Alert archive / New Jersey / Areal Flood Advisories in 2021

Areal Flood Advisory 85, NWS Philadelphia/Mount Holly

July 17, 2021Hunterdon County, New Jersey; Bucks County, Pennsylvania

NWS Philadelphia/Mount Holly issued this areal flood advisory at Jul 17, 2021, 1:31 PM EDT for Hunterdon County, New Jersey; Bucks County, Pennsylvania. It was in force for 97 min.

The area

The outline as issued.

The facts

Issued: Jul 17, 2021, 1:31 PM EDT (17:31 UTC)
Expired: Jul 17, 2021, 3:08 PM EDT
In force: 97 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

Counties Hunterdon County, NJ, Bucks County, PA

The radar

The Philadelphia radar (KDIX), 65 km from the middle of the area, began a volume at 17:34 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 12:00Z, 5.5 hours before the alert went out and 181 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: 1203 J/kg
Mixed-layer CIN: -55 J/kg
Mixed-layer LCL: 1054 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 35 m²/s²
0-3 km storm-relative helicity: 46 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 1.0

Open this sounding in Storm Lab

The text

As transmitted.

369 
WGUS81 KPHI 171731
FLSPHI

Flood Advisory
National Weather Service Mount Holly NJ
131 PM EDT Sat Jul 17 2021

NJC019-PAC017-171930-
/O.NEW.KPHI.FA.Y.0085.210717T1731Z-210717T1930Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hunterdon NJ-Bucks PA-
131 PM EDT Sat Jul 17 2021

The National Weather Service in Mount Holly has issued a

* Flood Advisory for...
  Southeastern Hunterdon County in northwestern New Jersey...
  Central Bucks County in southeastern Pennsylvania...

* Until 330 PM EDT.

* At 131 PM EDT, Doppler radar indicated heavy rain due to 
  thunderstorms. Minor flooding is ongoing or expected to begin 
  shortly in the advisory area. Between 0.5 and 1 inch of rain has 
  already fallen in spots with an addition inch possible.

* Some locations that may experience flooding include...
  Perkasie, Doylestown, Byram, Bedminster, Flemington, Tinicum, New 
  Hope, Dublin, Stockton, Lumberville, Sergeantsville, and Sand 
  Brook.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Be aware of your surroundings and do not drive on flooded roads.

&&

LAT...LON 4023 7508 4037 7528 4061 7486 4051 7479
      4051 7480 4042 7475 4042 7481 4038 7480
      4038 7487 4035 7486 4034 7494 4033 7493

$$

Iovino

2 follow-up statements

079 
WGUS81 KPHI 171847
FLSPHI

Flood Advisory
National Weather Service Mount Holly NJ
247 PM EDT Sat Jul 17 2021

PAC017-171857-
/O.CAN.KPHI.FA.Y.0085.000000T0000Z-210717T1930Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Bucks PA-
247 PM EDT Sat Jul 17 2021

...FLOOD ADVISORY IS CANCELLED FOR CENTRAL BUCKS COUNTY...

The initial batch of heavy rain has ended. Please continue to heed 
remaining road closures.

A Flash Flood Watch remains in effect until 200 AM Sunday.

LAT...LON 4049 7506 4061 7486 4051 7479 4051 7480
      4042 7475 4042 7481 4038 7480 4038 7487
      4035 7486 4034 7494 4036 7495 4040 7497
      4041 7499 4040 7503 4042 7506 4046 7507
      4048 7506

$$

NJC019-171930-
/O.CON.KPHI.FA.Y.0085.000000T0000Z-210717T1930Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hunterdon NJ-
247 PM EDT Sat Jul 17 2021

...FLOOD ADVISORY REMAINS IN EFFECT UNTIL 330 PM EDT THIS AFTERNOON 
FOR SOUTHEASTERN HUNTERDON COUNTY...

At 247 PM EDT, Doppler radar indicated heavy rain due to 
thunderstorms. Minor flooding is ongoing or expected to begin 
shortly in the advisory area. Between 1 and 1.5 inches of rain have 
already fallen in spots with an additional half inch of rain 
possible.

Some locations that may experience flooding include...
  Byram, Flemington, New Hope, Stockton, Sand Brook, Sergeantsville, 
  Lumberville, and Lambertville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Be aware of your surroundings and do not drive on flooded roads.

&&

LAT...LON 4049 7506 4061 7486 4051 7479 4051 7480
      4042 7475 4042 7481 4038 7480 4038 7487
      4035 7486 4034 7494 4036 7495 4040 7497
      4041 7499 4040 7503 4042 7506 4046 7507
      4048 7506

$$

Iovino

071 
WGUS81 KPHI 171908
FLSPHI

Flood Advisory
National Weather Service Mount Holly NJ
308 PM EDT Sat Jul 17 2021

NJC019-171918-
/O.CAN.KPHI.FA.Y.0085.000000T0000Z-210717T1930Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hunterdon NJ-
308 PM EDT Sat Jul 17 2021

...FLOOD ADVISORY IS CANCELLED FOR SOUTHEASTERN HUNTERDON COUNTY...

The heavy rain has ended for the time being. Additional heavy rain 
is possible. Please continue to heed remaining road closures.

LAT...LON 4049 7506 4061 7486 4051 7479 4051 7480
      4042 7475 4042 7481 4038 7480 4038 7487
      4035 7486 4034 7494 4036 7495 4040 7497
      4041 7499 4040 7503 4042 7506 4046 7507
      4048 7506

$$

Iovino

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 17, 12:55 PM EDT	Special Weather Statement	PHI	Hunterdon	50 min
Jul 17, 1:05 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Mercer	40 min
Jul 17, 1:50 PM EDT	Special Marine Warning	PHI		40 min
Jul 17, 1:56 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Morris, Somerset, Warren	36 min
Jul 17, 2:02 PM EDT	Areal Flood Advisory	PHI	Monmouth, Ocean	92 min
Jul 17, 2:56 PM EDT	Severe Thunderstorm Warning	PHI	Middlesex, Somerset	49 min
Jul 17, 3:06 PM EDT	Severe Thunderstorm Warning	PHI	Warren	39 min
Jul 17, 3:09 PM EDT	Tornado Warning	PHI	Middlesex	21 min
Jul 17, 3:38 PM EDT	Areal Flood Advisory	PHI	Middlesex	40 min
Jul 17, 3:51 PM EDT	Severe Thunderstorm Warning	PHI	Middlesex	24 min
Jul 17, 4:55 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Somerset	50 min
Jul 17, 5:13 PM EDT	Areal Flood Advisory	PHI	Hunterdon	4 hr
Jul 17, 5:19 PM EDT	Tornado Warning	PHI	Hunterdon	14 min
Jul 17, 5:25 PM EDT	Flash Flood Warning	PHI	Hunterdon	6 hr
Jul 17, 5:30 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Warren	19 min
Jul 17, 5:52 PM EDT	Areal Flood Advisory	PHI	Somerset	2 hr
Jul 17, 6:02 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Mercer, Somerset	43 min
Jul 17, 6:15 PM EDT	Flash Flood Warning	PHI	Morris, Somerset	5 hr
Jul 17, 6:39 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Mercer, Middlesex, Morris, Somerset	51 min
Jul 17, 6:51 PM EDT	Severe Thunderstorm Warning	PHI	Burlington	39 min
Jul 17, 6:59 PM EDT	Small Craft Advisory	PHI		7 hr
Jul 17, 7:01 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Somerset	44 min
Jul 17, 7:12 PM EDT	Areal Flood Advisory	PHI	Mercer, Somerset	3 hr
Jul 17, 7:26 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Mercer, Middlesex, Morris, Somerset	49 min
Jul 16, 8:14 PM EDT	Special Weather Statement	PHI	Montgomery	31 min
Jul 16, 8:41 PM EDT	Special Weather Statement	PHI	Bucks	34 min
Jul 16, 9:07 PM EDT	Special Weather Statement	PHI	Lehigh	23 min
Jul 16, 9:29 PM EDT	Special Weather Statement	PHI	Lehigh	31 min
Jul 16, 10:21 PM EDT	Special Weather Statement	PHI	Lehigh	24 min
Jul 17, 2:30 PM EDT	Special Weather Statement	PHI	Berks	45 min
Jul 17, 2:36 PM EDT	Severe Thunderstorm Warning	PHI	Berks	39 min
Jul 17, 7:36 PM EDT	Special Weather Statement	PHI	Carbon	54 min

Nearby

Areal Flood Advisories in New Jersey, 2021 Areal Flood Advisories in Pennsylvania, 2021 Every areal 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.