Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 7, NWS Philadelphia/Mount Holly

February 25, 2017Berks County, Chester County, Pennsylvania; Cecil County, Maryland

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Feb 25, 2017, 3:26 PM EST for Berks County, Chester County, Pennsylvania; Cecil County, Maryland. It was in force for 64 min. 10 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
Feb 25, 2017, 3:26 PM EST (20:26 UTC)
Expired
Feb 25, 2017, 4:30 PM EST
In force
64 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Tornado
Possible
Hail
1.0 in
Wind
60.0 mph

Counties Cecil County, MD, Berks County, PA, Chester County, PA

The radar

The Philadelphia radar (KDIX), 130 km from the middle of the area, began a volume at 20:28 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

TimeReportWhereRemark
Feb 25, 3:45 PM ESTHAIL 1Stouchsburg, PA
Feb 25, 3:50 PM ESTTSTM WND DMGSinking Spring, PASEVERAL TREES SNAPPED AND UPROOTED. TIME ESTIMATED FROM RADAR.
Feb 25, 3:50 PM ESTTSTM WND DMGWernersville, PA5 TREES DOWN. SMALL PART OF OF BARN ROOF BLOWN OFF. PEA SIZED HAIL.
Feb 25, 3:54 PM ESTHAIL 1Bernville, PA
Feb 25, 3:56 PM ESTTSTM WND GST 61Reading Regional Airpor, PA
Feb 25, 4:00 PM ESTTSTM WND GST 651 Ne Reading, PA
Feb 25, 4:05 PM ESTTSTM WND DMGFleetwood, PASEVERAL POWER POLES AND TREES BLOWN DOWN. BARN ROOF BLOWN OFF. TIME ESTIMATED FROM RADAR.
Feb 25, 4:07 PM ESTTSTM WND DMGKutztown, PAROOF OF A MEDIVAC HANGER BLOWN OFF HITTING A HOUSE AT A NEARBY MOBILE HOME PARK. POWER OUT IN THE AREA. TIME ESTIMATED FROM RADAR.
Feb 25, 4:09 PM ESTTSTM WND DMGBlandon, PAYARD FENCING BLOWN DOWN.
Feb 25, 4:15 PM ESTHAIL 0.75Boyertown, PA

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.

IssuedProductOfficeLasted
Feb 25, 1:30 PM ESTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 8.4 hours before the alert went out and 177 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.

Skew-T log-pSkew-T log-p diagram, Washington/Dulle, VA at 12:00Z on 2017-02-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 235 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 12:00Z on 2017-02-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 164 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
235 J/kg
Mixed-layer CIN
-194 J/kg
Mixed-layer LCL
676 m above ground
0-6 km bulk shear
46 kt
0-1 km storm-relative helicity
164 m²/s²
0-3 km storm-relative helicity
143 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

289 
WUUS51 KPHI 252026
SVRPHI
MDC015-PAC011-029-252130-
/O.NEW.KPHI.SV.W.0007.170225T2026Z-170225T2130Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
326 PM EST SAT FEB 25 2017

The National Weather Service in Mount Holly NJ  has issued a

* Severe Thunderstorm Warning for...
  Northwestern Cecil County in northeastern Maryland...
  Berks County in eastern Pennsylvania...
  Western Chester County in southeastern Pennsylvania...

* Until 430 PM EST

* At 325 PM EST, severe thunderstorms were located along a line
  extending from Lawn to near Mountville to near Stewartstown to
  Jarrettsville, moving northeast at 40 mph.

  HAZARD...60 mph wind gusts and quarter size hail. 

  SOURCE...Radar indicated. 

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees. 

* Severe thunderstorms will be near,
  Newmanstown and Rock Springs around 350 PM EST. 
  Womelsdorf and Robesonia around 355 PM EST. 
  Wernersville, Bernville and Glen Roy around 400 PM EST. 
  Oxford, Sinking Spring and Mount Vernon around 405 PM EST. 
  Reading, Wyomissing, Leesport, Elverson, New Morgan, Fairview 
  Hgts, Homeville and Spring Ridge around 410 PM EST. 
  Laureldale, Parkesburg, Shoemakersville and Cochranville around 
  415 PM EST. 
  Birdsboro and West Grove around 420 PM EST. 
  Coatesville, Fleetwood, Honey Brook, Lyons and Cedarville around 
  425 PM EST. 

Other locations impacted by these severe thunderstorms include
Wyomissing Hills, West Lawn, Boyertown, West Reading, South
Coatesville, Modena, Lorane, Kenhorst, Mount Penn and South
Pottstown.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare immediately for large hail and damaging winds. People outside
should move immediately to shelter inside a strong building. Stay
away from windows.

Intense thunderstorm lines can produce brief tornadoes and widespread
significant wind damage. Although a tornado is not immediately
likely, it is best to move to an interior room on the lowest floor of
a building. These storms may cause serious injury and significant
property damage.

In addition to large hail and damaging winds...frequent cloud to
ground lightning is occurring with this storm. Move indoors
immediately. Remember...if you can hear thunder...you are close
enough to be struck by lightning.

&&

LAT...LON 4059 7581 4034 7563 4024 7570 4024 7566
      4008 7571 3986 7572 3967 7619 3972 7623
      3973 7610 3976 7606 3983 7604 3987 7599
      3995 7600 4004 7593 4011 7594 4014 7588
      4039 7627
TIME...MOT...LOC 2025Z 240DEG 37KT 4021 7651 4001 7641 3973 7653 3962
7649

TORNADO...POSSIBLE
HAIL...1.00IN
WIND...60MPH
 
$$

DRAG
2 follow-up statements
349 
WWUS51 KPHI 252045
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
345 PM EST SAT FEB 25 2017

MDC015-PAC011-029-252130-
/O.CON.KPHI.SV.W.0007.000000T0000Z-170225T2130Z/
Cecil MD-Berks PA-Chester PA-
345 PM EST SAT FEB 25 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 430 PM EST
FOR NORTHWESTERN CECIL...BERKS AND WESTERN CHESTER COUNTIES...

At 345 PM EST, severe thunderstorms were located along a line
extending from near Myerstown to Denver to near Holtwood to near Rock
Springs, moving northeast at 50 mph.

HAZARD...60 mph wind gusts and quarter size hail. 

SOURCE...Radar indicated. 

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees. 

These severe storms will be near...
  Womelsdorf, Wernersville and Newmanstown around 350 PM EST. 
  Sinking Spring and Robesonia around 355 PM EST. 
  Reading, Wyomissing, Oxford, Bernville, Spring Ridge, Mount Vernon 
  and Fairview Hgts around 400 PM EST. 
  Laureldale, Leesport and Homeville around 405 PM EST. 
  Shoemakersville and Cochranville around 410 PM EST. 
  Fleetwood, Parkesburg, Honey Brook and Lyons around 415 PM EST. 
  Coatesville and Kutztown around 420 PM EST. 
  Elverson and New Morgan around 425 PM EST. 

Other locations impacted by these severe thunderstorms include
Wyomissing Hills, West Lawn, Boyertown, West Reading, South
Coatesville, Modena, Lorane, Kenhorst, Mount Penn and South
Pottstown.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Remain alert for a possible tornado! Tornadoes can develop quickly
from severe thunderstorms. If you spot a tornado go at once into the
basement or small central room in a sturdy structure.

Prepare immediately for large hail and damaging winds. People outside
should move to a shelter, inside a strong building and away from
windows.

To report severe weather contact your nearest law enforcement agency.
They will send your report to the National Weather Service office in
Mount Holly NJ .

Intense thunderstorm lines can produce brief tornadoes and widespread
significant wind damage. Although a tornado is not immediately
likely, it is best to move to an interior room on the lowest floor of
a building. These storms may cause serious injury and significant
property damage.

In addition to large hail and damaging winds...frequent cloud to
ground lightning is occurring with this storm. Move indoors
immediately. Remember...if you can hear thunder...you are close
enough to be struck by lightning.

Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4059 7581 4034 7563 4024 7570 4024 7566
      4008 7571 3986 7572 3967 7619 3970 7621
      3973 7610 3976 7606 3983 7604 3987 7599
      3995 7600 4004 7593 4011 7594 4014 7588
      4039 7627
TIME...MOT...LOC 2045Z 228DEG 42KT 4034 7630 4024 7613 3983 7627 3972
7623

TORNADO...POSSIBLE
HAIL...1.00IN
WIND...60MPH
 
$$

DRAG
580 
WWUS51 KPHI 252124
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
424 PM EST SAT FEB 25 2017

MDC015-PAC011-029-252134-
/O.EXP.KPHI.SV.W.0007.000000T0000Z-170225T2130Z/
Cecil MD-Berks PA-Chester PA-
424 PM EST SAT FEB 25 2017

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN CECIL...BERKS AND
WESTERN CHESTER COUNTIES WILL EXPIRE AT 430 PM EST...
    
The storms which prompted the warning have moved out of the area.
Therefore the warning will be allowed to expire.  However gusty winds
are still possible with these thunderstorms.

A severe thunderstorm watch remains in effect until 800 PM EST for
northeastern Maryland...and eastern and southeastern Pennsylvania.

LAT...LON 4059 7581 4034 7563 4024 7570 4024 7566
      4008 7571 3986 7572 3967 7619 3970 7621
      3973 7610 3976 7606 3983 7604 3987 7599
      3995 7600 4004 7593 4011 7594 4014 7588
      4039 7627
TIME...MOT...LOC 2124Z 240DEG 37KT 4054 7585 4044 7568 4003 7583 3992
7579

$$

DRAG

The office that day

Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 25, 2:22 PM ESTSpecial Weather StatementPHILebanon53 min
Feb 25, 2:47 PM ESTSevere Thunderstorm WarningPHIBerks43 min
Feb 25, 2:55 PM ESTSpecial Weather StatementPHICarbon50 min
Feb 25, 3:02 PM ESTSpecial Weather StatementPHIBerks58 min
Feb 25, 3:19 PM ESTSevere Thunderstorm WarningPHIBerks, Carbon, Lehigh, Northampton41 min
Feb 25, 3:57 PM ESTSpecial Weather StatementPHILehigh, Montgomery48 min
Feb 25, 4:04 PM ESTSevere Thunderstorm WarningPHIChester, Delaware41 min
Feb 25, 4:05 PM ESTSevere Thunderstorm WarningPHICarbon, Lehigh, Monroe40 min
Feb 25, 4:17 PM ESTSevere Thunderstorm WarningPHIBerks, Bucks, Chester, Delaware, Lehigh, Monroe and 3 more43 min
Feb 25, 4:34 PM ESTSpecial Weather StatementPHIMonroe41 min
Feb 25, 4:40 PM ESTSevere Thunderstorm WarningPHIDelaware, Montgomery, Philadelphia50 min
Feb 25, 4:54 PM ESTSevere Thunderstorm WarningPHIBucks, Monroe51 min
Feb 25, 5:01 PM ESTSpecial Weather StatementPHIBucks44 min
Feb 25, 5:17 PM ESTSevere Thunderstorm WarningPHIBucks, Montgomery, Philadelphia43 min
Feb 25, 6:10 PM ESTSpecial Weather StatementPHIDelaware35 min
Feb 25, 3:05 PM ESTSpecial Weather StatementPHICecil, Kent, Queen Anne's, Talbot55 min
Feb 25, 3:18 PM ESTSevere Thunderstorm WarningPHICaroline, Queen Anne's, Talbot57 min
Feb 25, 4:11 PM ESTSevere Thunderstorm WarningPHICaroline, Kent, Queen Anne's, Talbot49 min
Feb 25, 4:50 PM ESTSevere Thunderstorm WarningPHICaroline, Talbot55 min
Feb 25, 5:07 PM ESTSpecial Weather StatementPHIKent38 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2017Severe Thunderstorm Warnings in Maryland, 2017Every severe thunderstorm warning in 2017

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.