Alert archive / Delaware / Flash Flood Warnings in 2020
Flash Flood Warning 49, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 7, 2020, 7:21 PM EDT for Kent County, New Castle County, Delaware. It was in force for 5 hr. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- Aug 7, 2020, 7:21 PM EDT (23:21 UTC)
- Expired
- Aug 8, 2020, 12:01 AM EDT
- In force
- 5 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Flood severity
- None
Counties Kent County, DE, New Castle County, DE
The radar
The Dover AFB radar (KDOX), 51 km from the middle of the area, began a volume at 23:23 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, 11.4 hours before the alert went out and 150 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
- 248 J/kg
- Mixed-layer CIN
- -58 J/kg
- Mixed-layer LCL
- 738 m above ground
- 0-6 km bulk shear
- 30 kt
- 0-1 km storm-relative helicity
- 6 m²/s²
- 0-3 km storm-relative helicity
- 31 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.0
The text
As transmitted.
677
WGUS51 KPHI 072321
FFWPHI
DEC001-003-080515-
/O.NEW.KPHI.FF.W.0049.200807T2321Z-200808T0515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
721 PM EDT Fri Aug 7 2020
The National Weather Service in Mount Holly NJ has issued a
* Flash Flood Warning for...
Southwestern New Castle County in northern Delaware...
Northern Kent County in central Delaware...
* Until 115 AM EDT.
* At 720 PM EDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. Flash flooding is expected to
begin shortly.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Radar indicated.
IMPACT...Flooding of small creeks and streams, urban areas,
highways, streets and underpasses as well as other
poor drainage and low lying areas.
* Some locations that could experience flooding include...
Dover, Smyrna, Camden, Clayton, Cheswold, Woodside, Hartly, Rising
Sun-Lebanon, Woodland Beach, Hazlettville, Delaney Corner, Dover
Base Housing, Dover Speedway, Sandtown, Green Spring, Rising Sun,
Townsend, Wyoming, Kenton and Little Creek.
Additional rainfall amounts of 1 to 3 inches are possible in the
warned area.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Protecting yourself from immediate threats to life and safety shall
take priority. Whenever possible, as long as it does not cause
greater harm, all COVID-19 protective action guidance should be
followed.
Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, urban areas, highways, streets, and underpasses
as well as other poor drainage areas and low lying spots.
&&
LAT...LON 3942 7550 3912 7532 3902 7574 3938 7577
FLASH FLOOD...RADAR INDICATED
$$
Iovino1 follow-up statement
021 WGUS71 KPHI 080401 FFSPHI Flash Flood Statement National Weather Service Mount Holly NJ 1201 AM EDT Sat Aug 8 2020 DEC001-003-080411- /O.CAN.KPHI.FF.W.0049.000000T0000Z-200808T0515Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ New Castle DE-Kent DE- 1201 AM EDT Sat Aug 8 2020 ...THE FLASH FLOOD WARNING FOR SOUTHWESTERN NEW CASTLE AND NORTHERN KENT COUNTIES IS CANCELLED... Flood waters are receding. Flooding is no longer expected to pose a threat. Please continue to heed any remaining road closures. LAT...LON 3942 7550 3912 7532 3902 7574 3938 7577 $$ Iovino
The office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 7, 5:03 PM EDT | Flash Flood Warning | PHI | New Castle | 5 hr |
| Aug 7, 5:38 PM EDT | Severe Thunderstorm Warning | PHI | New Castle | 52 min |
| Aug 7, 5:49 PM EDT | Tornado Warning | PHI | New Castle | 26 min |
| Aug 7, 5:57 PM EDT | Severe Thunderstorm Warning | PHI | New Castle | 48 min |
| Aug 7, 6:00 PM EDT | Tornado Warning | PHI | New Castle | 30 min |
| Aug 7, 6:12 PM EDT | Severe Thunderstorm Warning | PHI | Kent, New Castle | 63 min |
| Aug 7, 6:43 PM EDT | Areal Flood Advisory | PHI | Kent, New Castle | 4 hr |
| Aug 7, 7:04 PM EDT | Severe Thunderstorm Warning | PHI | Kent, New Castle | 41 min |
| Aug 7, 7:28 PM EDT | River Flood Warning | PHI | New Castle | 2 hr |
| Aug 7, 7:36 PM EDT | Special Weather Statement | PHI | Kent | 39 min |
Nearby
Flash Flood Warnings in Delaware, 2020Every flash flood warning in 2020
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.