Alert archive / Pennsylvania / Flash Flood Warnings in 2021

Flash Flood Warning 31, NWS State College, PA

September 15, 2021Columbia County, Lycoming County, Sullivan County, Pennsylvania

NWS State College, PA issued this flash flood warning at Sep 15, 2021, 4:12 PM EDT for Columbia County, Lycoming County, Sullivan County, Pennsylvania. It was in force for 3 hr. 2 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: Sep 15, 2021, 4:12 PM EDT (20:12 UTC)
Expired: Sep 15, 2021, 7:15 PM EDT
In force: 3 hr
Issued by: NWS State College, PA
Area: Storm-based polygon
Flood severity: None

Counties Columbia County, PA, Lycoming County, PA, Sullivan County, PA

The radar

The Binghamton radar (KBGM), 98 km from the middle of the area, began a volume at 20:12 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
Sep 15, 4:50 PM EDT	FLASH FLOOD	4 E Muncy Valley, PA	MUNCY CREEK IS OUT OF ITS BANKS AND ACROSS NORDMONT ROAD.
Sep 15, 6:00 PM EDT	FLASH FLOOD	1 E Laporte, PA	CONKLIN RUN OUT OF ITS BANKS AND FLOWING OVER LAKE RD.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Albany, NY (KALY), launched 12:00Z, 8.2 hours before the alert went out and 257 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: 856 J/kg
Mixed-layer CIN: -92 J/kg
Mixed-layer LCL: 766 m above ground
0-6 km bulk shear: 51 kt
0-1 km storm-relative helicity: 214 m²/s²
0-3 km storm-relative helicity: 248 m²/s²
Significant tornado parameter: 0.7
Supercell composite: 6.3

Open this sounding in Storm Lab

The text

As transmitted.

758 
WGUS51 KCTP 152012
FFWCTP
PAC037-081-113-152315-
/O.NEW.KCTP.FF.W.0031.210915T2012Z-210915T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service State College PA
412 PM EDT Wed Sep 15 2021

The National Weather Service in State College has issued a

* Flash Flood Warning for...
  North Central Columbia County in central Pennsylvania...
  East Central Lycoming County in north central Pennsylvania...
  Southern Sullivan County in north central Pennsylvania...

* Until 715 PM EDT.

* At 412 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Flash flooding is ongoing or 
  expected to begin shortly.

  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...
  Hughesville, Jamison City, Waller, Biggertown, Muncy Valley, 
  Central, Lairdsville, Ricketts Glen State Park, Picture Rocks, 
  Laporte and Eagles Mere.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4149 7639 4147 7625 4146 7625 4145 7625
      4139 7628 4138 7628 4137 7628 4134 7630
      4131 7631 4128 7631 4120 7654 4123 7676
      4134 7674

FLASH FLOOD...RADAR INDICATED

$$

CR

3 follow-up statements

856 
WGUS71 KCTP 152105
FFSCTP

Flash Flood Statement
National Weather Service State College PA
505 PM EDT Wed Sep 15 2021

PAC037-081-113-152315-
/O.CON.KCTP.FF.W.0031.000000T0000Z-210915T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Columbia PA-Lycoming PA-Sullivan PA-
505 PM EDT Wed Sep 15 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 715 PM EDT THIS 
EVENING FOR NORTH CENTRAL COLUMBIA, EAST CENTRAL LYCOMING AND 
SOUTHERN SULLIVAN COUNTIES...

At 505 PM EDT, Trained weather spotters reported thunderstorms 
producing heavy rain in Muncy Creek. Flash flooding is already 
occurring along Muncy Creek near Sonestown.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Trained spotters reported.

IMPACT...Flash flooding of small creeks and streams, urban areas,
         highways, streets and underpasses as well as other poor
         drainage and low-lying areas.  Flash flooding is
         expected along and near Muncy Creek, likely on Route 220
         between Tivoli and Glen Mawr.

Some locations that will experience flash flooding include...
  Hughesville, Jamison City, Waller, Biggertown, Muncy Valley, 
  Central, Lairdsville, Ricketts Glen State Park, Picture Rocks, 
  Laporte and Eagles Mere.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be aware of your surroundings and do not drive on flooded roads.

&&

LAT...LON 4149 7639 4147 7625 4146 7625 4145 7625
      4139 7628 4138 7628 4137 7628 4134 7630
      4131 7631 4128 7631 4120 7654 4123 7676
      4134 7674

FLASH FLOOD...OBSERVED

$$

CR

439 
WGUS71 KCTP 152241
FFSCTP

Flash Flood Statement
National Weather Service State College PA
641 PM EDT Wed Sep 15 2021

PAC037-081-113-152315-
/O.CON.KCTP.FF.W.0031.000000T0000Z-210915T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Columbia PA-Lycoming PA-Sullivan PA-
641 PM EDT Wed Sep 15 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 715 PM EDT THIS 
EVENING FOR NORTH CENTRAL COLUMBIA, EAST CENTRAL LYCOMING AND 
SOUTHERN SULLIVAN COUNTIES...

At 641 PM EDT, Excessive runoff from earlier heavy rains continues 
over parts of the warning area. The Sonestown creek gage crested 
near 8 feet around 6 pm, and is now falling quickly below 6 feet. 
Conditions will continue to improve through mid evening, but please 
use caution as darkness falls, and remember not to drive through 
areas where water is crossing the road.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Trained spotters reported.

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...
  Hughesville, Jamison City, Waller, Biggertown, Muncy Valley, 
  Central, Lairdsville, Ricketts Glen State Park, Picture Rocks, 
  Laporte and Eagles Mere.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be aware of your surroundings and do not drive on flooded roads.

&&

LAT...LON 4149 7639 4147 7625 4146 7625 4145 7625
      4139 7628 4138 7628 4137 7628 4134 7630
      4131 7631 4128 7631 4120 7654 4123 7676
      4134 7674

FLASH FLOOD...OBSERVED

$$

DeVoir

922 
WGUS71 KCTP 152318
FFSCTP

Flash Flood Statement
National Weather Service State College PA
718 PM EDT Wed Sep 15 2021

PAC037-081-113-152328-
/O.EXP.KCTP.FF.W.0031.000000T0000Z-210915T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Columbia PA-Lycoming PA-Sullivan PA-
718 PM EDT Wed Sep 15 2021

...FLASH FLOOD WARNING HAS EXPIRED FOR NORTH CENTRAL COLUMBIA, EAST 
CENTRAL LYCOMING AND SOUTHERN SULLIVAN COUNTIES...

Flood waters have receded. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures.

LAT...LON 4149 7639 4147 7625 4146 7625 4145 7625
      4139 7628 4138 7628 4137 7628 4134 7630
      4131 7631 4128 7631 4120 7654 4123 7676
      4134 7674

$$

DeVoir

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 15, 11:48 AM EDT	Special Weather Statement	CTP	Warren	42 min
Sep 15, 1:11 PM EDT	Special Weather Statement	CTP	Sullivan	49 min
Sep 15, 1:27 PM EDT	Special Weather Statement	CTP	Centre	33 min
Sep 15, 1:44 PM EDT	Severe Thunderstorm Warning	CTP	Centre	31 min
Sep 15, 1:48 PM EDT	Severe Thunderstorm Warning	CTP	Sullivan	42 min
Sep 15, 2:14 PM EDT	Areal Flood Advisory	CTP	Lycoming, Sullivan	2 hr
Sep 15, 2:14 PM EDT	Severe Thunderstorm Warning	CTP	Centre, Clinton	31 min
Sep 15, 2:36 PM EDT	Flash Flood Warning	CTP	Lycoming, Sullivan	66 min
Sep 15, 2:45 PM EDT	Special Weather Statement	CTP	Union	30 min
Sep 15, 2:46 PM EDT	Special Weather Statement	CTP	Sullivan	44 min
Sep 15, 2:54 PM EDT	Severe Thunderstorm Warning	CTP	Clinton, Lycoming, Northumberland, Union	36 min
Sep 15, 3:13 PM EDT	Special Weather Statement	CTP	Union	17 min
Sep 15, 3:20 PM EDT	Severe Thunderstorm Warning	CTP	Juniata, Mifflin	40 min
Sep 15, 3:24 PM EDT	Severe Thunderstorm Warning	CTP	Montour, Northumberland, Union	36 min
Sep 15, 3:30 PM EDT	Special Weather Statement	CTP	Huntingdon	30 min
Sep 15, 3:55 PM EDT	Special Weather Statement	CTP	Snyder	35 min
Sep 15, 3:59 PM EDT	Special Weather Statement	CTP	Columbia, Montour	31 min
Sep 15, 4:03 PM EDT	Areal Flood Advisory	CTP	Lycoming, Sullivan	2 hr
Sep 15, 4:18 PM EDT	Severe Thunderstorm Warning	CTP	Columbia	27 min
Sep 15, 4:27 PM EDT	Special Weather Statement	CTP	Perry	33 min
Sep 15, 4:36 PM EDT	Special Weather Statement	CTP	Columbia, Northumberland	24 min
Sep 15, 4:43 PM EDT	Severe Thunderstorm Warning	CTP	Cumberland, Franklin, Perry	32 min
Sep 15, 4:46 PM EDT	Areal Flood Advisory	CTP	Montour, Northumberland	89 min
Sep 15, 4:58 PM EDT	Special Weather Statement	CTP	Northumberland	32 min
Sep 15, 4:59 PM EDT	Special Weather Statement	CTP	Perry	31 min
Sep 15, 5:15 PM EDT	Special Weather Statement	CTP	Perry	30 min
Sep 15, 5:19 PM EDT	Special Weather Statement	CTP	Franklin	26 min
Sep 15, 5:32 PM EDT	Special Weather Statement	CTP	Dauphin	28 min
Sep 15, 5:37 PM EDT	Special Weather Statement	CTP	Schuylkill	23 min
Sep 15, 5:54 PM EDT	Special Weather Statement	CTP	Lebanon	36 min
Sep 15, 6:16 PM EDT	Special Weather Statement	CTP	York	29 min
Sep 15, 6:17 PM EDT	Severe Thunderstorm Warning	CTP	Lebanon, Schuylkill	43 min
Sep 15, 6:24 PM EDT	Severe Thunderstorm Warning	CTP	Adams, Franklin	27 min
Sep 15, 6:41 PM EDT	Special Weather Statement	CTP	Dauphin	34 min
Sep 15, 6:54 PM EDT	Special Weather Statement	CTP	Berks	21 min
Sep 15, 7:09 PM EDT	Areal Flood Advisory	CTP	Dauphin, York	96 min

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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.