Alert archive / Pennsylvania / Flash Flood Warnings in 2018

Flash Flood Warning 49, NWS State College, PA

August 31, 2018Lebanon County, Pennsylvania

NWS State College, PA issued this flash flood warning at Aug 31, 2018, 9:58 AM EDT for Lebanon County, Pennsylvania. It was in force for 3 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
Aug 31, 2018, 9:58 AM EDT (13:58 UTC)
Expired
Aug 31, 2018, 1:00 PM EDT
In force
3 hr
Issued by
NWS State College, PA
Area
Storm-based polygon
Flood severity
None

County Lebanon County, PA

The radar

The State College radar (KCCX), 151 km from the middle of the area, began a volume at 14:01 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
Aug 31, 10:25 AM EDTFLASH FLOODJonestown, PAFLOODING OF QUARRY RD BETWEEN SWATARA RD AND SWEETBRIAR LANE.
Aug 31, 10:40 AM EDTFLASH FLOODJonestown, PACARS SUBMERGED IN WATER.
Aug 31, 11:00 AM EDTHEAVY RAIN 4.78Jonestown, PA2 HR RAINFALL TOTAL.

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, 2.0 hours before the alert went out and 183 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 2018-08-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 425 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 2018-08-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 20 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
425 J/kg
Mixed-layer CIN
-35 J/kg
Mixed-layer LCL
930 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
20 m²/s²
0-3 km storm-relative helicity
68 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

574 
WGUS51 KCTP 311358
FFWCTP
PAC075-311700-
/O.NEW.KCTP.FF.W.0049.180831T1358Z-180831T1700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service State College PA
958 AM EDT FRI AUG 31 2018

The National Weather Service in State College PA has issued a

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

* Until 100 PM EDT.

* At 958 AM EDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Flash flooding is expected to
  begin shortly.

* Some locations that may experience flooding include...
  Lebanon, Annville, Myerstown, Pleasant Hill, Sand Hill, Lebanon
  South, Cleona, Avon, Richland, Fredericksburg, Schaefferstown,
  Jonestown and Avon Heights.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4030 7628 4034 7653 4050 7646 4050 7644
      4038 7626 4037 7625

$$

CR
1 follow-up statement
386 
WGUS71 KCTP 311525
FFSCTP

Flash Flood Statement
National Weather Service State College PA
1125 AM EDT FRI AUG 31 2018

PAC075-311700-
/O.CON.KCTP.FF.W.0049.000000T0000Z-180831T1700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Lebanon PA-
1125 AM EDT FRI AUG 31 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 100 PM EDT FOR
CENTRAL LEBANON COUNTY...

At 1123 AM EDT, the public reported flooding in the Jonestown area 
and further flooding is expected until the rain diminishes.  The 
heaviest rain is currently located between Jonestown and 
Fredericksburg.

Some locations that will experience flooding include... Lebanon, 
Myerstown, Sand Hill, Avon, Richland, Fredericksburg, Jonestown and 
Avon Heights.

This may include the following streams and drainages...Monroe 
Creek... Brandywine Creek...Swatara Creek...Quittapahilla 
Creek...Trib. to Tulpehocken Creek near Myerstown...Little Swatara 
Creek...Sattazahn Run...Elizabeth Run...Earlakill Run...Trib. to 
Little Swatara Creek near Freeport Mills...Deep Run...Oil Creek and 
Tulpehocken Creek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4033 7627 4037 7652 4050 7646 4050 7644
      4038 7626 4037 7625

$$

CR

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 31, 6:29 AM EDTAreal Flood AdvisoryCTPBlair3 hr
Aug 31, 6:47 AM EDTAreal Flood AdvisoryCTPCentre, Huntingdon, Mifflin3 hr
Aug 31, 9:41 AM EDTAreal Flood AdvisoryCTPLebanon2 hr
Aug 31, 10:44 AM EDTAreal Flood AdvisoryCTPSchuylkill2 hr
Aug 31, 12:11 PM EDTAreal Flood AdvisoryCTPLancaster, Lebanon3 hr
Aug 31, 1:02 PM EDTAreal Flood WarningCTPLebanon118 min
Aug 31, 1:31 PM EDTFlash Flood Warning EmergencyCTPLancaster9 hr
Aug 31, 2:19 PM EDTAreal Flood AdvisoryCTPYork3 hr
Aug 31, 2:55 PM EDTFlash Flood WarningCTPYork3 hr
Aug 31, 3:06 PM EDTRiver Flood WarningCTPLebanon, Schuylkill14 hr
Aug 31, 3:26 PM EDTAreal Flood AdvisoryCTPSchuylkill3 hr
Aug 31, 3:35 PM EDTAreal Flood AdvisoryCTPLebanon115 min
Aug 31, 3:35 PM EDTAreal Flood AdvisoryCTPLancaster, York3 hr
Aug 31, 4:09 PM EDTAreal Flood AdvisoryCTPAdams, Cumberland3 hr
Aug 31, 4:38 PM EDTFlash Flood WarningCTPLancaster, York3 hr
Aug 31, 4:44 PM EDTFlash Flood WarningCTPAdams, Cumberland3 hr
Aug 31, 5:08 PM EDTFlash Flood WarningCTPYork3 hr
Aug 31, 5:44 PM EDTAreal Flood AdvisoryCTPLancaster2 hr
Aug 31, 6:13 PM EDTAreal Flood AdvisoryCTPSomerset2 hr
Aug 31, 7:35 PM EDTAreal Flood WarningCTPLancaster, York3 hr
Aug 31, 7:54 PM EDTAreal Flood WarningCTPYork3 hr

Nearby

Flash Flood Warnings in Pennsylvania, 2018Every flash flood warning in 2018

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.