Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 177, NWS State College, PA

July 17, 20215 counties in Pennsylvania

NWS State College, PA issued this severe thunderstorm warning at Jul 17, 2021, 4:50 PM EDT for 5 counties in Pennsylvania. It was in force for 55 min. 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: Jul 17, 2021, 4:50 PM EDT (20:50 UTC)
Expired: Jul 17, 2021, 5:45 PM EDT
In force: 55 min
Issued by: NWS State College, PA
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Juniata County, PA, Mifflin County, PA, Northumberland County, PA, Snyder County, PA, Union County, PA

The radar

The State College radar (KCCX), 84 km from the middle of the area, began a volume at 20:49 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
Jul 17, 5:38 PM EDT	TSTM WND DMG	1 Ne Milton, PA	TREE DOWN ON A HOUSE.
Jul 17, 5:40 PM EDT	TSTM WND DMG	1 Nnw West Milton, PA	PART OF A ROOF BLOWN OFF OF A BARN ON N RIDGE RD.

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

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Jul 17, 1:13 PM EDT	Severe Thunderstorm Watch	SPC	10 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 8.8 hours before the alert went out and 221 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: 538 J/kg
Mixed-layer CIN: -141 J/kg
Mixed-layer LCL: 1337 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: 37 m²/s²
0-3 km storm-relative helicity: 43 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

488 
WUUS51 KCTP 172050
SVRCTP
PAC067-087-097-109-119-172145-
/O.NEW.KCTP.SV.W.0177.210717T2050Z-210717T2145Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service State College PA
450 PM EDT Sat Jul 17 2021

The National Weather Service in State College PA has issued a

* Severe Thunderstorm Warning for...
  Western Northumberland County in central Pennsylvania...
  Northeastern Mifflin County in central Pennsylvania...
  Northeastern Juniata County in central Pennsylvania...
  Snyder County in central Pennsylvania...
  Union County in central Pennsylvania...

* Until 545 PM EDT.

* At 450 PM EDT, severe thunderstorms were located along a line
  extending from Weikert to near Mcalisterville, moving northeast at
  35 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to roofs, siding, and trees.

* Locations impacted include...
  Sunbury, Milton, Lewisburg, Selinsgrove, Northumberland,
  Mifflinburg, Winfield, Watsontown, Shamokin Dam, Linntown, Hummels
  Wharf, Middleburg, New Columbia, Mcalisterville, McClure,
  Montandon, Kreamer, Port Trevorton, Penns Creek and Beaver Springs.

For those driving on Interstate 80, this includes areas between the
Jersey Shore and Danville exits, specifically from mile markers 196
to 216.

This includes Interstate 180 from mile markers 1 to 8.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4107 7674 4095 7679 4095 7674 4072 7675
      4060 7706 4059 7717 4056 7717 4047 7741
      4083 7743 4085 7736 4099 7721 4109 7707
      4109 7698 4115 7696 4114 7690 4116 7687
      4117 7673
TIME...MOT...LOC 2050Z 236DEG 29KT 4086 7732 4059 7730 

HAIL...<.75IN
WIND...60MPH
 
$$

Banghoff

1 follow-up statement

787 
WWUS51 KCTP 172120
SVSCTP

Severe Weather Statement
National Weather Service State College PA
520 PM EDT Sat Jul 17 2021

PAC067-087-172130-
/O.CAN.KCTP.SV.W.0177.000000T0000Z-210717T2145Z/
Mifflin PA-Juniata PA-
520 PM EDT Sat Jul 17 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN MIFFLIN AND
NORTHEASTERN JUNIATA COUNTIES IS CANCELLED...

The storms which prompted the warning have moved out of the warned 
area. Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 1100 PM EDT for
central and north central Pennsylvania.

LAT...LON 4109 7674 4095 7679 4095 7674 4072 7675
      4068 7716 4101 7718 4108 7708 4109 7698
      4115 7696 4114 7690 4116 7686 4117 7674
      4116 7673
TIME...MOT...LOC 2120Z 232DEG 28KT 4099 7708 4072 7706 

$$

PAC097-109-119-172145-
/O.CON.KCTP.SV.W.0177.000000T0000Z-210717T2145Z/
Northumberland PA-Snyder PA-Union PA-
520 PM EDT Sat Jul 17 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 545 PM EDT
FOR WESTERN NORTHUMBERLAND...SNYDER AND UNION COUNTIES...

At 520 PM EDT, severe thunderstorms were located along a line
extending from Sand Bridge State Park to near Mount Pleasant Mills,
moving northeast at 30 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
Sunbury, Milton, Lewisburg, Selinsgrove, Northumberland, Mifflinburg,
Winfield, Watsontown, Shamokin Dam, Linntown, Hummels Wharf,
Middleburg, New Columbia, Montandon, Kreamer, Port Trevorton, Penns
Creek, Richfield, Mount Pleasant Mills and Kratzerville.

For those driving on Interstate 80, this includes areas between the
Jersey Shore and Danville exits, specifically from mile markers 196
to 216.

This includes Interstate 180 from mile markers 1 to 8.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4109 7674 4095 7679 4095 7674 4072 7675
      4068 7716 4101 7718 4108 7708 4109 7698
      4115 7696 4114 7690 4116 7686 4117 7674
      4116 7673
TIME...MOT...LOC 2120Z 232DEG 28KT 4099 7708 4072 7706 

HAIL...<.75IN
WIND...60MPH
 
$$

Banghoff

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 16, 9:11 PM EDT	Special Weather Statement	CTP	Cumberland	34 min
Jul 16, 10:39 PM EDT	Areal Flood Advisory	CTP	Cumberland, Dauphin, Juniata, Northumberland, Perry, Snyder	2 hr
Jul 17, 4:33 AM EDT	Special Weather Statement	CTP	Warren	57 min
Jul 17, 6:36 AM EDT	Special Weather Statement	CTP	Warren	69 min
Jul 17, 7:46 AM EDT	Special Weather Statement	CTP	Elk, McKean	59 min
Jul 17, 10:23 AM EDT	Special Weather Statement	CTP	McKean	37 min
Jul 17, 12:01 PM EDT	Areal Flood Advisory	CTP	McKean	119 min
Jul 17, 12:35 PM EDT	Special Weather Statement	CTP	Potter	40 min
Jul 17, 12:55 PM EDT	Areal Flood Advisory	CTP	Warren	2 hr
Jul 17, 1:23 PM EDT	Special Weather Statement	CTP	Clinton	37 min
Jul 17, 1:33 PM EDT	Special Weather Statement	CTP	Lancaster	27 min
Jul 17, 1:48 PM EDT	Severe Thunderstorm Warning	CTP	Lancaster, York	42 min
Jul 17, 1:55 PM EDT	Flash Flood Warning	CTP	Cameron, Elk, McKean, Potter, Warren	3 hr
Jul 17, 2:13 PM EDT	Severe Thunderstorm Warning	CTP	Lancaster, Lebanon	47 min
Jul 17, 2:29 PM EDT	Severe Thunderstorm Warning	CTP	Lancaster	46 min
Jul 17, 2:46 PM EDT	Special Weather Statement	CTP	Cambria	29 min
Jul 17, 2:47 PM EDT	Areal Flood Advisory	CTP	Lancaster, Lebanon, Schuylkill, York	2 hr
Jul 17, 2:52 PM EDT	Severe Thunderstorm Warning	CTP	Schuylkill	38 min
Jul 17, 2:56 PM EDT	Severe Thunderstorm Warning	CTP	Lancaster, York	34 min
Jul 17, 3:02 PM EDT	Severe Thunderstorm Warning	CTP	Lebanon, Schuylkill	43 min
Jul 17, 3:04 PM EDT	Severe Thunderstorm Warning	CTP	Cambria, Clearfield, Somerset	56 min
Jul 17, 3:06 PM EDT	Special Weather Statement	CTP	Blair	24 min
Jul 17, 3:14 PM EDT	Severe Thunderstorm Warning	CTP	Lancaster	61 min
Jul 17, 3:17 PM EDT	Flash Flood Warning Considerable damage threat	CTP	Lycoming, Tioga	3 hr
Jul 17, 3:35 PM EDT	Special Weather Statement	CTP	Centre	25 min
Jul 17, 3:42 PM EDT	Special Weather Statement	CTP	York	33 min
Jul 17, 3:45 PM EDT	Special Weather Statement	CTP	Huntingdon	30 min
Jul 17, 3:48 PM EDT	Special Weather Statement	CTP	Lancaster	27 min
Jul 17, 3:52 PM EDT	Severe Thunderstorm Warning	CTP	Centre, Clearfield	23 min
Jul 17, 4:03 PM EDT	Special Weather Statement	CTP	Dauphin	27 min
Jul 17, 4:05 PM EDT	Severe Thunderstorm Warning	CTP	Centre, Huntingdon, Juniata, Mifflin	55 min
Jul 17, 4:07 PM EDT	Areal Flood Advisory	CTP	Adams, Cumberland, Dauphin, Lancaster, Lebanon, York	2 hr
Jul 17, 4:14 PM EDT	Special Weather Statement	CTP	Dauphin	31 min
Jul 17, 4:14 PM EDT	Special Weather Statement	CTP	Tioga	46 min
Jul 17, 4:23 PM EDT	Special Weather Statement	CTP	Clinton	37 min
Jul 17, 4:24 PM EDT	Special Weather Statement	CTP	Dauphin	36 min
Jul 17, 4:32 PM EDT	Special Weather Statement	CTP	Lycoming	28 min
Jul 17, 4:34 PM EDT	Special Weather Statement	CTP	Centre	26 min
Jul 17, 4:38 PM EDT	Areal Flood Advisory	CTP	Clinton, Lycoming	2 hr
Jul 17, 4:44 PM EDT	Areal Flood Advisory	CTP	Bedford, Cumberland, Franklin, Fulton, Huntingdon, Juniata and 3 more	2 hr
Jul 17, 4:45 PM EDT	Special Weather Statement	CTP	Dauphin	30 min
Jul 17, 4:47 PM EDT	Special Weather Statement	CTP	Tioga	28 min
Jul 17, 4:50 PM EDT	Special Weather Statement	CTP	Somerset	25 min
Jul 17, 4:53 PM EDT	Areal Flood Advisory	CTP	Cameron, Elk, McKean, Potter, Warren	66 min
Jul 17, 4:56 PM EDT	Areal Flood Advisory	CTP	Columbia, Dauphin, Lycoming, Montour, Northumberland, Schuylkill and 3 more	61 min
Jul 17, 4:58 PM EDT	Special Weather Statement	CTP	Clinton	32 min
Jul 17, 5:02 PM EDT	Severe Thunderstorm Warning	CTP	Clinton, Lycoming	43 min
Jul 17, 5:08 PM EDT	Special Weather Statement	CTP	Franklin	37 min
Jul 17, 5:14 PM EDT	Flash Flood Warning Considerable damage threat	CTP	Lycoming, Sullivan	3 hr
Jul 17, 5:16 PM EDT	Special Weather Statement	CTP	Dauphin	29 min
Jul 17, 5:20 PM EDT	Areal Flood Advisory	CTP	Cumberland, Dauphin, Juniata, Lebanon, Perry	2 hr
Jul 17, 5:27 PM EDT	Special Weather Statement	CTP	Sullivan	33 min
Jul 17, 5:30 PM EDT	Special Weather Statement	CTP	Franklin	30 min
Jul 17, 5:42 PM EDT	Flash Flood Warning Considerable damage threat	CTP	Adams, Cumberland, Franklin, Fulton, Huntingdon, Perry	111 min
Jul 17, 5:44 PM EDT	Severe Thunderstorm Warning	CTP	Columbia, Cumberland, Dauphin, Juniata, Lycoming, Montour and 6 more	61 min
Jul 17, 5:56 PM EDT	Flash Flood Warning Considerable damage threat	CTP	Columbia, Cumberland, Dauphin, Juniata, Lebanon, Lycoming and 7 more	3 hr
Jul 17, 6:09 PM EDT	Severe Thunderstorm Warning	CTP	Adams, Cumberland, Dauphin, Franklin, York	36 min
Jul 17, 6:22 PM EDT	Severe Thunderstorm Warning	CTP	Columbia, Lycoming, Sullivan	28 min
Jul 17, 6:44 PM EDT	Severe Thunderstorm Warning	CTP	Adams, Dauphin, Lancaster, Lebanon, York	46 min
Jul 17, 6:57 PM EDT	Special Weather Statement	CTP	Schuylkill	33 min
Jul 17, 7:07 PM EDT	Areal Flood Advisory	CTP	Adams, York	2 hr
Jul 17, 7:34 PM EDT	Severe Thunderstorm Warning	CTP	Adams, York	56 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2021 Every severe thunderstorm 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.