Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 193, NWS State College, PA

August 10, 2021Lancaster County, York County, Pennsylvania

NWS State College, PA issued this severe thunderstorm warning at Aug 10, 2021, 6:29 PM EDT for Lancaster County, York County, Pennsylvania. It was in force for 58 min. 3 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 10, 2021, 6:29 PM EDT (22:29 UTC)
Expired: Aug 10, 2021, 7:27 PM EDT
In force: 58 min
Issued by: NWS State College, PA
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Lancaster County, PA, York County, PA

The radar

The Sterling radar (KLWX), 131 km from the middle of the area, began a volume at 22:29 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 10, 6:35 PM EDT	TSTM WND DMG	3 Wsw York, PA	WIRES DOWN.
Aug 10, 6:36 PM EDT	TSTM WND DMG	1 Se York, PA	WIRES DOWN.
Aug 10, 6:50 PM EDT	TSTM WND DMG	Spring Grove, PA	LARGE TREES DOWN.

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, 10.5 hours before the alert went out and 130 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: 529 J/kg
Mixed-layer CIN: -120 J/kg
Mixed-layer LCL: 1096 m above ground
0-6 km bulk shear: 14 kt
0-1 km storm-relative helicity: 37 m²/s²
0-3 km storm-relative helicity: 65 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

908 
WUUS51 KCTP 102229
SVRCTP
PAC071-133-102345-
/O.NEW.KCTP.SV.W.0193.210810T2229Z-210810T2345Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service State College PA
629 PM EDT Tue Aug 10 2021

The National Weather Service in State College PA has issued a

* Severe Thunderstorm Warning for...
  Northwestern Lancaster County in south central Pennsylvania...
  Central York County in south central Pennsylvania...

* Until 745 PM EDT.

* At 629 PM EDT, severe thunderstorms were located along a line
  extending from near Bainbridge to West York to near Parkville,
  moving east at 15 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  York, Hanover, Weigelstown, Elizabethtown, Columbia, Mount Joy,
  Parkville, Red Lion, Spry, Dallastown, Shiloh, East York,
  Stonybrook-Wilshire, West York, Maytown, Shrewsbury, Codorus,
  Grantley, Valley Green and Tyler Run-Queens Gate.

This includes Interstate 83 from mile markers 2 to 34.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 3978 7700 3993 7691 4015 7687 4017 7675
      4013 7674 4012 7672 4016 7670 4015 7668
      4018 7661 4020 7651 3999 7650 3972 7668
      3972 7699
TIME...MOT...LOC 2229Z 254DEG 15KT 4012 7670 3996 7676 3975 7693 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Colbert

2 follow-up statements

142 
WWUS51 KCTP 102247
SVSCTP

Severe Weather Statement
National Weather Service State College PA
647 PM EDT Tue Aug 10 2021

PAC071-133-102345-
/O.CON.KCTP.SV.W.0193.000000T0000Z-210810T2345Z/
Lancaster PA-York PA-
647 PM EDT Tue Aug 10 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 745 PM EDT
FOR WEST CENTRAL LANCASTER AND SOUTHWESTERN YORK COUNTIES...

At 647 PM EDT, severe thunderstorms were located along a line
extending from Mount Joy to Windsor to near Railroad, moving east at
15 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
York, Hanover, Weigelstown, Columbia, Mount Joy, Parkville, Red Lion,
Spry, Dallastown, Shiloh, East York, Stonybrook-Wilshire, West York,
Maytown, Shrewsbury, Codorus, Grantley, Tyler Run-Queens Gate,
Manchester and Hallam.

This includes Interstate 83 from mile markers 2 to 28.

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 3991 7689 4008 7677 4014 7651 3999 7650
      3972 7668 3972 7693 3977 7696 3983 7697
      3985 7696
TIME...MOT...LOC 2247Z 262DEG 15KT 4010 7650 3994 7659 3974 7674 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Colbert

192 
WWUS51 KCTP 102327
SVSCTP

Severe Weather Statement
National Weather Service State College PA
727 PM EDT Tue Aug 10 2021

PAC071-133-102336-
/O.CAN.KCTP.SV.W.0193.000000T0000Z-210810T2345Z/
Lancaster PA-York PA-
727 PM EDT Tue Aug 10 2021

...THE SEVERE THUNDERSTORM WARNING FOR FAR WESTERN LANCASTER AND 
SOUTHWESTERN YORK COUNTIES IS CANCELLED...
    
The storms which prompted the warning have moved out of the area.
Therefore, the warning has been cancelled. A separate severe 
thunderstorm warning continues for central and eastern Lancaster 
County.

To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
State College PA.

LAT...LON 3991 7689 4008 7677 4014 7651 3999 7650
      3972 7668 3972 7693 3977 7696 3983 7697
      3985 7696
TIME...MOT...LOC 2325Z 254DEG 15KT 4014 7630 3998 7639 3978 7654 

$$

Colbert

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 10, 12:55 PM EDT	Heat Advisory	CTP	Adams, Columbia, Cumberland, Dauphin, Franklin, Juniata and 10 more	30 hr
Aug 10, 12:55 PM EDT	Heat Advisory	CTP	Adams, Bedford, Blair, Centre, Clinton, Columbia and 19 more	54 hr
Aug 10, 2:21 PM EDT	Special Weather Statement	CTP	Dauphin, Lebanon	24 min
Aug 10, 2:32 PM EDT	Severe Thunderstorm Warning	CTP	Dauphin, Lebanon	43 min
Aug 10, 3:12 PM EDT	Special Weather Statement	CTP	Bedford, Blair, Cambria, Somerset	33 min
Aug 10, 3:23 PM EDT	Special Weather Statement	CTP	Berks	37 min
Aug 10, 3:25 PM EDT	Special Weather Statement	CTP	Huntingdon, Juniata	50 min
Aug 10, 3:28 PM EDT	Special Weather Statement	CTP	Schuylkill	47 min
Aug 10, 4:14 PM EDT	Special Weather Statement	CTP	Juniata	31 min
Aug 10, 4:31 PM EDT	Special Weather Statement	CTP	Centre	29 min
Aug 10, 4:48 PM EDT	Special Weather Statement	CTP	Perry	27 min
Aug 10, 5:18 PM EDT	Special Weather Statement	CTP	Dauphin	42 min
Aug 10, 5:50 PM EDT	Special Weather Statement	CTP	Adams	40 min
Aug 10, 5:52 PM EDT	Special Weather Statement	CTP	Lebanon	38 min
Aug 10, 6:12 PM EDT	Special Weather Statement	CTP	Lancaster	63 min
Aug 10, 6:17 PM EDT	Severe Thunderstorm Warning	CTP	Lancaster, Lebanon	73 min
Aug 10, 7:00 PM EDT	Severe Thunderstorm Warning	CTP	Lancaster, York	75 min
Aug 10, 7:33 PM EDT	Areal Flood Advisory	CTP	Lancaster	2 hr

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.