Alert archive / Pennsylvania / Tornado Warnings in 2021

Tornado Warning 9, NWS State College, PA

August 18, 2021Centre County, Huntingdon County, Pennsylvania

NWS State College, PA issued this tornado warning at Aug 18, 2021, 2:02 PM EDT for Centre County, Huntingdon County, Pennsylvania. It was in force for 28 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 18, 2021, 2:02 PM EDT (18:02 UTC)
Expired
Aug 18, 2021, 2:30 PM EDT
In force
28 min
Issued by
NWS State College, PA
Area
Storm-based polygon
Tornado
Radar indicated
Hail
0.75 in

Counties Centre County, PA, Huntingdon County, PA

The radar

The State College radar (KCCX), 34 km from the middle of the area, began a volume at 18:05 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 watch it was issued in

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

IssuedProductOfficeLasted
Aug 18, 11:37 AM EDTTornado WatchSPC11 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 6.0 hours before the alert went out and 195 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 2021-08-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1011 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 2021-08-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 151 square meters per square second.193958Sfc1 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
1011 J/kg
Mixed-layer CIN
-1 J/kg
Mixed-layer LCL
592 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
151 m²/s²
0-3 km storm-relative helicity
175 m²/s²
Significant tornado parameter
0.6
Supercell composite
4.6

Open this sounding in Storm Lab

The text

As transmitted.

315 
WFUS51 KCTP 181802
TORCTP
PAC027-061-181830-
/O.NEW.KCTP.TO.W.0009.210818T1802Z-210818T1830Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service State College PA
202 PM EDT Wed Aug 18 2021

The National Weather Service in State College PA has issued a

* Tornado Warning for...
  Northeastern Huntingdon County in central Pennsylvania...
  South central Centre County in central Pennsylvania...

* Until 230 PM EDT.
    
* At 201 PM EDT, a severe thunderstorm capable of producing a tornado
  was located over Mcalevys Fort, moving north at 30 mph.

  HAZARD...Tornado.

  SOURCE...Radar indicated rotation.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely.

* This dangerous storm will be near...
  State College, Boalsburg, Pine Grove Mills and Park Forest Village 
  around 220 PM EDT.
  Lemont and Houserville around 230 PM EDT.

Other locations impacted by this tornadic thunderstorm include Tussey
Mountain Ski Area, Pennsylvania State University, Pennsylvania
Military Museum and University Park Airport.

This includes Interstate 99 from mile markers 69 to 75.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 4056 7788 4085 7795 4082 7761 4073 7767
      4073 7768 4072 7768 4070 7770 4068 7770
      4065 7772 4061 7779 4056 7784
TIME...MOT...LOC 1801Z 188DEG 27KT 4063 7783 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...<.75 IN

$$

Colbert
3 follow-up statements
044 
WWUS51 KCTP 181814
SVSCTP

Severe Weather Statement
National Weather Service State College PA
214 PM EDT Wed Aug 18 2021

PAC027-061-181830-
/O.CON.KCTP.TO.W.0009.000000T0000Z-210818T1830Z/
Huntingdon PA-Centre PA-
214 PM EDT Wed Aug 18 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 230 PM EDT FOR NORTH
CENTRAL HUNTINGDON AND SOUTH CENTRAL CENTRE COUNTIES...
    
At 214 PM EDT, a severe thunderstorm capable of producing a tornado
was located near Whipple Dam State Park, moving north at 30 mph.

HAZARD...Tornado.

SOURCE...Radar indicated rotation.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

Locations impacted include...
State College, Park Forest Village, Boalsburg, Lemont, Houserville,
Pine Grove Mills, Whipple Dam State Park, Tussey Mountain Ski Area,
Pennsylvania State University, Pennsylvania Military Museum and
University Park Airport.

This includes Interstate 99 from mile markers 71 to 75.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

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

&&

LAT...LON 4065 7779 4066 7788 4085 7792 4082 7764
TIME...MOT...LOC 1814Z 188DEG 26KT 4071 7781 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...0.00 IN

$$

Colbert
656 
WWUS51 KCTP 181825
SVSCTP

Severe Weather Statement
National Weather Service State College PA
225 PM EDT Wed Aug 18 2021

PAC061-181834-
/O.CAN.KCTP.TO.W.0009.000000T0000Z-210818T1830Z/
Huntingdon PA-
225 PM EDT Wed Aug 18 2021

...THE TORNADO WARNING FOR NORTH CENTRAL HUNTINGDON COUNTY IS
CANCELLED...
    
The tornadic thunderstorm which prompted the warning has moved out 
of the warned area. Therefore, the warning has been cancelled.

A Tornado Watch remains in effect until 800 PM EDT for central
Pennsylvania.

LAT...LON 4083 7769 4074 7778 4074 7779 4075 7781
      4075 7784 4085 7788
TIME...MOT...LOC 1824Z 187DEG 27KT 4079 7780 

$$

PAC027-181830-
/O.CON.KCTP.TO.W.0009.000000T0000Z-210818T1830Z/
Centre PA-
225 PM EDT Wed Aug 18 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 230 PM EDT FOR SOUTH
CENTRAL CENTRE COUNTY...
    
At 224 PM EDT, a severe thunderstorm capable of producing a tornado
was located over Boalsburg, moving north at 30 mph.

HAZARD...Tornado.

SOURCE...Radar indicated rotation.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

Locations impacted include...
State College, Boalsburg, Lemont, Houserville, Tussey Mountain Ski
Area, Pennsylvania State University, Pennsylvania Military Museum and
University Park Airport.

This includes Interstate 99 from mile markers 73 to 75.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

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

&&

LAT...LON 4083 7769 4074 7778 4074 7779 4075 7781
      4075 7784 4085 7788
TIME...MOT...LOC 1824Z 187DEG 27KT 4079 7780 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...0.00 IN

$$

Colbert
802 
WWUS51 KCTP 181834
SVSCTP

Severe Weather Statement
National Weather Service State College PA
234 PM EDT Wed Aug 18 2021

PAC027-181843-
/O.EXP.KCTP.TO.W.0009.000000T0000Z-210818T1830Z/
Centre PA-
234 PM EDT Wed Aug 18 2021

...THE TORNADO WARNING FOR SOUTH CENTRAL CENTRE COUNTY HAS EXPIRED...
                
The storm which prompted the warning has weakened below severe
limits, and no longer appears capable of producing a tornado.
Therefore, the warning has been allowed to expire.

A Tornado Watch remains in effect until 800 PM EDT for central
Pennsylvania.

LAT...LON 4083 7769 4074 7778 4074 7779 4075 7781
      4075 7784 4085 7788
TIME...MOT...LOC 1833Z 188DEG 27KT 4085 7779 

$$

Colbert

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 18, 9:50 AM EDTSpecial Weather StatementCTPBedford55 min
Aug 18, 10:25 AM EDTAreal Flood AdvisoryCTPBedford3 hr
Aug 18, 10:32 AM EDTSevere Thunderstorm WarningCTPBedford, Blair43 min
Aug 18, 10:53 AM EDTSpecial Weather StatementCTPCambria37 min
Aug 18, 10:57 AM EDTSpecial Weather StatementCTPBedford18 min
Aug 18, 11:15 AM EDTSpecial Weather StatementCTPBlair, Cambria30 min
Aug 18, 11:33 AM EDTAreal Flood AdvisoryCTPBlair, Cambria3 hr
Aug 18, 12:04 PM EDTAreal Flood AdvisoryCTPBedford2 hr
Aug 18, 12:11 PM EDTSpecial Weather StatementCTPBlair34 min
Aug 18, 12:26 PM EDTSpecial Weather StatementCTPSchuylkill34 min
Aug 18, 12:35 PM EDTFlash Flood Warning Considerable damage threatCTPBedford, Blair, Huntingdon3 hr
Aug 18, 12:39 PM EDTSpecial Weather StatementCTPCumberland36 min
Aug 18, 12:54 PM EDTSevere Thunderstorm WarningCTPCumberland, Perry36 min
Aug 18, 1:01 PM EDTSpecial Weather StatementCTPHuntingdon44 min
Aug 18, 1:15 PM EDTSpecial Weather StatementCTPJuniata, Mifflin30 min
Aug 18, 1:31 PM EDTSevere Thunderstorm WarningCTPJuniata, Perry44 min
Aug 18, 1:37 PM EDTFlash Flood Warning Considerable damage threatCTPBlair, Centre, Huntingdon82 min
Aug 18, 2:00 PM EDTSpecial Weather StatementCTPSnyder30 min
Aug 18, 2:12 PM EDTSevere Thunderstorm WarningCTPCentre, Clinton33 min
Aug 18, 2:26 PM EDTSpecial Weather StatementCTPCumberland, Perry34 min
Aug 18, 2:29 PM EDTSpecial Weather StatementCTPCentre31 min
Aug 18, 2:36 PM EDTSevere Thunderstorm WarningCTPCumberland, Perry39 min
Aug 18, 3:03 PM EDTSpecial Weather StatementCTPCumberland42 min
Aug 18, 3:10 PM EDTTornado WarningCTPAdams, York40 min
Aug 18, 3:17 PM EDTAreal Flood WarningCTPBedford, Blair, Huntingdon118 min
Aug 18, 3:36 PM EDTSevere Thunderstorm WarningCTPCumberland, Dauphin, Lancaster, York24 min
Aug 18, 3:56 PM EDTSevere Thunderstorm WarningCTPDauphin, Juniata, Northumberland, Perry, Snyder34 min
Aug 18, 4:03 PM EDTSpecial Weather StatementCTPDauphin42 min
Aug 18, 4:05 PM EDTSevere Thunderstorm WarningCTPFranklin, Fulton40 min
Aug 18, 4:30 PM EDTAreal Flood AdvisoryCTPJuniata, Perry, Snyder4 hr
Aug 18, 4:30 PM EDTSpecial Weather StatementCTPSnyder30 min
Aug 18, 4:39 PM EDTSevere Thunderstorm WarningCTPFranklin36 min
Aug 18, 4:42 PM EDTAreal Flood AdvisoryCTPFulton, Huntingdon2 hr
Aug 18, 4:48 PM EDTAreal Flood AdvisoryCTPCameron, Clinton, Lycoming, Potter, Tioga5 hr
Aug 18, 5:10 PM EDTSevere Thunderstorm WarningCTPAdams, Cumberland, Franklin, Perry, York35 min
Aug 18, 5:18 PM EDTSevere Thunderstorm WarningCTPJuniata, Mifflin45 min
Aug 18, 5:31 PM EDTSevere Thunderstorm WarningCTPDauphin74 min
Aug 18, 5:35 PM EDTSpecial Weather StatementCTPLancaster25 min
Aug 18, 5:35 PM EDTSevere Thunderstorm WarningCTPAdams40 min
Aug 18, 5:38 PM EDTSevere Thunderstorm WarningCTPAdams, Cumberland, York37 min
Aug 18, 6:13 PM EDTSevere Thunderstorm WarningCTPAdams, Cumberland, Dauphin, Lancaster, Perry, York47 min
Aug 18, 6:37 PM EDTAreal Flood AdvisoryCTPAdams, Cumberland, Franklin, York2 hr
Aug 18, 6:47 PM EDTSevere Thunderstorm WarningCTPAdams, Dauphin, Lancaster, Lebanon, Schuylkill, York43 min
Aug 18, 6:56 PM EDTSpecial Weather StatementCTPSchuylkill19 min
Aug 18, 7:23 PM EDTAreal Flood AdvisoryCTPColumbia, Sullivan2 hr
Aug 18, 7:30 PM EDTSevere Thunderstorm WarningCTPLancaster, York45 min
Aug 18, 7:37 PM EDTFlash Flood Warning Considerable damage threatCTPSchuylkill2 hr
Aug 18, 7:40 PM EDTFlash Flood WarningCTPDauphin, Lancaster, York3 hr

Nearby

Tornado Warnings in Pennsylvania, 2021Every tornado warning in 2021Tornadoes 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.