Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 278, NWS State College, PA

September 15, 2021Montour County, Northumberland County, Union County, Pennsylvania

NWS State College, PA issued this severe thunderstorm warning at Sep 15, 2021, 3:24 PM EDT for Montour County, Northumberland County, Union County, Pennsylvania. It was in force for 36 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
Sep 15, 2021, 3:24 PM EDT (19:24 UTC)
Expired
Sep 15, 2021, 4:00 PM EDT
In force
36 min
Issued by
NWS State College, PA
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Montour County, PA, Northumberland County, PA, Union County, PA

The radar

The State College radar (KCCX), 110 km from the middle of the area, began a volume at 19:23 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
Sep 15, 3:30 PM EDTTSTM WND DMG1 Ene Lewisburg, PAMULTIPLE TREES DOWN NEAR PA ROUTES 45 AND 405.
Sep 15, 3:45 PM EDTTSTM WND DMG2 Nw Mooresburg, PATREES AND WIRES DOWN IN THE LIMESTONE AREA.

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
Sep 15, 11:55 AM EDTSevere Thunderstorm WatchSPC8 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 7.4 hours before the alert went out and 242 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 2021-09-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 13 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 2021-09-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 73 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
13 J/kg
Mixed-layer CIN
-270 J/kg
Mixed-layer LCL
1457 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
73 m²/s²
0-3 km storm-relative helicity
106 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

584 
WUUS51 KCTP 151924
SVRCTP
PAC093-097-119-152000-
/O.NEW.KCTP.SV.W.0278.210915T1924Z-210915T2000Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service State College PA
324 PM EDT Wed Sep 15 2021

The National Weather Service in State College PA has issued a

* Severe Thunderstorm Warning for...
  Northwestern Northumberland County in central Pennsylvania...
  Montour County in central Pennsylvania...
  Northeastern Union County in central Pennsylvania...

* Until 400 PM EDT.

* At 324 PM EDT, severe thunderstorms were located along a line
  extending from Watsontown to Vicksburg, moving east at 35 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...
  Milton, Lewisburg, Danville, Mifflinburg, Winfield, Watsontown,
  Riverside, Linntown, New Columbia, Montandon, Mechanicsville,
  Allenwood, Vicksburg, Spruce Run Reservoir, Exchange, Mooresburg,
  Delaware Run, West Milton, Turbotville and McEwensville.

For those driving on Interstate 80, this includes areas between the
Mile Run and Buckhorn exits, specifically from mile markers 204 to
227.

This includes Interstate 180 from mile markers 1 to 9.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4090 7653 4092 7703 4115 7696 4114 7690
      4116 7688 4117 7680 4117 7673 4115 7668
      4115 7664 4106 7661 4105 7657 4103 7656
      4100 7657 4096 7652
TIME...MOT...LOC 1924Z 265DEG 30KT 4108 7690 4096 7697 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Evanego
1 follow-up statement
823 
WWUS51 KCTP 151952
SVSCTP

Severe Weather Statement
National Weather Service State College PA
352 PM EDT Wed Sep 15 2021

PAC119-152001-
/O.CAN.KCTP.SV.W.0278.000000T0000Z-210915T2000Z/
Union PA-
352 PM EDT Wed Sep 15 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN UNION COUNTY 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 800 PM EDT for
central Pennsylvania.

LAT...LON 4090 7653 4092 7686 4096 7688 4117 7673
      4115 7668 4115 7664 4106 7661 4105 7657
      4103 7656 4100 7657 4096 7652
TIME...MOT...LOC 1951Z 252DEG 17KT 4111 7670 4099 7677 

$$

PAC093-097-152000-
/O.CON.KCTP.SV.W.0278.000000T0000Z-210915T2000Z/
Northumberland PA-Montour PA-
352 PM EDT Wed Sep 15 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 400 PM EDT
FOR NORTHWESTERN NORTHUMBERLAND AND MONTOUR COUNTIES...

At 351 PM EDT, severe thunderstorms were located along a line
extending from Exchange to near Mooresburg, moving east at 20 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...
Milton, Lewisburg, Danville, Riverside, Montandon, Mechanicsville,
Exchange, Mooresburg, Turbotville and Washingtonville.

For those driving on Interstate 80, this includes areas between the
Milton-Williamsport and Buckhorn exits, specifically from mile
markers 213 to 227.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4090 7653 4092 7686 4096 7688 4117 7673
      4115 7668 4115 7664 4106 7661 4105 7657
      4103 7656 4100 7657 4096 7652
TIME...MOT...LOC 1951Z 252DEG 17KT 4111 7670 4099 7677 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Evanego

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 15, 11:48 AM EDTSpecial Weather StatementCTPWarren42 min
Sep 15, 1:11 PM EDTSpecial Weather StatementCTPSullivan49 min
Sep 15, 1:27 PM EDTSpecial Weather StatementCTPCentre33 min
Sep 15, 1:44 PM EDTSevere Thunderstorm WarningCTPCentre31 min
Sep 15, 1:48 PM EDTSevere Thunderstorm WarningCTPSullivan42 min
Sep 15, 2:14 PM EDTAreal Flood AdvisoryCTPLycoming, Sullivan2 hr
Sep 15, 2:14 PM EDTSevere Thunderstorm WarningCTPCentre, Clinton31 min
Sep 15, 2:36 PM EDTFlash Flood WarningCTPLycoming, Sullivan66 min
Sep 15, 2:45 PM EDTSpecial Weather StatementCTPUnion30 min
Sep 15, 2:46 PM EDTSpecial Weather StatementCTPSullivan44 min
Sep 15, 2:54 PM EDTSevere Thunderstorm WarningCTPClinton, Lycoming, Northumberland, Union36 min
Sep 15, 3:13 PM EDTSpecial Weather StatementCTPUnion17 min
Sep 15, 3:20 PM EDTSevere Thunderstorm WarningCTPJuniata, Mifflin40 min
Sep 15, 3:30 PM EDTSpecial Weather StatementCTPHuntingdon30 min
Sep 15, 3:55 PM EDTSpecial Weather StatementCTPSnyder35 min
Sep 15, 3:59 PM EDTSpecial Weather StatementCTPColumbia, Montour31 min
Sep 15, 4:03 PM EDTAreal Flood AdvisoryCTPLycoming, Sullivan2 hr
Sep 15, 4:12 PM EDTFlash Flood WarningCTPColumbia, Lycoming, Sullivan3 hr
Sep 15, 4:18 PM EDTSevere Thunderstorm WarningCTPColumbia27 min
Sep 15, 4:27 PM EDTSpecial Weather StatementCTPPerry33 min
Sep 15, 4:36 PM EDTSpecial Weather StatementCTPColumbia, Northumberland24 min
Sep 15, 4:43 PM EDTSevere Thunderstorm WarningCTPCumberland, Franklin, Perry32 min
Sep 15, 4:46 PM EDTAreal Flood AdvisoryCTPMontour, Northumberland89 min
Sep 15, 4:58 PM EDTSpecial Weather StatementCTPNorthumberland32 min
Sep 15, 4:59 PM EDTSpecial Weather StatementCTPPerry31 min
Sep 15, 5:15 PM EDTSpecial Weather StatementCTPPerry30 min
Sep 15, 5:19 PM EDTSpecial Weather StatementCTPFranklin26 min
Sep 15, 5:32 PM EDTSpecial Weather StatementCTPDauphin28 min
Sep 15, 5:37 PM EDTSpecial Weather StatementCTPSchuylkill23 min
Sep 15, 5:54 PM EDTSpecial Weather StatementCTPLebanon36 min
Sep 15, 6:16 PM EDTSpecial Weather StatementCTPYork29 min
Sep 15, 6:17 PM EDTSevere Thunderstorm WarningCTPLebanon, Schuylkill43 min
Sep 15, 6:24 PM EDTSevere Thunderstorm WarningCTPAdams, Franklin27 min
Sep 15, 6:41 PM EDTSpecial Weather StatementCTPDauphin34 min
Sep 15, 6:54 PM EDTSpecial Weather StatementCTPBerks21 min
Sep 15, 7:09 PM EDTAreal Flood AdvisoryCTPDauphin, York96 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.