Alert archive / Pennsylvania / Flash Flood Warnings in 2018

Flash Flood Warning 39, NWS State College, PA

August 12, 2018Schuylkill County, Pennsylvania

NWS State College, PA issued this flash flood warning at Aug 12, 2018, 5:46 PM EDT for Schuylkill 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: Aug 12, 2018, 5:46 PM EDT (21:46 UTC)
Expired: Aug 12, 2018, 8:45 PM EDT
In force: 3 hr
Issued by: NWS State College, PA
Area: Storm-based polygon
Flood severity: None

County Schuylkill County, PA

The radar

The State College radar (KCCX), 151 km from the middle of the area, began a volume at 21:46 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

Time	Report	Where	Remark
Aug 12, 6:50 PM EDT	FLASH FLOOD	1 Wsw Mechanicsville, PA	MARKET STREET AT 3RD STREET IMPASSABLE
Aug 12, 6:55 PM EDT	FLASH FLOOD	Tremont, PA	CLAY STREET AND NORTH STREET IMPASSABLE
Aug 12, 7:00 PM EDT	FLASH FLOOD	Tremont, PA	SPRING STREET AT THE PINE STREET BRIDGE IMPASSABLE
Aug 12, 7:30 PM EDT	FLASH FLOOD	Pottsville, PA	WIDESPREAD FLOODING THROUGHOUT THE CITY OF POTTSVILLE. NUMEROUS FLOODED ROADWAYS AND HOMES.

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, 9.8 hours before the alert went out and 226 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 593 J/kg
Mixed-layer CIN: -38 J/kg
Mixed-layer LCL: 689 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: -13 m²/s²
0-3 km storm-relative helicity: 4 m²/s²
Significant tornado parameter: -0.0
Supercell composite: -0.2

Open this sounding in Storm Lab

The text

As transmitted.

101 
WGUS51 KCTP 122146
FFWCTP
PAC107-130045-
/O.NEW.KCTP.FF.W.0039.180812T2146Z-180813T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service State College PA
546 PM EDT SUN AUG 12 2018

The National Weather Service in State College PA has issued a

* Flash Flood Warning for...
  Schuylkill County in central Pennsylvania...

* Until 845 PM EDT.

* At 543 PM EDT, Doppler radar indicated very slow moving 
  thunderstorms producing heavy rain across the warned area. Up to 
  two inches of rain has already fallen in the past 2 hours. Minor 
  flooding has already been reported in a few areas near Frackville. 
  With the additional rainfall, Flash flooding is expected to begin 
  shortly.

* Some locations that will experience flooding include...
  Pottsville, Tamaqua, Shenandoah, Minersville, Mahanoy City,
  Frackville, St. Clair, Ashland, Mcadoo, Port Carbon, Tremont,
  Girardville, Hometown, Tower City, Tuscarora, New Philadelphia,
  Oneida, Grier City-Park Crest, Lavelle and Marlin.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

In hilly terrain there are hundreds of low water crossings which are
potentially dangerous in heavy rain. Do not attempt to cross flooded
roads. Find an alternate route.

&&

LAT...LON 4059 7632 4055 7653 4066 7670 4080 7631
      4089 7628 4095 7621 4090 7604 4091 7600
      4081 7589 4078 7583

$$

Jung

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 11, 11:34 PM EDT	Areal Flood Advisory	CTP	Clearfield	56 min
Aug 12, 3:49 PM EDT	Special Weather Statement	CTP	Fulton	26 min
Aug 12, 5:05 PM EDT	Areal Flood Advisory	CTP	Schuylkill	115 min
Aug 12, 5:09 PM EDT	Special Weather Statement	CTP	Schuylkill	36 min
Aug 12, 5:34 PM EDT	Special Weather Statement	CTP	Somerset	26 min
Aug 12, 5:52 PM EDT	Areal Flood Advisory	CTP	Bedford	113 min
Aug 12, 6:03 PM EDT	Areal Flood Advisory	CTP	Somerset	117 min
Aug 12, 6:06 PM EDT	Special Weather Statement	CTP	Schuylkill	24 min
Aug 12, 6:09 PM EDT	Severe Thunderstorm Warning	CTP	Somerset	20 min
Aug 12, 6:38 PM EDT	Special Weather Statement	CTP	Somerset	37 min
Aug 12, 7:53 PM EDT	Areal Flood Advisory	CTP	Lycoming	2 hr

Nearby

Flash Flood Warnings in Pennsylvania, 2018 Every 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.