Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 294, NWS Philadelphia/Mount Holly

September 8, 20214 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Sep 8, 2021, 7:17 PM EDT for 4 counties in Pennsylvania. It was in force for 43 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
Sep 8, 2021, 7:17 PM EDT (23:17 UTC)
Expired
Sep 8, 2021, 8:00 PM EDT
In force
43 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Carbon County, PA, Lehigh County, PA, Monroe County, PA, Northampton County, PA

The radar

The Binghamton radar (KBGM), 136 km from the middle of the area, began a volume at 23:18 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 8, 7:40 PM EDTTSTM WND DMG3 Nw Tobyhanna Twp, PATREES AND WIRES DOWN ALONG LOCUST RIDGE ROAD NEAR ARROWHEAD LAKE. TIME 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

Brookhaven, NY (KOKX), launched 12:00Z, 11.3 hours before the alert went out and 231 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, Brookhaven, NY at 12:00Z on 2021-09-08Temperature 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, Brookhaven, NY at 12:00Z on 2021-09-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 80 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
-76 J/kg
Mixed-layer LCL
1377 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
80 m²/s²
0-3 km storm-relative helicity
119 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

730 
WUUS51 KPHI 082317
SVRPHI
PAC025-077-089-095-090000-
/O.NEW.KPHI.SV.W.0294.210908T2317Z-210909T0000Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
717 PM EDT Wed Sep 8 2021

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Northwestern Lehigh County in eastern Pennsylvania...
  Carbon County in northeastern Pennsylvania...
  Monroe County in northeastern Pennsylvania...
  West central Northampton County in eastern Pennsylvania...

* Until 800 PM EDT.

* At 717 PM EDT, severe thunderstorms were located along a line
  extending from White Haven to Tamaqua, moving east at 35 mph.

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

  SOURCE...Radar indicated.

  IMPACT...Minor damage to vehicles is possible. Wind damage to 
           roofs, siding, trees, and power lines is possible.

* Locations impacted include...
  Lehighton, Mount Pocono, Northampton, Tobyhanna, Palmerton, Jim
  Thorpe, Slatington, Nesquehoning, Weatherly, Walnutport, Neffs,
  Pocono Pines, Lake Harmony, New Tripoli, Skytop, Tannersville, Long
  Pond, Kresgeville, Sun Valley and Reeders.

This includes the following highways...
 Northeast Extension between mile markers 62 and 97.
 Interstate 80 in Pennsylvania between mile markers 277 and 306.
 Interstate 380 in Pennsylvania between mile markers 0 and 13.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 4120 7514 4064 7549 4069 7583 4074 7576
      4083 7590 4091 7599 4101 7573 4105 7577
      4109 7577 4113 7569 4112 7564 4123 7554
      4125 7513
TIME...MOT...LOC 2317Z 271DEG 32KT 4106 7581 4080 7597 

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

$$

Staarmann
1 follow-up statement
393 
WWUS51 KPHI 082344
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
744 PM EDT Wed Sep 8 2021

PAC025-077-089-095-090000-
/O.CON.KPHI.SV.W.0294.000000T0000Z-210909T0000Z/
Lehigh PA-Carbon PA-Monroe PA-Northampton PA-
744 PM EDT Wed Sep 8 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 800 PM EDT
FOR NORTHWESTERN LEHIGH...CARBON...MONROE AND WEST CENTRAL
NORTHAMPTON COUNTIES...

At 743 PM EDT, severe thunderstorms were located along a line
extending from Blakeslee to Nesquehoning, moving east at 25 mph.

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

SOURCE...Radar indicated.

IMPACT...Minor damage to vehicles is possible. Wind damage to roofs, 
         siding, trees, and power lines is possible.

Locations impacted include...
Lehighton, Mount Pocono, Northampton, Tobyhanna, Palmerton, Jim
Thorpe, Slatington, Nesquehoning, Weatherly, Walnutport, Neffs,
Pocono Pines, Lake Harmony, New Tripoli, Skytop, Tannersville, Long
Pond, Kresgeville, Sun Valley and Reeders.

This includes the following highways...
 Northeast Extension between mile markers 62 and 97.
 Interstate 80 in Pennsylvania between mile markers 277 and 306.
 Interstate 380 in Pennsylvania between mile markers 0 and 13.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 4120 7514 4064 7549 4069 7583 4074 7576
      4083 7590 4087 7594 4101 7573 4105 7577
      4109 7577 4113 7569 4112 7564 4123 7554
      4125 7513
TIME...MOT...LOC 2343Z 265DEG 23KT 4110 7560 4084 7584 

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

$$

Staarmann

The office that day

Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 8, 7:59 PM EDTSevere Thunderstorm WarningPHIBerks, Carbon, Lehigh, Monroe, Northampton61 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.