Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 131, NWS Philadelphia/Mount Holly

July 24, 20174 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 24, 2017, 6:30 PM EDT for 4 counties in Pennsylvania. It was in force for 60 min. 3 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 24, 2017, 6:30 PM EDT (22:30 UTC)
Expired: Jul 24, 2017, 7:30 PM EDT
In force: 60 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Tornado: Possible
Hail: 0.75 in
Wind: 60.0 mph

Counties Berks County, PA, Bucks County, PA, Lehigh County, PA, Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 98 km from the middle of the area, began a volume at 22:33 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 24, 6:30 PM EDT	TSTM WND DMG	Alton Park, PA	A LARGE MAPLE TREE WAS UPROOTED AND DENTED THE GUTTER ON A HOME AND CRUSHED SOME BUSHES.
Jul 24, 6:30 PM EDT	TSTM WND DMG	Longswamp, PA	TREES DOWN
Jul 24, 6:40 PM EDT	FUNNEL CLOUD	Fountain Hill, PA	A SPOTTER REPORTED A FUNNEL CLOUD NEAR LEHIGH UNIVERSITY AND ROUTE 78.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 10.5 hours before the alert went out and 211 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 456 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 230 m²/s²
0-3 km storm-relative helicity: 314 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

014 
WUUS51 KPHI 242230
SVRPHI
PAC011-017-077-091-242330-
/O.NEW.KPHI.SV.W.0131.170724T2230Z-170724T2330Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service MOUNT HOLLY NJ
630 PM EDT MON JUL 24 2017

The National Weather Service in MOUNT HOLLY NJ  has issued a

* Severe Thunderstorm Warning for...
  East central Berks County in eastern Pennsylvania...
  Northwestern Montgomery County in southeastern Pennsylvania...
  Southeastern Lehigh County in eastern Pennsylvania...
  Northwestern Bucks County in southeastern Pennsylvania...

* Until 730 PM EDT

* At 629 PM EDT, severe thunderstorms were located along a line
  extending from Allentown to near Topton, moving southeast at 25
  mph.

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

  SOURCE...Radar indicated. 

  IMPACT...Expect damage to trees and power lines. 

* Locations impacted include...
  Allentown, Lansdale, West Norriton, East Norriton, Emmaus,
  Quakertown, Perkasie, Souderton, Bedminster, Chalfont, Tinicum,
  Hatfield, East Greenville, Dublin, Schwenksville, Bally,
  Bechtelsville, Green Lane, Pleasant Valley and Fricks.

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.

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

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 4064 7552 4060 7539 4058 7541 4054 7533
      4056 7530 4048 7506 4045 7507 4042 7506
      4041 7504 4015 7537 4045 7575
TIME...MOT...LOC 2229Z 304DEG 24KT 4060 7551 4046 7566 

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

amc

1 follow-up statement

852 
WWUS51 KPHI 242303
SVSPHI

Severe Weather Statement
National Weather Service MOUNT HOLLY NJ
703 PM EDT MON JUL 24 2017

PAC011-077-242312-
/O.CAN.KPHI.SV.W.0131.000000T0000Z-170724T2330Z/
Berks PA-Lehigh PA-
703 PM EDT MON JUL 24 2017

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL BERKS AND
SOUTHEASTERN LEHIGH COUNTIES IS CANCELLED...

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

LAT...LON 4043 7549 4042 7549 4047 7543 4056 7530
      4048 7506 4046 7507 4042 7506 4041 7504
      4015 7537 4034 7562
TIME...MOT...LOC 2302Z 304DEG 24KT 4048 7527 4034 7542 

$$

PAC017-091-242330-
/O.CON.KPHI.SV.W.0131.000000T0000Z-170724T2330Z/
Montgomery PA-Bucks PA-
703 PM EDT MON JUL 24 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 730 PM EDT
FOR NORTHWESTERN MONTGOMERY AND NORTHWESTERN BUCKS COUNTIES...

At 702 PM EDT, severe thunderstorms were located along a line
extending from near Pleasant Valley to near Green Lane, moving
southeast at 30 mph.

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

SOURCE...Radar indicated. 

IMPACT...Expect damage to trees and power lines. 

Locations impacted include...
Lansdale, West Norriton, East Norriton, Quakertown, Perkasie, Byram,
Souderton, Bedminster, Chalfont, Tinicum, Hatfield, East Greenville,
Dublin, Schwenksville, Green Lane, Pleasant Valley, Fricks, Spring
Mount, Ottsville and Geryville.

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.

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

&&

LAT...LON 4043 7549 4042 7549 4047 7543 4056 7530
      4048 7506 4046 7507 4042 7506 4041 7504
      4015 7537 4034 7562
TIME...MOT...LOC 2302Z 304DEG 24KT 4048 7527 4034 7542 

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

amc

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 24, 1:33 AM EDT	Areal Flood Advisory	PHI	Bucks, Delaware, Montgomery, Philadelphia	5 hr
Jul 24, 2:34 AM EDT	Severe Thunderstorm Warning	PHI	Delaware, Philadelphia	41 min
Jul 24, 3:00 AM EDT	Flash Flood Warning	PHI	Delaware, Montgomery, Philadelphia	4 hr
Jul 24, 3:17 AM EDT	Areal Flood Advisory	PHI	Berks, Bucks, Lehigh, Monroe, Montgomery, Northampton	118 min
Jul 24, 3:21 AM EDT	Areal Flood Advisory	PHI	Bucks	3 hr
Jul 24, 3:36 AM EDT	Areal Flood Advisory	PHI	Monroe, Northampton	6 hr
Jul 24, 3:47 AM EDT	Areal Flood Advisory	PHI	Carbon, Lehigh, Monroe, Northampton	118 min
Jul 24, 5:23 PM EDT	Special Weather Statement	PHI	Berks	37 min
Jul 24, 5:31 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Lehigh	59 min
Jul 24, 6:15 PM EDT	Special Weather Statement	PHI	Berks	45 min
Jul 24, 6:43 PM EDT	Flash Flood Warning	PHI	Berks, Lehigh, Northampton	4 hr
Jul 24, 6:47 PM EDT	Flash Flood Warning	PHI	Berks	4 hr
Jul 24, 7:07 PM EDT	Areal Flood Advisory	PHI	Northampton	113 min
Jul 24, 7:07 PM EDT	Special Weather Statement	PHI	Berks	23 min
Jul 24, 7:12 PM EDT	Areal Flood Advisory	PHI	Berks, Bucks, Lehigh, Montgomery, Northampton	2 hr
Jul 24, 7:16 PM EDT	Areal Flood Advisory	PHI	Berks, Montgomery	119 min
Jul 24, 7:23 PM EDT	Flash Flood Warning	PHI	Bucks, Lehigh, Montgomery	4 hr
Jul 24, 7:26 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Chester, Montgomery	49 min
Jul 24, 7:42 PM EDT	Areal Flood Advisory	PHI	Bucks, Chester, Montgomery	2 hr
Jul 24, 7:48 PM EDT	Areal Flood Advisory	PHI	Bucks	117 min
Jul 24, 7:50 PM EDT	Severe Thunderstorm Warning	PHI	Montgomery, Philadelphia	25 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2017 Every 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.