Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 310, NWS Pittsburgh, PA

October 16, 2021Armstrong County, Clarion County, Jefferson County, Pennsylvania

NWS Pittsburgh, PA issued this severe thunderstorm warning at Oct 16, 2021, 7:40 AM EDT for Armstrong County, Clarion County, Jefferson County, Pennsylvania. It was in force for 35 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: Oct 16, 2021, 7:40 AM EDT (11:40 UTC)
Expired: Oct 16, 2021, 8:15 AM EDT
In force: 35 min
Issued by: NWS Pittsburgh, PA
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Armstrong County, PA, Clarion County, PA, Jefferson County, PA

The radar

The State College radar (KCCX), 98 km from the middle of the area, began a volume at 11:40 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
Oct 16, 7:40 AM EDT	TSTM WND DMG	2 Nnw Brinkerton, PA	CORRECTED TIME FROM 226 PM. MULTIPLE TREES REPORTED DOWN ON DIVENS ROAD, DAMAGE TO A HOUSE ON SOUTH REIDSBURG ROAD. TIME ESTIMATED BASED ON RADAR.
Oct 16, 7:41 AM EDT	TSTM WND DMG	2 Ne Churchville, PA	PICTURES OF SNAPPED TREES AND TREES DOWN ON POWER LINES ALONG SOUTH REISBURG ROAD IN MONROE TOWNSHIP. TIME ESTIMATED BASED ON RADAR.
Oct 16, 7:42 AM EDT	TSTM WND DMG	2 Nw Limestone, PA	REPORT OF MULTIPLE DOWNED TREES AND ROOF DAMAGE TO 2 HOME IN MONROE AND MILLCREEK TOWNSHIPS.
Oct 16, 7:55 AM EDT	TSTM WND DMG	Summerville, PA	REPORT OF DAMAGE TO MULTIPLE UTILITY POLES AND TREES DOWN ON WIRES. TIME ESTIMATED BASED ON RADAR.
Oct 16, 8:03 AM EDT	TSTM WND DMG	2 Nnw Howe, PA	REPORT OF MULTIPLE TREES DOWN IN ELDRED TOWNSHIP. TIME ESTIMATED BASED ON RADAR.
Oct 16, 8:03 AM EDT	TSTM WND DMG	Sigel, PA	REPORT OF MULTIPLE TREES DOWN IN THE AREA. TIME ESTIMATED BASED ON RADAR.
Oct 16, 8:14 AM EDT	TSTM WND DMG	2 Wnw Green Briar, PA	REPORT OF MULTIPLE PHONE LINES AND SEVERAL POLES DOWN ALONG ROUTE 949. ROUTE CLOSED AT ONE POINT DUE TO DOWNED TREES. TIME ESTIMATED BASED ON RADAR.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Pittsburgh, PA (KPIT), launched 00:00Z, 11.7 hours before the alert went out and 117 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: 138 J/kg
Mixed-layer CIN: -23 J/kg
Mixed-layer LCL: 1149 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: 111 m²/s²
0-3 km storm-relative helicity: 153 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.7

Open this sounding in Storm Lab

The text

As transmitted.

596 
WUUS51 KPBZ 161140
SVRPBZ
PAC005-031-065-161215-
/O.NEW.KPBZ.SV.W.0310.211016T1140Z-211016T1215Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Pittsburgh PA
740 AM EDT Sat Oct 16 2021

The National Weather Service in Pittsburgh has issued a

* Severe Thunderstorm Warning for...
  Western Jefferson County in west central Pennsylvania...
  East central Armstrong County in west central Pennsylvania...
  Southeastern Clarion County in west central Pennsylvania...

* Until 815 AM EDT.

* At 739 AM EDT, Doppler radar detected a strong frontal squall line 
  from Clarion to near Rimersburg to just southwest of New 
  Bethlehem, moving east at 40 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to trees and power lines, resulting in some 
           power outages.

* Locations impacted include...
  Clarion, Brookville, New Bethlehem, Strattanville, Summerville,
  Limestone, Hawthorn, Corsica, Sigel, Timblin, Worthville, and
  Anita.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

There is no lightning associated with this activity. Do not wait for 
the sound of thunder in anticipation of these strong to damaging 
wind gusts.

&&

LAT...LON 4134 7894 4098 7890 4091 7942 4121 7943
TIME...MOT...LOC 1139Z 254DEG 32KT 4120 7941 4108 7941 4094 7941 

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

$$

Bookbinder

2 follow-up statements

475 
WWUS51 KPBZ 161158
SVSPBZ

Severe Weather Statement
National Weather Service Pittsburgh PA
758 AM EDT Sat Oct 16 2021

PAC005-031-065-161215-
/O.CON.KPBZ.SV.W.0310.000000T0000Z-211016T1215Z/
Jefferson PA-Armstrong PA-Clarion PA-
758 AM EDT Sat Oct 16 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 815 AM EDT
FOR WESTERN JEFFERSON...EAST CENTRAL ARMSTRONG AND EAST CENTRAL
CLARION COUNTIES...

At 756 AM EDT, an intense squall line extended from Corsica to 
Summerville to 7 miles east of New Bethlehem, moving east at 40 mph.

HAZARD...60 to 70 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Trees snapped and uprooted. Power outages can be expected.

Locations impacted include...
Brookville, Summerville, Corsica, Sigel, Timblin, Worthville,
Knox-Dale, Anita, and Mahoning Creek Lake.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

There is no lightning associated with this activity. Do not wait for 
the sound of thunder in anticipation of damaging wind gusts.

&&

LAT...LON 4134 7894 4098 7890 4093 7927 4109 7924
      4125 7927
TIME...MOT...LOC 1156Z 254DEG 36KT 4124 7923 4110 7919 4097 7924 

THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

Bookbinder

354 
WWUS51 KPBZ 161216
SVSPBZ

Severe Weather Statement
National Weather Service Pittsburgh PA
816 AM EDT Sat Oct 16 2021

PAC005-031-065-161224-
/O.EXP.KPBZ.SV.W.0310.000000T0000Z-211016T1215Z/
Jefferson PA-Armstrong PA-Clarion PA-
816 AM EDT Sat Oct 16 2021

...THE SEVERE THUNDERSTORM WARNING FOR WESTERN JEFFERSON...EAST
CENTRAL ARMSTRONG AND EAST CENTRAL CLARION COUNTIES WILL EXPIRE AT
815 AM EDT...

The threat for severe weather has ended for Armstrong and Clarion 
counties. For Jefferson county, the severe thunderstorm warning has 
been reissued through 830 AM for the eastern half of the county, 
with a continued threat for damaging winds.

LAT...LON 4134 7894 4098 7890 4093 7927 4109 7924
      4125 7927
TIME...MOT...LOC 1214Z 254DEG 32KT 4128 7906 4114 7902 4101 7907 

$$

Bookbinder

The office that day

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

Issued	Product	Office	Counties	Lasted
Oct 16, 4:52 AM EDT	Severe Thunderstorm Warning	PBZ	Beaver, Washington	38 min
Oct 16, 5:37 AM EDT	Special Weather Statement	PBZ	Beaver	38 min
Oct 16, 5:47 AM EDT	Severe Thunderstorm Warning	PBZ	Allegheny, Beaver, Washington	43 min
Oct 16, 6:07 AM EDT	Tornado Warning	PBZ	Beaver	23 min
Oct 16, 6:54 AM EDT	Tornado Warning	PBZ	Butler	21 min
Oct 16, 7:23 AM EDT	Special Weather Statement	PBZ	Clarion	22 min
Oct 16, 8:13 AM EDT	Severe Thunderstorm Warning	PBZ	Jefferson	17 min

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.