Alert archive / Pennsylvania / Flash Flood Warnings in 2024
Flash Flood Warning 54, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 9, 2024, 3:50 PM EDT for Bucks County, Montgomery County, Pennsylvania. It was in force for 2 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 9, 2024, 3:50 PM EDT (19:50 UTC)
- Expired
- Aug 9, 2024, 5:51 PM EDT
- In force
- 2 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Flood severity
- None
Counties Bucks County, PA, Montgomery County, PA
The radar
The Philadelphia radar (KDIX), 78 km from the middle of the area, began a volume at 19:54 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
Brookhaven, NY (KOKX), launched 12:00Z, 7.8 hours before the alert went out and 201 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
- 988 J/kg
- Mixed-layer CIN
- -3 J/kg
- Mixed-layer LCL
- 536 m above ground
- 0-6 km bulk shear
- 38 kt
- 0-1 km storm-relative helicity
- 223 m²/s²
- 0-3 km storm-relative helicity
- 245 m²/s²
- Significant tornado parameter
- 0.8
- Supercell composite
- 13.0
The text
As transmitted.
055
WGUS51 KPHI 091950
FFWPHI
PAC017-091-100000-
/O.NEW.KPHI.FF.W.0054.240809T1950Z-240810T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
350 PM EDT Fri Aug 9 2024
The National Weather Service in Mount Holly has issued a
* Flash Flood Warning for...
Central Bucks County in southeastern Pennsylvania...
Central Montgomery County in southeastern Pennsylvania...
* Until 800 PM EDT.
* At 350 PM EDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. Up to 1 inch of rain has
fallen. 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.
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...
Lansdale, Perkasie, Doylestown, Souderton, Bedminster, Chalfont,
Tinicum, Hatfield, Dublin, Fricks, Gardenville and Pipersville.
This includes Northeast Extension between mile markers 27 and 36.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around...don't drown when encountering flooded roads. Most
flood deaths occur in vehicles.
Be aware of your surroundings and do not drive on flooded roads.
&&
LAT...LON 4045 7519 4045 7507 4044 7507 4042 7506
4040 7503 4041 7501 4038 7498 4031 7504
4022 7521 4020 7533 4026 7542 4036 7537
FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL RATE...1-2 INCHES IN 1 HOUR
$$
MJL1 follow-up statement
905
WGUS71 KPHI 092151 RRA
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
551 PM EDT Fri Aug 9 2024
PAC017-091-092201-
/O.CAN.KPHI.FF.W.0054.000000T0000Z-240810T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Bucks PA-Montgomery PA-
551 PM EDT Fri Aug 9 2024
...FLASH FLOOD WARNING IS CANCELLED FOR CENTRAL BUCKS AND CENTRAL
MONTGOMERY COUNTIES...
The heavy rain has ended. Flooding is no longer expected to pose a
threat. Please continue to heed remaining road closures.
A Flood Watch remains in effect until 100 AM EDT Saturday for
portions of northern Delaware, New Jersey, and Pennsylvania.
&&
LAT...LON 4045 7519 4045 7507 4044 7507 4042 7506
4040 7503 4041 7501 4038 7498 4031 7504
4022 7521 4020 7533 4026 7542 4036 7537
$$
MJLThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 8, 8:52 PM EDT | Flash Flood Warning | PHI | Berks, Chester | 3 hr |
| 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, 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.