Alert archive / New Jersey / Areal Flood Advisories in 2021

Areal Flood Advisory 84, NWS Philadelphia/Mount Holly

July 16, 2021Sussex County, New Jersey

NWS Philadelphia/Mount Holly issued this areal flood advisory at Jul 16, 2021, 6:27 PM EDT for Sussex County, New Jersey. It was in force for 59 min.

The area

The outline as issued.

The facts

Issued
Jul 16, 2021, 6:27 PM EDT (22:27 UTC)
Expired
Jul 16, 2021, 7:26 PM EDT
In force
59 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

County Sussex County, NJ

The radar

The Philadelphia radar (KDIX), 132 km from the middle of the area, began a volume at 22:30 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, 10.5 hours before the alert went out and 147 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 12:00Z on 2021-07-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1044 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 12:00Z on 2021-07-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 108 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
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.

888 
WGUS81 KPHI 162227
FLSPHI

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

NJC037-170130-
/O.NEW.KPHI.FA.Y.0084.210716T2227Z-210717T0130Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Sussex NJ-
627 PM EDT Fri Jul 16 2021

The National Weather Service in Mount Holly has issued a

* Flood Advisory for...
  Central Sussex County in northwestern New Jersey...

* Until 930 PM EDT.

* At 627 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...
  Newton, Franklin, Hamburg, Ogdensburg, Branchville, Pellettown, 
  Crandon Lakes, Highland Lake, and Five Points.

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 4117 7483 4118 7467 4122 7440 4121 7438
      4120 7437 4116 7442 4115 7443 4113 7446
      4111 7448 4109 7450 4108 7450 4107 7453
      4106 7453 4105 7471 4106 7493 4112 7487

$$

Robertson
1 follow-up statement
020 
WGUS81 KPHI 162326
FLSPHI

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

NJC037-162336-
/O.CAN.KPHI.FA.Y.0084.000000T0000Z-210717T0130Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Sussex NJ-
726 PM EDT Fri Jul 16 2021

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

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 4117 7483 4118 7467 4122 7440 4121 7438
      4120 7437 4116 7442 4115 7443 4113 7446
      4111 7448 4109 7450 4108 7450 4107 7453
      4106 7453 4105 7471 4106 7493 4112 7487

$$

Robertson

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 16, 2:55 PM EDTAreal Flood AdvisoryPHISussex4 hr
Jul 16, 3:17 PM EDTFlash Flood WatchPHIAtlantic, Burlington, Camden, Gloucester, Hunterdon, Mercer and 8 more35 hr
Jul 16, 5:01 PM EDTAreal Flood AdvisoryPHISussex2 hr
Jul 16, 5:21 PM EDTFlash Flood WarningPHISussex2 hr
Jul 16, 5:25 PM EDTSpecial Weather StatementPHISussex35 min
Jul 16, 5:29 PM EDTSevere Thunderstorm WarningPHISussex46 min
Jul 16, 5:34 PM EDTAreal Flood AdvisoryPHISussex, Warren112 min
Jul 16, 6:10 PM EDTSpecial Weather StatementPHIWarren35 min
Jul 16, 6:14 PM EDTSpecial Weather StatementPHISussex31 min
Jul 16, 6:46 PM EDTSpecial Weather StatementPHIWarren29 min
Jul 16, 7:10 PM EDTSpecial Weather StatementPHIWarren35 min

Nearby

Areal Flood Advisories in New Jersey, 2021Every 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.