Alert archive / Pennsylvania / Coastal Flood Warnings in 2021

Coastal Flood Warning 3, NWS Philadelphia/Mount Holly

September 2, 20214 counties in Pennsylvania; 4 counties in New Jersey

NWS Philadelphia/Mount Holly issued this coastal flood warning at Sep 2, 2021, 6:05 AM EDT for 4 counties in Pennsylvania; 4 counties in New Jersey. It took effect at Sep 2, 2021, 7:00 AM EDT. It was in force for 5 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Sep 2, 2021, 6:05 AM EDT (10:05 UTC)
In effect from
Sep 2, 2021, 7:00 AM EDT
Expired
Sep 2, 2021, 11:43 AM EDT
In force
5 hr
Issued by
NWS Philadelphia/Mount Holly

Counties Burlington County, NJ, Camden County, NJ, Gloucester County, NJ, Mercer County, NJ, Bucks County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 56 km from the middle of the area, began a volume at 10:04 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

Brookhaven, NY (KOKX), launched 00:00Z, 10.1 hours before the alert went out and 208 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, Brookhaven, NY at 00:00Z on 2021-09-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 123 joules per kilogram.LCLLFCEL10008507005003002001001 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, Brookhaven, NY at 00:00Z on 2021-09-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 279 square meters per square second.19395878Sfc1 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
123 J/kg
Mixed-layer CIN
-47 J/kg
Mixed-layer LCL
512 m above ground
0-6 km bulk shear
53 kt
0-1 km storm-relative helicity
279 m²/s²
0-3 km storm-relative helicity
456 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.2

Open this sounding in Storm Lab

The text

As transmitted.

142 
WHUS41 KPHI 021005
CFWPHI

URGENT - IMMEDIATE BROADCAST REQUESTED
Coastal Hazard Message
National Weather Service Mount Holly NJ
605 AM EDT Thu Sep 2 2021

NJZ015-019-PAZ106-021800-
/O.NEW.KPHI.CF.W.0003.210902T1100Z-210902T1800Z/
Mercer-Northwestern Burlington-Lower Bucks-
605 AM EDT Thu Sep 2 2021

...COASTAL FLOOD WARNING IN EFFECT UNTIL 2 PM EDT THIS
AFTERNOON...

* WHAT...One to two feet of inundation above ground level 
  expected in low-lying areas near shorelines and tidal 
  waterways.

* WHERE...In New Jersey, Mercer and Northwestern Burlington. In 
  Pennsylvania, Lower Bucks.

* WHEN...Until 2 PM EDT this afternoon.

* IMPACTS...At this level, flooding may become severe enough to 
  cause some structural damage along with widespread roadway 
  flooding near tidal waterways. Some locations may become 
  isolated by the flood waters.

* ADDITIONAL DETAILS...The unusually high water levels are the
  result of the combination of high tide and excessive rainfall
  runoff.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Coastal Flood Warning means that moderate or major tidal
flooding is occurring or imminent. Be prepared for rising water
levels and take appropriate action to protect life and property.
Follow the recommendations of local emergency management
officials. 

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 River at Burlington
MLLW Categories - Minor 9.3 ft, Moderate 10.3 ft, Major 11.3 ft
MHHW Categories - Minor 1.6 ft, Moderate 2.6 ft, Major 3.6 ft

             Total      Total    Departure          
 Day/Time    Tide       Tide     from Norm   Flood  
            ft MLLW    ft MHHW       ft      Impact 
 --------  ---------  ---------  ---------  --------
 02/12 PM    11.3        3.6       4.7      Major    
 03/12 AM     9.8        2.1       2.3      Minor    
 03/12 PM     7.4       -0.3       0.9       None    
 04/01 AM     8.4        0.7       0.7       None    
 04/01 PM     7.6       -0.1       0.7       None    
 05/02 AM     8.8        1.1       0.9       None

&&

$$

NJZ017-018-PAZ070-071-104-021800-
/O.NEW.KPHI.CF.W.0003.210902T1100Z-210902T1800Z/
Gloucester-Camden-Delaware-Philadelphia-Eastern Montgomery-
605 AM EDT Thu Sep 2 2021

...COASTAL FLOOD WARNING IN EFFECT UNTIL 2 PM EDT THIS
AFTERNOON...

* WHAT...One to two feet of inundation above ground level 
  expected in low-lying areas near shorelines and tidal 
  waterways.

* WHERE...In New Jersey, Gloucester and Camden. In Pennsylvania, 
  Delaware, Philadelphia and Eastern Montgomery.

* WHEN...Until 2 PM EDT this afternoon.

* IMPACTS...At this level, widespread roadway flooding occurs 
  along tidal waterways. Some roads become impassable. Minor 
  damage to vulnerable structures may begin to occur.

* ADDITIONAL DETAILS...The unusually high water levels are the
  result of the combination of high tide and excessive rainfall
  runoff.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Coastal Flood Warning means that moderate or major tidal
flooding is occurring or imminent. Be prepared for rising water
levels and take appropriate action to protect life and property.
Follow the recommendations of local emergency management
officials. 

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 River at Philadelphia
MLLW Categories - Minor 8.2 ft, Moderate 9.2 ft, Major 10.2 ft
MHHW Categories - Minor 1.5 ft, Moderate 2.5 ft, Major 3.5 ft

             Total      Total    Departure          
 Day/Time    Tide       Tide     from Norm   Flood  
            ft MLLW    ft MHHW       ft      Impact 
 --------  ---------  ---------  ---------  --------
 02/11 AM     9.3        2.6       3.5     Moderate  
 02/11 PM     7.6        0.9       0.8       None    
 03/12 PM     6.6       -0.1       0.7       None    
 04/12 AM     7.6        0.9       0.6       None    
 04/01 PM     6.9        0.2       0.8       None    
 05/01 AM     8.0        1.3       0.9       None

&&

$$

NJZ026-022315-
/O.CON.KPHI.CF.S.0006.000000T0000Z-210902T2200Z/
/O.CON.KPHI.RP.S.0006.000000T0000Z-210903T0000Z/
Coastal Ocean-
605 AM EDT Thu Sep 2 2021

...HIGH RIP CURRENT RISK REMAINS IN EFFECT THROUGH THIS EVENING...

* WHAT...For the High Rip Current Risk, dangerous rip currents.
  For the Coastal Flood Statement, up to one foot of inundation 
  above ground level in low- lying areas near shorelines and tidal
  waterways.

* WHERE...Coastal Ocean.

* WHEN...For the High Rip Current Risk, through this evening. 
  For the, until 6 PM EDT this evening.

* IMPACTS...Minor roadway flooding is possible. Rip currents can
  sweep even the best swimmers away from shore into deeper water.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Do not drive through flooded roadways.

Entering the surf is discouraged. If caught in a rip current,
relax and float. Don't swim against the current. If able, swim in
a direction following the shoreline. If unable to escape, face
the shore and call or wave for help.

&&

$$

NJZ020-022200-
/O.CON.KPHI.CF.S.0006.000000T0000Z-210902T2200Z/
Ocean-
605 AM EDT Thu Sep 2 2021

* WHAT...Up to one foot of inundation above ground level in low-
  lying areas near shorelines and tidal waterways for the northern
  portions of Barnegat Bay.

* WHERE...Ocean.

* WHEN...Until 6 PM EDT this evening.

* IMPACTS...Minor roadway flooding is possible.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Do not drive through flooded roadways.

&&

$$

DEZ003-004-022200-
/O.CON.KPHI.CF.S.0006.000000T0000Z-210902T2200Z/
Inland Sussex-Delaware Beaches-
605 AM EDT Thu Sep 2 2021

* WHAT...Up to one foot of inundation above ground level in low- 
  lying areas near shorelines and tidal waterways. 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...Until 6 PM EDT this evening.

* IMPACTS...Minor roadway flooding is possible.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Do not drive through flooded roadways.

&&

$$

NJZ014-024-025-022315-
/O.CON.KPHI.RP.S.0006.000000T0000Z-210903T0000Z/
Eastern Monmouth-Atlantic Coastal Cape May-Coastal Atlantic-
605 AM EDT Thu Sep 2 2021

...HIGH RIP CURRENT RISK REMAINS IN EFFECT THROUGH THIS EVENING...

* WHAT...Dangerous rip currents.

* WHERE...Atlantic Coastal Cape May, Coastal Atlantic and 
  Eastern Monmouth.

* WHEN...Through this evening.

* IMPACTS...Rip currents can sweep even the best swimmers away 
  from shore into deeper water.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Entering the surf is discouraged. If caught in a rip current,
relax and float. Don't swim against the current. If able, swim in
a direction following the shoreline. If unable to escape, face
the shore and call or wave for help.

&&

$$

Staarmann
1 follow-up statement
263 
WHUS41 KPHI 021543
CFWPHI

Coastal Hazard Message
National Weather Service Mount Holly NJ
1143 AM EDT Thu Sep 2 2021

NJZ015-017>019-PAZ070-071-104-106-021645-
/O.CAN.KPHI.CF.W.0003.000000T0000Z-210902T1800Z/
Mercer-Gloucester-Camden-Northwestern Burlington-Delaware-
Philadelphia-Eastern Montgomery-Lower Bucks-
1143 AM EDT Thu Sep 2 2021

...COASTAL FLOOD WARNING IS CANCELLED...

Water levels are not expected to reach flood criteria therefore
the coastal flood warning has been cancelled. However, freshwater
flooding will continue to occur along portions of the Delaware 
River through the day so be sure to heed any road closures.

$$

NJZ026-030000-
/O.CAN.KPHI.CF.S.0006.000000T0000Z-210902T2200Z/
/O.CON.KPHI.RP.S.0006.000000T0000Z-210903T0000Z/
Coastal Ocean-
1143 AM EDT Thu Sep 2 2021

...HIGH RIP CURRENT RISK REMAINS IN EFFECT UNTIL 8 PM EDT THIS
EVENING...

* WHAT...Dangerous rip currents.

* WHERE...Coastal Ocean.

* WHEN...Until 8 PM EDT this evening.

* IMPACTS...Rip currents can sweep even the best swimmers away 
  from shore into deeper water.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

Entering the surf is discouraged. If caught in a rip current,
relax and float. Don't swim against the current. If able, swim in
a direction following the shoreline. If unable to escape, face
the shore and call or wave for help.

&&

$$

DEZ003-004-NJZ020-021645-
/O.CAN.KPHI.CF.S.0006.000000T0000Z-210902T2200Z/
Inland Sussex-Delaware Beaches-Ocean-
1143 AM EDT Thu Sep 2 2021

...COASTAL FLOOD STATEMENT IS CANCELLED...

The Coastal Flood Statement has been cancelled as stronger
offshore flow has allowed water lvls to evacuate the backbays. 

$$

NJZ014-024-025-030000-
/O.CON.KPHI.RP.S.0006.000000T0000Z-210903T0000Z/
Eastern Monmouth-Atlantic Coastal Cape May-Coastal Atlantic-
1143 AM EDT Thu Sep 2 2021

...HIGH RIP CURRENT RISK REMAINS IN EFFECT UNTIL 8 PM EDT THIS
EVENING...

* WHAT...Dangerous rip currents.

* WHERE...Atlantic Coastal Cape May, Coastal Atlantic and 
  Eastern Monmouth.

* WHEN...Until 8 PM EDT this evening.

* IMPACTS...Rip currents can sweep even the best swimmers away 
  from shore into deeper water.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Entering the surf is discouraged. If caught in a rip current,
relax and float. Don't swim against the current. If able, swim in
a direction following the shoreline. If unable to escape, face
the shore and call or wave for help.

&&

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 1, 8:29 PM EDTRiver Flood WarningPHILehigh10 hr
Sep 1, 9:47 PM EDTRiver Flood WarningPHIBerks18 hr
Sep 1, 10:24 PM EDTFlash Flood WarningPHIBucks, Philadelphia4 hr
Sep 1, 10:29 PM EDTRiver Flood WarningPHIBucks49 hr
Sep 1, 10:32 PM EDTRiver Flood WarningPHIBucks31 hr
Sep 1, 10:42 PM EDTAreal Flood WarningPHIBerks, Bucks, Montgomery12 hr
Sep 1, 10:47 PM EDTAreal Flood WarningPHIBucks, Carbon, Lehigh, Northampton23 hr
Sep 1, 10:52 PM EDTAreal Flood WarningPHIBucks12 hr
Sep 1, 11:38 PM EDTAreal Flood WarningPHIBerks, Chester, Delaware, Montgomery10 hr
Sep 2, 12:01 AM EDTAreal Flood WarningPHIMonroe, Northampton40 hr
Sep 2, 2:23 AM EDTAreal Flood WarningPHIBucks, Delaware, Montgomery, Philadelphia9 hr
Sep 2, 2:29 AM EDTAreal Flood WarningPHIBucks, Philadelphia5 hr
Sep 2, 2:41 AM EDTAreal Flood WarningPHIBucks14 hr
Sep 2, 3:52 AM EDTAreal Flood WarningPHIBucks8 hr
Sep 2, 4:45 AM EDTRiver Flood WarningPHIBucks37 hr
Sep 2, 4:45 AM EDTRiver Flood WarningPHINorthampton37 hr
Sep 2, 4:45 AM EDTRiver Flood WarningPHIBucks37 hr
Sep 2, 4:45 AM EDTRiver Flood WarningPHIBucks33 hr
Sep 2, 4:45 AM EDTRiver Flood WarningPHIBucks34 hr
Sep 2, 4:45 AM EDTRiver Flood WarningPHIMonroe, Northampton5 hr
Sep 2, 5:02 AM EDTRiver Flood WarningPHILehigh11 hr
Sep 2, 6:44 PM EDTCoastal Flood AdvisoryPHIBucks, Delaware, Philadelphia7 hr
Sep 1, 8:02 PM EDTFlash Flood Warning EmergencyCatastrophic damage threatPHIMiddlesex, Morris, Somerset5 hr
Sep 1, 9:01 PM EDTFlash Flood WarningPHIBurlington, Mercer, Middlesex, Monmouth, Ocean5 hr
Sep 1, 9:43 PM EDTRiver Flood WarningPHIMercer33 hr
Sep 1, 10:05 PM EDTFlash Flood Warning Considerable damage threatPHIMorris, Somerset4 hr
Sep 1, 10:23 PM EDTCoastal Flood StatementPHIOcean13 hr
Sep 1, 10:35 PM EDTRiver Flood WarningPHIBergen, Morris, Passaic30 hr
Sep 1, 10:37 PM EDTRiver Flood WarningPHIMorris, Passaic41 hr
Sep 1, 10:38 PM EDTRiver Flood WarningPHIMorris, Somerset21 days
Sep 2, 12:28 AM EDTAreal Flood AdvisoryPHIAtlantic, Burlington, Camden, Gloucester3 hr
Sep 2, 12:31 AM EDTAreal Flood AdvisoryPHIMonmouth, Ocean2 hr
Sep 2, 1:38 AM EDTAreal Flood WarningPHIBurlington, Mercer, Middlesex, Monmouth, Ocean4 hr
Sep 2, 1:52 AM EDTAreal Flood WarningPHIMorris, Somerset13 hr
Sep 2, 3:53 AM EDTAreal Flood WarningPHIHunterdon, Mercer, Middlesex, Morris, Somerset8 hr
Sep 2, 4:00 AM EDTRiver Flood WarningPHIMorris48 hr
Sep 2, 1:20 PM EDTAreal Flood WarningPHIMiddlesex21 hr

Nearby

Coastal Flood Warnings in Pennsylvania, 2021Coastal Flood Warnings in New Jersey, 2021Every coastal flood warning 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.