Alert archive / Pennsylvania / Flash Flood Warnings in 2021

Flash Flood Warning 24, NWS State College, PA

September 1, 20219 counties in Pennsylvania

NWS State College, PA issued this flash flood warning at Sep 1, 2021, 8:54 AM EDT for 9 counties in Pennsylvania. It was in force for 8 hr. 3 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, 8:54 AM EDT (12:54 UTC)
Expired
Sep 1, 2021, 4:40 PM EDT
In force
8 hr
Issued by
NWS State College, PA
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

Counties Bedford County, PA, Blair County, PA, Cambria County, PA, Centre County, PA, Clearfield County, PA, Fulton County, PA, Huntingdon County, PA, Mifflin County, PA, Somerset County, PA

The radar

The State College radar (KCCX), 58 km from the middle of the area, began a volume at 12:54 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, 9:54 AM EDTHEAVY RAIN 1.581 E State College, PA
Sep 1, 1:00 PM EDTFLASH FLOOD1 Se Bedford, PAFLOODING REPORTED ACROSS ROADWAYS.
Sep 1, 2:28 PM EDTFLASH FLOOD1 Ene Boalsburg, PAFLASH FLOODING. CREEKS OVERFLOWING.

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, 0.9 hours before the alert went out and 153 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.

878 
WGUS51 KCTP 011254
FFWCTP
PAC009-013-021-027-033-057-061-087-111-011900-
/O.NEW.KCTP.FF.W.0024.210901T1254Z-210901T1900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in State College has issued a

* Flash Flood Warning for...
  Blair County in central Pennsylvania...
  Eastern Cambria County in central Pennsylvania...
  Southwestern Centre County in central Pennsylvania...
  South Central Clearfield County in central Pennsylvania...
  Huntingdon County in central Pennsylvania...
  Southwestern Mifflin County in central Pennsylvania...
  Bedford County in south central Pennsylvania...
  Fulton County in south central Pennsylvania...
  Northeastern Somerset County in south central Pennsylvania...

* Until 300 PM EDT Wednesday.

* At 854 AM EDT, Doppler radar and automated rain gauges indicated 
  heavy rain falling 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. Heavy rain 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...
  Altoona, State College, Huntingdon, Hollidaysburg, Tyrone, 
  Bedford, Portage, Breezewood, Park Forest Village, Boalsburg, 
  Pleasant Gap, Roaring Spring, Mount Union, Stormstown, Lemont, 
  Clearville, Bald Eagle, New Enterprise, Martinsburg and Lakemont.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

&&

LAT...LON 4035 7872 4070 7846 4086 7840 4090 7791
      4085 7767 4024 7780 3986 7798 3994 7893

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

$$

CR
2 follow-up statements
025 
WGUS51 KCTP 011814
FFWCTP
PAC009-013-021-027-033-057-061-087-111-012100-
/O.EXT.KCTP.FF.W.0024.000000T0000Z-210901T2100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in State College has extended the

* Flash Flood Warning for...
  Blair County in central Pennsylvania...
  Eastern Cambria County in central Pennsylvania...
  Southwestern Centre County in central Pennsylvania...
  South Central Clearfield County in central Pennsylvania...
  Huntingdon County in central Pennsylvania...
  Southwestern Mifflin County in central Pennsylvania...
  Bedford County in south central Pennsylvania...
  Fulton County in south central Pennsylvania...
  Northeastern Somerset County in south central Pennsylvania...

* Until 500 PM EDT.

* At 214 PM EDT, Doppler radar and automated rain gauges indicated 
  heavy rain falling across the warned area. Between 2 and 4 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. Heavy rain 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...
  Altoona, State College, Huntingdon, Hollidaysburg, Tyrone, 
  Bedford, Portage, Breezewood, Park Forest Village, Boalsburg, 
  Pleasant Gap, Roaring Spring, Mount Union, Stormstown, Lemont, 
  Clearville, Bald Eagle, New Enterprise, Martinsburg and Lakemont.

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 4035 7872 4070 7846 4086 7840 4090 7791
      4085 7767 4024 7780 3986 7798 3994 7893

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

$$

CR
688 
WGUS71 KCTP 012040
FFSCTP

Flash Flood Statement
National Weather Service State College PA
440 PM EDT Wed Sep 1 2021

PAC009-013-021-027-033-057-061-087-111-012050-
/O.CAN.KCTP.FF.W.0024.000000T0000Z-210901T2100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Bedford PA-Blair PA-Cambria PA-Centre PA-Clearfield PA-Fulton PA-
Huntingdon PA-Mifflin PA-Somerset PA-
440 PM EDT Wed Sep 1 2021

...FLASH FLOOD WARNING FOR BLAIR, EASTERN CAMBRIA, SOUTHWESTERN 
CENTRE, SOUTH CENTRAL CLEARFIELD, HUNTINGDON, SOUTHWESTERN MIFFLIN, 
BEDFORD, FULTON AND NORTHEASTERN SOMERSET COUNTIES HAS BEEN REPLACED 
WITH A FLOOD WARNING...

Flooding continues in portions of the warned area. Between 3 and 6 
inches of rain has fallen. Up to an additional inch of rain is 
possible.

LAT...LON 4035 7872 4070 7846 4086 7840 4090 7791
      4085 7767 4024 7780 3986 7798 3994 7893

$$

Colbert

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 1, 9:37 AM EDTFlash Flood Warning Considerable damage threatCTPCambria, Clearfield, Somerset6 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.