Alert archive / Pennsylvania / Flash Flood Warnings in 2018
Flash Flood Warning 37, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 22, 2018, 8:43 PM EDT for Chester County, Pennsylvania. It was in force for 4 hr. 8 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
- Jul 22, 2018, 8:43 PM EDT (00:43 UTC)
- Expired
- Jul 23, 2018, 12:45 AM EDT
- In force
- 4 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Flood severity
- None
County Chester County, PA
The radar
The Philadelphia radar (KDIX), 128 km from the middle of the area, began a volume at 00:43 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 |
|---|---|---|---|
| Jul 22, 8:47 PM EDT | FLASH FLOOD | Upper Oxford Twp, PA | WATER RESCUE OF A PERSON IN A VEHICLE IN HIGH WATER. |
| Jul 22, 9:00 PM EDT | HEAVY RAIN 3.53 | West Grove, PA | |
| Jul 22, 9:10 PM EDT | FLASH FLOOD | 1 Ene Coatesville, PA | OCCUPIED VEHICLE IN HIGH WATER AT FOUNDRY STREET AND 11TH AVENUE IN CALN TOWNSHIP. FIRE DEPARTMENT ON SCENE TO CONDUCT A WATER RESCUE. |
| Jul 22, 9:18 PM EDT | FLASH FLOOD | West Grove, PA | NUMEROUS ROADS ARE CLOSED DUE TO FLASH FLOODING IN WESTERN CHESTER COUNTY. THERE WERE 27 VEHICLE RESCUES SUCCESSFULLY CONDUCTED AND NO INJURIES WERE REPORTED. |
| Jul 22, 9:20 PM EDT | FLASH FLOOD | Caln, PA | WATER RESCUE AT LINCOLN HIGHWAY AND NORTH CALN ROAD. |
| Jul 22, 9:30 PM EDT | HEAVY RAIN 3.22 | Glenmoore, PA | |
| Jul 22, 10:30 PM EDT | HEAVY RAIN 2.1 | Atglen, PA | |
| Jul 22, 10:30 PM EDT | HEAVY RAIN 3.36 | Glenmoore, PA |
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, 0.7 hours before the alert went out and 168 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
- 1533 J/kg
- Mixed-layer CIN
- -2 J/kg
- Mixed-layer LCL
- 664 m above ground
- 0-6 km bulk shear
- 40 kt
- 0-1 km storm-relative helicity
- 83 m²/s²
- 0-3 km storm-relative helicity
- 147 m²/s²
- Significant tornado parameter
- 0.8
- Supercell composite
- 5.5
The text
As transmitted.
371
WGUS51 KPHI 230043
FFWPHI
PAC029-230445-
/O.NEW.KPHI.FF.W.0037.180723T0043Z-180723T0445Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
843 PM EDT SUN JUL 22 2018
The National Weather Service in Mount Holly NJ has issued a
* Flash Flood Warning for...
Western Chester County in southeastern Pennsylvania...
* Until 1245 AM EDT.
* At 841 PM EDT, county officials reported flash flooding across the
warned area, especially in West Marlborough Township. Up to two
inches of rain have already fallen, which is on top of the 1 to 2
inches that fell earlier. Flash flooding is already occurring in
areas of heaviest rain.
* Some locations that could experience flooding include...
Coatesville, Oxford, Parkesburg, West Grove, Honey Brook,
Homeville, Cochranville, Glenmoore, Ladenberg, Kemblesville, North
Star, Atglen, South Coatesville, Avondale, Christiana, Modena,
Thorndale and Toughkenamon.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around...don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
A Flash Flood Warning means that flooding is imminent or occurring.
If you are in the warned area move to higher ground immediately.
Residents living along streams and creeks should take immediate
precautions to protect life and property.
&&
LAT...LON 3989 7599 3992 7600 3994 7598 3995 7600
4004 7593 4011 7594 4014 7587 4013 7574
3977 7574 3972 7577 3972 7599
$$
Gorse2 follow-up statements
511
WGUS71 KPHI 230129
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
929 PM EDT SUN JUL 22 2018
PAC029-230445-
/O.CON.KPHI.FF.W.0037.000000T0000Z-180723T0445Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Chester PA-
929 PM EDT SUN JUL 22 2018
...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1245 AM EDT FOR
WESTERN CHESTER COUNTY...
At 915 PM EDT, fire department officials reported flash flooding and
a water rescue occurring in Caln Township. Mesonet sites indicate
between 3 and 4 inches of rain has fallen. While the heaviest rain
is now moving north of much of the warned area, excessive runoff
will continue and some additional showers are developing from the
south.
Some locations that could experience flooding include...
Coatesville, Oxford, Parkesburg, West Grove, Honey Brook, Homeville,
Cochranville, Glenmoore, Ladenberg, Kemblesville, North Star, Atglen,
South Coatesville, Avondale, Christiana, Modena, Thorndale and
Toughkenamon.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around...don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Be especially cautious at night when it is harder to recognize the
dangers of flooding.
&&
LAT...LON 3989 7599 3992 7600 3994 7598 3995 7600
4004 7593 4011 7594 4014 7587 4013 7574
3977 7574 3972 7577 3972 7599
$$
Gorse830
WGUS71 KPHI 230441
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
1241 AM EDT MON JUL 23 2018
PAC029-230450-
/O.EXP.KPHI.FF.W.0037.000000T0000Z-180723T0445Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Chester PA-
1241 AM EDT MON JUL 23 2018
...THE FLASH FLOOD WARNING FOR WESTERN CHESTER COUNTY WILL EXPIRE AT
1245 AM EDT...
The heavy rain has ended. Scattered showers will occur the rest of
the night. Water in running high in the West Branch of Brandywine
Creek, but the levels are now trending down. Please continue to heed
any remaining road closures.
LAT...LON 3989 7599 3992 7600 3994 7598 3995 7600
4004 7593 4011 7594 4014 7587 4013 7574
3977 7574 3972 7577 3972 7599
$$
POThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 22, 8:18 PM EDT | Areal Flood Warning | PHI | Chester | 117 min |
| Jul 22, 8:54 PM EDT | Flash Flood Warning | PHI | Berks, Chester | 4 hr |
| Jul 22, 9:40 PM EDT | Flash Flood Warning | PHI | Lehigh | 3 hr |
| Jul 22, 10:21 PM EDT | Special Weather Statement | PHI | Monroe | 54 min |
| Jul 22, 11:18 PM EDT | Areal Flood Advisory | PHI | Carbon, Monroe, Northampton | 3 hr |
| Jul 23, 12:19 AM EDT | River Flood Warning | PHI | Chester | 5 hr |
| Jul 23, 3:45 AM EDT | Flash Flood Watch | PHI | Berks, Bucks, Carbon, Chester, Delaware, Lehigh and 4 more | 68 hr |
| Jul 23, 7:00 AM EDT | River Flood Warning | PHI | Chester, Delaware | 9 hr |
| Jul 23, 12:58 PM EDT | Special Weather Statement | PHI | Chester | 32 min |
| Jul 23, 1:01 PM EDT | Areal Flood Advisory | PHI | Chester | 34 min |
Nearby
Flash Flood Warnings in Pennsylvania, 2018Every flash flood warning in 2018
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.