Alert archive / Pennsylvania / Flash Flood Warnings in 2017

Flash Flood Warning 13, NWS State College, PA

July 23, 2017Dauphin County, Lebanon County, Pennsylvania

NWS State College, PA issued this flash flood warning at Jul 23, 2017, 6:36 PM EDT for Dauphin County, Lebanon County, Pennsylvania. It was in force for 3 hr. 7 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
Jul 23, 2017, 6:36 PM EDT (22:36 UTC)
Expired
Jul 23, 2017, 9:30 PM EDT
In force
3 hr
Issued by
NWS State College, PA
Area
Storm-based polygon
Flood severity
None

Counties Dauphin County, PA, Lebanon County, PA

The radar

The State College radar (KCCX), 139 km from the middle of the area, began a volume at 22:39 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 23, 6:50 PM EDTFLASH FLOODClifton, PAFLOODED CARS AND STREET FLOODING ON MIDDLETOWN ROAD
Jul 23, 7:03 PM EDTFLASH FLOODMiddletown, PAWIDESPREAD ROAD FLOODING AND CARS FLOODED
Jul 23, 7:06 PM EDTFLASH FLOODOakmont, PAWALTONVILLE ROAD IMPASSABLE DUE TO FLOODING
Jul 23, 7:14 PM EDTFLASH FLOOD1 Nnw Highspire, PAPERSONS TRAPPED IN HOME DUE TO FLOODING
Jul 23, 7:20 PM EDTFLASH FLOODGreenwood Hills, PALUMBER STREET IMPASSABLE DUE TO FLOODING
Jul 23, 7:25 PM EDTFLASH FLOODLebanon, PAWIDESPREAD ROADS FLOODED AND IMPASSABLE COUNTYWIDE
Jul 23, 7:36 PM EDTFLASH FLOOD1 Nnw Royalton, PAENTRAPMENT RESCUE DUE TO FLOODING AT 149 WILSON 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 12:00Z, 10.6 hours before the alert went out and 154 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 12:00Z on 2017-07-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 186 joules per kilogram.LCLLFCEL10008507005003002001001 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, Washington/Dulle, VA at 12:00Z on 2017-07-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 19 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
186 J/kg
Mixed-layer CIN
-43 J/kg
Mixed-layer LCL
983 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
19 m²/s²
0-3 km storm-relative helicity
31 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted.

382 
WGUS51 KCTP 232236
FFWCTP
PAC043-075-240130-
/O.NEW.KCTP.FF.W.0013.170723T2236Z-170724T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service State College PA
636 PM EDT SUN JUL 23 2017

The National Weather Service in State College PA has issued a

* Flash Flood Warning for...
  Southeastern Dauphin County in south central Pennsylvania...
  Lebanon County in south central Pennsylvania...

* Until 930 PM EDT.

* At 634 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain over southern Dauphion County and Central Lebanon 
  County. The storms are nearly stationary. Minor flooding is 
  occurring in southern Dauphin County, and should become worse. The 
  rain in Lebanon County is falling over very wet ground. Flash 
  flooding is expected to begin shortly. 

* Some locations that will experience flooding include...
  Myerstown, Hummelstown, Palmyra, Annville, Middletown, Steelton,
  Hershey, Lebanon, Cornwall and Colonial Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, urban areas, highways, streets and underpasses as
well as other drainage areas and low lying spots.

&&

LAT...LON 4020 7657 4017 7664 4017 7666 4015 7668
      4015 7670 4012 7672 4013 7674 4018 7676
      4020 7680 4020 7682 4025 7688 4049 7643
      4036 7622

$$

Dangelo
1 follow-up statement
222 
WGUS71 KCTP 232357
FFSCTP

Flash Flood Statement
National Weather Service State College PA
757 PM EDT SUN JUL 23 2017

PAC043-075-240130-
/O.CON.KCTP.FF.W.0013.000000T0000Z-170724T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Dauphin PA-Lebanon PA-
757 PM EDT SUN JUL 23 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 930 PM EDT FOR
SOUTHEASTERN DAUPHIN AND LEBANON COUNTIES...

At 751 PM EDT, local law enforcement reported widespread flash 
flooding around all of southern Dauphin County, specifically in 
Middletown. The heavy rain has tapered off and it should be dry over 
the next few hours. Expect the current flooding to get briefly 
worse, but the water should begin to recede later this evening. 

However, additional heavy rain may develop later tonight. 

Some locations that will experience flooding include...
Myerstown, Hummelstown, Palmyra, Annville, Middletown, Steelton,
Hershey, Lebanon, Cornwall and Colonial Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, urban areas, highways, streets and underpasses as
well as other drainage areas and low lying spots.

&&

LAT...LON 4020 7657 4017 7664 4017 7666 4015 7668
      4015 7670 4012 7672 4013 7674 4018 7676
      4020 7680 4020 7682 4025 7688 4049 7643
      4036 7622

$$

Dangelo

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 22, 8:54 PM EDTAreal Flood AdvisoryCTPSomerset3 hr
Jul 23, 2:27 PM EDTFlash Flood WatchCTPAdams, Cameron, Clinton, Columbia, Cumberland, Dauphin and 17 more18 hr
Jul 23, 2:47 PM EDTSpecial Weather StatementCTPLancaster13 min
Jul 23, 2:52 PM EDTSpecial Weather StatementCTPTioga38 min
Jul 23, 3:22 PM EDTSevere Thunderstorm WarningCTPTioga38 min
Jul 23, 3:29 PM EDTSpecial Weather StatementCTPTioga46 min
Jul 23, 3:40 PM EDTSevere Thunderstorm WarningCTPPotter, Tioga80 min
Jul 23, 3:57 PM EDTSpecial Weather StatementCTPTioga33 min
Jul 23, 4:06 PM EDTAreal Flood AdvisoryCTPYork3 hr
Jul 23, 4:35 PM EDTAreal Flood AdvisoryCTPFranklin3 hr
Jul 23, 4:50 PM EDTFlash Flood WarningCTPYork4 hr
Jul 23, 4:55 PM EDTAreal Flood AdvisoryCTPAdams, York3 hr
Jul 23, 5:00 PM EDTSpecial Weather StatementCTPTioga30 min
Jul 23, 5:07 PM EDTSevere Thunderstorm WarningCTPLycoming, Sullivan53 min
Jul 23, 5:17 PM EDTSpecial Weather StatementCTPLebanon28 min
Jul 23, 5:34 PM EDTSpecial Weather StatementCTPCumberland26 min
Jul 23, 5:36 PM EDTSevere Thunderstorm WarningCTPDauphin, Lancaster, York54 min
Jul 23, 6:00 PM EDTSevere Thunderstorm WarningCTPLycoming, Montour, Northumberland60 min
Jul 23, 6:05 PM EDTAreal Flood AdvisoryCTPCumberland, Dauphin, Lancaster, York3 hr
Jul 23, 6:59 PM EDTSevere Thunderstorm WarningCTPColumbia, Lycoming, Montour, Northumberland61 min
Jul 23, 7:08 PM EDTSpecial Weather StatementCTPDauphin37 min
Jul 23, 7:32 PM EDTAreal Flood AdvisoryCTPDauphin, Northumberland3 hr
Jul 23, 7:59 PM EDTFlash Flood WarningCTPDauphin, Northumberland3 hr

Nearby

Flash Flood Warnings in Pennsylvania, 2017Every flash flood warning in 2017

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.