Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2010
Severe Thunderstorm Warning 99, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 19, 2010, 5:39 PM EDT for Berks County, Chester County, Pennsylvania; Cecil County, Maryland. It was in force for 66 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
- Jul 19, 2010, 5:39 PM EDT (21:39 UTC)
- Expired
- Jul 19, 2010, 6:45 PM EDT
- In force
- 66 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
Counties Cecil County, MD, Berks County, PA, Chester County, PA
The radar
The Dover AFB radar (KDOX), 129 km from the middle of the area, began a volume at 21:42 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 |
|---|---|---|---|
| Jul 19, 5:45 PM EDT | TSTM WND DMG | Downingtown, PA | TREES DOWN THROUGHOUT THE COUNTY. |
| Jul 19, 6:07 PM EDT | TSTM WND DMG | Calvert, MD | NUMEROUS WIRES DOWN ACROSS THE COUNTY. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 9.7 hours before the alert went out and 51 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
- 775 J/kg
- Mixed-layer CIN
- -101 J/kg
- Mixed-layer LCL
- 883 m above ground
- 0-6 km bulk shear
- 33 kt
- 0-1 km storm-relative helicity
- -31 m²/s²
- 0-3 km storm-relative helicity
- 75 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 0.6
The text
As transmitted, in the capitals the NWS used until 2016.
475
WUUS51 KPHI 192139
SVRPHI
MDC015-PAC011-029-192245-
/O.NEW.KPHI.SV.W.0099.100719T2139Z-100719T2245Z/
BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
539 PM EDT MON JUL 19 2010
THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A
* SEVERE THUNDERSTORM WARNING FOR...
EXTREME SOUTH CENTRAL BERKS COUNTY IN EASTERN PENNSYLVANIA...
NORTHWESTERN CECIL COUNTY IN NORTHEAST MARYLAND...
CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA...
* UNTIL 645 PM EDT
* AT 537 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING WINDS IN
EXCESS OF 60 MPH. THESE STORMS WERE LOCATED ALONG A LINE EXTENDING
FROM HONEY BROOK TO 7 MILES NORTHWEST OF HOMEVILLE TO ROCK
SPRINGS...OR ALONG A LINE EXTENDING FROM 15 MILES SOUTH OF READING
TO 14 MILES SOUTHEAST OF LANCASTER TO 20 MILES SOUTH OF
LANCASTER...AND MOVING EAST AT 30 MPH.
* SEVERE THUNDERSTORMS WILL BE NEAR...
ELVERSON...CONOWINGO AND ROCK SPRINGS AROUND 545 PM EDT...
MOUNT VERNON...HOMEVILLE...RICHARDSMERE AND PARKESBURG AROUND 550
PM EDT...
GLENMOORE...GLEN ROY AND COCHRANVILLE AROUND 555 PM EDT...
PRECAUTIONARY/PREPAREDNESS ACTIONS...
THIS STORM HAS A HISTORY OF PRODUCING DESTRUCTIVE WINDS AND LARGE
DAMAGING HAIL. SEEK SHELTER NOW INSIDE A STURDY STRUCTURE AND STAY
AWAY FROM WINDOWS!
&&
LAT...LON 3973 7623 3973 7615 3976 7609 3987 7601
3992 7602 4003 7596 4011 7595 4014 7590
4020 7597 4016 7554 4015 7553 4016 7551
3991 7569 3965 7594 3967 7620 3969 7623
TIME...MOT...LOC 2139Z 284DEG 27KT 4010 7591 3994 7604
3974 7622
$$
HAYES2 follow-up statements
606
WWUS51 KPHI 192155
SVSPHI
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
555 PM EDT MON JUL 19 2010
MDC015-PAC011-029-192245-
/O.CON.KPHI.SV.W.0099.000000T0000Z-100719T2245Z/
CECIL MD-CHESTER PA-BERKS PA-
555 PM EDT MON JUL 19 2010
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 645 PM EDT
FOR EXTREME SOUTH CENTRAL BERKS...CHESTER AND NORTHWESTERN CECIL
COUNTIES...
AT 550 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING
WINDS IN EXCESS OF 60 MPH. THESE STORMS WERE LOCATED ALONG A LINE
EXTENDING FROM FROM 15 MILES NORTHWEST OF WEST CHESTER TO 19 MILES
NORTHWEST OF ELKTON...MOVING EAST AT 30 MPH.
SEVERE THUNDERSTORMS WILL BE NEAR...
FARMINGTON...WEST NOTTINGHAM...SOUTH COATESVILLE AND OXFORD BY 600
PM EDT...
CALVERT...THORNDALE AND DOWNINGTOWN BY 605 PM EDT...
CHESTER SPRINGS...ZION AND LOMBARD BY 610 PM EDT...
LAT...LON 3973 7623 3973 7615 3976 7609 3987 7601
3992 7602 4003 7596 4011 7595 4014 7590
4020 7597 4016 7554 4015 7553 4016 7551
3991 7569 3965 7594 3967 7620 3969 7623
TIME...MOT...LOC 2154Z 284DEG 27KT 4010 7579 3990 7591
3971 7611
$$
HAYES906
WWUS51 KPHI 192233
SVSPHI
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
633 PM EDT MON JUL 19 2010
PAC011-192243-
/O.CAN.KPHI.SV.W.0099.000000T0000Z-100719T2245Z/
BERKS PA-
633 PM EDT MON JUL 19 2010
...THE SEVERE THUNDERSTORM WARNING FOR EXTREME SOUTH CENTRAL BERKS
COUNTY IS CANCELLED...
LAT...LON 3974 7601 3979 7596 3985 7593 3992 7584
4004 7576 4010 7578 4016 7575 4016 7554
4014 7553 3991 7569 3965 7594 3965 7601
TIME...MOT...LOC 2233Z 284DEG 27KT 4003 7542 3983 7554
3964 7574
$$
MDC015-PAC029-192245-
/O.CON.KPHI.SV.W.0099.000000T0000Z-100719T2245Z/
CECIL MD-CHESTER PA-
633 PM EDT MON JUL 19 2010
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 645 PM EDT
FOR CHESTER AND NORTH CENTRAL CECIL COUNTIES...
AT 632 PM EDT...A LINE OF SEVERE THUNDERSTORMS WAS REPORTED CAPABLE
OF PRODUCING DAMAGING WINDS IN EXCESS OF 60 MPH. THESE STORMS WERE
LOCATED ALONG A LINE EXTENDING FROM 11 MILES EAST OF EXTON TO 11
MILES SOUTHEAST OF MARSHALLTON TO 10 MILES SOUTHEAST OF BLAKE...OR
ALONG A LINE EXTENDING FROM 10 MILES NORTHEAST OF WEST CHESTER TO 7
MILES NORTH OF WILMINGTON TO NEWARK...MOVING EAST AT 30 MPH.
LAT...LON 3974 7601 3979 7596 3985 7593 3992 7584
4004 7576 4010 7578 4016 7575 4016 7554
4014 7553 3991 7569 3965 7594 3965 7601
TIME...MOT...LOC 2233Z 284DEG 27KT 4003 7542 3983 7554
3964 7574
$$
HAYESThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 19, 5:15 AM EDT | Special Weather Statement | PHI | Berks | 60 min |
| Jul 19, 6:04 AM EDT | Special Weather Statement | PHI | Berks, Carbon, Lehigh, Monroe, Montgomery, Northampton | 56 min |
| Jul 19, 6:58 AM EDT | Special Weather Statement | PHI | Carbon, Lehigh, Monroe, Northampton | 62 min |
| Jul 19, 7:46 AM EDT | Special Weather Statement | PHI | Bucks, Chester, Delaware, Montgomery, Philadelphia | 59 min |
| Jul 19, 8:19 AM EDT | Special Weather Statement | PHI | Montgomery | 56 min |
| Jul 19, 8:47 AM EDT | Special Weather Statement | PHI | Delaware | 58 min |
| Jul 19, 9:07 AM EDT | Severe Thunderstorm Warning | PHI | Bucks, Delaware, Montgomery, Philadelphia | 53 min |
| Jul 19, 2:09 PM EDT | Special Weather Statement | PHI | Carbon | 51 min |
| Jul 19, 2:21 PM EDT | Severe Thunderstorm Warning | PHI | Carbon, Monroe | 54 min |
| Jul 19, 4:24 PM EDT | Special Weather Statement | PHI | Carbon | 36 min |
| Jul 19, 5:11 PM EDT | Special Weather Statement | PHI | Monroe | 49 min |
| Jul 19, 5:24 PM EDT | Special Weather Statement | PHI | Northampton | 51 min |
| Jul 19, 5:25 PM EDT | Special Weather Statement | PHI | Chester, Delaware, Montgomery | 65 min |
| Jul 19, 6:22 PM EDT | Severe Thunderstorm Warning | PHI | Chester, Delaware, Montgomery, Philadelphia | 53 min |
| Jul 19, 6:34 PM EDT | Severe Thunderstorm Warning | PHI | Bucks, Montgomery, Philadelphia | 56 min |
| Jul 19, 6:57 PM EDT | Special Weather Statement | PHI | Berks, Lehigh, Northampton | 48 min |
| Jul 18, 11:12 PM EDT | Special Weather Statement | PHI | Caroline, Kent, Queen Anne's, Talbot | 93 min |
| Jul 19, 12:00 AM EDT | Severe Thunderstorm Warning | PHI | Caroline, Cecil, Kent, Queen Anne's, Talbot | 60 min |
| Jul 19, 6:52 PM EDT | Special Weather Statement | PHI | Cecil | 68 min |
Nearby
Severe Thunderstorm Warnings in Pennsylvania, 2010Severe Thunderstorm Warnings in Maryland, 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.