Alert archive / Pennsylvania / Areal Flood Warnings in 2021
Areal Flood Warning 5, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this areal flood warning at Jun 8, 2021, 6:21 PM EDT for Chester County, Delaware County, Pennsylvania. It was in force for 15 hr. 3 reports 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
- Jun 8, 2021, 6:21 PM EDT (22:21 UTC)
- Expired
- Jun 9, 2021, 9:30 AM EDT
- In force
- 15 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Flood severity
- None
Counties Chester County, PA, Delaware County, PA
The radar
The Philadelphia radar (KDIX), 108 km from the middle of the area, began a volume at 22:24 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 |
|---|---|---|---|
| Jun 8, 6:49 PM EDT | HEAVY RAIN 5.4 | Downington, PA | STORM TOTAL RAINFALL. |
| Jun 8, 6:50 PM EDT | FLOOD | 1 W Downington, PA | FLOODING ON MARY ST AT WHELEN AVE. THE ROAD IS FLOODED WITH FLOODWATERS ENTERING THE BASEMENT OF AT LEAST ONE RESIDENCE. |
| Jun 8, 7:07 PM EDT | HEAVY RAIN 4.1 | Downington, PA | SOCIAL MEDIA. |
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 12:00Z, 10.4 hours before the alert went out and 183 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
- 254 J/kg
- Mixed-layer CIN
- -121 J/kg
- Mixed-layer LCL
- 1088 m above ground
- 0-6 km bulk shear
- 12 kt
- 0-1 km storm-relative helicity
- -39 m²/s²
- 0-3 km storm-relative helicity
- 23 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
823
WGUS41 KPHI 082221
FLWPHI
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Flood Warning
National Weather Service Mount Holly NJ
621 PM EDT Tue Jun 8 2021
PAC029-045-091200-
/O.NEW.KPHI.FA.W.0005.210608T2221Z-210609T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Chester PA-Delaware PA-
621 PM EDT Tue Jun 8 2021
The National Weather Service in Mount Holly has issued a
* Flood Warning for...
Central Chester County in southeastern Pennsylvania...
Western Delaware County in southeastern Pennsylvania...
* Until 800 AM EDT Wednesday.
* At 621 PM EDT, Doppler radar and spotter reports indicate that up
to 3 to 7 inches of rain fell in the Brandywine Creek basin in
Chester County this afternoon. Significant flooding is already
occurring in the warned area.
* Some locations that will continue to experience flooding include...
West Chester, Coatesville, Downingtown, Parkesburg, Honey Brook,
Marshallton, Glenmoore, Lionville-Marchwood, South Coatesville,
Modena, Thorndale, and Exton.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Motorists should not attempt to drive around barricades or drive
cars through flooded areas.
&&
LAT...LON 4011 7568 3984 7554 3984 7555 3984 7557
3984 7558 3984 7559 3984 7560 3983 7562
3983 7564 3983 7565 3989 7572 3991 7595
4011 7591 4014 7583
$$
Iovino3 follow-up statements
114
WGUS81 KPHI 090456
FLSPHI
Flood Statement
National Weather Service Mount Holly NJ
1256 AM EDT Wed Jun 9 2021
PAC029-045-091200-
/O.CON.KPHI.FA.W.0005.000000T0000Z-210609T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Chester PA-Delaware PA-
1256 AM EDT Wed Jun 9 2021
...FLOOD WARNING REMAINS IN EFFECT UNTIL 8 AM EDT THIS MORNING FOR
CENTRAL CHESTER AND WESTERN DELAWARE COUNTIES...
At 1256 AM EDT, Doppler radar and automated rain gauges indicated
between 3 and 7 inches of rain fell from earlier storms. Most creeks
and streams in the area have crested and are falling. However, there
could continue to be some residual flooding for some areas.
Some locations that will experience flooding include...
West Chester, Coatesville, Downingtown, Parkesburg, Honey Brook,
Marshallton, Glenmoore, Lionville-Marchwood, South Coatesville,
Modena, Thorndale, and Exton.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around...don't drown when encountering flooded roads. Most
flood deaths occur in vehicles.
Be especially cautious at night when it is harder to recognize the
dangers of flooding.
In hilly terrain there are hundreds of low water crossings which are
potentially dangerous in heavy rain. Do not attempt to cross flooded
roads. Find an alternate route.
&&
LAT...LON 4011 7568 3984 7554 3984 7555 3984 7557
3984 7558 3984 7559 3984 7560 3983 7562
3983 7564 3983 7565 3989 7572 3991 7595
4011 7591 4014 7583
$$
Robertson550
WGUS41 KPHI 091152
FLWPHI
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Flood Warning
National Weather Service Mount Holly NJ
752 AM EDT Wed Jun 9 2021
PAC029-045-091330-
/O.EXT.KPHI.FA.W.0005.000000T0000Z-210609T1330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Chester PA-Delaware PA-
752 AM EDT Wed Jun 9 2021
The National Weather Service in Mount Holly has extended the
* Flood Warning for...
Central Chester County in southeastern Pennsylvania...
Western Delaware County in southeastern Pennsylvania...
* Until 930 AM EDT.
* At 752 AM EDT, Doppler radar and automated rain gauges indicated
that between 3 and 7 inches of rain fell yesterday and flood
waters have not yet completely receded. Most streams have crested
and are falling however minor flooding is still occuring in some
residential areas.
* Some locations that will experience flooding include...
West Chester, Coatesville, Downingtown, Parkesburg, Honey Brook,
Marshallton, Glenmoore, Lionville-Marchwood, South Coatesville,
Modena, Thorndale, and Exton.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around...don't drown when encountering flooded roads. Most
flood deaths occur in vehicles.
&&
LAT...LON 4011 7568 3984 7554 3984 7555 3984 7557
3984 7558 3984 7559 3984 7560 3983 7562
3983 7564 3983 7565 3989 7572 3991 7595
4011 7591 4014 7583
$$
Deal792
WGUS81 KPHI 091322
FLSPHI
Flood Statement
National Weather Service Mount Holly NJ
922 AM EDT Wed Jun 9 2021
PAC029-045-091332-
/O.EXP.KPHI.FA.W.0005.000000T0000Z-210609T1330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Chester PA-Delaware PA-
922 AM EDT Wed Jun 9 2021
...FLOOD WARNING WILL EXPIRE AT 930 AM EDT THIS MORNING FOR CENTRAL
CHESTER AND WESTERN DELAWARE COUNTIES...
Flood waters have receded and flooding is no longer expected to pose
a threat this morning. Please continue to heed remaining road
closures.
LAT...LON 4011 7568 3984 7554 3984 7555 3984 7557
3984 7558 3984 7559 3984 7560 3983 7562
3983 7564 3983 7565 3989 7572 3991 7595
4011 7591 4014 7583
$$
FitzsimmonsThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 8, 11:54 AM EDT | Areal Flood Advisory | PHI | Monroe | 2 hr |
| Jun 8, 12:34 PM EDT | Flash Flood Warning | PHI | Monroe | 2 hr |
| Jun 8, 12:40 PM EDT | Special Weather Statement | PHI | Monroe | 35 min |
| Jun 8, 1:09 PM EDT | Special Weather Statement | PHI | Monroe | 21 min |
| Jun 8, 1:17 PM EDT | Special Weather Statement | PHI | Chester | 13 min |
| Jun 8, 1:18 PM EDT | Areal Flood Advisory | PHI | Chester, Delaware, Montgomery, Philadelphia | 3 hr |
| Jun 8, 1:24 PM EDT | Special Weather Statement | PHI | Delaware | 21 min |
| Jun 8, 1:27 PM EDT | Areal Flood Advisory | PHI | Carbon, Lehigh, Monroe, Northampton | 3 hr |
| Jun 8, 1:35 PM EDT | Flash Flood Warning | PHI | Chester, Delaware, Montgomery | 5 hr |
| Jun 8, 2:07 PM EDT | Special Weather Statement | PHI | Bucks | 23 min |
| Jun 8, 2:19 PM EDT | Areal Flood Advisory | PHI | Bucks | 2 hr |
| Jun 8, 2:43 PM EDT | Special Weather Statement | PHI | Montgomery | 32 min |
| Jun 8, 3:15 PM EDT | Special Weather Statement | PHI | Chester | 30 min |
| Jun 8, 3:21 PM EDT | Flash Flood Warning | PHI | Chester, Montgomery | 3 hr |
| Jun 8, 3:43 PM EDT | Special Weather Statement | PHI | Chester | 32 min |
| Jun 8, 4:20 PM EDT | Special Weather Statement | PHI | Chester | 25 min |
| Jun 8, 4:25 PM EDT | River Flood Warning | PHI | Chester | 11 hr |
| Jun 8, 7:14 PM EDT | River Flood Warning | PHI | Chester, Delaware | 18 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.