Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2010
Severe Thunderstorm Warning 43, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at May 27, 2010, 5:53 PM EDT for Chester County, Delaware County, Montgomery County, Pennsylvania. It was in force for 37 min. 4 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, 5:53 PM EDT (21:53 UTC)
- Expired
- May 27, 2010, 6:30 PM EDT
- In force
- 37 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
Counties Chester County, PA, Delaware County, PA, Montgomery County, PA
The radar
The Philadelphia radar (KDIX), 107 km from the middle of the area, began a volume at 21:56 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, 5:53 PM EDT | HAIL 1 | 1 S Pottstown, PA | 1 INCH HAIL REPORTED NEAR MONTGOMERY AND CHESTER COUNTY LINE. |
| May 27, 6:03 PM EDT | HAIL 0.5 | 3 N Royersford, PA | DIME SIZE HAIL REPORTED IN LIMERICK. |
| May 27, 6:07 PM EDT | HAIL 1 | Spring City, PA | QUARTER SIZE HAIL REPORTED IN SPRING CITY. |
| May 27, 6:35 PM EDT | HAIL 0.25 | Spring City, PA | PEA SIZE HAIL REPORTED IN SPRING CITY. |
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, 9.9 hours before the alert went out and 89 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.
305
WUUS51 KPHI 272153
SVRPHI
PAC029-045-091-272300-
/O.NEW.KPHI.SV.W.0043.100527T2153Z-100527T2300Z/
BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
553 PM EDT THU MAY 27 2010
THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A
* SEVERE THUNDERSTORM WARNING FOR...
NORTHEASTERN CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA...
THIS INCLUDES THE CITY OF WEST CHESTER...
NORTHERN DELAWARE COUNTY IN SOUTHEAST PENNSYLVANIA...
SOUTHWESTERN MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA...
* UNTIL 700 PM EDT
* AT 551 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
POTTSTOWN...OR 18 MILES NORTH OF WEST CHESTER...AND MOVING
SOUTHEAST AT 25 MPH.
* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
PUGHTOWN...ROYERSFORD...TRAPPE...COLLEGEVILLE...PHOENIXVILLE...
CHESTER SPRINGS...LIONVILLE...VALLEY FORGE...KING OF PRUSSIA...
PAOLI...RADNOR TOWNSHIP...WESTTOWN...BRYN MAWR...NEWTOWN SQUARE...
TROUT LAKE...CHEYNEY...GRADYVILLE...NARBERTH AND BROOMALL
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 4022 7573 4024 7570 4026 7569 4029 7566
4033 7555 4000 7524 3987 7558 4022 7574
TIME...MOT...LOC 2153Z 333DEG 20KT 4021 7560
$$
PO2 follow-up statements
296
WWUS51 KPHI 272217
SVSPHI
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
617 PM EDT THU MAY 27 2010
PAC029-045-091-272300-
/O.CON.KPHI.SV.W.0043.000000T0000Z-100527T2300Z/
DELAWARE PA-CHESTER PA-MONTGOMERY PA-
617 PM EDT THU MAY 27 2010
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 700 PM EDT
FOR SOUTHWESTERN MONTGOMERY...NORTHEASTERN CHESTER AND NORTH CENTRAL
DELAWARE COUNTIES...
AT 613 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE
HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH. THIS STORM WAS
LOCATED NEAR PHOENIXVILLE...OR 11 MILES NORTH OF WEST CHESTER...
MOVING SOUTHEAST AT 25 MPH.
OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
AUDUBON...VALLEY FORGE...EXTON...CHESTERBROOK...KING OF PRUSSIA...
MALVERN...PAOLI...DEVON-BERWYN...WEST GOSHEN AND RADNOR TOWNSHIP
PRECAUTIONARY/PREPAREDNESS ACTIONS...
A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM EDT
THURSDAY EVENING FOR NORTHERN DELAWARE AND NORTHEASTERN MARYLAND AND
NEW JERSEY AND EASTERN PENNSYLVANIA.
&&
LAT...LON 4017 7568 4021 7568 4022 7568 4024 7564
4025 7556 4005 7531 3993 7560 4019 7569
TIME...MOT...LOC 2215Z 333DEG 20KT 4010 7553
$$
PO436
WWUS51 KPHI 272230
SVSPHI
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
630 PM EDT THU MAY 27 2010
PAC029-045-091-272238-
/O.CAN.KPHI.SV.W.0043.000000T0000Z-100527T2300Z/
DELAWARE PA-CHESTER PA-MONTGOMERY PA-
630 PM EDT THU MAY 27 2010
...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN MONTGOMERY...
NORTHEASTERN CHESTER AND NORTH CENTRAL DELAWARE COUNTIES IS
CANCELLED...
THE STORM NEAR PHOENIXVILLE HAS WEAKENED AND THE WARNING FOR THIS
STORM IS BEING CANCELLED. ANOTHER SEVERE THUNDERSTORM OVER EASTERN
BERKS COUNTY MAY AFFECT THE AREA BEFORE 730 PM.
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 4017 7568 4021 7568 4022 7568 4024 7564
4025 7556 4005 7531 3993 7560 4019 7569
TIME...MOT...LOC 2228Z 333DEG 20KT 4004 7549
$$
POThe 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, 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, 7:12 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.