Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 106, NWS State College, PA

July 9, 20214 counties in Pennsylvania

NWS State College, PA issued this severe thunderstorm warning at Jul 9, 2021, 5:24 PM EDT for 4 counties in Pennsylvania. It was in force for 81 min. 7 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 9, 2021, 5:24 PM EDT (21:24 UTC)
Expired
Jul 9, 2021, 6:45 PM EDT
In force
81 min
Issued by
NWS State College, PA
Area
Storm-based polygon
Hail
0.75 in
Wind
70.0 mph

Counties Dauphin County, PA, Lancaster County, PA, Lebanon County, PA, York County, PA

The radar

The Dover AFB radar (KDOX), 139 km from the middle of the area, began a volume at 21:25 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

TimeReportWhereRemark
Jul 9, 5:24 PM EDTTSTM WND DMG1 Sw Lawn, PATREES DOWN ACROSS BACHMANVILLE ROAD NEAR THE PA TURNPIKE AND THE LAWN SERVICE PLAZA.
Jul 9, 5:31 PM EDTTSTM WND DMG3 W Elizabethtown, PAWIRES REPORTED DOWN ON BOSSLER ROAD NEAR THE AMTRAK MAINLINE.
Jul 9, 5:38 PM EDTTSTM WND DMG2 Sse Mount Gretna, PAMULTIPLE REPORTS OF TREES ON WIRES ACROSS THE NORTHERN PORTION OF RAPHO TOWNSHIP.
Jul 9, 5:49 PM EDTTSTM WND DMG1 Nne Manheim, PATREE ON A HOME NEAR HERSHEY DRIVE AND EAST ADELE AVE.
Jul 9, 5:53 PM EDTTSTM WND DMG2 Nne East Petersburg, PATREE FELL ON AN OCCUPIED VEHICLE ON FRUITVILLE PIKE BETWEEN LITITZ ROAD AND ERBS QUARRY ROAD. NO INJURIES.
Jul 9, 5:56 PM EDTTSTM WND DMG1 W Rothsville, PATREES DOWN ON ROUTE 772 BETWEEN LITITZ AND BROWNSTOWN.
Jul 9, 6:05 PM EDTTSTM WND DMG2 Nnw Leola, PATREES DOWN NEAR THE INTERSECTION OF STONE QUARRY ROAD AND ROUTE 772 IN BROWNSTOWN.

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, 9.4 hours before the alert went out and 147 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-pSkew-T log-p diagram, Washington/Dulle, VA at 12:00Z on 2021-07-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 12:00Z on 2021-07-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 42 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
862 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
42 m²/s²
0-3 km storm-relative helicity
55 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

312 
WUUS51 KCTP 092124
SVRCTP
PAC043-071-075-133-092245-
/O.NEW.KCTP.SV.W.0106.210709T2124Z-210709T2245Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service State College PA
524 PM EDT Fri Jul 9 2021

The National Weather Service in State College PA has issued a

* Severe Thunderstorm Warning for...
  Lancaster County in south central Pennsylvania...
  Central York County in south central Pennsylvania...
  Southeastern Dauphin County in south central Pennsylvania...
  South central Lebanon County in south central Pennsylvania...

* Until 645 PM EDT.

* At 523 PM EDT, a severe thunderstorm was located over
  Elizabethtown, moving southeast at 40 mph.

  HAZARD...70 mph wind gusts and penny size hail.

  SOURCE...Radar indicated.

  IMPACT...Expect considerable tree damage. Damage is likely to 
           mobile homes, roofs, and outbuildings.

* Locations impacted include...
  Lancaster, Hershey, Elizabethtown, Columbia, Lititz, Middletown,
  Millersville, Willow Street, Mount Joy, New Holland, Manheim, East
  Petersburg, Akron, Leola, Paradise, Salunga-Landisville, Maytown,
  Rothsville, Strasburg and Mountville.

This includes The Pennsylvania Turnpike from mile markers 248 to 269.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Intense thunderstorm lines can produce brief tornadoes and widespread
significant wind damage. Although a tornado is not immediately
likely, it is best to move to an interior room on the lowest floor of
a building. This storm may cause serious injury and significant
property damage.

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

&&

LAT...LON 4021 7679 4026 7676 4023 7639 4004 7593
      3996 7599 3987 7599 3985 7602 3981 7603
      3980 7605 3976 7606 3976 7608 3973 7610
      3974 7611 3972 7614 3972 7639
TIME...MOT...LOC 2123Z 301DEG 33KT 4019 7660 

HAIL...0.75IN
WIND...70MPH
 
$$

Lambert
2 follow-up statements
567 
WWUS51 KCTP 092158
SVSCTP

Severe Weather Statement
National Weather Service State College PA
558 PM EDT Fri Jul 9 2021

PAC043-075-092205-
/O.CAN.KCTP.SV.W.0106.000000T0000Z-210709T2245Z/
Dauphin PA-Lebanon PA-
558 PM EDT Fri Jul 9 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN DAUPHIN AND SOUTH
CENTRAL LEBANON COUNTIES IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved 
southeast of the warned area. Therefore, the warning has been 
cancelled.

LAT...LON 4005 7666 4011 7661 4022 7649 4023 7639
      4004 7593 3996 7599 3987 7599 3985 7602
      3981 7603 3980 7605 3976 7606 3976 7608
      3973 7610 3974 7611 3972 7614 3972 7639
TIME...MOT...LOC 2155Z 290DEG 28KT 4010 7629 

$$

PAC071-133-092245-
/O.CON.KCTP.SV.W.0106.000000T0000Z-210709T2245Z/
Lancaster PA-York PA-
558 PM EDT Fri Jul 9 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 645 PM EDT
FOR LANCASTER AND SOUTHEASTERN YORK COUNTIES...

At 555 PM EDT, a severe thunderstorm was located near East
Petersburg, moving southeast at 30 mph.

This is a very dangerous storm.

HAZARD...80 mph wind gusts and penny size hail.

SOURCE...Radar indicated.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be heavily damaged. Expect 
         considerable damage to roofs, windows, and vehicles. 
         Extensive tree damage and power outages are likely.

This severe storm will be near...
  Akron, Willow Street and Leacock around 600 PM EDT.
  Bareville, Leola and Strasburg around 610 PM EDT.
  New Holland and Paradise around 620 PM EDT.
  Gap around 630 PM EDT.

Other locations impacted by this severe thunderstorm include Buck,
East Prospect, Peach Bottom, Rawlinsville, Susquehanna Trails,
Georgetown, Farmersville, Smoketown, Christiana and Washington Boro.

This includes The Pennsylvania Turnpike from mile markers 268 to 269.

This includes the following highways...
 Route 30 from Hallam to the Chester County line.
 Route 222 from the Maryland Border to near Akron.
 State Road 41 from Gap to the Chester County line.
 State Road 501 from Lancaster to Lititz.
 State Highway 283 from Mount Joy to Lancaster.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This is an EXTREMELY DANGEROUS SITUATION with tornado like wind
speeds expected. Mobile homes and high profile vehicles are
especially susceptible to winds of this magnitude and may be
overturned. For your protection move to an interior room on the
lowest floor of a building. This storm has the potential to cause
serious injury and significant property damage.

&&

LAT...LON 4005 7666 4011 7661 4022 7649 4023 7639
      4004 7593 3996 7599 3987 7599 3985 7602
      3981 7603 3980 7605 3976 7606 3976 7608
      3973 7610 3974 7611 3972 7614 3972 7639
TIME...MOT...LOC 2155Z 290DEG 28KT 4010 7629 

HAIL...0.75IN
WIND...80MPH
 
$$

Lambert
922 
WWUS51 KCTP 092229
SVSCTP

Severe Weather Statement
National Weather Service State College PA
629 PM EDT Fri Jul 9 2021

PAC071-133-092245-
/O.CON.KCTP.SV.W.0106.000000T0000Z-210709T2245Z/
Lancaster PA-York PA-
629 PM EDT Fri Jul 9 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 645 PM EDT
FOR SOUTHEASTERN LANCASTER AND SOUTHEASTERN YORK COUNTIES...

At 628 PM EDT, severe thunderstorms were located along a line
extending from Paradise to near Smithville to near Sunnyburn, moving
southeast at 20 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Lancaster, Millersville, Willow Street, Paradise, Strasburg,
Quarryville, Gap, Delta, Wakefield, Brogue, Smithville, Holtwood,
Sunnyburn, Shenks Ferry, Safe Harbor, Susquehanna Trails, Lampeter,
Intercourse, Conestoga and Christiana.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3992 7656 3995 7648 3999 7637 4007 7621
      4001 7595 3996 7599 3987 7599 3985 7602
      3981 7603 3980 7605 3976 7606 3976 7608
      3973 7610 3974 7611 3972 7614 3972 7639
TIME...MOT...LOC 2228Z 311DEG 17KT 4001 7609 3989 7626 3981 7644 

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

Lambert

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 9, 3:36 PM EDTSpecial Weather StatementCTPJuniata24 min
Jul 9, 3:49 PM EDTSpecial Weather StatementCTPYork26 min
Jul 9, 4:02 PM EDTSpecial Weather StatementCTPLycoming28 min
Jul 9, 4:04 PM EDTSpecial Weather StatementCTPPerry26 min
Jul 9, 4:16 PM EDTSevere Thunderstorm WarningCTPDauphin, Juniata, Lebanon, Perry, Schuylkill74 min
Jul 9, 4:21 PM EDTSpecial Weather StatementCTPYork24 min
Jul 9, 4:49 PM EDTSevere Thunderstorm WarningCTPDauphin, Lebanon56 min
Jul 9, 6:13 PM EDTSevere Thunderstorm WarningCTPLancaster47 min
Jul 9, 6:22 PM EDTSpecial Weather StatementCTPYork38 min
Jul 9, 6:41 PM EDTSpecial Weather StatementCTPSchuylkill49 min
Jul 9, 7:00 PM EDTSpecial Weather StatementCTPLancaster30 min
Jul 9, 7:16 PM EDTSpecial Weather StatementCTPTioga29 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2021Every 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.