Alert archive / Pennsylvania / Flash Flood Warnings in 2021
Flash Flood Warning 18, NWS State College, PA
NWS State College, PA issued this flash flood warning at Aug 18, 2021, 7:40 PM EDT for Dauphin County, Lancaster County, York County, Pennsylvania. It was in force for 3 hr. 2 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
- Aug 18, 2021, 7:40 PM EDT (23:40 UTC)
- Expired
- Aug 18, 2021, 10:34 PM EDT
- In force
- 3 hr
- Issued by
- NWS State College, PA
- Area
- Storm-based polygon
- Flood severity
- None
Counties Dauphin County, PA, Lancaster County, PA, York County, PA
The radar
The State College radar (KCCX), 136 km from the middle of the area, began a volume at 23:39 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 18, 8:00 PM EDT | FLASH FLOOD | York, PA | NUMEROUS SUBMERGED CARS WITH RESCUES AROUND YORK. |
| Aug 18, 9:41 PM EDT | FLOOD | 3 Se Landisville, PA | BASEMENT WALL COLLAPSE. |
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, 11.7 hours before the alert went out and 139 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
- 1011 J/kg
- Mixed-layer CIN
- -1 J/kg
- Mixed-layer LCL
- 592 m above ground
- 0-6 km bulk shear
- 30 kt
- 0-1 km storm-relative helicity
- 151 m²/s²
- 0-3 km storm-relative helicity
- 175 m²/s²
- Significant tornado parameter
- 0.6
- Supercell composite
- 4.6
The text
As transmitted.
807
WGUS51 KCTP 182340
FFWCTP
PAC043-071-133-190245-
/O.NEW.KCTP.FF.W.0018.210818T2340Z-210819T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service State College PA
740 PM EDT Wed Aug 18 2021
The National Weather Service in State College has issued a
* Flash Flood Warning for...
Southeastern Dauphin County in south central Pennsylvania...
Western Lancaster County in south central Pennsylvania...
York County in south central Pennsylvania...
* Until 1045 PM EDT.
* At 740 PM EDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. Between 1 and 3 inches of rain
have fallen. Additional rainfall amounts up to 2 inches are
possible in the warned area. Flash flooding is ongoing or expected
to begin shortly.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Radar.
IMPACT...Flash flooding of small creeks and streams, urban
areas, highways, streets and underpasses as well as
other poor drainage and low-lying areas.
* Some locations that will experience flash flooding include...
Lancaster, York, Weigelstown, Elizabethtown, Columbia, Middletown,
Millersville, Mount Joy, Parkville, Red Lion, Steelton, Spry,
Manheim, East Petersburg, Dallastown, Shiloh, East York,
Stonybrook-Wilshire, West York and Salunga-Landisville.
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 4016 7694 4016 7693 4017 7691 4018 7692
4019 7693 4018 7691 4019 7691 4020 7692
4020 7693 4021 7692 4021 7662 4020 7657
4020 7656 4018 7633 3972 7638 3972 7675
3977 7696
FLASH FLOOD...RADAR INDICATED
$$
CR3 follow-up statements
325
WGUS71 KCTP 190043
FFSCTP
Flash Flood Statement
National Weather Service State College PA
843 PM EDT Wed Aug 18 2021
PAC043-071-133-190245-
/O.CON.KCTP.FF.W.0018.000000T0000Z-210819T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Dauphin PA-Lancaster PA-York PA-
843 PM EDT Wed Aug 18 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1045 PM EDT THIS
EVENING FOR SOUTHEASTERN DAUPHIN, WESTERN LANCASTER AND YORK
COUNTIES...
At 843 PM EDT, Doppler radar indicated thunderstorms producing heavy
rain across the warned area. Flash flooding has been reported across
the area with water rescues occurring. Additional rainfall amounts
up to 1 inch are possible in the warned area.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Radar.
IMPACT...Flash flooding of small creeks and streams, urban areas,
highways, streets and underpasses as well as other poor
drainage and low-lying areas.
Some locations that will experience flash flooding include...
Lancaster, York, Weigelstown, Elizabethtown, Columbia, Middletown,
Millersville, Mount Joy, Parkville, Red Lion, Steelton, Spry,
Manheim, East Petersburg, Dallastown, Shiloh, East York,
Stonybrook-Wilshire, West York and Salunga-Landisville.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Be especially cautious at night when it is harder to recognize the
dangers of flooding.
&&
LAT...LON 4016 7694 4016 7693 4017 7691 4018 7692
4019 7693 4018 7691 4019 7691 4020 7692
4020 7693 4021 7692 4021 7662 4020 7657
4020 7656 4018 7633 3972 7638 3972 7675
3977 7696
FLASH FLOOD...RADAR INDICATED
$$
CR150
WGUS71 KCTP 190213
FFSCTP
Flash Flood Statement
National Weather Service State College PA
1013 PM EDT Wed Aug 18 2021
PAC043-190223-
/O.CAN.KCTP.FF.W.0018.000000T0000Z-210819T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Dauphin PA-
1013 PM EDT Wed Aug 18 2021
...FLASH FLOOD WARNING IS CANCELLED FOR SOUTHEASTERN DAUPHIN
COUNTY...
Flooding is no longer expected to pose a threat. Please continue to
heed remaining road closures.
A Flash Flood Watch remains in effect until 200 AM EDT for a portion
of central Pennsylvania.
LAT...LON 4006 7663 4014 7643 4016 7641 4018 7640
4018 7633 3972 7638 3972 7675 3973 7679
3984 7678 3994 7679 3997 7679 3998 7677
4001 7675 4003 7671 4004 7668
$$
PAC071-133-190245-
/O.CON.KCTP.FF.W.0018.000000T0000Z-210819T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Lancaster PA-York PA-
1013 PM EDT Wed Aug 18 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1045 PM EDT THIS
EVENING FOR SOUTHWESTERN LANCASTER AND SOUTHEASTERN YORK COUNTIES...
At 1013 PM EDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. Between 1 and 3 inches of rain
have fallen. Additional rainfall amounts up to 1 inch are possible
in the warned area. Flash flooding is ongoing or expected to begin
shortly.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Radar.
IMPACT...Flash flooding of small creeks and streams, urban areas,
highways, streets and underpasses as well as other poor
drainage and low-lying areas.
Some locations that will experience flash flooding include...
Lancaster, York, Columbia, Millersville, Mount Joy, Red Lion,
Spry, Manheim, East Petersburg, Dallastown, Shiloh, East York,
Stonybrook-Wilshire, West York, Salunga-Landisville, Maytown,
Shrewsbury, Grantley, Tyler Run-Queens Gate and Valley View.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Be especially cautious at night when it is harder to recognize the
dangers of flooding.
&&
LAT...LON 4006 7663 4014 7643 4016 7641 4018 7640
4018 7633 3972 7638 3972 7675 3973 7679
3984 7678 3994 7679 3997 7679 3998 7677
4001 7675 4003 7671 4004 7668
FLASH FLOOD...RADAR INDICATED
$$
CR461
WGUS71 KCTP 190234
FFSCTP
Flash Flood Statement
National Weather Service State College PA
1034 PM EDT Wed Aug 18 2021
PAC071-133-190244-
/O.CAN.KCTP.FF.W.0018.000000T0000Z-210819T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Lancaster PA-York PA-
1034 PM EDT Wed Aug 18 2021
...FLASH FLOOD WARNING FOR SOUTHWESTERN LANCASTER AND SOUTHEASTERN
YORK COUNTIES HAS BEEN REPLACED WITH A FLOOD WARNING...
LAT...LON 4006 7663 4014 7643 4016 7641 4018 7640
4018 7633 3972 7638 3972 7675 3973 7679
3984 7678 3994 7679 3997 7679 3998 7677
4001 7675 4003 7671 4004 7668
$$
CRThe office that day
Everything else NWS State College, PA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 18, 9:50 AM EDT | Special Weather Statement | CTP | Bedford | 55 min |
| Aug 18, 10:25 AM EDT | Areal Flood Advisory | CTP | Bedford | 3 hr |
| Aug 18, 10:32 AM EDT | Severe Thunderstorm Warning | CTP | Bedford, Blair | 43 min |
| Aug 18, 10:53 AM EDT | Special Weather Statement | CTP | Cambria | 37 min |
| Aug 18, 10:57 AM EDT | Special Weather Statement | CTP | Bedford | 18 min |
| Aug 18, 11:15 AM EDT | Special Weather Statement | CTP | Blair, Cambria | 30 min |
| Aug 18, 11:33 AM EDT | Areal Flood Advisory | CTP | Blair, Cambria | 3 hr |
| Aug 18, 12:04 PM EDT | Areal Flood Advisory | CTP | Bedford | 2 hr |
| Aug 18, 12:11 PM EDT | Special Weather Statement | CTP | Blair | 34 min |
| Aug 18, 12:26 PM EDT | Special Weather Statement | CTP | Schuylkill | 34 min |
| Aug 18, 12:35 PM EDT | Flash Flood Warning | CTP | Bedford, Blair, Huntingdon | 3 hr |
| Aug 18, 12:39 PM EDT | Special Weather Statement | CTP | Cumberland | 36 min |
| Aug 18, 12:54 PM EDT | Severe Thunderstorm Warning | CTP | Cumberland, Perry | 36 min |
| Aug 18, 1:01 PM EDT | Special Weather Statement | CTP | Huntingdon | 44 min |
| Aug 18, 1:15 PM EDT | Special Weather Statement | CTP | Juniata, Mifflin | 30 min |
| Aug 18, 1:31 PM EDT | Severe Thunderstorm Warning | CTP | Juniata, Perry | 44 min |
| Aug 18, 1:37 PM EDT | Flash Flood Warning | CTP | Blair, Centre, Huntingdon | 82 min |
| Aug 18, 2:00 PM EDT | Special Weather Statement | CTP | Snyder | 30 min |
| Aug 18, 2:02 PM EDT | Tornado Warning | CTP | Centre, Huntingdon | 28 min |
| Aug 18, 2:12 PM EDT | Severe Thunderstorm Warning | CTP | Centre, Clinton | 33 min |
| Aug 18, 2:26 PM EDT | Special Weather Statement | CTP | Cumberland, Perry | 34 min |
| Aug 18, 2:29 PM EDT | Special Weather Statement | CTP | Centre | 31 min |
| Aug 18, 2:36 PM EDT | Severe Thunderstorm Warning | CTP | Cumberland, Perry | 39 min |
| Aug 18, 3:03 PM EDT | Special Weather Statement | CTP | Cumberland | 42 min |
| Aug 18, 3:10 PM EDT | Tornado Warning | CTP | Adams, York | 40 min |
| Aug 18, 3:17 PM EDT | Areal Flood Warning | CTP | Bedford, Blair, Huntingdon | 118 min |
| Aug 18, 3:36 PM EDT | Severe Thunderstorm Warning | CTP | Cumberland, Dauphin, Lancaster, York | 24 min |
| Aug 18, 3:56 PM EDT | Severe Thunderstorm Warning | CTP | Dauphin, Juniata, Northumberland, Perry, Snyder | 34 min |
| Aug 18, 4:03 PM EDT | Special Weather Statement | CTP | Dauphin | 42 min |
| Aug 18, 4:05 PM EDT | Severe Thunderstorm Warning | CTP | Franklin, Fulton | 40 min |
| Aug 18, 4:30 PM EDT | Areal Flood Advisory | CTP | Juniata, Perry, Snyder | 4 hr |
| Aug 18, 4:30 PM EDT | Special Weather Statement | CTP | Snyder | 30 min |
| Aug 18, 4:39 PM EDT | Severe Thunderstorm Warning | CTP | Franklin | 36 min |
| Aug 18, 4:42 PM EDT | Areal Flood Advisory | CTP | Fulton, Huntingdon | 2 hr |
| Aug 18, 4:48 PM EDT | Areal Flood Advisory | CTP | Cameron, Clinton, Lycoming, Potter, Tioga | 5 hr |
| Aug 18, 5:10 PM EDT | Severe Thunderstorm Warning | CTP | Adams, Cumberland, Franklin, Perry, York | 35 min |
| Aug 18, 5:18 PM EDT | Severe Thunderstorm Warning | CTP | Juniata, Mifflin | 45 min |
| Aug 18, 5:31 PM EDT | Severe Thunderstorm Warning | CTP | Dauphin | 74 min |
| Aug 18, 5:35 PM EDT | Special Weather Statement | CTP | Lancaster | 25 min |
| Aug 18, 5:35 PM EDT | Severe Thunderstorm Warning | CTP | Adams | 40 min |
| Aug 18, 5:38 PM EDT | Severe Thunderstorm Warning | CTP | Adams, Cumberland, York | 37 min |
| Aug 18, 6:13 PM EDT | Severe Thunderstorm Warning | CTP | Adams, Cumberland, Dauphin, Lancaster, Perry, York | 47 min |
| Aug 18, 6:37 PM EDT | Areal Flood Advisory | CTP | Adams, Cumberland, Franklin, York | 2 hr |
| Aug 18, 6:47 PM EDT | Severe Thunderstorm Warning | CTP | Adams, Dauphin, Lancaster, Lebanon, Schuylkill, York | 43 min |
| Aug 18, 6:56 PM EDT | Special Weather Statement | CTP | Schuylkill | 19 min |
| Aug 18, 7:23 PM EDT | Areal Flood Advisory | CTP | Columbia, Sullivan | 2 hr |
| Aug 18, 7:30 PM EDT | Severe Thunderstorm Warning | CTP | Lancaster, York | 45 min |
| Aug 18, 7:37 PM EDT | Flash Flood Warning | CTP | Schuylkill | 2 hr |
Nearby
Flash Flood Warnings in Pennsylvania, 2021Every flash 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.