Alert archive / Pennsylvania / Special Weather Statements in 2021

Special Weather Statement, NWS Pittsburgh, PA

August 1, 2021Armstrong County, Clarion County, Jefferson County, Pennsylvania

NWS Pittsburgh, PA issued this special weather statement at Aug 1, 2021, 2:21 PM EDT for Armstrong County, Clarion County, Jefferson County, Pennsylvania. It was in force for 39 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 1, 2021, 2:21 PM EDT (18:21 UTC)
Expired
Aug 1, 2021, 3:00 PM EDT
In force
39 min
Issued by
NWS Pittsburgh, PA

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

The radar

The Pittsburgh radar (KPBZ), 95 km from the middle of the area, began a volume at 18:22 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 nearest sounding before it

Pittsburgh, PA (KPIT), launched 12:00Z, 6.4 hours before the alert went out and 97 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, Pittsburgh, PA at 12:00Z on 2021-08-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 9 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, Pittsburgh, PA at 12:00Z on 2021-08-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 46 square meters per square second.1939587897117Sfc1 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
9 J/kg
Mixed-layer CIN
-104 J/kg
Mixed-layer LCL
1078 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
46 m²/s²
0-3 km storm-relative helicity
95 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

423 
WWUS81 KPBZ 011821
SPSPBZ

Special Weather Statement
National Weather Service Pittsburgh PA
221 PM EDT Sun Aug 1 2021

PAZ008-014>016-022-011900-
Armstrong-Jefferson-Butler-Clarion-Venango-
221 PM EDT Sun Aug 1 2021

...A LINE OF STRONG THUNDERSTORMS CAPABLE OF PRODUCING SMALL HAIL
WILL AFFECT SOUTHERN VENANGO...NORTHEASTERN BUTLER...SOUTHWESTERN
JEFFERSON...CENTRAL ARMSTRONG AND CLARION COUNTIES...

At 221 PM EDT, radar indicated strong thunderstorms were located
along a line extending from near Knox to 10 miles northeast of
Shanor-Northvue. Movement was southeast at 35 mph.

Small hail is possible with these storms.

Locations impacted include...
Clarion...                        Kittanning...
Brookville...                     Knox...
Rimersburg...                     Ford City...
Reynoldsville...                  New Bethlehem...
West Kittanning...                Chicora...
East Brady...                     Parker...

This includes Interstate 80 in Pennsylvania between mile markers 43
and 81, and
  between mile markers 85 and 86.
 
LAT...LON 4110 7887 4074 7960 4107 7991 4133 7944
TIME...MOT...LOC 1821Z 307DEG 32KT 4127 7945 4104 7982 

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 1, 1:27 PM EDTSpecial Weather StatementPBZMercer33 min
Aug 1, 1:44 PM EDTSpecial Weather StatementPBZForest31 min
Aug 1, 1:50 PM EDTSevere Thunderstorm WarningPBZClarion, Forest, Jefferson, Venango25 min
Aug 1, 1:52 PM EDTSpecial Weather StatementPBZJefferson38 min
Aug 1, 2:03 PM EDTSpecial Weather StatementPBZVenango27 min
Aug 1, 3:06 PM EDTSpecial Weather StatementPBZArmstrong39 min
Aug 1, 3:38 PM EDTSpecial Weather StatementPBZAllegheny37 min

Nearby

Special Weather Statements in Pennsylvania, 2021Every special weather statement 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.