Alert archive / Pennsylvania / Areal Flood Warnings in 2024

Areal Flood Warning 94, NWS Philadelphia/Mount Holly

August 9, 20244 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this areal flood warning at Aug 9, 2024, 6:46 PM EDT for 4 counties in Pennsylvania. It was in force for 4 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: Aug 9, 2024, 6:46 PM EDT (22:46 UTC)
Expired: Aug 9, 2024, 10:29 PM EDT
In force: 4 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

Counties Berks County, PA, Bucks County, PA, Lehigh County, PA, Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 105 km from the middle of the area, began a volume at 22:45 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

Washington/Dulle, VA (KIAD), launched 12:00Z, 10.8 hours before the alert went out and 229 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 284 J/kg
Mixed-layer CIN: -1 J/kg
Mixed-layer LCL: 620 m above ground
0-6 km bulk shear: 36 kt
0-1 km storm-relative helicity: 267 m²/s²
0-3 km storm-relative helicity: 271 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 7.2

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this areal flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Philadelphia/Mount Holly wrote its last area forecast discussion before this areal flood warning went out at Aug 9, 5:23 PM EDT, 1 hour 23 minutes earlier.

Area forecast discussion, Aug 9, 5:23 PM EDT, 1 hour 23 minutes before

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

In the hours before

Local storm report, Aug 9, 4:39 PM EDT, 2 hours 7 minutes before

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

Local storm report, Aug 9, 4:52 PM EDT, 1 hour 54 minutes before

Preliminary Local Storm Report
National Weather Service Mount Holly NJ
452 PM EDT Fri Aug 9 2024

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0415 PM     Coastal Flood    1 N Mantoloking         40.06N 74.05W
08/09/2024                   Ocean              NJ   NWS Employee

            Coastal flooding causing minor street
            flooding on the bay side areas of Bay Head
            and Mantoloking.

&&

Staarmann

Local storm report, Aug 9, 4:55 PM EDT, 1 hour 51 minutes before

Preliminary Local Storm Report
National Weather Service Mount Holly NJ
455 PM EDT Fri Aug 9 2024

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0415 PM     Coastal Flood    2 N Lavallette          39.99N 74.07W
08/09/2024                   Ocean              NJ   NWS Employee

            Coastal flooding causing minor street
            flooding on Route 35 in Chadwick Beach.
            Water is coming up through storm drains on
            the bay side of the island. Some lagoons are
            completely covered by water.

&&

Staarmann

Local storm report, Aug 9, 5:08 PM EDT, 1 hour 38 minutes before

Preliminary Local Storm Report
National Weather Service Mount Holly NJ
508 PM EDT Fri Aug 9 2024

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0342 PM     Non-Tstm Wnd Dmg 2 SE Long Hill Twp      40.66N 74.46W
08/09/2024                   Somerset           NJ   Public

            Report from mPING: 1-inch tree limbs broken.

&&

Staarmann

Local storm report, Aug 9, 5:10 PM EDT, 1 hour 36 minutes before

Preliminary Local Storm Report
National Weather Service Mount Holly NJ
510 PM EDT Fri Aug 9 2024

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0236 PM     Non-Tstm Wnd Gst Trenton Mercer Airport  40.28N 74.82W
08/09/2024  M51 MPH          Mercer             NJ   ASOS

            ASOS station KTTN Trenton.

&&

Staarmann

Local storm report, Aug 9, 5:11 PM EDT, 1 hour 35 minutes before

Preliminary Local Storm Report...Summary
National Weather Service Mount Holly NJ
511 PM EDT Fri Aug 9 2024

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0732 AM     Non-Tstm Wnd Dmg 2 NNW Toughkenamon      39.86N 75.77W
08/09/2024                   Chester            PA   Dept of Highways

            Downed utility on NEWARK RD both directions
            between BARTRAM RD and SPENCER RD. All lanes
            closed.

0900 AM     Coastal Flood    1 NNW Centreville       39.06N 76.07W
08/09/2024                   Queen Annes       MD   County Official

            Photos of minor coastal flooding at
            Centreville Wharf.

0919 AM     Non-Tstm Wnd Dmg 1 SSE Lenape            39.90N 75.62W
08/09/2024                   Chester            PA   Dept of Highways

            Downed tree in wires on POTTSTOWN PK / SOUTH
            CREEK RD / CREEK RD / HIGH ST both
            directions between STREET RD and CREEK
            RDLENAPE RD. All lanes closed.

0924 AM     Coastal Flood    5 N Rock Hall           39.22N 76.23W
08/09/2024                   Kent               MD   Other Federal

            The Tolchester Beach tide gauge reached
            moderate flood stage.

0945 AM     Non-Tstm Wnd Dmg 2 NNW Paoli             40.06N 75.50W
08/09/2024                   Chester            PA   Dept of Highways

            Downed tree in wires on SWEDESFORD RD both
            directions between WISTERIA DR and N VALLEY
            RD. All lanes closed.

0945 AM     Non-Tstm Wnd Gst Fortescue               39.24N 75.18W
08/09/2024  M45 MPH          Cumberland         NJ   Mesonet

            Mesonet station NJ67 Fortescue.

0950 AM     Non-Tstm Wnd Gst 2 ENE Upper Deerfield T 39.52N 75.20W
08/09/2024  M45 MPH          Cumberland         NJ   Mesonet

            Mesonet station NJ50 Upper Deerfield.

0950 AM     Non-Tstm Wnd Gst Easton Municipal Airpor 38.80N 76.07W
08/09/2024  M45 MPH          Talbot             MD   AWOS

            AWOS station KESN Easton Newnam.

0958 AM     Non-Tstm Wnd Gst 1 SW Delaware Coastal A 38.68N 75.37W
08/09/2024  M45 MPH          Sussex             DE   ASOS

            ASOS station KGED Georgetown.

1030 AM     Non-Tstm Wnd Dmg 1 E East Side           41.06N 75.75W
08/09/2024                   Carbon             PA   Dept of Highways

            Downed tree on PA 534 both directions
            between Exit: I 80 EAST - STROUDSBURG and
            TANNERY RD. All lanes closed.

1042 AM     Coastal Flood    2 E Chester             38.97N 76.25W
08/09/2024                   Queen Annes       MD   Public

            Coastal Flooding At Kent Narrows With Road
            Closures. Water has flooded some parking
            lots and roads with a few feet of water.
            Wind Restrictions On The Bay Bridge Causing
            Travel Delays. Photos via social media.

1047 AM     Non-Tstm Wnd Gst Trenton Mercer Airport  40.28N 74.82W
08/09/2024  M46 MPH          Mercer             NJ   ASOS

            ASOS station KTTN Trenton.

1100 AM     Non-Tstm Wnd Dmg 1 W Chestnut Hill       40.07N 75.24W
08/09/2024                   Philadelphia       PA   Public

            Some power outages including traffic lights
            out in Upper Roxborough/Shawmont area. Trees
            were reported down on Bells Mill this
            morning. Time estimated.

1100 AM     Coastal Flood    4 SW Chester            38.93N 76.36W
08/09/2024                   Queen Annes       MD   County Official

            Photo of minor coastal flooding with about 1
            foot of water covering the road in the
            Chesapeake Estates community.

1103 AM     Non-Tstm Wnd Dmg 1 E Newtown Square      39.99N 75.38W
08/09/2024                   Delaware           PA   Public

            Report from mPING: 3-inch tree limbs broken.

1104 AM     Non-Tstm Wnd Gst 2 E Fort Dix            40.02N 74.58W
08/09/2024  M47 MPH          Burlington         NJ   AWOS

            AWOS station KWRI McGuire AFB.

1110 AM     Non-Tstm Wnd Dmg 1 SSE Macungie          40.50N 75.55W
08/09/2024                   Lehigh             PA   Public

            Downed tree in wires on MACUNGIE MT RD /
            SWEETWOOD DR / BUCKEYE RD / CHESTNUT ST both
            directions between SWEETWOOD DR and MAPLE
            ST. All lanes closed.

1127 AM     Non-Tstm Wnd Dmg Norristown              40.12N 75.34W
08/09/2024                   Montgomery         PA   Public

            Report from mPING: 1-inch tree limbs broken.

1132 AM     Non-Tstm Wnd Gst 2 W Lakehurst           40.02N 74.33W
08/09/2024  M55 MPH          Ocean              NJ   AWOS

            AWOS station KNEL Lakehurst NAS.

1136 AM     Non-Tstm Wnd Dmg 1 NE Hammonton          39.64N 74.78W
08/09/2024                   Atlantic           NJ   Public

            Report from mPING: 1-inch tree limbs broken.

1148 AM     Non-Tstm Wnd Dmg 1 ESE Berwyn            40.04N 75.42W
08/09/2024                   Chester            PA   Dept of Highways

            Downed tree in wires on WATERLOO RD / DEVON
            STATE RD / VALLEY FORGE RD both directions
            between EXETER RD and SUGARTOWN RD. All
            lanes closed.

1204 PM     Non-Tstm Wnd Dmg 5 W Rosemont            40.44N 75.06W
08/09/2024                   Hunterdon          NJ   Dept of Highways

            Downed tree on NJ 29 northbound North of CR
            651/Byram Kingswood Rd (Kingwood Twp). All
            lanes closed.

1205 PM     Non-Tstm Wnd Dmg 1 S Lambertville        40.35N 74.94W
08/09/2024                   Hunterdon          NJ   Dept of Highways

            Downed tree on NJ 29 northbound North of Old
            River Rd (West Amwell Twp). All lanes
            closed.

1210 PM     Non-Tstm Wnd Gst Coyle Field             39.81N 74.42W
08/09/2024  M45 MPH          Burlington         NJ   Mesonet

            Mesonet station CTWN4 Coyle Field.

1224 PM     Non-Tstm Wnd Dmg 1 SSE Emmaus            40.53N 75.49W
08/09/2024                   Lehigh             PA   Dept of Highways

            Downed tree in wires on FIFTH ST / FOURTH ST
            both directions between COLUMBUS DR and
            FAIRVIEW ST. All lanes closed.

1225 PM     Non-Tstm Wnd Dmg 1 S North Wildwood      39.00N 74.80W
08/09/2024                   Cape May           NJ   Public

            Report from mPING: 1-inch tree limbs broken.

1230 PM     Coastal Flood    2 E Chester             38.97N 76.25W
08/09/2024                   Queen Annes       MD   Emergency Mngr

            Drone photos showing extensive and
            significant coastal flooding along Route 18
            at Kent Narrows. A couple restaurants
            sustained some inundation of water inside
            the structures. The roadway was impassible
            and closed.

1231 PM     Non-Tstm Wnd Dmg 1 NW Amity Gardens      40.28N 75.74W
08/09/2024                   Berks              PA   Public

            Report from mPING: 1-inch tree limbs broken.

1235 PM     Non-Tstm Wnd Dmg 2 NNW Stroud Twp        41.01N 75.24W
08/09/2024                   Monroe             PA   Dept of Highways

            Downed tree in wires on CLEARVIEW AV /
            CRANBERRY RD both directions between PARKER
            LN and CRANBERRY HEIGHTS DR. All lanes
            closed.

1238 PM     Non-Tstm Wnd Dmg 1 SE Greentree          39.89N 74.95W
08/09/2024                   Camden             NJ   Public

            Report from mPING: 1-inch tree limbs broken.

1243 PM     Non-Tstm Wnd Dmg Avalon                  39.10N 74.72W
08/09/2024                   Cape May           NJ   Public

            Report from mPING: 1-inch tree limbs broken.

1245 PM     Non-Tstm Wnd Gst Indian Beach            38.68N 75.08W
08/09/2024  M47 MPH          Sussex             DE   Mesonet

            Mesonet station XDEW Dewey Beach.

1247 PM     Non-Tstm Wnd Dmg 1 E Egg Harbor City     39.52N 74.64W
08/09/2024                   Atlantic           NJ   Public

            Report from mPING: 3-inch tree limbs broken.

1249 PM     Non-Tstm Wnd Dmg 3 NW Blakeslee          41.13N 75.62W
08/09/2024                   Monroe             PA   Dept of Highways

            Downed tree in wires on PA 115 both
            directions between KERRICK RD and CAUGHBAUGH
            RD. All lanes closed.

1254 PM     Non-Tstm Wnd Gst Atlantic City Internati 39.45N 74.57W
08/09/2024  M47 MPH          Atlantic           NJ   ASOS

            ASOS station KACY Atlantic City.

1255 PM     Non-Tstm Wnd Gst Atlantic City Internati 39.45N 74.57W
08/09/2024  M48 MPH          Atlantic           NJ   ASOS

            ASOS station KACY Atlantic City.

1256 PM     Non-Tstm Wnd Dmg Bedminster Twp          40.68N 74.65W
08/09/2024                   Somerset           NJ   Dept of Highways

            Downed tree on US 206 both directions North
            of CR 523/Lamington Rd (Bedminster Twp). All
            lanes closed.

0108 PM     Non-Tstm Wnd Dmg Green Ridge             39.87N 75.42W
08/09/2024                   Delaware           PA   Public

            Report from mPING: 1-inch tree limbs broken.

0113 PM     Non-Tstm Wnd Dmg 2 W Folsom              39.59N 74.87W
08/09/2024                   Atlantic           NJ   Public

            Report from mPING: 1-inch tree limbs broken.

0115 PM     Non-Tstm Wnd Gst 1 N Eastlawn Gardens    40.76N 75.30W
08/09/2024  M45 MPH          Northampton        PA   Mesonet

            Mesonet station AW001 NAZARETH.

0115 PM     Non-Tstm Wnd Gst Pocono Mountains Munici 41.13N 75.38W
08/09/2024  M53 MPH          Monroe             PA   ASOS

            ASOS station KMPO Mt. Pocono.

0128 PM     Non-Tstm Wnd Dmg Washington Crossing     40.30N 74.87W
08/09/2024                   Mercer             NJ   Dept of Highways

            Downed tree on NJ 29 southbound South of CR
            546/Washington Crossing Rd (Hopewell Twp).
            All lanes shifted.

0133 PM     Non-Tstm Wnd Dmg 2 WNW Pocono Mountains  41.15N 75.41W
08/09/2024                   Monroe             PA   Dept of Highways

            Downed utility on I-380 southbound between
            Exit 8: PA 611 SOUTH/TO PA 423 - TOBYHANNA
            and Exit 3: PA 940 - POCONO PINES/MT POCONO.
            All lanes closed.

0138 PM     Non-Tstm Wnd Dmg 3 S Pocono Lake         41.08N 75.52W
08/09/2024                   Monroe             PA   Public

            Report from mPING: 3-inch tree limbs broken.

0140 PM     Non-Tstm Wnd Gst 2 WNW Yardley           40.25N 74.87W
08/09/2024  M46 MPH          Bucks              PA   Mesonet

            Mesonet station 11379 1 WNW Yardley.

0145 PM     Non-Tstm Wnd Dmg Albrightsville          41.02N 75.59W
08/09/2024                   Carbon             PA   Dept of Highways

            Downed tree in wires on PA 534 both
            directions between OLD STAGE RD and SR 0903
            SH. All lanes closed.

0146 PM     Non-Tstm Wnd Dmg 1 WSW Lower Southampton 40.15N 75.00W
08/09/2024                   Bucks              PA   Public

            Social media report and photo of a large oak
            tree uprooted and blocking half of Street
            Road near Bustleton Pike in Festerville.

0200 PM     Non-Tstm Wnd Dmg Lakewood                40.07N 74.17W
08/09/2024                   Ocean              NJ   Newspaper

            A large tree fell on a school bus in
            Lakewood this afternoon, damaging it. Nobody
            was injured. Time estimated.

0208 PM     Non-Tstm Wnd Dmg Pocopson Twp            39.91N 75.64W
08/09/2024                   Chester            PA   Public

            Report from mPING: 3-inch tree limbs broken.

0213 PM     Non-Tstm Wnd Dmg 1 NW Amity Gardens      40.28N 75.74W
08/09/2024                   Berks              PA   Public

            Report from mPING: 1-inch tree limbs broken.

0218 PM     Non-Tstm Wnd Dmg 1 W Hopelawn            40.53N 74.32W
08/09/2024                   Middlesex          NJ   Public

            Report from mPING: 1-inch tree limbs broken.

0219 PM     Non-Tstm Wnd Dmg 1 SE Belmont Hills      40.01N 75.23W
08/09/2024                   Montgomery         PA   Public

            Report from mPING: 3-inch tree limbs broken.

0228 PM     Non-Tstm Wnd Dmg 1 NNW North Princeton   40.38N 74.66W
08/09/2024                   Mercer             NJ   Dept of Highways

            Downed tree on US 206 both directions North
            of Ewing St (Princeton Twp). All lanes
            closed northbound.

0231 PM     Non-Tstm Wnd Dmg 1 NE Paoli              40.05N 75.47W
08/09/2024                   Chester            PA   Public

            Power lines down at the intersection of
            Hilltop Rd and Friendship Dr in Paoli.

0236 PM     Non-Tstm Wnd Gst Trenton Mercer Airport  40.28N 74.82W
08/09/2024  M51 MPH          Mercer             NJ   ASOS

            ASOS station KTTN Trenton.

0242 PM     Coastal Flood    1 E Bayville            39.91N 74.14W
08/09/2024                   Ocean              NJ   Trained Spotter

            Coastal flooding beginning to occur along
            bayside roads in Bayville, including Eugene
            Ferry Rd (impassable), flooding on Balsam
            Dr, and flooding in spots on Bayview Ave.

0244 PM     Non-Tstm Wnd Dmg Oaks                    40.13N 75.46W
08/09/2024                   Montgomery         PA   Public

            Corrects previous tstm wnd dmg report from
            Oaks. Report from mPING: 1-inch tree limbs
            broken.

0245 PM     Non-Tstm Wnd Dmg 1 ENE Marksboro         40.99N 74.90W
08/09/2024                   Warren             NJ   Trained Spotter

            Two trees on wires along Route 94.

0255 PM     Non-Tstm Wnd Dmg 1 SE Lenola             39.95N 74.98W
08/09/2024                   Burlington         NJ   Public

            Report from mPING: 3-inch tree limbs broken.

0300 PM     Non-Tstm Wnd Dmg Roxborough              40.01N 75.22W
08/09/2024                   Montgomery         PA   Public

            Report from mPING: Trees uprooted or
            snapped.

0342 PM     Non-Tstm Wnd Dmg 2 SE Long Hill Twp      40.66N 74.46W
08/09/2024                   Somerset           NJ   Public

            Report from mPING: 1-inch tree limbs broken.

0415 PM     Coastal Flood    1 N Mantoloking         40.06N 74.05W
08/09/2024                   Ocean              NJ   NWS Employee

            Coastal flooding causing minor street
            flooding on the bay side areas of Bay Head
            and Mantoloking.

0415 PM     Coastal Flood    2 N Lavallette          39.99N 74.07W
08/09/2024                   Ocean              NJ   NWS Employee

            Coastal flooding causing minor street
            flooding on Route 35 in Chadwick Beach.
            Water is coming up through storm drains on
            the bay side of the island. Some lagoons are
            completely covered by water.

&&

Staarmann

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 9, 3:31 PM EDT	Flash Flood Warning	PHI	Warren	108 min
Aug 9, 4:11 PM EDT	Flash Flood Warning	PHI	Warren	100 min
Aug 9, 5:30 PM EDT	Flash Flood Warning	PHI	Mercer	83 min
Aug 8, 8:52 PM EDT	Flash Flood Warning	PHI	Berks, Chester	3 hr
Aug 8, 9:06 PM EDT	River Flood Warning	PHI	Chester	9 hr
Aug 8, 11:40 PM EDT	Areal Flood Warning	PHI	Chester	4 hr
Aug 9, 12:12 AM EDT	River Flood Warning	PHI	Chester, Delaware	16 hr
Aug 9, 2:50 PM EDT	Flash Flood Warning	PHI	Lehigh, Northampton	2 hr
Aug 9, 3:50 PM EDT	Flash Flood Warning	PHI	Bucks, Montgomery	2 hr
Aug 9, 5:56 PM EDT	River Flood Warning	PHI	Chester	6 hr
Aug 8, 9:56 PM EDT	River Flood Warning	PHI	New Castle	7 hr
Aug 8, 10:20 PM EDT	Areal Flood Warning	PHI	New Castle	11 hr

Nearby

Areal Flood Warnings in Pennsylvania, 2024 Every areal flood warning in 2024

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.