Alert archive / Pennsylvania / Flash Flood Watches in 2020
Flash Flood Watch 9, NWS State College, PA
NWS State College, PA issued this flash flood watch at Aug 12, 2020, 3:09 AM EDT for Lancaster County, York County, Pennsylvania. It took effect at Aug 12, 2020, 12:00 PM EDT. It was in force for 7 hr.
The area
The counties it named.
The facts
- Issued
- Aug 12, 2020, 3:09 AM EDT (07:09 UTC)
- In effect from
- Aug 12, 2020, 12:00 PM EDT
- Expired
- Aug 12, 2020, 7:05 PM EDT
- In force
- 7 hr
- Issued by
- NWS State College, PA
- Flood severity
- None
Counties Lancaster County, PA, York County, PA
The radar
The Sterling radar (KLWX), 141 km from the middle of the area, began a volume at 07:11 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.
The nearest sounding before it
Washington/Dulle, VA (KIAD), launched 00:00Z, 7.2 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
- 1124 J/kg
- Mixed-layer CIN
- -15 J/kg
- Mixed-layer LCL
- 1414 m above ground
- 0-6 km bulk shear
- 14 kt
- 0-1 km storm-relative helicity
- 24 m²/s²
- 0-3 km storm-relative helicity
- 88 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
What forecasters said that day
The local office's own words before this flash flood watch went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS State College, PA wrote its last area forecast discussion before this flash flood watch went out at Aug 12, 2:54 AM EDT, 15 minutes earlier.
Area forecast discussion, Aug 12, 2:54 AM EDT, 15 minutes before
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</html>Hazardous weather outlook, Aug 11, 4:12 AM EDT, 22 hours 57 minutes before
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</html>The office that day
Everything else NWS State College, PA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 12, 3:42 PM EDT | Areal Flood Advisory | CTP | Lancaster, York | 3 hr |
| Aug 12, 4:15 PM EDT | Flash Flood Warning | CTP | Lancaster, York | 2 hr |
Nearby
Flash Flood Watches in Pennsylvania, 2020Every flash flood watch in 2020
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.