Alert archive / Pennsylvania / Flash Flood Warnings in 2021

Flash Flood Warning 13, NWS State College, PA

July 18, 2021Tioga County, Pennsylvania

NWS State College, PA issued this flash flood warning at Jul 18, 2021, 2:29 AM EDT for Tioga County, Pennsylvania. It was in force for 2 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Jul 18, 2021, 2:29 AM EDT (06:29 UTC)
Expired: Jul 18, 2021, 4:30 AM EDT
In force: 2 hr
Issued by: NWS State College, PA
Area: Storm-based polygon
Flood severity: None

County Tioga County, PA

The radar

The Binghamton radar (KBGM), 102 km from the middle of the area, began a volume at 06:30 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.

The nearest sounding before it

Buffalo Intl Airport, NY (KBUF), launched 00:00Z, 6.5 hours before the alert went out and 166 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 626 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 82 m²/s²
0-3 km storm-relative helicity: 168 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

274 
WGUS51 KCTP 180629
FFWCTP
PAC117-180830-
/O.NEW.KCTP.FF.W.0013.210718T0629Z-210718T0830Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service State College PA
229 AM EDT Sun Jul 18 2021

The National Weather Service in State College has issued a

* Flash Flood Warning for...
  Northern Tioga County in north central Pennsylvania...

* Until 430 AM EDT.

* At 229 AM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain in Training heavy showers and thunderstorms with 
  rainfall rates of 1 inch in just 20 minutes will cause flash 
  flooding of streams, creeks and low lying areas in towns. High 
  water and debris washing over roads near Keeneyville and points to 
  the northwest of town from flooding of Losey Creek could block 
  travel.

  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...
  Elkland, Millerton, Keeneyville, Tioga, Knoxville, Tioga Junction 
  and Osceola.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4194 7692 4185 7708 4179 7730 4182 7743
      4187 7751 4196 7745 4200 7730 4200 7726
      4200 7724 4200 7720 4200 7717 4200 7713
      4200 7711 4200 7709 4200 7706 4200 7704
      4200 7693

FLASH FLOOD...RADAR INDICATED

$$

Lambert

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 17, 8:28 PM EDT	Special Weather Statement	CTP	Lancaster	32 min
Jul 18, 1:30 AM EDT	Areal Flood Advisory	CTP	Potter, Tioga	3 hr

Nearby

Flash Flood Warnings in Pennsylvania, 2021 Every 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.