Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2023

Severe Thunderstorm Warning 26, NWS Philadelphia/Mount Holly

April 15, 20234 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Apr 15, 2023, 1:03 PM EDT for 4 counties in Pennsylvania. It was in force for 27 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: Apr 15, 2023, 1:03 PM EDT (17:03 UTC)
Expired: Apr 15, 2023, 1:30 PM EDT
In force: 27 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 Philadelphia radar (KDIX), 115 km from the middle of the area, began a volume at 17:04 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
Apr 15, 1:20 PM EDT	HAIL 0.25	Fountain Hill, PA
Apr 15, 1:35 PM EDT	HAIL 0.25	Bushkill Twp, PA

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, 5.1 hours before the alert went out and 212 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: 26 J/kg
Mixed-layer CIN: -187 J/kg
Mixed-layer LCL: 927 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: -16 m²/s²
0-3 km storm-relative helicity: 26 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.0

Open this sounding in Storm Lab

The text

As transmitted.

161 
WUUS51 KPHI 151703
SVRPHI
PAC025-077-089-095-151730-
/O.NEW.KPHI.SV.W.0026.230415T1703Z-230415T1730Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
103 PM EDT Sat Apr 15 2023

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Northeastern Lehigh County in eastern Pennsylvania...
  East central Carbon County in northeastern Pennsylvania...
  Southwestern Monroe County in northeastern Pennsylvania...
  Northampton County in eastern Pennsylvania...

* Until 130 PM EDT.

* At 102 PM EDT, a severe thunderstorm was located over Steuben, or 7
  miles northeast of Allentown, moving north at 20 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...
  Allentown, Easton, Bethlehem, Forks, Emmaus, Northampton, Wilson,
  Hellertown, Nazareth, Bangor, Pen Argyl, Wind Gap, Bath, Belfast,
  West Easton, Tatamy, East Bangor, Steuben, Glendon and Kunkletown.

This includes the following highways...
 Northeast Extension between mile markers 54 and 55.
 Interstate 78 in Pennsylvania between mile markers 55 and 76.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 4054 7534 4055 7555 4092 7557 4091 7518
      4062 7521
TIME...MOT...LOC 1702Z 184DEG 19KT 4068 7539 

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

$$

Fitzsimmons

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 15, 12:42 PM EDT	Special Weather Statement	PHI	Northampton	48 min
Apr 15, 1:22 PM EDT	Flash Flood Warning	PHI	Lehigh, Northampton	4 hr
Apr 15, 1:34 PM EDT	Severe Thunderstorm Warning	PHI	Monroe, Northampton	26 min
Apr 15, 1:51 PM EDT	Severe Thunderstorm Warning	PHI	Chester	24 min
Apr 15, 1:58 PM EDT	Severe Thunderstorm Warning	PHI	Monroe, Northampton	32 min
Apr 15, 2:02 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Lehigh, Northampton	28 min
Apr 15, 2:17 PM EDT	Areal Flood Advisory	PHI	Chester	3 hr
Apr 15, 4:05 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Philadelphia	25 min
Apr 15, 4:56 PM EDT	Severe Thunderstorm Warning	PHI	Bucks	14 min
Apr 15, 5:20 PM EDT	Flash Flood Warning	PHI	Lehigh	3 hr
Apr 15, 6:05 PM EDT	Areal Flood Advisory	PHI	Bucks	96 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2023 Every severe thunderstorm warning in 2023

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.