Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2008

Severe Thunderstorm Warning 168, NWS Philadelphia/Mount Holly

July 27, 20084 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 27, 2008, 12:19 PM EDT for 4 counties in Pennsylvania. It was in force for 56 min. 3 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
Jul 27, 2008, 12:19 PM EDT (16:19 UTC)
Expired
Jul 27, 2008, 1:15 PM EDT
In force
56 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

Counties Berks County, PA, Chester County, PA, Lehigh County, PA, Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 120 km from the middle of the area, began a volume at 16:22 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.

What was reported inside it

TimeReportWhereRemark
Jul 27, 12:30 PM EDTHAIL 0.51 Nne Lorane, PAMARBLE SIZE HAIL, ONE-HALF INCH IN DIAMETER, WAS REPORTED IN EXETER TOWNSHIP.
Jul 27, 12:48 PM EDTHAIL 0.753 Nw Boyertown, PAHAIL UP TO THE SIZE OF PENNIES REPORTED NEAR BOYERTOWN.
Jul 27, 12:50 PM EDTHAIL 0.753 N Pottstown, PAPENNY SIZE HAIL REPORTED NEAR POTTSTOWN.

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

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Jul 27, 11:26 AM EDTSevere Thunderstorm WatchSPC8 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 4.3 hours before the alert went out and 216 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, Washington/Dulle, VA at 12:00Z on 2008-07-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1356 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, Washington/Dulle, VA at 12:00Z on 2008-07-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -17 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
1356 J/kg
Mixed-layer CIN
-70 J/kg
Mixed-layer LCL
1062 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
-17 m²/s²
0-3 km storm-relative helicity
63 m²/s²
Significant tornado parameter
0.1
Supercell composite
1.3

Open this sounding in Storm Lab

The text

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

000 
WUUS51 KPHI 271619
SVRPHI
PAC011-029-077-091-271715-
/O.NEW.KPHI.SV.W.0168.080727T1619Z-080727T1715Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1219 PM EDT SUN JUL 27 2008

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  EAST CENTRAL BERKS COUNTY IN EASTERN PENNSYLVANIA...
  SOUTH CENTRAL LEHIGH COUNTY IN EASTERN PENNSYLVANIA...
  EXTREME NORTH CENTRAL CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA...
  NORTHWESTERN MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA...

* UNTIL 115 PM EDT

* AT 1217 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING NICKEL SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR
  READING...AND MOVING EAST AT 28 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  BIRDSBORO BY 1235 PM...
  POTTSTOWN BY 1255 PM...
  GILBERTSVILLE BY 100 PM...
  EAST GREENVILLE BY 110 PM...
  ZIONSVILLE BY 115 PM...

IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...CONTINUOUS CLOUD TO
GROUND LIGHTNING IS OCCURRING WITH THIS STORM. MOVE INDOORS
IMMEDIATELY LIGHTNING IS ONE OF NATURES NUMBER ONE KILLERS.
REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE
STRUCK BY LIGHTNING.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 800 PM SUNDAY
EVENING FOR DELAWARE AND NORTHEASTERN MARYLAND AND NEW JERSEY AND
EASTERN PENNSYLVANIA.

LAT...LON 4055 7549 4021 7549 4027 7601 4037 7602
TIME...MOT...LOC 1619Z 261DEG 24KT 4033 7597

$$

IOVINO

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 27, 11:50 AM EDTSevere Thunderstorm WarningPHIBerks, Carbon, Lehigh, Monroe, Northampton70 min
Jul 27, 12:07 PM EDTSevere Thunderstorm WarningPHIChester53 min
Jul 27, 12:25 PM EDTAreal Flood AdvisoryPHIBerks, Bucks, Chester, Lehigh, Montgomery3 hr
Jul 27, 12:38 PM EDTSevere Thunderstorm WarningPHIChester67 min
Jul 27, 12:50 PM EDTAreal Flood AdvisoryPHIBucks, Chester, Montgomery3 hr
Jul 27, 12:57 PM EDTSevere Thunderstorm WarningPHIChester63 min
Jul 27, 1:00 PM EDTSevere Thunderstorm WarningPHIBucks, Montgomery60 min
Jul 27, 1:34 PM EDTFlash Flood WarningPHIChester3 hr
Jul 27, 1:44 PM EDTSevere Thunderstorm WarningPHIBucks, Montgomery61 min
Jul 27, 2:11 PM EDTSevere Thunderstorm WarningPHIBucks64 min
Jul 27, 2:14 PM EDTSevere Thunderstorm WarningPHIBucks, Philadelphia61 min
Jul 27, 2:17 PM EDTSevere Thunderstorm WarningPHIDelaware, Philadelphia58 min
Jul 27, 2:30 PM EDTAreal Flood AdvisoryPHIBucks2 hr
Jul 27, 5:04 PM EDTSevere Thunderstorm WarningPHIBerks, Chester56 min
Jul 27, 6:44 PM EDTAreal Flood AdvisoryPHIChester72 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2008Every severe thunderstorm warning in 2008

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.