Alert archive / Pennsylvania / Areal Flood Warnings in 2021
Areal Flood Warning 33, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this areal flood warning at Sep 1, 2021, 10:42 PM EDT for Berks County, Bucks County, Montgomery County, Pennsylvania. It was in force for 12 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
- Sep 1, 2021, 10:42 PM EDT (02:42 UTC)
- Expired
- Sep 2, 2021, 10:45 AM EDT
- In force
- 12 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Flood severity
- None
Counties Berks County, PA, Bucks County, PA, Montgomery County, PA
The radar
The Philadelphia radar (KDIX), 103 km from the middle of the area, began a volume at 02:43 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 |
|---|---|---|---|
| Sep 2, 12:10 AM EDT | HEAVY RAIN 7.7 | Eagleville, PA | STORM TOTAL. |
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, 2.7 hours before the alert went out and 217 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 569 m above ground
- 0-6 km bulk shear
- 32 kt
- 0-1 km storm-relative helicity
- 14 m²/s²
- 0-3 km storm-relative helicity
- 167 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
661
WGUS41 KPHI 020242
FLWPHI
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Flood Warning
National Weather Service Mount Holly NJ
1042 PM EDT Wed Sep 1 2021
PAC011-017-091-021445-
/O.NEW.KPHI.FA.W.0033.210902T0242Z-210902T1445Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Berks PA-Bucks PA-Montgomery PA-
1042 PM EDT Wed Sep 1 2021
The National Weather Service in Mount Holly has issued a
* Flood Warning for...
East Central Berks County in eastern Pennsylvania...
West Central Bucks County in southeastern Pennsylvania...
Montgomery County in southeastern Pennsylvania...
* Until 1045 AM EDT Thursday.
* At 1042 PM EDT, local law enforcement reported flooding in the
warned area. Several gauges are in flood and will likely remain so
for the next several hours. Avoid travel in this area. Flooding is
already occurring.
* Some locations that may experience flooding include...
Norristown, Pottstown, Lansdale, West Norriton, East Norriton,
Souderton, Collegeville, Trappe, Hatfield, East Greenville,
Schwenksville, and Bally.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around...don't drown when encountering flooded roads. Most
flood deaths occur in vehicles.
&&
LAT...LON 4027 7572 4051 7563 4042 7548 4024 7518
4011 7530 4022 7559 4024 7560 4024 7561
4023 7560
$$
CMS1 follow-up statement
788
WGUS81 KPHI 021439
FLSPHI
Flood Statement
National Weather Service Mount Holly NJ
1039 AM EDT Thu Sep 2 2021
PAC011-017-091-021449-
/O.EXP.KPHI.FA.W.0033.000000T0000Z-210902T1445Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Berks PA-Bucks PA-Montgomery PA-
1039 AM EDT Thu Sep 2 2021
...FLOOD WARNING WILL EXPIRE AT 1045 AM EDT THIS MORNING FOR EAST
CENTRAL BERKS, WEST CENTRAL BUCKS, AND MONTGOMERY COUNTIES...
This flood warning will be allowed to expire. Other flood warnings
remain in effect including for the Perkiomen Creek.
LAT...LON 4027 7572 4051 7563 4042 7548 4024 7518
4011 7530 4022 7559 4024 7560 4024 7561
4023 7560
$$
KruzdloThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 1, 8:29 PM EDT | River Flood Warning | PHI | Lehigh | 10 hr |
| Sep 1, 9:47 PM EDT | River Flood Warning | PHI | Berks | 18 hr |
| Sep 1, 10:24 PM EDT | Flash Flood Warning | PHI | Bucks, Philadelphia | 4 hr |
| Sep 1, 10:29 PM EDT | River Flood Warning | PHI | Bucks | 49 hr |
| Sep 1, 10:32 PM EDT | River Flood Warning | PHI | Bucks | 31 hr |
| Sep 1, 10:47 PM EDT | Areal Flood Warning | PHI | Bucks, Carbon, Lehigh, Northampton | 23 hr |
| Sep 1, 10:52 PM EDT | Areal Flood Warning | PHI | Bucks | 12 hr |
| Sep 1, 11:38 PM EDT | Areal Flood Warning | PHI | Berks, Chester, Delaware, Montgomery | 10 hr |
| Sep 2, 12:01 AM EDT | Areal Flood Warning | PHI | Monroe, Northampton | 40 hr |
| Sep 2, 2:23 AM EDT | Areal Flood Warning | PHI | Bucks, Delaware, Montgomery, Philadelphia | 9 hr |
| Sep 2, 2:29 AM EDT | Areal Flood Warning | PHI | Bucks, Philadelphia | 5 hr |
| Sep 2, 2:41 AM EDT | Areal Flood Warning | PHI | Bucks | 14 hr |
| Sep 2, 3:52 AM EDT | Areal Flood Warning | PHI | Bucks | 8 hr |
| Sep 2, 4:45 AM EDT | River Flood Warning | PHI | Bucks | 37 hr |
| Sep 2, 4:45 AM EDT | River Flood Warning | PHI | Northampton | 37 hr |
| Sep 2, 4:45 AM EDT | River Flood Warning | PHI | Bucks | 37 hr |
| Sep 2, 4:45 AM EDT | River Flood Warning | PHI | Bucks | 33 hr |
| Sep 2, 4:45 AM EDT | River Flood Warning | PHI | Bucks | 34 hr |
| Sep 2, 4:45 AM EDT | River Flood Warning | PHI | Monroe, Northampton | 5 hr |
| Sep 2, 5:02 AM EDT | River Flood Warning | PHI | Lehigh | 11 hr |
| Sep 2, 6:05 AM EDT | Coastal Flood Warning | PHI | Bucks, Delaware, Montgomery, Philadelphia | 6 hr |
| Sep 2, 6:44 PM EDT | Coastal Flood Advisory | PHI | Bucks, Delaware, Philadelphia | 7 hr |
Nearby
Areal Flood Warnings in Pennsylvania, 2021Every areal flood warning in 2021
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.