Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2010
Severe Thunderstorm Warning 46, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at May 27, 2010, 7:12 PM EDT for 4 counties in Pennsylvania. It was in force for 48 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
- May 27, 2010, 7:12 PM EDT (23:12 UTC)
- Expired
- May 27, 2010, 8:00 PM EDT
- In force
- 48 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
Counties Berks County, PA, Chester County, PA, Delaware County, PA, Montgomery County, PA
The radar
The Philadelphia radar (KDIX), 99 km from the middle of the area, began a volume at 23:12 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 |
|---|---|---|---|
| May 27, 7:13 PM EDT | HAIL 1.5 | Pottstown, PA | 1.5 INCH HAIL REPORTED IN POTTSTOWN JUST WEST OF ROUTE 100 AND HIGH STREET. |
| May 27, 7:45 PM EDT | HAIL 0.25 | 1 Ne Downingtown, PA | 10 MINUTES OF PEA TO NICKEL SIZE HAIL REPORTED IN EAST CALN. |
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.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| May 27, 1:23 PM EDT | Severe Thunderstorm Watch | SPC | 8 hr |
The nearest sounding before it
Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 11.2 hours before the alert went out and 86 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.
- Mixed-layer CAPE
- 759 J/kg
- Mixed-layer CIN
- -227 J/kg
- Mixed-layer LCL
- 1358 m above ground
- 0-6 km bulk shear
- 22 kt
- 0-1 km storm-relative helicity
- -74 m²/s²
- 0-3 km storm-relative helicity
- 53 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.2
The text
As transmitted, in the capitals the NWS used until 2016.
363 WUUS51 KPHI 272312 SVRPHI PAC011-029-045-091-280000- /O.NEW.KPHI.SV.W.0046.100527T2312Z-100528T0000Z/ BULLETIN - EAS ACTIVATION REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 712 PM EDT THU MAY 27 2010 THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A * SEVERE THUNDERSTORM WARNING FOR... SOUTHEASTERN BERKS COUNTY IN EASTERN PENNSYLVANIA... NORTHEASTERN CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA... EXTREME NORTH CENTRAL DELAWARE COUNTY IN SOUTHEAST PENNSYLVANIA... SOUTHWESTERN MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA... * UNTIL 800 PM EDT * AT 708 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL. THIS STORM WAS LOCATED NEAR CEDARVILLE...OR 15 MILES SOUTHEAST OF READING...AND MOVING SOUTHEAST AT 25 MPH. * THE SEVERE THUNDERSTORM WILL BE NEAR... PUGHTOWN AROUND 720 PM EDT... ROYERSFORD AROUND 725 PM EDT... CHESTER SPRINGS AND PHOENIXVILLE AROUND 735 PM EDT... VALLEY FORGE AND LIONVILLE AROUND 740 PM EDT... 9 MILES NORTHEAST OF DOWNINGTOWN AROUND 745 PM EDT... PAOLI AROUND 750 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. HAIL UP TO THE SIZE OF QUARTERS HAS BEEN REPORTED AROUND POTTSTOWN WITH THIS STORM. IF YOU ARE IN THE PATH OF THE STORM...TAKE IMMEDIATE ACTION TO PROTECT LIFE AND PROPERTY. A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM EDT THURSDAY EVENING FOR NORTHERN DELAWARE AND NORTHEASTERN MARYLAND AND NEW JERSEY AND EASTERN PENNSYLVANIA. && LAT...LON 4005 7533 3993 7576 4025 7575 4030 7560 TIME...MOT...LOC 2311Z 334DEG 20KT 4023 7565 $$ PO
The office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 27, 2:00 PM EDT | Severe Thunderstorm Warning | PHI | Bucks, Monroe, Northampton | 60 min |
| May 27, 2:30 PM EDT | Flash Flood Warning | PHI | Northampton | 33 min |
| May 27, 2:45 PM EDT | Special Weather Statement | PHI | Chester | 60 min |
| May 27, 3:19 PM EDT | Severe Thunderstorm Warning | PHI | Bucks, Northampton | 41 min |
| May 27, 4:53 PM EDT | Special Weather Statement | PHI | Bucks, Montgomery | 52 min |
| May 27, 5:11 PM EDT | Severe Thunderstorm Warning | PHI | Berks, Carbon, Lehigh, Northampton | 64 min |
| May 27, 5:36 PM EDT | Severe Thunderstorm Warning | PHI | Monroe, Northampton | 54 min |
| May 27, 5:44 PM EDT | Special Weather Statement | PHI | Delaware, Montgomery | 61 min |
| May 27, 5:53 PM EDT | Severe Thunderstorm Warning | PHI | Chester, Delaware, Montgomery | 37 min |
| May 27, 6:05 PM EDT | Severe Thunderstorm Warning | PHI | Berks, Bucks, Lehigh, Montgomery | 25 min |
| May 27, 6:20 PM EDT | Severe Thunderstorm Warning | PHI | Berks, Chester, Lehigh, Montgomery | 55 min |
| May 27, 6:35 PM EDT | Special Weather Statement | PHI | Northampton | 55 min |
| May 27, 7:25 PM EDT | Special Weather Statement | PHI | Montgomery | 65 min |
| May 27, 7:40 PM EDT | Special Weather Statement | PHI | Bucks | 65 min |
| May 27, 7:44 PM EDT | Areal Flood Advisory | PHI | Berks, Chester, Montgomery | 3 hr |
| May 27, 7:56 PM EDT | Severe Thunderstorm Warning | PHI | Chester, Delaware | 34 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.