Alert archive / Pennsylvania / Flash Flood Warnings in 2024
Flash Flood Warning 51, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 8, 2024, 8:52 PM EDT for Berks County, Chester County, Pennsylvania. It was in force for 3 hr. 1 report came from inside the area while it was in force.
The area
The outline as issued, with what was reported inside it.
The facts
- Issued
- Aug 8, 2024, 8:52 PM EDT (00:52 UTC)
- Expired
- Aug 9, 2024, 12:00 AM EDT
- In force
- 3 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Flood severity
- None
Counties Berks County, PA, Chester County, PA
The radar
The Philadelphia radar (KDIX), 127 km from the middle of the area, began a volume at 00:56 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.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Aug 8, 9:38 PM EDT | RAIN 2.14 | 2 Wnw Upper Uwchlan Twp, PA | Mesonet station FW0827 Glenmoore. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Washington/Dulle, VA (KIAD), launched 00:00Z, 0.9 hours before the alert went out and 189 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
- 886 J/kg
- Mixed-layer CIN
- -5 J/kg
- Mixed-layer LCL
- 607 m above ground
- 0-6 km bulk shear
- 22 kt
- 0-1 km storm-relative helicity
- 70 m²/s²
- 0-3 km storm-relative helicity
- 132 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 1.4
The text
As transmitted.
767
WGUS51 KPHI 090052
FFWPHI
PAC011-029-090400-
/O.NEW.KPHI.FF.W.0051.240809T0052Z-240809T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
852 PM EDT Thu Aug 8 2024
The National Weather Service in Mount Holly has issued a
* Flash Flood Warning for...
Southeastern Berks County in eastern Pennsylvania...
North Central Chester County in southeastern Pennsylvania...
* Until midnight EDT tonight.
* At 852 PM EDT, Doppler radar and automated rain gauges indicated
showers and isolated thunderstorms producing very heavy rain
across the warned area. Between 1 and 2.5 inches of rain have
fallen. The expected rainfall rate is 2 to 3 inches in 1 hour.
Flash flooding is ongoing or expected to begin shortly.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Radar and 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 may experience flash flooding include...
Reading, Coatesville, Wyomissing, Downingtown, Birdsboro,
Laureldale, Honey Brook, Elverson, New Morgan, Glenmoore, Spring
Ridge and Shillington.
This includes the following highways...
Interstate 176 in Pennsylvania between mile markers 1 and 11.
Pennsylvania Turnpike between mile markers 296 and 310.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around...don't drown when encountering flooded roads. Most
flood deaths occur in vehicles.
Be especially cautious at night when it is harder to recognize the
dangers of flooding.
&&
LAT...LON 4037 7599 4039 7586 4037 7575 4015 7571
4001 7568 4002 7576 3999 7589 4011 7593
4012 7592 4014 7588 4015 7589 4015 7590
4016 7592 4017 7593 4019 7595
FLASH FLOOD...RADAR AND GAUGE INDICATED
EXPECTED RAINFALL RATE...2-3 INCHES IN 1 HOUR
$$
Gorse2 follow-up statements
713
WGUS71 KPHI 090213
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
1013 PM EDT Thu Aug 8 2024
PAC011-029-090400-
/O.CON.KPHI.FF.W.0051.000000T0000Z-240809T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Berks PA-Chester PA-
1013 PM EDT Thu Aug 8 2024
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL MIDNIGHT EDT TONIGHT
FOR SOUTHEASTERN BERKS AND NORTH CENTRAL CHESTER COUNTIES...
At 1013 PM EDT, Doppler radar and automated rain gauges indicated
the heaviest showers and isolated thunderstorms are shifting north
of the warned area, however some additional showers continue.
Between 1.5 and 3 inches of rain have fallen with the highest
amounts in northern Chester County. The expected rainfall rate is 1
to 2 inches in 1 hour. Flash flooding is ongoing or expected to
begin shortly.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Radar and automated gauges.
IMPACT...Flooding of small creeks and streams, urban areas,
highways, streets, and underpasses as well as other
drainage and low lying areas.
Some locations that may experience flash flooding include...
Reading, Coatesville, Wyomissing, Downingtown, Birdsboro,
Laureldale, Honey Brook, Elverson, New Morgan, Glenmoore, Spring
Ridge and Shillington.
This includes the following highways...
Interstate 176 in Pennsylvania between mile markers 1 and 11.
Pennsylvania Turnpike between mile markers 296 and 310.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around...don't drown when encountering flooded roads. Most
flood deaths occur in vehicles.
Be especially cautious at night when it is harder to recognize the
dangers of flooding.
&&
LAT...LON 4037 7599 4039 7586 4037 7575 4015 7571
4001 7568 4002 7576 3999 7589 4011 7593
4012 7592 4014 7588 4015 7589 4015 7590
4016 7592 4017 7593 4019 7595
FLASH FLOOD...RADAR AND GAUGE INDICATED
EXPECTED RAINFALL RATE...1-2 INCHES IN 1 HOUR
$$
Gorse513
WGUS71 KPHI 090353
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
1153 PM EDT Thu Aug 8 2024
PAC011-029-090403-
/O.EXP.KPHI.FF.W.0051.000000T0000Z-240809T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Berks PA-Chester PA-
1153 PM EDT Thu Aug 8 2024
...FLASH FLOOD WARNING WILL EXPIRE AT MIDNIGHT EDT TONIGHT FOR
SOUTHEASTERN BERKS AND NORTH CENTRAL CHESTER COUNTIES...
The heavy rain has ended. Flooding is no longer expected to pose a
threat. Please continue to heed remaining road closures And stay up
to date for any new warnings that may be issued.
A Flood Watch remains in effect until 100 AM EDT Saturday for
portions of northern Delaware and Pennsylvania.
&&
LAT...LON 4037 7599 4039 7586 4037 7575 4015 7571
4001 7568 4002 7576 3999 7589 4011 7593
4012 7592 4014 7588 4015 7589 4015 7590
4016 7592 4017 7593 4019 7595
$$
SFJThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 8, 9:06 PM EDT | River Flood Warning | PHI | Chester | 9 hr |
| Aug 8, 11:40 PM EDT | Areal Flood Warning | PHI | Chester | 4 hr |
| Aug 9, 12:12 AM EDT | River Flood Warning | PHI | Chester, Delaware | 16 hr |
| Aug 9, 2:50 PM EDT | Flash Flood Warning | PHI | Lehigh, Northampton | 2 hr |
| Aug 9, 3:31 PM EDT | Flash Flood Warning | PHI | Monroe, Northampton | 108 min |
| Aug 9, 3:50 PM EDT | Flash Flood Warning | PHI | Bucks, Montgomery | 2 hr |
| Aug 9, 4:11 PM EDT | Flash Flood Warning | PHI | Northampton | 100 min |
| Aug 9, 5:30 PM EDT | Flash Flood Warning | PHI | Bucks | 83 min |
| Aug 9, 5:56 PM EDT | River Flood Warning | PHI | Chester | 6 hr |
| Aug 9, 6:46 PM EDT | Areal Flood Warning | PHI | Berks, Bucks, Lehigh, Montgomery | 4 hr |
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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.