Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2019

Severe Thunderstorm Warning 228, NWS Philadelphia/Mount Holly

July 17, 20194 states

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 17, 2019, 7:15 PM EDT for 4 states. It was in force for 45 min. 9 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 17, 2019, 7:15 PM EDT (23:15 UTC)
Expired: Jul 17, 2019, 8:00 PM EDT
In force: 45 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Tornado: Possible
Hail: 0.75 in
Wind: 70.0 mph

Counties New Castle County, DE, Cecil County, MD, Gloucester County, NJ, Salem County, NJ, Chester County, PA, Delaware County, PA, Montgomery County, PA

The radar

The Dover AFB radar (KDOX), 109 km from the middle of the area, began a volume at 23:16 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 17, 7:15 PM EDT	TSTM WND DMG	2 Wnw Brandamore, PA	POLES AND WIRES DOWN ON BIRDELL RD AT GOOSEBERRY LN. TIME ESTIMATED FROM RADAR.
Jul 17, 7:17 PM EDT	TSTM WND DMG	1 E Parkesburg, PA	REPORT OF POWER POLES AND WIRES BLOWN DOWN ONTO CARS NEAR TIMACULA RD AT ROUTE 372. TIME ESTIMATED FROM RADAR.
Jul 17, 7:20 PM EDT	TSTM WND DMG	1 Nnw Caln Twp, PA	POLES AND WIRES DOWN ON FISHERVILLE RD AT N BAILEY RD. TIME ESTIMATED FROM RADAR.
Jul 17, 7:45 PM EDT	TSTM WND DMG	1 Wnw Lenape, PA	WIRES DOWN.
Jul 17, 7:46 PM EDT	TSTM WND DMG	1 W East Marlborough Tw, PA	POLES AND WIRES DOWN ON WOLLASTON RD AT W STREET RD.
Jul 17, 7:55 PM EDT	TSTM WND DMG	1 Ne Berwyn, PA	POLES AND WIRES DOWN. TIME ESTIMATED FROM RADAR.
Jul 17, 7:55 PM EDT	TSTM WND DMG	Gibbstown, NJ	MPING REPORT OF 3 INCH TREE LIMBS OR POWER POLES BROKEN.
Jul 17, 7:56 PM EDT	TSTM WND DMG	1 E Logan Twp., NJ	DOWNED TREE CLOSING 1 OR 2 LANES OF US-130 NORTHBOUND AT NJ-44. TIME ESTIMATED FROM RADAR.
Jul 17, 8:01 PM EDT	TSTM WND GST 58	Newtown Square, PA	MEASURED GUST TO 58MPH.

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
Jul 17, 4:51 PM EDT	Severe Thunderstorm Watch	SPC	6 hr
Jul 17, 1:58 PM EDT	Severe Thunderstorm Watch	SPC	8 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 11.3 hours before the alert went out and 172 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 237 J/kg
Mixed-layer CIN: -90 J/kg
Mixed-layer LCL: 1666 m above ground
0-6 km bulk shear: 19 kt
0-1 km storm-relative helicity: 67 m²/s²
0-3 km storm-relative helicity: 69 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

904 
WUUS51 KPHI 172315
SVRPHI
DEC003-MDC015-NJC015-033-PAC029-045-091-180000-
/O.NEW.KPHI.SV.W.0228.190717T2315Z-190718T0000Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
715 PM EDT Wed Jul 17 2019

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Northern New Castle County in northern Delaware...
  Northeastern Cecil County in northeastern Maryland...
  Northwestern Salem County in southern New Jersey...
  Northwestern Gloucester County in southern New Jersey...
  Western Montgomery County in southeastern Pennsylvania...
  Chester County in southeastern Pennsylvania...
  Delaware County in southeastern Pennsylvania...

* Until 800 PM EDT.

* At 715 PM EDT, severe thunderstorms were located along a line
  extending from near Elverson to near Glasgow, moving northeast at
  30 mph.

  HAZARD...70 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Expect considerable tree damage. Damage is likely to 
           mobile homes, roofs, and outbuildings.

* Locations impacted include...
  Wilmington, Newark, West Chester, Elkton, Calvert, Norristown,
  Chester, Pottstown, Phoenixville, West Norriton, East Norriton,
  Pennsville, Coatesville, Westtown, Carneys Point, Downingtown,
  Folcroft, Swarthmore, Elsmere and Paulsboro.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

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

&&

LAT...LON 3987 7599 3995 7600 4004 7593 4009 7594
      4037 7542 3973 7522 3962 7557 3966 7552
      3971 7549 3972 7551 3971 7551 3967 7555
      3963 7561 3960 7561 3947 7599 3952 7598
      3985 7602
TIME...MOT...LOC 2315Z 246DEG 28KT 4013 7584 3959 7571 

TORNADO...POSSIBLE
HAIL...<.75IN
WIND...70MPH
 
$$

Fitzsimmons

2 follow-up statements

489 
WWUS51 KPHI 172339
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
739 PM EDT Wed Jul 17 2019

MDC015-172348-
/O.CAN.KPHI.SV.W.0228.000000T0000Z-190718T0000Z/
Cecil MD-
739 PM EDT Wed Jul 17 2019

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN CECIL COUNTY IS
CANCELLED...

The storms which prompted the warning have moved out of the warned 
area. Therefore, the warning has been cancelled.

A severe thunderstorm watch remains in effect until 1000 PM EDT for
southern New Jersey...and southeastern Pennsylvania. A severe
thunderstorm watch also remains in effect until midnight EDT for
northern Delaware...and southern New Jersey.

LAT...LON 3959 7565 4017 7580 4037 7542 3973 7522
      3962 7557 3966 7552 3971 7549 3972 7551
      3971 7551 3967 7555 3963 7561 3960 7561
TIME...MOT...LOC 2338Z 246DEG 31KT 4020 7555 3969 7543 

$$

DEC003-NJC015-033-PAC029-045-091-180000-
/O.CON.KPHI.SV.W.0228.000000T0000Z-190718T0000Z/
New Castle DE-Salem NJ-Gloucester NJ-Montgomery PA-Chester PA-
Delaware PA-
739 PM EDT Wed Jul 17 2019

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 800 PM EDT
FOR NORTHEASTERN NEW CASTLE...NORTHWESTERN SALEM...NORTHWESTERN
GLOUCESTER...WESTERN MONTGOMERY...EASTERN CHESTER AND DELAWARE
COUNTIES...

At 738 PM EDT, severe thunderstorms were located along a line
extending from Royersford to near Carneys Point, moving northeast at
35 mph. This storm has a history of producing wind damage.

HAZARD...70 mph wind gusts.

SOURCE...Law enforcement.

IMPACT...Expect considerable tree damage. Damage is likely to mobile 
         homes, roofs, and outbuildings.

Locations impacted include...
Wilmington, West Chester, Norristown, Chester, Pottstown,
Phoenixville, West Norriton, East Norriton, Pennsville, Westtown,
Carneys Point, Downingtown, Folcroft, Swarthmore, Elsmere, Paulsboro,
Kennett Square, New Castle, Penns Grove and Collegeville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

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

&&

LAT...LON 3959 7565 4017 7580 4037 7542 3973 7522
      3962 7557 3966 7552 3971 7549 3972 7551
      3971 7551 3967 7555 3963 7561 3960 7561
TIME...MOT...LOC 2338Z 246DEG 31KT 4020 7555 3969 7543 

TORNADO...POSSIBLE
HAIL...<.75IN
WIND...70MPH
 
$$

Staarmann

627 
WWUS51 KPHI 172353
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
753 PM EDT Wed Jul 17 2019

DEC003-NJC015-033-PAC029-045-091-180003-
/O.EXP.KPHI.SV.W.0228.000000T0000Z-190718T0000Z/
New Castle DE-Salem NJ-Gloucester NJ-Montgomery PA-Chester PA-
Delaware PA-
753 PM EDT Wed Jul 17 2019

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN NEW CASTLE...
NORTHWESTERN SALEM...NORTHWESTERN GLOUCESTER...WESTERN MONTGOMERY...
EASTERN CHESTER AND DELAWARE COUNTIES WILL EXPIRE AT 800 PM EDT...
            
The storms which prompted the warning have weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  However gusty 
winds up to 40 mph and heavy rain are still possible with these 
thunderstorms.

A severe thunderstorm watch remains in effect until 1000 PM EDT for
southern New Jersey...and southeastern Pennsylvania. A severe
thunderstorm watch also remains in effect until midnight EDT for
northern Delaware...and southern New Jersey.

LAT...LON 3959 7565 4017 7580 4037 7542 3973 7522
      3962 7557 3966 7552 3971 7549 3972 7551
      3971 7551 3967 7555 3963 7561 3960 7561
TIME...MOT...LOC 2353Z 246DEG 28KT 4024 7543 3973 7531 

$$

Staarmann

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 17, 3:54 AM EDT	Flash Flood Watch	PHI	Cecil	19 hr
Jul 17, 3:14 PM EDT	Excessive Heat Watch	PHI	Caroline, Cecil, Kent, Queen Anne's, Talbot	24 hr
Jul 17, 6:35 PM EDT	Severe Thunderstorm Warning	PHI	Cecil	40 min
Jul 17, 6:44 PM EDT	Severe Thunderstorm Warning	PHI	Caroline, Cecil, Kent, Queen Anne's	46 min
Jul 17, 7:17 PM EDT	Severe Thunderstorm Warning	PHI	Caroline, Queen Anne's	43 min
Jul 17, 7:44 PM EDT	Severe Thunderstorm Warning	PHI	Kent, New Castle	46 min
Jul 16, 9:15 PM EDT	Special Weather Statement	PHI	Philadelphia	45 min
Jul 17, 1:26 PM EDT	Special Weather Statement	PHI	Pike	34 min
Jul 17, 1:50 PM EDT	Areal Flood Advisory	PHI	Carbon, Lehigh, Monroe, Northampton	80 min
Jul 17, 2:05 PM EDT	Special Weather Statement	PHI	Lehigh	25 min
Jul 17, 5:05 PM EDT	Special Weather Statement	PHI	Carbon, Monroe	40 min
Jul 17, 5:14 PM EDT	Special Weather Statement	PHI	Lehigh	46 min
Jul 17, 5:44 PM EDT	Special Weather Statement	PHI	Monroe	46 min
Jul 17, 5:46 PM EDT	Areal Flood Advisory	PHI	Monroe	119 min
Jul 17, 5:49 PM EDT	Special Weather Statement	PHI	Lehigh, Northampton	41 min
Jul 17, 6:24 PM EDT	Special Weather Statement	PHI	Berks	51 min
Jul 17, 6:51 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Chester, Montgomery	54 min
Jul 17, 6:52 PM EDT	Areal Flood Advisory	PHI	Berks	113 min
Jul 17, 7:06 PM EDT	Flash Flood Warning	PHI	Berks	3 hr
Jul 17, 7:21 PM EDT	Flash Flood Warning	PHI	Chester	97 min
Jul 17, 7:31 PM EDT	Special Weather Statement	PHI	Lehigh, Northampton	44 min
Jul 17, 7:36 PM EDT	Flash Flood Warning	PHI	Bucks, Lehigh, Montgomery	3 hr
Jul 17, 7:44 PM EDT	Special Weather Statement	PHI	Lehigh	31 min
Jul 17, 7:56 PM EDT	Special Weather Statement	PHI	Bucks, Montgomery, Philadelphia	64 min
Jul 17, 3:50 AM EDT	Rip Current Statement	PHI	Atlantic, Cape May, Monmouth, Ocean	17 hr
Jul 17, 1:57 PM EDT	Severe Thunderstorm Warning	PHI	Sussex, Warren	32 min
Jul 17, 2:21 PM EDT	Special Weather Statement	PHI	Warren	24 min
Jul 17, 2:28 PM EDT	Special Weather Statement	PHI	Sussex	32 min
Jul 17, 2:44 PM EDT	Special Weather Statement	PHI	Sussex	31 min
Jul 17, 6:22 PM EDT	Special Weather Statement	PHI	Sussex	38 min
Jul 17, 6:39 PM EDT	Severe Thunderstorm Warning	PHI	Morris, Sussex, Warren	51 min
Jul 17, 7:16 PM EDT	Special Marine Warning	PHI		59 min
Jul 17, 7:27 PM EDT	Special Weather Statement	PHI	Hunterdon, Morris	48 min
Jul 17, 7:44 PM EDT	Flash Flood Warning	PHI	Hunterdon, Morris, Somerset	3 hr

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2019 Severe Thunderstorm Warnings in New Jersey, 2019 Severe Thunderstorm Warnings in Maryland, 2019 Every severe thunderstorm warning in 2019

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.