Alert archive / Pennsylvania / Flash Flood Watches in 2021

Flash Flood Watch 4, NWS State College, PA

July 13, 20218 counties in Pennsylvania

NWS State College, PA issued this flash flood watch at Jul 13, 2021, 12:39 PM EDT for 8 counties in Pennsylvania. It was in force for 11 hr.

The area

The counties it named.

The facts

Issued: Jul 13, 2021, 12:39 PM EDT (16:39 UTC)
Expired: Jul 14, 2021, 12:00 AM EDT
In force: 11 hr
Issued by: NWS State College, PA
Flood severity: None

Counties Columbia County, PA, Lycoming County, PA, Montour County, PA, Northumberland County, PA, Snyder County, PA, Sullivan County, PA, Tioga County, PA, Union County, PA

The radar

The State College radar (KCCX), 101 km from the middle of the area, began a volume at 16:38 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

Washington/Dulle, VA (KIAD), launched 12:00Z, 4.7 hours before the alert went out and 250 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: 842 J/kg
Mixed-layer CIN: -126 J/kg
Mixed-layer LCL: 1101 m above ground
0-6 km bulk shear: 27 kt
0-1 km storm-relative helicity: -28 m²/s²
0-3 km storm-relative helicity: 32 m²/s²
Significant tornado parameter: -0.0
Supercell composite: -0.2

Open this sounding in Storm Lab

The text

As transmitted.

970 
WGUS61 KCTP 131639
FFACTP

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service State College PA
1239 PM EDT Tue Jul 13 2021

PAZ037-041-042-046-049>053-140400-
/O.NEW.KCTP.FF.A.0004.210713T1639Z-210714T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Tioga-Northern Lycoming-Sullivan-Southern Lycoming-Union-Snyder-
Montour-Northumberland-Columbia-
Including the cities of Selinsgrove, Wellsboro, Shamokin, Laporte, 
Sunbury, Trout Run, Williamsport, Mansfield, Danville, Bloomsburg, 
Berwick, and Lewisburg
1239 PM EDT Tue Jul 13 2021

...FLASH FLOOD WATCH IN EFFECT UNTIL MIDNIGHT EDT TONIGHT...

The National Weather Service in State College has issued a

* Flash Flood Watch for a portion of central Pennsylvania, including 
  the following areas, Columbia, Montour, Northern Lycoming, 
  Northumberland, Snyder, Southern Lycoming, Sullivan, Tioga and 
  Union.

* Until Midnight EDT tonight.

* Several thunderstorms moving northeast across the region late this 
  afternoon and this evening could bring locally excessive rainfall 
  within a short period of time. Some locations could see 2 to 3 
  inches in less than one hour.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

Lambert/Wagner

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 12, 8:26 PM EDT	Areal Flood Advisory	CTP	Tioga	2 hr
Jul 12, 8:50 PM EDT	Areal Flood Advisory	CTP	Lycoming, Sullivan	2 hr
Jul 12, 9:47 PM EDT	Areal Flood Advisory	CTP	Sullivan	118 min
Jul 12, 11:21 PM EDT	Special Weather Statement	CTP	York	24 min
Jul 12, 11:52 PM EDT	Special Weather Statement	CTP	Adams, Lancaster, Lebanon, York	23 min
Jul 13, 12:53 AM EDT	Special Weather Statement	CTP	Lebanon	22 min
Jul 13, 1:31 AM EDT	Special Weather Statement	CTP	Schuylkill	29 min
Jul 13, 2:02 AM EDT	Special Weather Statement	CTP	Schuylkill	28 min
Jul 13, 4:18 PM EDT	Special Weather Statement	CTP	Somerset	42 min
Jul 13, 4:31 PM EDT	Areal Flood Advisory	CTP	Tioga	119 min
Jul 13, 4:34 PM EDT	Severe Thunderstorm Warning	CTP	Somerset	41 min
Jul 13, 4:35 PM EDT	Severe Thunderstorm Warning	CTP	Warren	55 min
Jul 13, 4:38 PM EDT	Areal Flood Advisory	CTP	Somerset	3 hr
Jul 13, 5:14 PM EDT	Special Weather Statement	CTP	Somerset	46 min
Jul 13, 5:23 PM EDT	Severe Thunderstorm Warning	CTP	Elk, McKean, Warren	52 min
Jul 13, 5:35 PM EDT	Special Weather Statement	CTP	Clearfield	40 min
Jul 13, 5:38 PM EDT	Severe Thunderstorm Warning	CTP	Bedford, Somerset	41 min
Jul 13, 5:49 PM EDT	Severe Thunderstorm Warning	CTP	Cameron, Centre, Clearfield, Clinton, Potter	56 min
Jul 13, 5:53 PM EDT	Severe Thunderstorm Warning	CTP	Cameron, Clearfield, Elk	67 min
Jul 13, 5:56 PM EDT	Special Weather Statement	CTP	Clearfield	34 min
Jul 13, 6:01 PM EDT	Severe Thunderstorm Warning	CTP	Bedford, Blair, Cambria, Clearfield	59 min
Jul 13, 6:07 PM EDT	Severe Thunderstorm Warning	CTP	Clearfield, Elk	38 min
Jul 13, 6:19 PM EDT	Severe Thunderstorm Warning	CTP	McKean, Potter	41 min
Jul 13, 6:27 PM EDT	Severe Thunderstorm Warning	CTP	Somerset	37 min
Jul 13, 6:33 PM EDT	Special Weather Statement	CTP	Clearfield	27 min
Jul 13, 6:35 PM EDT	Special Weather Statement	CTP	Huntingdon	40 min
Jul 13, 6:43 PM EDT	Severe Thunderstorm Warning	CTP	Clinton, Potter, Tioga	47 min
Jul 13, 6:46 PM EDT	Severe Thunderstorm Warning	CTP	Blair, Centre, Clearfield	44 min
Jul 13, 6:46 PM EDT	Severe Thunderstorm Warning	CTP	Blair, Huntingdon	44 min
Jul 13, 6:54 PM EDT	Areal Flood Advisory	CTP	Cameron, Clearfield, Clinton	3 hr
Jul 13, 6:59 PM EDT	Severe Thunderstorm Warning	CTP	Potter	61 min
Jul 13, 7:01 PM EDT	Severe Thunderstorm Warning	CTP	Centre, Clinton	44 min
Jul 13, 7:07 PM EDT	Special Weather Statement	CTP	Clinton	23 min
Jul 13, 7:08 PM EDT	Special Weather Statement	CTP	Somerset	37 min
Jul 13, 7:16 PM EDT	Severe Thunderstorm Warning	CTP	Centre, Huntingdon, Mifflin	44 min
Jul 13, 7:26 PM EDT	Severe Thunderstorm Warning	CTP	Lycoming, Tioga	64 min
Jul 13, 7:29 PM EDT	Areal Flood Advisory	CTP	Centre, Clinton	3 hr
Jul 13, 7:44 PM EDT	Severe Thunderstorm Warning	CTP	Clinton, Lycoming, Tioga	61 min
Jul 13, 7:55 PM EDT	Flash Flood Warning	CTP	Lycoming, Tioga	2 hr
Jul 13, 7:58 PM EDT	Areal Flood Advisory	CTP	Centre, Clinton	2 hr
Jul 13, 7:59 PM EDT	Severe Thunderstorm Warning	CTP	Centre, Clinton, Mifflin, Snyder, Union	46 min

Nearby

Flash Flood Watches in Pennsylvania, 2021 Every flash flood watch 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.