Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 174, NWS State College, PA

July 17, 2021Lancaster County, Pennsylvania

NWS State College, PA issued this severe thunderstorm warning at Jul 17, 2021, 3:14 PM EDT for Lancaster County, Pennsylvania. It was in force for 61 min. 1 report 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, 3:14 PM EDT (19:14 UTC)
Expired
Jul 17, 2021, 4:15 PM EDT
In force
61 min
Issued by
NWS State College, PA
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

County Lancaster County, PA

The radar

The Dover AFB radar (KDOX), 138 km from the middle of the area, began a volume at 19:13 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 17, 3:53 PM EDTTSTM WND DMG1 Wnw Paradise, PASTORM DAMAGE REPORTED ON LIVE INCIDENT LIST.

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.

IssuedProductOfficeLasted
Jul 17, 1:13 PM EDTSevere Thunderstorm WatchSPC10 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 7.2 hours before the alert went out and 162 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 2021-07-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 538 joules per kilogram.LCLLFCEL10008507005003002001001 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 2021-07-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 37 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
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.

251 
WUUS51 KCTP 171914
SVRCTP
PAC071-172015-
/O.NEW.KCTP.SV.W.0174.210717T1914Z-210717T2015Z/

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

The National Weather Service in State College PA has issued a

* Severe Thunderstorm Warning for...
  East central Lancaster County in south central Pennsylvania...

* Until 415 PM EDT.

* At 314 PM EDT, a severe thunderstorm was located over Smithville,
  moving northeast at 15 mph.

  HAZARD...60 mph wind gusts and quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees.

* Locations impacted include...
  Lancaster, Willow Street, New Holland, Leola, Paradise, Strasburg,
  Quarryville, Gap, Leacock, Bareville, Smithville, Lampeter,
  Intercourse, Conestoga, Christiana, Georgetown, Gordonville,
  Bird-In-Hand, Smoketown and Refton.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 4010 7594 4004 7594 3997 7599 3995 7599
      3993 7598 3993 7600 3987 7599 3987 7600
      3986 7601 3988 7632 3992 7638 4008 7628
      4012 7592
TIME...MOT...LOC 1914Z 226DEG 11KT 3990 7630 

HAIL...1.00IN
WIND...60MPH
 
$$

Evanego
1 follow-up statement
904 
WWUS51 KCTP 171950
SVSCTP

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

PAC071-172015-
/O.CON.KCTP.SV.W.0174.000000T0000Z-210717T2015Z/
Lancaster PA-
350 PM EDT Sat Jul 17 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 415 PM EDT
FOR EAST CENTRAL LANCASTER COUNTY...

At 350 PM EDT, a severe thunderstorm was located over Strasburg,
moving northeast at 15 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

Locations impacted include...
Lancaster, Willow Street, New Holland, Leola, Paradise, Strasburg,
Gap, Leacock, Bareville, Lampeter, Intercourse, Christiana,
Georgetown, Gordonville, Bird-In-Hand, Smoketown, Refton, White Horse
and Dutch Wonderland.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 4010 7594 4004 7594 3997 7599 3995 7599
      3993 7624 4000 7633 4008 7628 4012 7592
TIME...MOT...LOC 1950Z 226DEG 11KT 3998 7620 

HAIL...1.00IN
WIND...60MPH
 
$$

Evanego

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 16, 9:11 PM EDTSpecial Weather StatementCTPCumberland34 min
Jul 16, 10:39 PM EDTAreal Flood AdvisoryCTPCumberland, Dauphin, Juniata, Northumberland, Perry, Snyder2 hr
Jul 17, 4:33 AM EDTSpecial Weather StatementCTPWarren57 min
Jul 17, 6:36 AM EDTSpecial Weather StatementCTPWarren69 min
Jul 17, 7:46 AM EDTSpecial Weather StatementCTPElk, McKean59 min
Jul 17, 10:23 AM EDTSpecial Weather StatementCTPMcKean37 min
Jul 17, 12:01 PM EDTAreal Flood AdvisoryCTPMcKean119 min
Jul 17, 12:35 PM EDTSpecial Weather StatementCTPPotter40 min
Jul 17, 12:55 PM EDTAreal Flood AdvisoryCTPWarren2 hr
Jul 17, 1:23 PM EDTSpecial Weather StatementCTPClinton37 min
Jul 17, 1:33 PM EDTSpecial Weather StatementCTPLancaster27 min
Jul 17, 1:48 PM EDTSevere Thunderstorm WarningCTPLancaster, York42 min
Jul 17, 1:55 PM EDTFlash Flood WarningCTPCameron, Elk, McKean, Potter, Warren3 hr
Jul 17, 2:13 PM EDTSevere Thunderstorm WarningCTPLancaster, Lebanon47 min
Jul 17, 2:29 PM EDTSevere Thunderstorm WarningCTPLancaster46 min
Jul 17, 2:46 PM EDTSpecial Weather StatementCTPCambria29 min
Jul 17, 2:47 PM EDTAreal Flood AdvisoryCTPLancaster, Lebanon, Schuylkill, York2 hr
Jul 17, 2:52 PM EDTSevere Thunderstorm WarningCTPSchuylkill38 min
Jul 17, 2:56 PM EDTSevere Thunderstorm WarningCTPLancaster, York34 min
Jul 17, 3:02 PM EDTSevere Thunderstorm WarningCTPLebanon, Schuylkill43 min
Jul 17, 3:04 PM EDTSevere Thunderstorm WarningCTPCambria, Clearfield, Somerset56 min
Jul 17, 3:06 PM EDTSpecial Weather StatementCTPBlair24 min
Jul 17, 3:17 PM EDTFlash Flood Warning Considerable damage threatCTPLycoming, Tioga3 hr
Jul 17, 3:35 PM EDTSpecial Weather StatementCTPCentre25 min
Jul 17, 3:42 PM EDTSpecial Weather StatementCTPYork33 min
Jul 17, 3:45 PM EDTSpecial Weather StatementCTPHuntingdon30 min
Jul 17, 3:48 PM EDTSpecial Weather StatementCTPLancaster27 min
Jul 17, 3:52 PM EDTSevere Thunderstorm WarningCTPCentre, Clearfield23 min
Jul 17, 4:03 PM EDTSpecial Weather StatementCTPDauphin27 min
Jul 17, 4:05 PM EDTSevere Thunderstorm WarningCTPCentre, Huntingdon, Juniata, Mifflin55 min
Jul 17, 4:07 PM EDTAreal Flood AdvisoryCTPAdams, Cumberland, Dauphin, Lancaster, Lebanon, York2 hr
Jul 17, 4:14 PM EDTSpecial Weather StatementCTPDauphin31 min
Jul 17, 4:14 PM EDTSpecial Weather StatementCTPTioga46 min
Jul 17, 4:23 PM EDTSpecial Weather StatementCTPClinton37 min
Jul 17, 4:24 PM EDTSpecial Weather StatementCTPDauphin36 min
Jul 17, 4:32 PM EDTSpecial Weather StatementCTPLycoming28 min
Jul 17, 4:34 PM EDTSpecial Weather StatementCTPCentre26 min
Jul 17, 4:38 PM EDTAreal Flood AdvisoryCTPClinton, Lycoming2 hr
Jul 17, 4:44 PM EDTAreal Flood AdvisoryCTPBedford, Cumberland, Franklin, Fulton, Huntingdon, Juniata and 3 more2 hr
Jul 17, 4:45 PM EDTSpecial Weather StatementCTPDauphin30 min
Jul 17, 4:47 PM EDTSpecial Weather StatementCTPTioga28 min
Jul 17, 4:50 PM EDTSpecial Weather StatementCTPSomerset25 min
Jul 17, 4:50 PM EDTSevere Thunderstorm WarningCTPJuniata, Mifflin, Northumberland, Snyder, Union55 min
Jul 17, 4:53 PM EDTAreal Flood AdvisoryCTPCameron, Elk, McKean, Potter, Warren66 min
Jul 17, 4:56 PM EDTAreal Flood AdvisoryCTPColumbia, Dauphin, Lycoming, Montour, Northumberland, Schuylkill and 3 more61 min
Jul 17, 4:58 PM EDTSpecial Weather StatementCTPClinton32 min
Jul 17, 5:02 PM EDTSevere Thunderstorm WarningCTPClinton, Lycoming43 min
Jul 17, 5:08 PM EDTSpecial Weather StatementCTPFranklin37 min
Jul 17, 5:14 PM EDTFlash Flood Warning Considerable damage threatCTPLycoming, Sullivan3 hr
Jul 17, 5:16 PM EDTSpecial Weather StatementCTPDauphin29 min
Jul 17, 5:20 PM EDTAreal Flood AdvisoryCTPCumberland, Dauphin, Juniata, Lebanon, Perry2 hr
Jul 17, 5:27 PM EDTSpecial Weather StatementCTPSullivan33 min
Jul 17, 5:30 PM EDTSpecial Weather StatementCTPFranklin30 min
Jul 17, 5:42 PM EDTFlash Flood Warning Considerable damage threatCTPAdams, Cumberland, Franklin, Fulton, Huntingdon, Perry111 min
Jul 17, 5:44 PM EDTSevere Thunderstorm WarningCTPColumbia, Cumberland, Dauphin, Juniata, Lycoming, Montour and 6 more61 min
Jul 17, 5:56 PM EDTFlash Flood Warning Considerable damage threatCTPColumbia, Cumberland, Dauphin, Juniata, Lebanon, Lycoming and 7 more3 hr
Jul 17, 6:09 PM EDTSevere Thunderstorm WarningCTPAdams, Cumberland, Dauphin, Franklin, York36 min
Jul 17, 6:22 PM EDTSevere Thunderstorm WarningCTPColumbia, Lycoming, Sullivan28 min
Jul 17, 6:44 PM EDTSevere Thunderstorm WarningCTPAdams, Dauphin, Lancaster, Lebanon, York46 min
Jul 17, 6:57 PM EDTSpecial Weather StatementCTPSchuylkill33 min
Jul 17, 7:07 PM EDTAreal Flood AdvisoryCTPAdams, York2 hr
Jul 17, 7:34 PM EDTSevere Thunderstorm WarningCTPAdams, York56 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.