM     4.7        0.1       1.1       None    
 13/02 PM     5.8        1.2       1.1       None    
 14/03 AM     4.5       -0.1       1.0       None    
 14/03 PM     5.7        1.1       1.1       None

Great Egg Harbor Bay at Ocean City
MLLW Categories - Minor 5.3 ft, Moderate 6.3 ft, Major 7.3 ft
MHHW Categories - Minor 1.3 ft, Moderate 2.3 ft, Major 3.3 ft

             Total      Total    Departure          
 Day/Time    Tide       Tide     from Norm   Flood  
            ft MLLW    ft MHHW       ft      Impact 
 --------  ---------  ---------  ---------  --------
 12/02 AM     4.6        0.6       1.3       None    
 12/01 PM     5.8        1.8       1.2      Minor    
 13/02 AM     4.2        0.2       0.8       None    
 13/03 PM     5.2        1.2       0.7       None    
 14/03 AM     4.1        0.1       0.8       None    
 14/04 PM     5.1        1.1       0.7       None

Cape May Harbor at Cape May
MLLW Categories - Minor 6.2 ft, Moderate 7.2 ft, Major 8.2 ft
MHHW Categories - Minor 1.1 ft, Moderate 2.1 ft, Major 3.1 ft

             Total      Total    Departure          
 Day/Time    Tide       Tide     from Norm   Flood  
            ft MLLW    ft MHHW       ft      Impact 
 --------  ---------  ---------  ---------  --------
 12/02 AM     5.4        0.3       1.5       None    
 12/01 PM     6.8        1.7       1.5      Minor    
 13/02 AM     5.1        0.0       1.1       None    
 13/03 PM     6.3        1.2       1.1      Minor    
 14/04 AM     5.0       -0.1       1.0       None    
 14/04 PM     6.1        1.0       1.0       None

&&

$$

NJZ020-026-122100-
/O.EXT.KPHI.CF.S.0007.000000T0000Z-211012T2100Z/
Ocean-Coastal Ocean-
407 AM EDT Tue Oct 12 2021

...MINOR FLOODING ALONG BARNEGAT BAY TODAY...

* WHAT...Up to one foot of inundation above ground level in low- 
  lying areas near shorelines and tidal waterways.

* WHERE...Barnegat Bay and the tidal waterways that flow into it.

* WHEN...Through this afternoon.

* IMPACTS...At this level, flooding begins on the most 
  vulnerable roads in coastal and bayside communities, and along 
  inland tidal waterways. Some partial or full road closures are 
  possible.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Do not drive through flooded roadways.

&&

$$
1 follow-up statement
312 
WHUS41 KPHI 122123
CFWPHI

Coastal Hazard Message
National Weather Service Mount Holly NJ
523 PM EDT Tue Oct 12 2021

DEZ003-004-131030-
/O.EXP.KPHI.CF.Y.0013.000000T0000Z-211012T2100Z/
/O.NEW.KPHI.CF.S.0008.211012T2123Z-211013T1200Z/
Inland Sussex-Delaware Beaches-
523 PM EDT Tue Oct 12 2021

...COASTAL FLOOD ADVISORY HAS EXPIRED...

* WHAT...Up to one foot of inundation above ground level in low- 
  lying areas near shorelines and tidal waterways.

* WHERE...Little Assawoman Bay and the tidal waterways that flow 
  into it.

* WHEN...Through Wednesday morning.

* IMPACTS...Minor roadway flooding is possible.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Do not drive through flooded roadways.

&&

Time of high total tides are approximate to the nearest hour.

Delaware Bay at Lewes
MLLW Categories - Minor 6.0 ft, Moderate 7.0 ft, Major 8.0 ft
MHHW Categories - Minor 1.3 ft, Moderate 2.3 ft, Major 3.3 ft

             Total      Total    Departure          
 Day/Time    Tide       Tide     from Norm   Flood  
            ft MLLW    ft MHHW       ft      Impact 
 --------  ---------  ---------  ---------  --------
 12/02 PM     6.1        1.5       1.1      Minor    
 13/03 AM     4.9        0.2       1.2       None    
 13/03 PM     6.1        1.5       1.2      Minor    
 14/04 AM     4.8        0.2       1.1       None    
 14/04 PM     5.9        1.2       1.2       None    
 15/05 AM     5.0        0.3       1.2       None

&&

$$

DEZ002-NJZ021>025-122230-
/O.EXP.KPHI.CF.Y.0013.000000T0000Z-211012T2100Z/
Kent-Cumberland-Atlantic-Cape May-Atlantic Coastal Cape May-
Coastal Atlantic-
523 PM EDT Tue Oct 12 2021

...COASTAL FLOOD ADVISORY HAS EXPIRED...

The tidal levels are falling and will continue to fall through
tonight. Therefore, the coastal flood advisory was allowed expire.

$$

NJZ020-026-131030-
/O.EXP.KPHI.CF.S.0007.000000T0000Z-211012T2100Z/
/O.NEW.KPHI.CF.S.0008.211012T2123Z-211013T1200Z/
Ocean-Coastal Ocean-
523 PM EDT Tue Oct 12 2021

* WHAT...Up to one half foot of inundation above ground level in
  low-lying areas near shorelines and tidal waterways.

* WHERE...Barnegat Bay and the tidal waterways that flow into it.

* WHEN...Through Wednesday morning.

* IMPACTS...Minor roadway flooding is possible.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Do not drive through flooded roadways.

&&

Time of high total tides are approximate to the nearest hour.

Barnegat Bay at Barnegat Light
MLLW Categories - Minor 3.5 ft, Moderate 4.5 ft, Major 5.5 ft
MHHW Categories - Minor 1.0 ft, Moderate 2.0 ft, Major 3.0 ft

             Total      Total    Departure          
 Day/Time    Tide       Tide     from Norm   Flood  
            ft MLLW    ft MHHW       ft      Impact 
 --------  ---------  ---------  ---------  --------
 12/01 PM     3.6        1.1       0.7      Minor    
 13/02 AM     2.9        0.4       0.8       None    
 13/03 PM     3.5        1.0       0.8      Minor    
 14/03 AM     2.8        0.3       0.7       None    
 14/04 PM     3.5        1.0       0.8      Minor    
 15/04 AM     2.9        0.4       0.7       None

&&

$$

The office that day

Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Oct 12, 5:23 PM EDTCoastal Flood StatementPHISussex7 hr

Nearby

Coastal Flood Advisories in New Jersey, 2021Coastal Flood Advisories in Delaware, 2021Every coastal flood advisory in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.