Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2013

Severe Thunderstorm Warning 5, NWS Philadelphia/Mount Holly

April 10, 2013Lehigh County, Northampton County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Apr 10, 2013, 6:21 PM EDT for Lehigh County, Northampton County, Pennsylvania. It was in force for 54 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
Apr 10, 2013, 6:21 PM EDT (22:21 UTC)
Expired
Apr 10, 2013, 7:15 PM EDT
In force
54 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

Counties Lehigh County, PA, Northampton County, PA

The radar

The Philadelphia radar (KDIX), 116 km from the middle of the area, began a volume at 22:23 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
Apr 10, 6:30 PM EDTTSTM WND DMGWashington Twp, PATREES DOWN
Apr 10, 6:47 PM EDTHAIL 0.5Allentown, PAHALF INCH HAIL COVERED HALF OF THE GROUND.
Apr 10, 6:50 PM EDTTSTM WND DMG3 Sw Hanover Twp, PATREES DOWN
Apr 10, 6:50 PM EDTHAIL 0.62Allentown, PA
Apr 10, 6:50 PM EDTHAIL 0.75Allentown, PA
Apr 10, 7:00 PM EDTHAIL 0.88Bethlehem, PA
Apr 10, 7:00 PM EDTHAIL 1Freemansburg, PAPENNY TO QUARTER SIZE HAIL COVERED THE GROUND.

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

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 10.4 hours before the alert went out and 160 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, Phillips Aaf/Abe, MD at 12:00Z on 2013-04-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1 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, Phillips Aaf/Abe, MD at 12:00Z on 2013-04-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 180 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
1 J/kg
Mixed-layer CIN
-437 J/kg
Mixed-layer LCL
1938 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
180 m²/s²
0-3 km storm-relative helicity
181 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.

485 
WUUS51 KPHI 102221
SVRPHI
PAC077-095-102315-
/O.NEW.KPHI.SV.W.0005.130410T2221Z-130410T2315Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
621 PM EDT WED APR 10 2013

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  LEHIGH COUNTY IN EASTERN PENNSYLVANIA...
  THIS INCLUDES THE CITY OF ALLENTOWN...
  NORTHAMPTON COUNTY IN EASTERN PENNSYLVANIA...
  THIS INCLUDES THE CITY OF EASTON...

* UNTIL 715 PM EDT

* AT 619 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM.  THIS STORM WAS LOCATED NEAR JORDAN VALLEY...
  OR 7 MILES SOUTH OF LEHIGHTON...AND MOVING EAST AT 35 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  WALNUTPORT...NEFFS AND BERLINSVILLE AROUND 630 PM EDT...
  NORTHAMPTON AND DANIELSVILLE AROUND 635 PM EDT...
  BEERSVILLE AND NORTHAMPTON AROUND 640 PM EDT...
  BATH AROUND 645 PM EDT...
  STEUBEN AROUND 650 PM EDT...
  NAZARETH AROUND 655 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH...PREPARE
IMMEDIATELY FOR DAMAGING WINDS...LARGE 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 4087 7505 4085 7507 4085 7509 4080 7510
      4075 7520 4073 7518 4069 7520 4067 7518
      4061 7520 4054 7533 4042 7549 4068 7589
      4078 7568 4082 7542 4086 7529 4093 7521
      4095 7512
TIME...MOT...LOC 2221Z 266DEG 32KT 4072 7569

$$

JJM
1 follow-up statement
363 
WWUS51 KPHI 102304
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
704 PM EDT WED APR 10 2013

PAC077-102314-
/O.CAN.KPHI.SV.W.0005.000000T0000Z-130410T2315Z/
LEHIGH PA-
704 PM EDT WED APR 10 2013

...THE SEVERE THUNDERSTORM WARNING FOR LEHIGH COUNTY IS CANCELLED...

SEVERE THUNDERSTORMS HAVE MOVED OUT OF THE COUNTY.

LAT...LON 4087 7505 4085 7509 4080 7510 4075 7520
      4073 7518 4070 7520 4067 7518 4061 7520
      4054 7533 4058 7541 4063 7539 4067 7543
      4066 7548 4074 7553 4072 7556 4074 7560
      4079 7561 4086 7529 4093 7521 4095 7512
TIME...MOT...LOC 2304Z 266DEG 32KT 4075 7519

$$

PAC095-102315-
/O.CON.KPHI.SV.W.0005.000000T0000Z-130410T2315Z/
NORTHAMPTON PA-
704 PM EDT WED APR 10 2013

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 715 PM EDT
FOR NORTHAMPTON COUNTY...

AT 702 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM.  THIS STORM WAS LOCATED NEAR
TATAMY...OR NEAR EASTON...MOVING EAST AT 35 MPH.


LAT...LON 4087 7505 4085 7509 4080 7510 4075 7520
      4073 7518 4070 7520 4067 7518 4061 7520
      4054 7533 4058 7541 4063 7539 4067 7543
      4066 7548 4074 7553 4072 7556 4074 7560
      4079 7561 4086 7529 4093 7521 4095 7512
TIME...MOT...LOC 2304Z 266DEG 32KT 4075 7519

$$

JJM

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 10, 4:53 PM EDTSpecial Weather StatementPHICarbon, Monroe112 min
Apr 10, 5:25 PM EDTSevere Thunderstorm WarningPHICarbon, Monroe65 min
Apr 10, 6:56 PM EDTSevere Thunderstorm WarningPHIBucks, Northampton49 min
Apr 10, 7:41 PM EDTSpecial Weather StatementPHIBucks, Chester, Montgomery64 min
Apr 10, 7:44 PM EDTSevere Thunderstorm WarningPHIBerks, Bucks, Chester, Delaware, Montgomery46 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2013Every severe thunderstorm warning in 2013

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.