Alert archive / Pennsylvania / Areal Flood Advisories in 2021

Areal Flood Advisory 83, NWS Philadelphia/Mount Holly

July 16, 20214 counties in Pennsylvania; Sussex County, Warren County, New Jersey

NWS Philadelphia/Mount Holly issued this areal flood advisory at Jul 16, 2021, 5:34 PM EDT for 4 counties in Pennsylvania; Sussex County, Warren County, New Jersey. It was in force for 112 min.

The area

The outline as issued.

The facts

Issued: Jul 16, 2021, 5:34 PM EDT (21:34 UTC)
Expired: Jul 16, 2021, 7:26 PM EDT
In force: 112 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

Counties Sussex County, NJ, Warren County, NJ, Carbon County, PA, Lehigh County, PA, Monroe County, PA, Northampton County, PA

The radar

The Philadelphia radar (KDIX), 138 km from the middle of the area, began a volume at 21:37 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, 9.6 hours before the alert went out and 211 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: 1044 J/kg
Mixed-layer CIN: -56 J/kg
Mixed-layer LCL: 994 m above ground
0-6 km bulk shear: 17 kt
0-1 km storm-relative helicity: 108 m²/s²
0-3 km storm-relative helicity: 105 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

391 
WGUS81 KPHI 162134
FLSPHI

Flood Advisory
National Weather Service Mount Holly NJ
534 PM EDT Fri Jul 16 2021

NJC037-041-PAC025-077-089-095-170045-
/O.NEW.KPHI.FA.Y.0083.210716T2134Z-210717T0045Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Sussex NJ-Warren NJ-Carbon PA-Lehigh PA-Monroe PA-Northampton PA-
534 PM EDT Fri Jul 16 2021

The National Weather Service in Mount Holly has issued a

* Flood Advisory for...
  West Central Sussex County in northwestern New Jersey...
  Northwestern Warren County in northwestern New Jersey...
  Northwestern Lehigh County in eastern Pennsylvania...
  Northwestern Northampton County in eastern Pennsylvania...
  Southeastern Carbon County in northeastern Pennsylvania...
  Central Monroe County in northeastern Pennsylvania...

* Until 845 PM EDT.

* At 534 PM EDT, Doppler radar indicated heavy rain due to 
  thunderstorms moving across portions of the area. Rain rates of 
  one to two inches per hour can be expected. Minor flooding is 
  ongoing or expected to begin shortly in the advisory area.

* Some locations that will experience flooding include...
  Lehighton, East Stroudsburg, Palmerton, Bangor, Jim Thorpe, 
  Slatington, Pen Argyl, Wind Gap, Walnutport, East Bangor, Delaware 
  Water Gap, and Brodheadsville.

This includes the following highways...
	Interstate 80 in New Jersey between mile markers 0 and 3.
	Interstate 80 in Pennsylvania between mile markers 298 and 314.
	Northeast Extension between mile markers 65 and 84.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

In hilly terrain there are hundreds of low water crossings which are 
potentially dangerous in heavy rain. Do not attempt to cross flooded 
roads. Find an alternate route.

Please report observed flooding to local emergency services or law 
enforcement and request they pass this information to the National 
Weather Service when you can do so safely.

&&

LAT...LON 4082 7589 4108 7536 4116 7515 4115 7516
      4114 7508 4108 7503 4114 7492 4119 7488
      4117 7482 4103 7495 4085 7525 4068 7566
      4065 7584 4068 7589 4074 7576 4074 7577

$$

Robertson

2 follow-up statements

757 
WGUS81 KPHI 162304
FLSPHI

Flood Advisory
National Weather Service Mount Holly NJ
704 PM EDT Fri Jul 16 2021

PAC025-077-089-095-162314-
/O.CAN.KPHI.FA.Y.0083.000000T0000Z-210717T0045Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Carbon PA-Lehigh PA-Monroe PA-Northampton PA-
704 PM EDT Fri Jul 16 2021

...FLOOD ADVISORY IS CANCELLED FOR NORTHWESTERN LEHIGH, NORTHWESTERN 
NORTHAMPTON, SOUTHEASTERN CARBON, AND CENTRAL MONROE COUNTIES...

Heavy rain has ended and flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures. Additional 
showers and thunderstorms are possible through this evening.

LAT...LON 4111 7498 4114 7492 4119 7488 4117 7482
      4103 7495 4100 7500 4105 7502 4107 7501
      4108 7497 4109 7497 4110 7497 4109 7499

$$

NJC037-041-170045-
/O.CON.KPHI.FA.Y.0083.000000T0000Z-210717T0045Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Sussex NJ-Warren NJ-
704 PM EDT Fri Jul 16 2021

...FLOOD ADVISORY REMAINS IN EFFECT UNTIL 845 PM EDT THIS EVENING 
FOR WEST CENTRAL SUSSEX AND NORTH CENTRAL WARREN COUNTIES...

At 704 PM EDT, Doppler radar indicated one to one and a half inches 
fell from earlier thunderstorms. This will cause minor flooding in 
the advisory area. Additional showers and thunderstorms are possible 
through this afternoon.

Some locations that will experience flooding include...
  Flatbrookville and Millbrook.

LAT...LON 4111 7498 4114 7492 4119 7488 4117 7482
      4103 7495 4100 7500 4105 7502 4107 7501
      4108 7497 4109 7497 4110 7497 4109 7499

$$

Robertson

017 
WGUS81 KPHI 162326 RRA
FLSPHI

Flood Advisory
National Weather Service Mount Holly NJ
726 PM EDT Fri Jul 16 2021

NJC037-041-162336-
/O.CAN.KPHI.FA.Y.0083.000000T0000Z-210717T0045Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Sussex NJ-Warren NJ-
726 PM EDT Fri Jul 16 2021

...FLOOD ADVISORY IS CANCELLED FOR WEST CENTRAL SUSSEX AND NORTH 
CENTRAL WARREN COUNTIES...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures. Additional
showers and thunderstorms are possible through this evening.

LAT...LON 4111 7498 4114 7492 4119 7488 4117 7482
      4103 7495 4100 7500 4105 7502 4107 7501
      4108 7497 4109 7497 4110 7497 4109 7499

$$

Robertson

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 16, 3:17 PM EDT	Flash Flood Watch	PHI	Berks, Bucks, Carbon, Chester, Delaware, Lehigh and 4 more	35 hr
Jul 16, 5:07 PM EDT	Special Weather Statement	PHI	Carbon	23 min
Jul 16, 5:21 PM EDT	Severe Thunderstorm Warning	PHI	Carbon, Lehigh, Monroe, Northampton	39 min
Jul 16, 5:25 PM EDT	Special Weather Statement	PHI	Monroe	35 min
Jul 16, 5:38 PM EDT	Severe Thunderstorm Warning	PHI	Monroe	20 min
Jul 16, 7:42 PM EDT	Special Weather Statement	PHI	Berks	33 min
Jul 16, 2:55 PM EDT	Areal Flood Advisory	PHI	Sussex	4 hr
Jul 16, 5:01 PM EDT	Areal Flood Advisory	PHI	Sussex	2 hr
Jul 16, 5:21 PM EDT	Flash Flood Warning	PHI	Sussex	2 hr
Jul 16, 5:29 PM EDT	Severe Thunderstorm Warning	PHI	Sussex	46 min
Jul 16, 6:10 PM EDT	Special Weather Statement	PHI	Warren	35 min
Jul 16, 6:14 PM EDT	Special Weather Statement	PHI	Sussex	31 min
Jul 16, 6:27 PM EDT	Areal Flood Advisory	PHI	Sussex	59 min
Jul 16, 6:46 PM EDT	Special Weather Statement	PHI	Warren	29 min
Jul 16, 7:10 PM EDT	Special Weather Statement	PHI	Warren	35 min

Nearby

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