Alert archive / Delaware / Areal Flood Advisories in 2021
Areal Flood Advisory 129, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this areal flood advisory at Aug 20, 2021, 8:18 AM EDT for Kent County, Sussex County, Delaware. It was in force for 117 min.
The area
The outline as issued.
The facts
- Issued
- Aug 20, 2021, 8:18 AM EDT (12:18 UTC)
- Expired
- Aug 20, 2021, 10:15 AM EDT
- In force
- 117 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
Counties Kent County, DE, Sussex County, DE
The radar
The Dover AFB radar (KDOX), 14 km from the middle of the area, began a volume at 12:17 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
Wallops Is Stn, VA (KWAL), launched 12:00Z, 0.3 hours before the alert went out and 109 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.
- Mixed-layer CAPE
- 166 J/kg
- Mixed-layer CIN
- -119 J/kg
- Mixed-layer LCL
- 987 m above ground
- 0-6 km bulk shear
- 35 kt
- 0-1 km storm-relative helicity
- -53 m²/s²
- 0-3 km storm-relative helicity
- -29 m²/s²
- Significant tornado parameter
- -0.0
- Supercell composite
- -0.2
The text
As transmitted.
550
WGUS81 KPHI 201218
FLSPHI
Flood Advisory
National Weather Service Mount Holly NJ
818 AM EDT Fri Aug 20 2021
DEC001-005-201415-
/O.NEW.KPHI.FA.Y.0129.210820T1218Z-210820T1415Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kent DE-Sussex DE-
818 AM EDT Fri Aug 20 2021
The National Weather Service in Mount Holly has issued a
* Flood Advisory for...
Southeastern Kent County in central Delaware...
Northeastern Sussex County in southern Delaware...
* Until 1015 AM EDT.
* At 818 AM 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 1.5 inches of rain
have fallen.
* Some locations that will experience flooding include...
Milford, Lewes, Milton, Big Stone Beach, Cape Henlopen State Park,
Frederica, and Houston.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Be aware of your surroundings and do not drive on flooded roads.
&&
LAT...LON 3896 7555 3901 7549 3905 7540 3907 7535
3883 7517 3883 7507 3878 7504 3866 7526
$$
CMS1 follow-up statement
569
WGUS81 KPHI 201408
FLSPHI
Flood Advisory
National Weather Service Mount Holly NJ
1008 AM EDT Fri Aug 20 2021
DEC001-005-201418-
/O.EXP.KPHI.FA.Y.0129.000000T0000Z-210820T1415Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kent DE-Sussex DE-
1008 AM EDT Fri Aug 20 2021
...FLOOD ADVISORY WILL EXPIRE AT 1015 AM EDT THIS MORNING FOR
SOUTHEASTERN KENT AND NORTHEASTERN SUSSEX COUNTIES...
The heavy rain has ended. Flooding is no longer expected to pose a
threat. Please continue to heed remaining road closures.
LAT...LON 3896 7555 3901 7549 3905 7540 3907 7535
3883 7517 3883 7507 3878 7504 3866 7526
$$
CMSThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 19, 8:15 PM EDT | Rip Current Statement | PHI | Sussex | 3 days |
| Aug 20, 6:39 AM EDT | Areal Flood Advisory | PHI | Kent | 8 hr |
| Aug 20, 6:46 AM EDT | Areal Flood Advisory | PHI | Sussex | 3 hr |
Nearby
Areal Flood Advisories in Delaware, 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.