Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2010

Severe Thunderstorm Warning 18, NWS Philadelphia/Mount Holly

May 14, 2010Berks County, Chester County, Montgomery County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at May 14, 2010, 5:49 PM EDT for Berks County, Chester County, Montgomery County, Pennsylvania. It was in force for 56 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
May 14, 2010, 5:49 PM EDT (21:49 UTC)
Expired
May 14, 2010, 6:45 PM EDT
In force
56 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

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

The radar

The Philadelphia radar (KDIX), 105 km from the middle of the area, began a volume at 21:51 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
May 14, 6:00 PM EDTTSTM WND DMGMount Penn, PATREES DOWN ON MULTIPLE CARS ON BRIGHTON AVE IN MOUNT PENN.

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
May 14, 3:43 PM EDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 9.8 hours before the alert went out and 100 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 2010-05-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1 joules per kilogram.LCLEL10008507005003002001001 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 2010-05-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 160 square meters per square second.19395878Sfc1 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
No buoyant parcel
Mixed-layer LCL
557 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
160 m²/s²
0-3 km storm-relative helicity
187 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.1

Open this sounding in Storm Lab

The text

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

735 
WUUS51 KPHI 142149
SVRPHI
PAC011-029-091-142245-
/O.NEW.KPHI.SV.W.0018.100514T2149Z-100514T2245Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
549 PM EDT FRI MAY 14 2010

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHEASTERN BERKS COUNTY IN EASTERN PENNSYLVANIA...
  THIS INCLUDES THE CITY OF READING...
  NORTHEASTERN CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA...
  CENTRAL MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA...

* UNTIL 645 PM EDT

* AT 547 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR
  READING...AND MOVING EAST AT 40 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  BIRDSBORO AROUND 600 PM EDT...
  POTTSTOWN...GILBERTSVILLE AND CEDARVILLE AROUND 610 PM EDT...
  ROYERSFORD AROUND 620 PM EDT...
  SCHWENKSVILLE...SPRING MOUNT...TRAPPE AND COLLEGEVILLE AROUND 625
  PM EDT...
  HATFIELD AROUND 635 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1000 PM EDT
FRIDAY EVENING FOR DELAWARE AND NORTHEASTERN MARYLAND AND NEW JERSEY
AND EASTERN PENNSYLVANIA.

&&

LAT...LON 4027 7524 4007 7536 4028 7603 4045 7596
TIME...MOT...LOC 2149Z 288DEG 36KT 4035 7591

$$

HAYES
2 follow-up statements
824 
WWUS51 KPHI 142230
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
630 PM EDT FRI MAY 14 2010

PAC011-142240-
/O.CAN.KPHI.SV.W.0018.000000T0000Z-100514T2245Z/
BERKS PA-
630 PM EDT FRI MAY 14 2010

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN BERKS COUNTY IS
CANCELLED...

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1000 PM EDT
FRIDAY EVENING FOR DELAWARE AND NORTHEASTERN MARYLAND AND NEW JERSEY
AND EASTERN PENNSYLVANIA.

LAT...LON 4019 7562 4034 7553 4028 7530 4027 7524
      4007 7536
TIME...MOT...LOC 2230Z 288DEG 36KT 4022 7540

$$

PAC029-091-142245-
/O.CON.KPHI.SV.W.0018.000000T0000Z-100514T2245Z/
CHESTER PA-MONTGOMERY PA-
630 PM EDT FRI MAY 14 2010

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 645 PM EDT
FOR CENTRAL MONTGOMERY AND EXTREME NORTHEASTERN CHESTER COUNTIES...

AT 625 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE
HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS
LOCATED NEAR SCHWENKSVILLE...OR 20 MILES NORTH OF WEST CHESTER...
MOVING EAST AT 40 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  KULPSVILLE...EAST NORRITON...HATFIELD AND 6 MILES NORTH OF
  NORRISTOWN BY 635 PM EDT...
  NORTH WALES...LANSDALE AND 7 MILES NORTH OF BRIDGEPORT BY 640 PM
  EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1000 PM EDT
FRIDAY EVENING FOR DELAWARE AND NORTHEASTERN MARYLAND AND NEW JERSEY
AND EASTERN PENNSYLVANIA.

&&

LAT...LON 4019 7562 4034 7553 4028 7530 4027 7524
      4007 7536
TIME...MOT...LOC 2230Z 288DEG 36KT 4022 7540

$$

HAYES
565 
WWUS51 KPHI 142241
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
641 PM EDT FRI MAY 14 2010

PAC029-091-142252-
/O.EXP.KPHI.SV.W.0018.000000T0000Z-100514T2245Z/
CHESTER PA-MONTGOMERY PA-
641 PM EDT FRI MAY 14 2010

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL MONTGOMERY AND EXTREME
NORTHEASTERN CHESTER COUNTIES WILL EXPIRE AT 645 PM EDT...

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1000 PM EDT
FRIDAY EVENING FOR DELAWARE AND NORTHEASTERN MARYLAND AND NEW JERSEY
AND EASTERN PENNSYLVANIA.

LAT...LON 4019 7562 4034 7553 4028 7530 4027 7524
      4007 7536
TIME...MOT...LOC 2242Z 288DEG 36KT 4018 7525

$$

HAYES

The office that day

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

IssuedProductOfficeCountiesLasted
May 14, 3:52 PM EDTSpecial Weather StatementPHICarbon, Monroe53 min
May 14, 4:18 PM EDTSpecial Weather StatementPHICarbon57 min
May 14, 4:26 PM EDTSpecial Weather StatementPHICarbon, Northampton64 min
May 14, 4:42 PM EDTSevere Thunderstorm WarningPHIBerks63 min
May 14, 5:04 PM EDTSevere Thunderstorm WarningPHIBucks, Lehigh, Northampton56 min
May 14, 5:07 PM EDTSpecial Weather StatementPHINorthampton53 min
May 14, 5:38 PM EDTTornado WarningPHIBerks, Lehigh37 min
May 14, 5:53 PM EDTSevere Thunderstorm WarningPHIBerks, Bucks, Lehigh, Northampton67 min
May 14, 6:11 PM EDTSpecial Weather StatementPHICarbon64 min
May 14, 6:25 PM EDTSevere Thunderstorm WarningPHIBucks, Chester, Montgomery, Philadelphia65 min
May 14, 6:35 PM EDTSevere Thunderstorm WarningPHIChester, Delaware55 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2010Every severe thunderstorm warning in 2010

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.