Alert archive / Pennsylvania / Flash Flood Warnings in 2021

Flash Flood Warning 25, NWS State College, PA

September 1, 2021Cambria County, Clearfield County, Somerset County, Pennsylvania

NWS State College, PA issued this flash flood warning at Sep 1, 2021, 9:37 AM EDT for Cambria County, Clearfield County, Somerset County, Pennsylvania. It was in force for 6 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
Sep 1, 2021, 9:37 AM EDT (13:37 UTC)
Expired
Sep 1, 2021, 3:30 PM EDT
In force
6 hr
Issued by
NWS State College, PA
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

Counties Cambria County, PA, Clearfield County, PA, Somerset County, PA

The radar

The Pittsburgh radar (KPBZ), 103 km from the middle of the area, began a volume at 13:40 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

TimeReportWhereRemark
Sep 1, 12:28 PM EDTFLASH FLOOD1 N Somerset, PAFLOODED ROADWAY.
Sep 1, 1:04 PM EDTFLASH FLOOD2 Wsw Acosta, PAFLOODED ROADWAY.
Sep 1, 1:54 PM EDTFLASH FLOOD3 Ssw Stoystown, PAFLOODED ROAD.
Sep 1, 2:04 PM EDTFLASH FLOOD2 Ene Salisbury, PALANDSLIDE.
Sep 1, 3:38 PM EDTFLASH FLOOD1 Ene Meyersdale, PAFLOODED ROAD.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Pittsburgh, PA (KPIT), launched 12:00Z, 1.6 hours before the alert went out and 88 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.

Skew-T log-pSkew-T log-p diagram, Pittsburgh, PA at 12:00Z on 2021-09-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Pittsburgh, PA at 12:00Z on 2021-09-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -93 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
666 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
-93 m²/s²
0-3 km storm-relative helicity
-7 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

961 
WGUS51 KCTP 011337
FFWCTP
PAC021-033-111-011930-
/O.NEW.KCTP.FF.W.0025.210901T1337Z-210901T1930Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service State College PA
937 AM EDT Wed Sep 1 2021

The National Weather Service in State College has issued a

* Flash Flood Warning for...
  Cambria County in central Pennsylvania...
  Southwestern Clearfield County in central Pennsylvania...
  Somerset County in south central Pennsylvania...

* Until 330 PM EDT.

* At 937 AM 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. Additional rainfall amounts of 
  1 to 3 inches are possible in the warned area. 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...
  Johnstown, Somerset, Westmont, Windber, Ebensburg, Belmont, 
  Nanty-Glo, Portage, Northern Cambria, Curwensville, Geistown, 
  Southmont, Meyersdale, Berlin, Patton, Friedens, Vinco, Loretto, 
  Hastings and Boswell.

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 4034 7901 4072 7880 4102 7880 4096 7833
      3985 7897 3972 7901 3972 7939 3973 7941
      3977 7938 3978 7939 3979 7935 3979 7937
      3982 7937 3985 7942 3990 7940 4009 7926
      4012 7921 4012 7918 4016 7916 4016 7914

FLASH FLOOD...RADAR AND GAUGE INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

CR

The office that day

Everything else NWS State College, PA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 1, 8:54 AM EDTFlash Flood Warning Considerable damage threatCTPBedford, Blair, Cambria, Centre, Clearfield, Fulton and 3 more8 hr
Sep 1, 9:45 AM EDTAreal Flood AdvisoryCTPAdams, Columbia, Cumberland, Dauphin, Franklin, Juniata and 10 more2 hr
Sep 1, 11:04 AM EDTRiver Flood WarningCTPSnyder, Union17 hr
Sep 1, 11:04 AM EDTRiver Flood WarningCTPCambria17 hr
Sep 1, 11:04 AM EDTRiver Flood WarningCTPHuntingdon23 hr
Sep 1, 11:04 AM EDTRiver Flood WarningCTPJuniata, Mifflin20 hr
Sep 1, 11:04 AM EDTRiver Flood WarningCTPBedford, Huntingdon30 hr
Sep 1, 11:04 AM EDTRiver Flood WarningCTPDauphin55 hr
Sep 1, 12:04 PM EDTFlash Flood Warning Considerable damage threatCTPAdams, Columbia, Cumberland, Dauphin, Franklin, Juniata and 10 more6 hr
Sep 1, 1:09 PM EDTFlash Flood Warning EmergencyCatastrophic damage threatCTPCambria5 hr
Sep 1, 2:07 PM EDTSevere Thunderstorm WarningCTPAdams53 min
Sep 1, 2:28 PM EDTSevere Thunderstorm WarningCTPYork77 min
Sep 1, 3:05 PM EDTTornado WarningCTPYork23 min
Sep 1, 3:25 PM EDTSevere Thunderstorm WarningCTPLancaster, York35 min
Sep 1, 3:34 PM EDTAreal Flood WarningCTPCambria, Clearfield, Somerset6 hr
Sep 1, 4:21 PM EDTSevere Thunderstorm WarningCTPLancaster39 min
Sep 1, 4:24 PM EDTFlash Flood Warning EmergencyCatastrophic damage threatCTPAdams, York4 hr
Sep 1, 4:40 PM EDTAreal Flood WarningCTPBedford, Blair, Cambria, Centre, Clearfield, Franklin and 4 more6 hr
Sep 1, 5:41 PM EDTAreal Flood WarningCTPAdams, Centre, Columbia, Cumberland, Dauphin, Franklin and 15 more14 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.