Alert archive / Pennsylvania / Flash Flood Warnings in 2020
Flash Flood Warning 24, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 24, 2020, 12:24 AM EDT for Chester County, Pennsylvania; Cecil County, Maryland; New Castle County, Delaware. It was in force for 114 min. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- Jul 24, 2020, 12:24 AM EDT (04:24 UTC)
- Expired
- Jul 24, 2020, 2:18 AM EDT
- In force
- 114 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Flood severity
- None
Counties New Castle County, DE, Cecil County, MD, Chester County, PA
The radar
The Dover AFB radar (KDOX), 96 km from the middle of the area, began a volume at 04:26 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
Washington/Dulle, VA (KIAD), launched 00:00Z, 4.4 hours before the alert went out and 166 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
- 229 J/kg
- Mixed-layer CIN
- -13 J/kg
- Mixed-layer LCL
- 2029 m above ground
- 0-6 km bulk shear
- 22 kt
- 0-1 km storm-relative helicity
- 10 m²/s²
- 0-3 km storm-relative helicity
- 26 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
926
WGUS51 KPHI 240424
FFWPHI
DEC003-MDC015-PAC029-240830-
/O.NEW.KPHI.FF.W.0024.200724T0424Z-200724T0830Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
1224 AM EDT Fri Jul 24 2020
The National Weather Service in Mount Holly NJ has issued a
* Flash Flood Warning for...
Northwestern New Castle County in northern Delaware...
Northeastern Cecil County in northeastern Maryland...
Southwestern Chester County in southeastern Pennsylvania...
* Until 430 AM EDT.
* At 1223 AM EDT, gauge reports indicated flash flooding is imminent
on the Christina River at Coochs Bridge. Spotters and surface
gauges indicate between 2 and 3 inches of rain occurred near
Newark and Glasgow in the past hour. Flash flooding is expected to
begin shortly.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Automated gauges.
IMPACT...Flooding of small creeks and streams, urban areas,
highways, streets and underpasses as well as other
drainage and low lying areas.
* Some locations that could experience flooding include...
Wilmington, Newark, Elkton, Elsmere, Newport, Barksdale, Stanton,
North Star, Glasgow, Bear, Andora, Brantwood, Cherry Hill, Pike
Creek, Kemblesville, Fair Hill, Glen Westover, Appleton, Saint
Georges and Wilmington Manor.
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.
Turn around...don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3977 7556 3951 7567 3952 7580 3977 7593
FLASH FLOOD...GAUGE INDICATED
$$
CMS1 follow-up statement
736 WGUS71 KPHI 240618 FFSPHI Flash Flood Statement National Weather Service Mount Holly NJ 218 AM EDT Fri Jul 24 2020 DEC003-MDC015-PAC029-240628- /O.CAN.KPHI.FF.W.0024.000000T0000Z-200724T0830Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ New Castle DE-Cecil MD-Chester PA- 218 AM EDT Fri Jul 24 2020 ...THE FLASH FLOOD WARNING FOR NORTHWESTERN NEW CASTLE...NORTHEASTERN CECIL AND SOUTHWESTERN CHESTER COUNTIES IS CANCELLED... Flood waters have receded. Flooding is no longer expected to pose a threat. Please continue to heed any remaining road closures. LAT...LON 3977 7556 3951 7567 3952 7580 3977 7593 $$ CMS
The office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 23, 10:26 PM EDT | Severe Thunderstorm Warning | PHI | Chester | 49 min |
| Jul 23, 10:44 PM EDT | Areal Flood Advisory | PHI | Chester | 2 hr |
| Jul 23, 11:10 PM EDT | Areal Flood Advisory | PHI | Chester, Delaware | 2 hr |
| Jul 23, 11:16 PM EDT | Severe Thunderstorm Warning | PHI | Delaware | 44 min |
| Jul 23, 11:38 PM EDT | Special Weather Statement | PHI | Chester | 37 min |
| Jul 23, 11:44 PM EDT | Severe Thunderstorm Warning | PHI | Chester, Delaware, Montgomery, Philadelphia | 46 min |
| Jul 24, 12:32 AM EDT | Special Weather Statement | PHI | Bucks, Montgomery | 28 min |
| Jul 24, 12:42 AM EDT | Severe Thunderstorm Warning | PHI | Bucks, Montgomery | 48 min |
| Jul 24, 1:13 AM EDT | Severe Thunderstorm Warning | PHI | Bucks | 62 min |
| Jul 24, 10:43 AM EDT | Flash Flood Warning | PHI | Philadelphia | 76 min |
| Jul 24, 1:43 PM EDT | Areal Flood Advisory | PHI | Bucks, Philadelphia | 3 hr |
| Jul 24, 2:19 PM EDT | Areal Flood Advisory | PHI | Bucks, Montgomery, Philadelphia | 2 hr |
| Jul 24, 2:26 PM EDT | Flash Flood Warning | PHI | Bucks, Montgomery, Philadelphia | 2 hr |
| Jul 23, 10:18 PM EDT | Special Weather Statement | PHI | Cecil | 27 min |
| Jul 23, 11:00 PM EDT | Severe Thunderstorm Warning | PHI | Cecil, Kent | 45 min |
| Jul 24, 4:35 PM EDT | Special Weather Statement | PHI | Cecil | 25 min |
| Jul 24, 12:37 AM EDT | River Flood Warning | PHI | New Castle | 102 min |
| Jul 24, 5:34 PM EDT | Special Weather Statement | PHI | Sussex | 26 min |
Nearby
Flash Flood Warnings in Pennsylvania, 2020Flash Flood Warnings in Maryland, 2020Flash 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.