Alert archive / Pennsylvania / Flash Flood Warnings in 2024
Flash Flood Warning 12, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this flash flood warning at Jun 30, 2024, 5:19 PM EDT for Chester County, Delaware County, Philadelphia County, Pennsylvania. It was in force for 3 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
- Jun 30, 2024, 5:19 PM EDT (21:19 UTC)
- Expired
- Jun 30, 2024, 8:15 PM EDT
- In force
- 3 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Flood severity
- None
Counties Chester County, PA, Delaware County, PA, Philadelphia County, PA
The radar
The Philadelphia radar (KDIX), 116 km from the middle of the area, began a volume at 21:19 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 12:00Z, 9.3 hours before the alert went out and 175 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
- 958 J/kg
- Mixed-layer CIN
- -163 J/kg
- Mixed-layer LCL
- 1517 m above ground
- 0-6 km bulk shear
- 23 kt
- 0-1 km storm-relative helicity
- 44 m²/s²
- 0-3 km storm-relative helicity
- 20 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.2
The text
As transmitted.
384
WGUS51 KPHI 302119
FFWPHI
PAC029-045-101-010015-
/O.NEW.KPHI.FF.W.0012.240630T2119Z-240701T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
519 PM EDT Sun Jun 30 2024
The National Weather Service in Mount Holly has issued a
* Flash Flood Warning for...
Central Chester County in southeastern Pennsylvania...
Delaware County in southeastern Pennsylvania...
Western Philadelphia County in southeastern Pennsylvania...
* Until 815 PM EDT.
* At 519 PM EDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. Between 0.5 and 1 inch of rain
has fallen. The expected rainfall rate is 0.5 to 1.5 inches in 1
hour. Additional rainfall amounts of 1 to 2 inches are possible in
the warned area. Flash flooding is ongoing or expected to begin
shortly.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Radar.
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 may experience flash flooding include...
Philadelphia, West Chester, Chester, Coatesville, Yeadon,
Westtown, Downingtown, Folcroft, Swarthmore, Kennett Square,
Oxford and Parkesburg.
This includes the following highways...
Interstate 476 in Pennsylvania between mile markers 0 and 9.
Interstate 95 in Pennsylvania between mile markers 2 and 12.
Pennsylvania Turnpike between mile markers 310 and 316.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around...don't drown when encountering flooded roads. Most
flood deaths occur in vehicles.
&&
LAT...LON 4005 7545 3994 7524 3986 7525 3985 7533
3982 7540 3985 7550 3984 7581 3977 7606
3981 7603 3983 7604 3983 7602 3985 7602
3985 7601 3987 7600 3987 7599 3993 7600
3993 7598 3995 7599 4002 7595 4008 7569
FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL RATE...0.5-1.5 INCHES IN 1 HOUR
$$
SFJ2 follow-up statements
909
WGUS71 KPHI 302215
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
615 PM EDT Sun Jun 30 2024
PAC029-045-101-010015-
/O.CON.KPHI.FF.W.0012.000000T0000Z-240701T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Chester PA-Delaware PA-Philadelphia PA-
615 PM EDT Sun Jun 30 2024
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 815 PM EDT THIS
EVENING FOR CENTRAL CHESTER, DELAWARE AND WESTERN PHILADELPHIA
COUNTIES...
At 615 PM EDT, Doppler radar indicated thunderstorms producing heavy
rain across the warned area. Between 1 and 2 inches of rain have
fallen. The expected rainfall rate is 0.5 inches in 1 hour.
Additional rainfall amounts up to 0.5 inches are possible in the
warned area. Flash flooding is ongoing or expected to begin shortly.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Radar.
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 may experience flash flooding include...
Philadelphia, West Chester, Chester, Coatesville, Yeadon,
Westtown, Downingtown, Folcroft, Swarthmore, Kennett Square,
Oxford and Parkesburg.
This includes the following highways...
Interstate 476 in Pennsylvania between mile markers 0 and 10.
Interstate 95 in Pennsylvania between mile markers 2 and 12.
Pennsylvania Turnpike between mile markers 311 and 316.
Although the line of heaviest rain has left the warned area,
additional showers could exacerbate any flooding that may already be
ongoing.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around...don't drown when encountering flooded roads. Most
flood deaths occur in vehicles.
&&
LAT...LON 4005 7545 3994 7524 3986 7525 3985 7533
3982 7540 3985 7550 3984 7581 3977 7606
3981 7603 3983 7604 3983 7602 3985 7602
3985 7601 3987 7600 3987 7599 3993 7600
3993 7598 3995 7599 4002 7595 4008 7569
FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL RATE...0.5 INCHES IN 1 HOUR
$$
SFJ072
WGUS71 KPHI 010005
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
805 PM EDT Sun Jun 30 2024
PAC029-045-101-010015-
/O.EXP.KPHI.FF.W.0012.000000T0000Z-240701T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Chester PA-Delaware PA-Philadelphia PA-
805 PM EDT Sun Jun 30 2024
...FLASH FLOOD WARNING WILL EXPIRE AT 815 PM EDT THIS EVENING FOR
CENTRAL CHESTER, DELAWARE AND WESTERN PHILADELPHIA COUNTIES...
The heavy rain has ended. Flooding is no longer expected to pose a
threat. Please continue to heed remaining road closures.
&&
LAT...LON 4005 7545 3994 7524 3986 7525 3985 7533
3982 7540 3985 7550 3984 7581 3977 7606
3981 7603 3983 7604 3983 7602 3985 7602
3985 7601 3987 7600 3987 7599 3993 7600
3993 7598 3995 7599 4002 7595 4008 7569
$$
SFJThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 29, 8:22 PM EDT | Severe Thunderstorm Warning | PHI | Bucks, Montgomery | 53 min |
| Jun 29, 10:23 PM EDT | Flash Flood Warning | PHI | Chester | 4 hr |
| Jun 30, 1:18 PM EDT | Severe Thunderstorm Warning | PHI | Carbon, Monroe | 42 min |
| Jun 30, 1:57 PM EDT | Severe Thunderstorm Warning | PHI | Monroe | 48 min |
| Jun 30, 2:10 PM EDT | Severe Thunderstorm Warning | PHI | Monroe, Northampton | 50 min |
| Jun 30, 2:42 PM EDT | Severe Thunderstorm Warning | PHI | Northampton | 63 min |
| Jun 30, 2:45 PM EDT | Severe Thunderstorm Warning | PHI | Carbon, Lehigh, Monroe, Northampton | 45 min |
| Jun 30, 3:01 PM EDT | Severe Thunderstorm Warning | PHI | Berks, Chester, Montgomery | 59 min |
| Jun 30, 3:26 PM EDT | Severe Thunderstorm Warning | PHI | Northampton | 49 min |
| Jun 30, 3:46 PM EDT | Severe Thunderstorm Warning | PHI | Berks, Bucks, Lehigh, Montgomery | 44 min |
| Jun 30, 3:52 PM EDT | Severe Thunderstorm Warning | PHI | Berks, Chester, Delaware, Montgomery | 38 min |
| Jun 30, 4:25 PM EDT | Severe Thunderstorm Warning | PHI | Bucks, Chester, Delaware, Montgomery, Philadelphia | 50 min |
| Jun 30, 4:37 PM EDT | Severe Thunderstorm Warning | PHI | Bucks, Lehigh, Northampton | 53 min |
| Jun 30, 4:54 PM EDT | Severe Thunderstorm Warning | PHI | Berks, Chester, Montgomery | 51 min |
| Jun 30, 5:20 PM EDT | Severe Thunderstorm Warning | PHI | Chester, Delaware | 40 min |
| Jun 30, 5:51 PM EDT | Severe Thunderstorm Warning | PHI | Delaware, Philadelphia | 39 min |
| Jun 30, 5:54 PM EDT | Flash Flood Warning | PHI | Delaware, Philadelphia | 3 hr |
| Jun 30, 7:31 PM EDT | Severe Thunderstorm Warning | PHI | Chester | 44 min |
Nearby
Flash Flood Warnings in Pennsylvania, 2024Every flash flood warning in 2024
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.