Alert archive / Pennsylvania / Flash Flood Warnings in 2021

Flash Flood Warning 2, NWS State College, PA

July 11, 20214 counties in Pennsylvania

NWS State College, PA issued this flash flood warning at Jul 11, 2021, 10:06 PM EDT for 4 counties in Pennsylvania. It was in force for 118 min. 1 report 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
Jul 11, 2021, 10:06 PM EDT (02:06 UTC)
Expired
Jul 12, 2021, 12:04 AM EDT
In force
118 min
Issued by
NWS State College, PA
Area
Storm-based polygon
Flood severity
None

Counties Cumberland County, PA, Dauphin County, PA, Lebanon County, PA, York County, PA

The radar

The State College radar (KCCX), 123 km from the middle of the area, began a volume at 02:09 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
Jul 11, 10:15 PM EDTFLASH FLOOD2 Sse Harrisburg, PASEVERAL CARS STRANDED IN WATER ON CAMERON STREET.

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 00:00Z, 2.1 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, Washington/Dulle, VA at 00:00Z on 2021-07-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 811 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 00:00Z on 2021-07-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 25 square meters per square second.1939Sfc1 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
811 J/kg
Mixed-layer CIN
-23 J/kg
Mixed-layer LCL
1342 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
25 m²/s²
0-3 km storm-relative helicity
57 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

401 
WGUS51 KCTP 120206
FFWCTP
PAC041-043-075-133-120415-
/O.NEW.KCTP.FF.W.0002.210712T0206Z-210712T0415Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service State College PA
1006 PM EDT Sun Jul 11 2021

The National Weather Service in State College has issued a

* Flash Flood Warning for...
  Northeastern Cumberland County in south central Pennsylvania...
  Southern Dauphin County in south central Pennsylvania...
  West Central Lebanon County in south central Pennsylvania...
  Northwestern York County in south central Pennsylvania...

* Until 1215 AM EDT.

* At 1006 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Flash flooding is ongoing or 
  expected to begin shortly. Up to 2 inches of rain has fallen in 
  the warned area over the past 90 minutes and an additional 1 inch 
  of rain is expected between 10 and 11 pm.

  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...
  Harrisburg, Lower Allen, Hershey, Colonial Park, Progress, 
  Mechanicsburg, Middletown, Camp Hill, Palmyra, New Cumberland, 
  Linglestown, Enola, Steelton, Lemoyne, Hummelstown, Paxtonia, 
  Rutherford, Skyline View, Lawnton and Valley Green.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4023 7704 4030 7698 4037 7678 4041 7665
      4037 7651 4029 7659 4017 7674 4009 7699
      4013 7703

FLASH FLOOD...RADAR INDICATED

$$

Lambert
1 follow-up statement
197 
WGUS71 KCTP 120404
FFSCTP

Flash Flood Statement
National Weather Service State College PA
1204 AM EDT Mon Jul 12 2021

PAC041-043-075-133-120414-
/O.CAN.KCTP.FF.W.0002.000000T0000Z-210712T0415Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Cumberland PA-Dauphin PA-Lebanon PA-York PA-
1204 AM EDT Mon Jul 12 2021

...FLASH FLOOD WARNING FOR NORTHEASTERN CUMBERLAND, SOUTHERN 
DAUPHIN, WEST CENTRAL LEBANON AND NORTHWESTERN YORK COUNTIES HAS 
BEEN REPLACED WITH A FLOOD ADVISORY...

LAT...LON 4023 7704 4030 7698 4037 7678 4041 7665
      4037 7651 4029 7659 4017 7674 4009 7699
      4013 7703

$$

Dangelo

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 11, 8:03 PM EDTSevere Thunderstorm WarningCTPClinton, Columbia, Lycoming, Montour, Northumberland, Snyder and 1 more42 min
Jul 11, 8:43 PM EDTSevere Thunderstorm WarningCTPColumbia, Lycoming, Montour, Northumberland, Sullivan62 min
Jul 11, 8:44 PM EDTSevere Thunderstorm WarningCTPCumberland, Dauphin, Lebanon, Perry, Schuylkill76 min
Jul 11, 8:52 PM EDTTornado WarningCTPDauphin23 min
Jul 11, 9:07 PM EDTAreal Flood AdvisoryCTPColumbia, Lycoming, Montour, Northumberland, Sullivan, Union2 hr
Jul 11, 9:08 PM EDTSpecial Weather StatementCTPFranklin37 min
Jul 11, 9:32 PM EDTSpecial Weather StatementCTPFulton28 min
Jul 11, 9:32 PM EDTSevere Thunderstorm WarningCTPCumberland, Dauphin, Lebanon, York58 min
Jul 11, 9:52 PM EDTSevere Thunderstorm WarningCTPSchuylkill53 min
Jul 11, 10:35 PM EDTSpecial Weather StatementCTPLebanon, York70 min
Jul 12, 12:04 AM EDTAreal Flood AdvisoryCTPCumberland, Dauphin, Lebanon, York116 min
Jul 12, 1:21 PM EDTFlash Flood WatchCTPColumbia, Cumberland, Dauphin, Juniata, Lebanon, Lycoming and 12 more13 hr
Jul 12, 2:15 PM EDTSpecial Weather StatementCTPLancaster60 min
Jul 12, 2:34 PM EDTSpecial Weather StatementCTPMifflin26 min
Jul 12, 2:36 PM EDTSpecial Weather StatementCTPPerry24 min
Jul 12, 2:45 PM EDTSpecial Weather StatementCTPAdams, Franklin60 min
Jul 12, 2:49 PM EDTSevere Thunderstorm WarningCTPCumberland, Perry41 min
Jul 12, 2:59 PM EDTSpecial Weather StatementCTPMifflin31 min
Jul 12, 3:17 PM EDTSpecial Weather StatementCTPLebanon43 min
Jul 12, 3:30 PM EDTSpecial Weather StatementCTPJuniata45 min
Jul 12, 3:31 PM EDTAreal Flood AdvisoryCTPLancaster119 min
Jul 12, 3:55 PM EDTSevere Thunderstorm WarningCTPDauphin, Perry35 min
Jul 12, 3:56 PM EDTFlash Flood WarningCTPLancaster2 hr
Jul 12, 3:57 PM EDTSevere Thunderstorm WarningCTPLancaster63 min
Jul 12, 3:59 PM EDTSevere Thunderstorm WarningCTPCumberland, York46 min
Jul 12, 4:11 PM EDTSevere Thunderstorm WarningCTPCumberland, Dauphin, Lancaster, Lebanon, York34 min
Jul 12, 4:42 PM EDTSevere Thunderstorm WarningCTPDauphin, Lancaster, Lebanon, York63 min
Jul 12, 4:57 PM EDTAreal Flood AdvisoryCTPLancaster2 hr
Jul 12, 5:29 PM EDTSevere Thunderstorm WarningCTPLancaster61 min
Jul 12, 5:42 PM EDTAreal Flood AdvisoryCTPLancaster93 min
Jul 12, 6:31 PM EDTAreal Flood AdvisoryCTPLancaster119 min
Jul 12, 6:43 PM EDTAreal Flood AdvisoryCTPTioga92 min

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.