Alert archive / Pennsylvania / Flash Flood Warnings in 2021
Flash Flood Warning 20, NWS State College, PA
NWS State College, PA issued this flash flood warning at Aug 22, 2021, 2:35 PM EDT for Lancaster County, Pennsylvania. It was in force for 2 hr. 5 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 22, 2021, 2:35 PM EDT (18:35 UTC)
- Expired
- Aug 22, 2021, 4:45 PM EDT
- In force
- 2 hr
- Issued by
- NWS State College, PA
- Area
- Storm-based polygon
- Damage threat
- Considerable
- Flood severity
- None
County Lancaster County, PA
The radar
The Philadelphia radar (KDIX), 146 km from the middle of the area, began a volume at 18:38 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 22, 3:13 PM EDT | FLASH FLOOD | 1 Ene New Holland, PA | STREET/ROAD FLOODING; STREET/ROAD CLOSED; VEHICLES STRANDED; ROADWAY IMPASSABLE. |
| Aug 22, 4:00 PM EDT | FLASH FLOOD | 2 Wsw Terre Hill, PA | FLASH FLOODING ON GRISTMILL RD. ROADWAY IMPASSABLE. |
| Aug 22, 4:00 PM EDT | FLASH FLOOD | 3 Nnw New Holland, PA | FLASH FLOODING ON GRISTMILL RD. ROADWAY IMPASSABLE. |
| Aug 22, 4:04 PM EDT | FLASH FLOOD | 2 Nnw New Holland, PA | STREET/ROAD FLOODING; STREET/ROAD CLOSED; ROADWAY IMPASSABLE. |
| Aug 22, 4:22 PM EDT | FLASH FLOOD | 3 Nnw New Holland, PA | STREET/ROAD FLOODING; STREET/ROAD CLOSED; ROADWAY IMPASSABLE. |
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, 6.6 hours before the alert went out and 170 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
- 870 J/kg
- Mixed-layer CIN
- -80 J/kg
- Mixed-layer LCL
- 1065 m above ground
- 0-6 km bulk shear
- 5 kt
- 0-1 km storm-relative helicity
- -21 m²/s²
- 0-3 km storm-relative helicity
- -39 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
809
WGUS51 KCTP 221835
FFWCTP
PAC071-222045-
/O.NEW.KCTP.FF.W.0020.210822T1835Z-210822T2045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service State College PA
235 PM EDT Sun Aug 22 2021
The National Weather Service in State College has issued a
* Flash Flood Warning for...
Northeastern Lancaster County in south central Pennsylvania...
* Until 445 PM EDT.
* At 235 PM EDT, Doppler radar and automated rain gauges indicated
thunderstorms producing heavy rain across the warned area. Between
1 and 3 inches of rain have fallen. Flash flooding is ongoing or
expected to begin shortly.
HAZARD...Life threatening flash flooding. Thunderstorms
producing flash flooding.
SOURCE...Radar and automated gauges.
IMPACT...Life threatening flash flooding of creeks and streams,
urban areas, highways, streets and underpasses.
* Some locations that will experience flash flooding include...
Ephrata, New Holland, Akron, Leola, Terre Hill, Churchtown,
Bareville, Intercourse, Blue Ball, Farmersville, Goodville and
White Horse.
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 4019 7621 4015 7596 4001 7600 4005 7620
FLASH FLOOD...RADAR AND GAUGE INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
$$
CRThe office that day
Everything else NWS State College, PA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 22, 12:26 AM EDT | Areal Flood Advisory | CTP | Lancaster | 2 hr |
| Aug 22, 5:01 AM EDT | Flood Watch | CTP | Lancaster, Lebanon, Schuylkill | 24 hr |
| Aug 22, 5:47 AM EDT | Areal Flood Advisory | CTP | Dauphin, Lancaster, Lebanon | 118 min |
| Aug 22, 8:55 AM EDT | Areal Flood Advisory | CTP | Lancaster | 2 hr |
| Aug 22, 10:19 AM EDT | Areal Flood Advisory | CTP | Lancaster, York | 2 hr |
| Aug 22, 2:11 PM EDT | Areal Flood Advisory | CTP | Lancaster | 2 hr |
| Aug 22, 2:18 PM EDT | Areal Flood Advisory | CTP | York | 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.