Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 41, NWS Philadelphia/Mount Holly

May 15, 2011Berks County, Lehigh County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at May 15, 2011, 3:39 PM EDT for Berks County, Lehigh County, Pennsylvania. It was in force for 44 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: May 15, 2011, 3:39 PM EDT (19:39 UTC)
Expired: May 15, 2011, 4:23 PM EDT
In force: 44 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

Counties Berks County, PA, Lehigh County, PA

The radar

The Philadelphia radar (KDIX), 157 km from the middle of the area, began a volume at 19:39 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

Washington/Dulle, VA (KIAD), launched 12:00Z, 7.7 hours before the alert went out and 215 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: 55 J/kg
Mixed-layer CIN: -69 J/kg
Mixed-layer LCL: 545 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: 3 m²/s²
0-3 km storm-relative helicity: 50 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

766 
WUUS51 KPHI 151939
SVRPHI
PAC011-077-152045-
/O.NEW.KPHI.SV.W.0041.110515T1939Z-110515T2045Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
339 PM EDT SUN MAY 15 2011

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTH CENTRAL BERKS COUNTY IN EASTERN PENNSYLVANIA...
  NORTHWESTERN LEHIGH COUNTY IN EASTERN PENNSYLVANIA...

* UNTIL 445 PM EDT

* AT 335 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL.  THIS
  STORM WAS LOCATED 8 MILES WEST OF HAMBURG...OR 18 MILES NORTHWEST
  OF READING...AND MOVING NORTHEAST AT 20 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  HAMBURG AROUND 400 PM EDT...
  WANAMAKERS AROUND 430 PM EDT...
  NEW TRIPOLI AROUND 445 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH...PREPARE
IMMEDIATELY FOR DAMAGING WINDS...DESTRUCTIVE HAIL...AND DEADLY CLOUD
TO GROUND LIGHTNING. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...
PREFERABLY INSIDE A STRONG BUILDING BUT AWAY FROM WINDOWS.

&&

LAT...LON 4054 7621 4054 7618 4057 7614 4058 7609
      4060 7605 4059 7603 4064 7600 4073 7579
      4068 7571 4047 7613 4053 7622
TIME...MOT...LOC 1940Z 236DEG 16KT 4055 7611

$$

HAYES

2 follow-up statements

024 
WWUS51 KPHI 152000
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
400 PM EDT SUN MAY 15 2011

PAC011-077-152045-
/O.CON.KPHI.SV.W.0041.000000T0000Z-110515T2045Z/
BERKS PA-LEHIGH PA-
400 PM EDT SUN MAY 15 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 445 PM EDT
FOR WEST CENTRAL LEHIGH AND NORTH CENTRAL BERKS COUNTIES...

AT 356 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE
HAIL.  THIS STORM WAS LOCATED NEAR PORT CLINTON...OR 19 MILES NORTH
OF READING...MOVING NORTHEAST AT 20 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  WANAMAKERS BY 430 PM EDT...
  NEW TRIPOLI BY 445 PM EDT...

LAT...LON 4051 7606 4057 7614 4058 7609 4060 7605
      4059 7603 4064 7600 4073 7579 4068 7571
TIME...MOT...LOC 2000Z 236DEG 16KT 4060 7601

$$

HAYES

315 
WWUS51 KPHI 152023
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
423 PM EDT SUN MAY 15 2011

PAC011-077-152033-
/O.CAN.KPHI.SV.W.0041.000000T0000Z-110515T2045Z/
BERKS PA-LEHIGH PA-
423 PM EDT SUN MAY 15 2011

...THE SEVERE THUNDERSTORM WARNING FOR WEST CENTRAL LEHIGH AND NORTH
CENTRAL BERKS COUNTIES IS CANCELLED...

THE STORM THAT PROMPTED THE WARNING HAS WEAKENED.

LAT...LON 4051 7606 4057 7614 4058 7609 4060 7605
      4059 7603 4064 7600 4073 7579 4068 7571
TIME...MOT...LOC 2023Z 236DEG 16KT 4066 7590

$$

HAYES

The office that day

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

Issued	Product	Office	Counties	Lasted
May 14, 11:46 PM EDT	Special Weather Statement	PHI	Berks, Chester, Delaware, Montgomery	89 min
May 15, 12:52 AM EDT	Special Weather Statement	PHI	Bucks, Carbon, Lehigh, Monroe, Montgomery, Northampton and 1 more	83 min
May 15, 2:26 PM EDT	Special Weather Statement	PHI	Berks	64 min
May 15, 2:46 PM EDT	Special Weather Statement	PHI	Schuylkill	59 min
May 15, 2:55 PM EDT	Special Weather Statement	PHI	Delaware	65 min
May 15, 3:30 PM EDT	Special Weather Statement	PHI	Berks	60 min
May 15, 3:37 PM EDT	Severe Thunderstorm Warning	PHI	Bucks	53 min
May 15, 4:14 PM EDT	Special Weather Statement	PHI	Lehigh	61 min
May 15, 4:19 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Lehigh	56 min
May 15, 4:31 PM EDT	Special Weather Statement	PHI	Delaware, Philadelphia	59 min
May 15, 4:35 PM EDT	Special Weather Statement	PHI	Lehigh	55 min
May 15, 4:52 PM EDT	Special Weather Statement	PHI	Northampton	68 min
May 15, 5:03 PM EDT	Severe Thunderstorm Warning	PHI	Lehigh, Monroe, Northampton	57 min
May 15, 5:33 PM EDT	Special Weather Statement	PHI	Berks, Carbon, Lehigh	57 min
May 15, 5:37 PM EDT	Special Weather Statement	PHI	Bucks	53 min
May 15, 5:46 PM EDT	Severe Thunderstorm Warning	PHI	Bucks	59 min
May 15, 6:39 PM EDT	Special Weather Statement	PHI	Berks	66 min
May 15, 7:20 PM EDT	Areal Flood Advisory	PHI	Berks, Lehigh	3 hr
May 15, 7:28 PM EDT	Special Weather Statement	PHI	Delaware, Montgomery, Philadelphia	62 min
May 15, 7:37 PM EDT	Special Weather Statement	PHI	Berks	53 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2011 Every severe thunderstorm warning in 2011

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.