Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2011
Severe Thunderstorm Warning 84, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jun 1, 2011, 4:55 PM EDT for Chester County, Pennsylvania; New Castle County, Delaware; Cecil County, Maryland. It was in force for 26 min. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- Jun 1, 2011, 4:55 PM EDT (20:55 UTC)
- Expired
- Jun 1, 2011, 5:21 PM EDT
- In force
- 26 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
Counties New Castle County, DE, Cecil County, MD, Chester County, PA
The radar
The Dover AFB radar (KDOX), 113 km from the middle of the area, began a volume at 20:56 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.
The watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Jun 1, 12:58 PM EDT | Tornado Watch | SPC | 7 hr |
| Jun 1, 2:24 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
The nearest sounding before it
Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 8.9 hours before the alert went out and 28 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
- 2843 J/kg
- Mixed-layer CIN
- -97 J/kg
- Mixed-layer LCL
- 1042 m above ground
- 0-6 km bulk shear
- 21 kt
- 0-1 km storm-relative helicity
- 319 m²/s²
- 0-3 km storm-relative helicity
- 336 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 4.1
The text
As transmitted, in the capitals the NWS used until 2016.
717
WUUS51 KPHI 012055
SVRPHI
DEC003-MDC015-PAC029-012200-
/O.NEW.KPHI.SV.W.0084.110601T2055Z-110601T2200Z/
BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
455 PM EDT WED JUN 1 2011
THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A
* SEVERE THUNDERSTORM WARNING FOR...
NORTHERN CECIL COUNTY IN NORTHEAST MARYLAND...
THIS INCLUDES THE CITY OF ELKTON...
WESTERN NEW CASTLE COUNTY IN NORTHERN DELAWARE...
THIS INCLUDES THE CITY OF NEWARK...
SOUTHWESTERN CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA...
* UNTIL 600 PM EDT
* AT 454 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL. THIS
STORM WAS LOCATED 8 MILES WEST OF ROCK SPRINGS...OR 21 MILES SOUTH
OF LANCASTER...AND MOVING EAST AT 30 MPH.
* THE SEVERE THUNDERSTORM WILL BE NEAR...
ROCK SPRINGS...CONOWINGO AND OCTORARO AROUND 510 PM EDT...
RICHARDSMERE AROUND 515 PM EDT...
RISING SUN...GLEN ROY AND WEST NOTTINGHAM AROUND 520 PM EDT...
FARMINGTON AND GLEN ROY AROUND 525 PM EDT...
CALVERT AROUND 530 PM EDT...
PRECAUTIONARY/PREPAREDNESS ACTIONS...
IF A TORNADO IS SPOTTED...ACT QUICKLY AND MOVE TO A PLACE OF SAFETY
IN A STURDY STRUCTURE...SUCH AS A BASEMENT OR SMALL INTERIOR ROOM.
A TORNADO WATCH REMAINS IN EFFECT UNTIL 800 PM EDT WEDNESDAY EVENING
FOR NEW JERSEY AND EASTERN PENNSYLVANIA. A SEVERE THUNDERSTORM WATCH
ALSO REMAINS IN EFFECT UNTIL 1000 PM EDT WEDNESDAY EVENING FOR
DELAWARE AND NORTHEASTERN MARYLAND AND SOUTHERN NEW JERSEY.
&&
LAT...LON 3973 7623 3973 7615 3975 7611 3975 7610
3986 7602 3988 7564 3955 7570 3961 7615
3965 7617 3970 7624
TIME...MOT...LOC 2055Z 275DEG 25KT 3974 7630
$$
MPD1 follow-up statement
947
WWUS51 KPHI 012121
SVSPHI
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
521 PM EDT WED JUN 1 2011
DEC003-MDC015-PAC029-012131-
/O.CAN.KPHI.SV.W.0084.000000T0000Z-110601T2200Z/
CECIL MD-CHESTER PA-NEW CASTLE DE-
521 PM EDT WED JUN 1 2011
...THE SEVERE THUNDERSTORM WARNING FOR WESTERN NEW CASTLE...
SOUTHWESTERN CHESTER AND NORTHERN CECIL COUNTIES IS CANCELLED...
A TORNADO WATCH REMAINS IN EFFECT UNTIL 800 PM EDT WEDNESDAY EVENING
FOR NEW JERSEY AND EASTERN PENNSYLVANIA. A SEVERE THUNDERSTORM WATCH
ALSO REMAINS IN EFFECT UNTIL 1000 PM EDT WEDNESDAY EVENING FOR
DELAWARE AND NORTHEASTERN MARYLAND AND SOUTHERN NEW JERSEY.
LAT...LON 3973 7623 3973 7615 3975 7611 3975 7610
3986 7602 3988 7564 3955 7570 3961 7615
3965 7617 3970 7624
TIME...MOT...LOC 2121Z 275DEG 25KT 3972 7607
$$
MPDThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 1, 12:56 PM EDT | Severe Thunderstorm Warning | PHI | Carbon, Monroe | 60 min |
| Jun 1, 1:57 PM EDT | Severe Thunderstorm Warning | PHI | Carbon, Monroe, Northampton | 63 min |
| Jun 1, 2:42 PM EDT | Severe Thunderstorm Warning | PHI | Berks, Chester, Lehigh | 52 min |
| Jun 1, 3:08 PM EDT | Severe Thunderstorm Warning | PHI | Bucks, Lehigh, Northampton | 16 min |
| Jun 1, 4:15 PM EDT | Severe Thunderstorm Warning | PHI | Bucks | 45 min |
| Jun 1, 3:06 PM EDT | Severe Thunderstorm Warning | PHI | Talbot | 54 min |
Nearby
Severe Thunderstorm Warnings in Pennsylvania, 2011Severe Thunderstorm Warnings in Delaware, 2011Severe Thunderstorm Warnings in Maryland, 2011Every severe thunderstorm warning in 2011
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.