Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 133, NWS Philadelphia/Mount Holly

July 24, 2017Montgomery County, Philadelphia County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 24, 2017, 7:50 PM EDT for Montgomery County, Philadelphia County, Pennsylvania. It was in force for 25 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Jul 24, 2017, 7:50 PM EDT (23:50 UTC)
Expired: Jul 24, 2017, 8:15 PM EDT
In force: 25 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Montgomery County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 65 km from the middle of the area, began a volume at 23:50 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.

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 11.8 hours before the alert went out and 216 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.

519 
WUUS51 KPHI 242350
SVRPHI
PAC091-101-250015-
/O.NEW.KPHI.SV.W.0133.170724T2350Z-170725T0015Z/

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

The National Weather Service in MOUNT HOLLY NJ  has issued a

* Severe Thunderstorm Warning for...
  Southeastern Montgomery County in southeastern Pennsylvania...
  Philadelphia County in southeastern Pennsylvania...

* Until 815 PM EDT

* At 750 PM EDT, a severe thunderstorm was located over Plymouth
  Meeting, or 11 miles northwest of Philadelphia, moving southeast at
  30 mph.

  HAZARD...60 mph wind gusts. 

  SOURCE...Radar indicated. 

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

* Locations impacted include...
  Philadelphia, Norristown, West Norriton, East Norriton,
  Conshohocken, Palmyra, Ambler, Jenkintown, Narberth, Rockledge,
  Abington, Wissinoming, Germantown, Northeast Philadelphia, Center
  City, Tacony, Ben Franklin Bridge, Holmesburg, Plymouth Meeting and
  Kensington.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4006 7498 4005 7498 3997 7510 3996 7513
      3994 7514 3992 7517 4004 7534 4007 7536
      4007 7538 4008 7540 4017 7527 4009 7496
TIME...MOT...LOC 2350Z 296DEG 27KT 4011 7530 

HAIL...<.75IN
WIND...60MPH
 
$$

amc

1 follow-up statement

558 
WWUS51 KPHI 242355
SVSPHI

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

PAC091-101-250015-
/O.CON.KPHI.SV.W.0133.000000T0000Z-170725T0015Z/
Montgomery PA-Philadelphia PA-
755 PM EDT MON JUL 24 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 815 PM EDT
FOR SOUTHEASTERN MONTGOMERY AND PHILADELPHIA COUNTIES...

At 754 PM EDT, a severe thunderstorm was located over Plymouth
Meeting, or 8 miles northwest of Philadelphia, moving southeast at 30
mph.

HAZARD...60 mph wind gusts. 

SOURCE...Radar indicated. 

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

Locations impacted include...
Philadelphia, Norristown, West Norriton, East Norriton, Conshohocken,
Palmyra, Ambler, Jenkintown, Narberth, Rockledge, Abington,
Wissinoming, Germantown, Northeast Philadelphia, Center City, Tacony,
Ben Franklin Bridge, Holmesburg, Plymouth Meeting and Kensington.

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 4006 7498 4005 7498 3997 7510 3996 7513
      3994 7514 3992 7517 4004 7534 4007 7536
      4007 7538 4008 7540 4017 7527 4009 7496
TIME...MOT...LOC 2354Z 296DEG 27KT 4009 7526 

TORNADO...POSSIBLE
HAIL...<.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, 6:30 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Bucks, Lehigh, Montgomery	60 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

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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.