Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2010
Severe Thunderstorm Warning 45, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at May 27, 2010, 6:20 PM EDT for 4 counties in Pennsylvania. It was in force for 55 min. 6 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, 6:20 PM EDT (22:20 UTC)
- Expired
- May 27, 2010, 7:15 PM EDT
- In force
- 55 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), 104 km from the middle of the area, began a volume at 22:21 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, 6:35 PM EDT | HAIL 0.25 | Spring City, PA | PEA SIZE HAIL REPORTED IN SPRING CITY. |
| May 27, 6:40 PM EDT | HAIL 0.25 | Boyertown, PA | PEA SIZE HAIL REPORTED IN EARL TOWNSHIP. |
| May 27, 6:43 PM EDT | HAIL 0.25 | Boyertown, PA | PEA SIZE HAIL REPORTED IN BOYERTOWN. |
| May 27, 7:09 PM EDT | HAIL 1 | Pottstown, PA | NICKEL TO QUARTER SIZE HAIL REPORTED IN POTTSTOWN. |
| May 27, 7:10 PM EDT | HAIL 1 | 1 S Pottstown, PA | QUARTER SIZE HAIL REPORTED JUST SOUTH OF POTTSTOWN. |
| 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. |
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, 10.3 hours before the alert went out and 101 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.
548 WUUS51 KPHI 272220 SVRPHI PAC011-029-077-091-272315- /O.NEW.KPHI.SV.W.0045.100527T2220Z-100527T2315Z/ BULLETIN - EAS ACTIVATION REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 620 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... SOUTH CENTRAL LEHIGH COUNTY IN EASTERN PENNSYLVANIA... NORTH CENTRAL CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA... WESTERN MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA... * UNTIL 715 PM EDT * AT 617 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 TOPTON...OR 14 MILES SOUTHWEST OF ALLENTOWN...AND MOVING SOUTH AT 25 MPH. * OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO BALLY...EAST GREENVILLE...BECHTELSVILLE...GILBERTSVILLE...GREEN LANE...SPRING MOUNT...POTTSTOWN...SCHWENKSVILLE...CEDARVILLE... TRAPPE...ROYERSFORD...PUGHTOWN...COLLEGEVILLE AND PHOENIXVILLE 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. 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 4014 7534 4010 7576 4050 7577 4051 7556 TIME...MOT...LOC 2221Z 350DEG 22KT 4042 7566 $$ PO
1 follow-up statement
764 WWUS51 KPHI 272247 SVSPHI SEVERE WEATHER STATEMENT NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 647 PM EDT THU MAY 27 2010 PAC077-272257- /O.CAN.KPHI.SV.W.0045.000000T0000Z-100527T2315Z/ LEHIGH PA- 647 PM EDT THU MAY 27 2010 ...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL LEHIGH COUNTY IS CANCELLED... A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM EDT THURSDAY EVENING FOR NORTHERN DELAWARE AND NORTHEASTERN MARYLAND AND NEW JERSEY AND EASTERN PENNSYLVANIA. LAT...LON 4014 7534 4010 7576 4043 7577 4044 7553 TIME...MOT...LOC 2247Z 350DEG 22KT 4026 7562 $$ PAC011-029-091-272315- /O.CON.KPHI.SV.W.0045.000000T0000Z-100527T2315Z/ CHESTER PA-MONTGOMERY PA-BERKS PA- 647 PM EDT THU MAY 27 2010 ...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 715 PM EDT FOR SOUTHEASTERN BERKS...WESTERN MONTGOMERY AND NORTH CENTRAL CHESTER COUNTIES... AT 642 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 HALFWAY HOUSE...OR 16 MILES EAST OF READING...MOVING SOUTH AT 25 MPH. OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO SPRING MOUNT...POTTSTOWN...SANATOGA...SOUTH POTTSTOWN...SCHWENKSVILLE... CEDARVILLE...KENILWORTH...SKIPPACK...TRAPPE...ROYERSFORD... PUGHTOWN...SPRING CITY...EVANSBURG...COLLEGEVILLE...EAGLEVILLE... PHOENIXVILLE AND TROOPER PRECAUTIONARY/PREPAREDNESS ACTIONS... 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 4014 7534 4010 7576 4043 7577 4044 7553 TIME...MOT...LOC 2247Z 350DEG 22KT 4026 7562 $$ 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, 6:35 PM EDT | Special Weather Statement | PHI | Northampton | 55 min |
| May 27, 7:12 PM EDT | Severe Thunderstorm Warning | PHI | Berks, Chester, Delaware, Montgomery | 48 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.