Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2019

Severe Thunderstorm Warning 286, NWS Philadelphia/Mount Holly

July 31, 2019New Castle County, Delaware; 5 counties in Pennsylvania; Hunterdon County, Mercer County, New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 31, 2019, 2:46 PM EDT for New Castle County, Delaware; 5 counties in Pennsylvania; Hunterdon County, Mercer County, New Jersey. It was in force for 44 min. 6 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 31, 2019, 2:46 PM EDT (18:46 UTC)
Expired
Jul 31, 2019, 3:30 PM EDT
In force
44 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties New Castle County, DE, Hunterdon County, NJ, Mercer County, NJ, Bucks County, PA, Chester County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 79 km from the middle of the area, began a volume at 18:47 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
Jul 31, 2:49 PM EDTTSTM WND DMG2 Sse East Caln Twp, PAREPORT OF TREES BLOWN DOWN.
Jul 31, 3:00 PM EDTTSTM WND DMG2 Sw Skippack, PATREES DOWN. TIME ESTIMATED FROM RADAR.
Jul 31, 3:06 PM EDTTSTM WND DMGPaoli, PAREPORT OF TREES BLOWN DOWN.
Jul 31, 3:24 PM EDTTSTM WND DMG2 Ne Plymouth Meeting, PATREES BLOWN DOWN.
Jul 31, 3:24 PM EDTTSTM WND DMGLafayette Hill, PALARGE TREE LIMBS DOWNED IN LAFAYETTE HILL. TIME ESTIMATED FROM RADAR.
Jul 31, 3:25 PM EDTTSTM WND DMGLafayette Hill, PAMULTIPLE TREES AND LIMBS DOWN. TIME ESTIMATED FROM RADAR.

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
Jul 31, 1:17 PM EDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 6.8 hours before the alert went out and 219 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, Brookhaven, NY at 12:00Z on 2019-07-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 885 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, Brookhaven, NY at 12:00Z on 2019-07-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 28 square meters per square second.193958Sfc1 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
885 J/kg
Mixed-layer CIN
-80 J/kg
Mixed-layer LCL
1207 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
28 m²/s²
0-3 km storm-relative helicity
33 m²/s²
Significant tornado parameter
0.1
Supercell composite
0.8

Open this sounding in Storm Lab

The text

As transmitted.

529 
WUUS51 KPHI 311846
SVRPHI
DEC003-NJC019-021-PAC017-029-045-091-101-311930-
/O.NEW.KPHI.SV.W.0286.190731T1846Z-190731T1930Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
246 PM EDT Wed Jul 31 2019

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  North central New Castle County in northern Delaware...
  Southeastern Hunterdon County in northwestern New Jersey...
  Northwestern Mercer County in central New Jersey...
  Montgomery County in southeastern Pennsylvania...
  Central Bucks County in southeastern Pennsylvania...
  Eastern Chester County in southeastern Pennsylvania...
  Northwestern Philadelphia County in southeastern Pennsylvania...
  Delaware County in southeastern Pennsylvania...

* Until 330 PM EDT.

* At 246 PM EDT, severe thunderstorms were located along a line
  extending from Ottsville to near Phoenixville to near Marshallton,
  moving east at 20 mph.

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

  SOURCE...Radar indicated.

  IMPACT...Damage to roofs, siding, trees, and power lines is 
           possible.

* Locations impacted include...
  Philadelphia, Wilmington, West Chester, Norristown, Phoenixville,
  Lansdale, West Norriton, East Norriton, Westtown, Perkasie,
  Doylestown, Byram, Downingtown, Conshohocken, Hatboro, Souderton,
  Bedminster, Ambler, Kennett Square and Collegeville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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.

&&

LAT...LON 4046 7477 4001 7523 3974 7557 3990 7588
      4014 7563 4055 7518
TIME...MOT...LOC 1846Z 290DEG 18KT 4049 7516 4012 7556 3994 7575 

HAIL...0.75IN
WIND...60MPH
 
$$

MPS
2 follow-up statements
892 
WWUS51 KPHI 311908
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
308 PM EDT Wed Jul 31 2019

DEC003-NJC019-021-PAC017-029-045-091-101-311930-
/O.CON.KPHI.SV.W.0286.000000T0000Z-190731T1930Z/
New Castle DE-Hunterdon NJ-Mercer NJ-Montgomery PA-Bucks PA-
Chester PA-Philadelphia PA-Delaware PA-
308 PM EDT Wed Jul 31 2019

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 330 PM EDT
FOR NORTH CENTRAL NEW CASTLE...SOUTHEASTERN HUNTERDON...NORTHWESTERN
MERCER...MONTGOMERY...CENTRAL BUCKS...EASTERN CHESTER...NORTHWESTERN
PHILADELPHIA AND DELAWARE COUNTIES...

At 308 PM EDT, severe thunderstorms were located along a line
extending from near Byram to Valley Forge to near West Chester,
moving east at 20 mph.

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

SOURCE...Radar indicated.

IMPACT...Damage to roofs, siding, trees, and power lines is 
         possible.

Locations impacted include...
Philadelphia, Wilmington, West Chester, Norristown, Phoenixville,
Lansdale, West Norriton, East Norriton, Westtown, Perkasie,
Doylestown, Byram, Downingtown, Conshohocken, Hatboro, Souderton,
Bedminster, Ambler, Swarthmore and Kennett Square.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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.

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

&&

LAT...LON 3976 7554 3992 7586 3993 7585 4016 7558
      4055 7518 4046 7477 4001 7523
TIME...MOT...LOC 1908Z 289DEG 18KT 4046 7504 4009 7544 3991 7563 

HAIL...0.75IN
WIND...60MPH
 
$$

Fitzsimmons
521 
WWUS51 KPHI 311925
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
325 PM EDT Wed Jul 31 2019

DEC003-NJC019-021-PAC017-029-045-091-101-311934-
/O.EXP.KPHI.SV.W.0286.000000T0000Z-190731T1930Z/
New Castle DE-Hunterdon NJ-Mercer NJ-Montgomery PA-Bucks PA-
Chester PA-Philadelphia PA-Delaware PA-
325 PM EDT Wed Jul 31 2019

...THE SEVERE THUNDERSTORM WARNING FOR NORTH CENTRAL NEW CASTLE...
SOUTHEASTERN HUNTERDON...NORTHWESTERN MERCER...MONTGOMERY...CENTRAL
BUCKS...EASTERN CHESTER...NORTHWESTERN PHILADELPHIA AND DELAWARE
COUNTIES WILL EXPIRE AT 330 PM EDT...
    
A new Severe Thunderstorm Warning is now in effect. Please refer to 
Warning 290 which is in effect until 4:15 PM.

A severe thunderstorm watch remains in effect until 900 PM EDT for
northern Delaware...central and northwestern New Jersey...and
southeastern Pennsylvania.

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

LAT...LON 3976 7554 3992 7586 3993 7585 4016 7558
      4055 7518 4046 7477 4001 7523
TIME...MOT...LOC 1924Z 290DEG 18KT 4044 7495 4007 7535 3989 7554 

$$

MPS

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 31, 3:28 AM EDTFlash Flood WatchPHINew Castle17 hr
Jul 31, 4:00 PM EDTSpecial Weather StatementPHISussex30 min
Jul 31, 4:33 PM EDTSevere Thunderstorm WarningPHISussex9 min
Jul 31, 6:05 PM EDTSevere Thunderstorm WarningPHISussex26 min
Jul 30, 10:45 PM EDTSpecial Weather StatementPHIBerks45 min
Jul 30, 11:38 PM EDTSpecial Weather StatementPHILehigh52 min
Jul 31, 12:06 AM EDTSpecial Weather StatementPHICarbon39 min
Jul 31, 1:02 PM EDTSevere Thunderstorm WarningPHIBucks, Montgomery, Philadelphia28 min
Jul 31, 1:14 PM EDTAreal Flood AdvisoryPHIBucks, Delaware, Montgomery, Philadelphia3 hr
Jul 31, 1:19 PM EDTFlash Flood WarningPHIBucks, Delaware, Philadelphia5 hr
Jul 31, 1:30 PM EDTSevere Thunderstorm WarningPHIBucks, Delaware, Montgomery, Philadelphia45 min
Jul 31, 1:46 PM EDTFlash Flood WarningPHIBucks3 hr
Jul 31, 2:11 PM EDTSevere Thunderstorm WarningPHIBucks49 min
Jul 31, 2:27 PM EDTAreal Flood AdvisoryPHIBerks, Chester, Montgomery3 hr
Jul 31, 2:32 PM EDTAreal Flood AdvisoryPHIBucks, Delaware, Philadelphia3 hr
Jul 31, 3:24 PM EDTSevere Thunderstorm WarningPHIBucks, Chester, Delaware, Montgomery, Philadelphia51 min
Jul 31, 3:49 PM EDTSevere Thunderstorm WarningPHIBucks, Delaware, Montgomery, Philadelphia41 min
Jul 31, 4:36 PM EDTAreal Flood AdvisoryPHIBucks, Monroe, Northampton4 hr
Jul 31, 4:52 PM EDTSevere Thunderstorm WarningPHIMonroe, Northampton38 min
Jul 31, 4:58 PM EDTFlash Flood WarningPHIMonroe4 hr
Jul 31, 1:43 PM EDTSpecial Marine WarningPHI62 min
Jul 31, 1:49 PM EDTSpecial Marine WarningPHI86 min
Jul 31, 1:57 PM EDTSpecial Weather StatementPHIOcean33 min
Jul 31, 2:21 PM EDTAreal Flood AdvisoryPHIOcean4 hr
Jul 31, 2:23 PM EDTSevere Thunderstorm WarningPHIMonmouth52 min
Jul 31, 2:29 PM EDTSevere Thunderstorm WarningPHIBurlington, Mercer, Monmouth, Ocean46 min
Jul 31, 2:29 PM EDTSevere Thunderstorm WarningPHIMonmouth, Ocean46 min
Jul 31, 2:53 PM EDTSevere Thunderstorm WarningPHIMonmouth52 min
Jul 31, 3:00 PM EDTAreal Flood AdvisoryPHIMonmouth, Ocean3 hr
Jul 31, 3:05 PM EDTSevere Thunderstorm WarningPHIMonmouth, Ocean40 min
Jul 31, 3:06 PM EDTSpecial Marine WarningPHI54 min
Jul 31, 3:20 PM EDTSevere Thunderstorm WarningPHIHunterdon, Middlesex, Morris, Somerset40 min
Jul 31, 3:24 PM EDTFlash Flood WarningPHIMonmouth4 hr
Jul 31, 3:39 PM EDTAreal Flood AdvisoryPHIHunterdon, Middlesex, Morris, Somerset, Sussex, Warren4 hr
Jul 31, 3:39 PM EDTSevere Thunderstorm WarningPHIMonmouth, Ocean51 min
Jul 31, 3:48 PM EDTFlash Flood WarningPHIOcean2 hr
Jul 31, 3:51 PM EDTSpecial Marine WarningPHI54 min
Jul 31, 3:58 PM EDTSevere Thunderstorm WarningPHIMorris, Somerset17 min
Jul 31, 5:02 PM EDTSpecial Weather StatementPHIAtlantic28 min
Jul 31, 5:16 PM EDTSpecial Weather StatementPHIAtlantic44 min
Jul 31, 5:27 PM EDTSevere Thunderstorm WarningPHIAtlantic, Burlington, Cumberland, Ocean, Salem48 min
Jul 31, 5:41 PM EDTAreal Flood AdvisoryPHIAtlantic, Burlington, Camden, Cape May, Cumberland, Gloucester and 2 more3 hr
Jul 31, 5:44 PM EDTSevere Thunderstorm WarningPHISussex25 min
Jul 31, 5:51 PM EDTSpecial Marine WarningPHI54 min
Jul 31, 5:55 PM EDTSevere Thunderstorm WarningPHIAtlantic, Burlington, Ocean35 min
Jul 31, 5:57 PM EDTSpecial Marine WarningPHI63 min
Jul 31, 6:05 PM EDTSpecial Marine WarningPHI55 min
Jul 31, 6:41 PM EDTSpecial Marine WarningPHI64 min
Jul 31, 6:53 PM EDTSpecial Marine WarningPHI54 min
Jul 31, 7:36 PM EDTSpecial Marine WarningPHI54 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2019Severe Thunderstorm Warnings in New Jersey, 2019Severe Thunderstorm Warnings in Delaware, 2019Every 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.