Alert archive / Pennsylvania / Flash Flood Warnings in 2018

Flash Flood Warning 3, NWS State College, PA

June 1, 2018Lancaster County, Pennsylvania

NWS State College, PA issued this flash flood warning at Jun 1, 2018, 11:38 PM EDT for Lancaster County, Pennsylvania. It was in force for 3 hr. 4 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
Jun 1, 2018, 11:38 PM EDT (03:38 UTC)
Expired
Jun 2, 2018, 2:30 AM EDT
In force
3 hr
Issued by
NWS State College, PA
Area
Storm-based polygon
Flood severity
None

County Lancaster County, PA

The radar

The Dover AFB radar (KDOX), 137 km from the middle of the area, began a volume at 03:37 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
Jun 2, 1:25 AM EDTFLASH FLOOD1 Nw Windom, PAWEST BRANCH OF LITTLE CONESTOGA CREEK OVER CHARLESTOWN ROAD. WATER RESCUE UNDERWAY.
Jun 2, 1:25 AM EDTFLASH FLOODWillow Street, PANUMEROUS ROADS IMPASSABLE THORUGHOUT WILLOW STREET
Jun 2, 1:26 AM EDTFLASH FLOODWindom, PALITTLE CONESTOGA CREEK OVER BLUE ROCK ROAD. THREE PERSONS TRAPPED IN RESIDENCE. WATER RESCUE UNDERWAY.
Jun 2, 1:40 AM EDTFLASH FLOODMillersville, PANUMEROUS ROADS IMPASSABLE THROUGHOUT MILLERSVILLE

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, 3.6 hours before the alert went out and 150 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 2018-06-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 678 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 00:00Z on 2018-06-02The 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
678 J/kg
Mixed-layer CIN
-6 J/kg
Mixed-layer LCL
1436 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
25 m²/s²
0-3 km storm-relative helicity
45 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.4

Open this sounding in Storm Lab

The text

As transmitted.

754 
WGUS51 KCTP 020338
FFWCTP
PAC071-020630-
/O.NEW.KCTP.FF.W.0003.180602T0338Z-180602T0630Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service State College PA
1138 PM EDT FRI JUN 1 2018

The National Weather Service in State College PA has issued a

* Flash Flood Warning for...
  Southern Lancaster County in south central Pennsylvania...

* Until 230 AM EDT.

* At 1136 PM EDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Up to two inches of rain have
  already fallen. Flash flooding is expected to begin shortly.

* Some locations that will experience the most significant flooding include...
  Millersville, Willow Street and Smithville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Be especially cautious at night when it is harder to recognize the
dangers of flooding.

&&

LAT...LON 3987 7638 3991 7639 3995 7648 3999 7650
      4005 7656 4000 7596 3996 7599 3993 7598
      3993 7600 3990 7599 3985 7601 3985 7602
      3983 7602 3982 7604

$$

KF
1 follow-up statement
826 
WGUS71 KCTP 020546
FFSCTP

Flash Flood Statement
National Weather Service State College PA
146 AM EDT SAT JUN 2 2018

PAC071-020630-
/O.CON.KCTP.FF.W.0003.000000T0000Z-180602T0630Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Lancaster PA-
146 AM EDT SAT JUN 2 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 230 AM EDT FOR
SOUTHERN LANCASTER COUNTY...

At 142 AM EDT, local law enforcement reported significant flooding 
from heavy rain in the Mountville, Millersville and Willow Street 
areas. Over three inches of rain have already fallen in some of 
these locations, causing numerous roads to flood. 

Although the heaviest rain has ended, moderate rain will continue 
until at least 3 am, causing the flooding to persist.  

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Be especially cautious at night when it is harder to recognize the
dangers of flooding.

&&

LAT...LON 3987 7638 3991 7639 3995 7648 3999 7650
      4005 7656 4000 7596 3996 7599 3993 7598
      3993 7600 3990 7599 3985 7601 3985 7602
      3983 7602 3982 7604

$$

KF

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 1, 9:39 PM EDTAreal Flood AdvisoryCTPAdams111 min
Jun 1, 10:40 PM EDTFlash Flood WatchCTPAdams, Lancaster, York7 hr
Jun 1, 11:53 PM EDTAreal Flood AdvisoryCTPYork3 hr
Jun 2, 12:47 AM EDTFlash Flood WarningCTPYork3 hr
Jun 2, 1:02 AM EDTAreal Flood AdvisoryCTPLancaster3 hr
Jun 2, 2:29 AM EDTFlash Flood WarningCTPLancaster3 hr
Jun 2, 5:40 AM EDTFlash Flood WatchCTPAdams, Bedford, Franklin, Fulton, Lancaster, Somerset and 1 more22 hr
Jun 2, 3:44 PM EDTAreal Flood AdvisoryCTPBedford, Somerset2 hr
Jun 2, 5:38 PM EDTAreal Flood AdvisoryCTPLancaster, York112 min
Jun 2, 6:07 PM EDTSpecial Weather StatementCTPYork38 min
Jun 2, 7:10 PM EDTAreal Flood AdvisoryCTPYork4 hr
Jun 2, 7:12 PM EDTSpecial Weather StatementCTPYork33 min
Jun 2, 7:39 PM EDTFlash Flood WarningCTPLancaster, York6 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.