Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2018
Severe Thunderstorm Warning 75, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 13, 2018, 8:51 PM EDT for Bucks County, Montgomery County, Pennsylvania. It was in force for 54 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
- Aug 13, 2018, 8:51 PM EDT (00:51 UTC)
- Expired
- Aug 13, 2018, 9:45 PM EDT
- In force
- 54 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Hail
- 0.75 in
- Wind
- 60.0 mph
Counties Bucks County, PA, Montgomery County, PA
The radar
The Philadelphia radar (KDIX), 83 km from the middle of the area, began a volume at 00:51 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 00:00Z, 0.9 hours before the alert went out and 221 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.
- Mixed-layer CAPE
- 399 J/kg
- Mixed-layer CIN
- -8 J/kg
- Mixed-layer LCL
- 664 m above ground
- 0-6 km bulk shear
- 31 kt
- 0-1 km storm-relative helicity
- 98 m²/s²
- 0-3 km storm-relative helicity
- 82 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 2.4
The text
As transmitted.
708
WUUS51 KPHI 140051
SVRPHI
PAC017-091-140145-
/O.NEW.KPHI.SV.W.0075.180814T0051Z-180814T0145Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
851 PM EDT MON AUG 13 2018
The National Weather Service in Mount Holly NJ has issued a
* Severe Thunderstorm Warning for...
Central Montgomery County in southeastern Pennsylvania...
West central Bucks County in southeastern Pennsylvania...
* Until 945 PM EDT.
* At 850 PM EDT, a severe thunderstorm was located over East
Norriton, or 15 miles northwest of Philadelphia, moving northeast
at 10 mph. There are some other storms within this warning. It
will not take as much wind to down some trees due to the saturated
ground.
HAZARD...60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Damage to roofs, siding, trees, and power lines is
possible.
* Locations impacted include...
Norristown, Lansdale, West Norriton, East Norriton, Perkasie,
Doylestown, Conshohocken, Souderton, Ambler, Collegeville,
Chalfont, Trappe, Hatfield, Fricks, Plymouth Meeting, King Of
Prussia, Skippack, Telford, Bridgeport and Sellersville.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
In addition to 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 4004 7532 4016 7549 4044 7540 4031 7509
TIME...MOT...LOC 0050Z 205DEG 8KT 4016 7536
HAIL...<.75IN
WIND...60MPH
$$
Gorse2 follow-up statements
434
WWUS51 KPHI 140119
SVSPHI
Severe Weather Statement
National Weather Service Mount Holly NJ
919 PM EDT MON AUG 13 2018
PAC017-091-140145-
/O.CON.KPHI.SV.W.0075.000000T0000Z-180814T0145Z/
Montgomery PA-Bucks PA-
919 PM EDT MON AUG 13 2018
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 945 PM EDT
FOR CENTRAL MONTGOMERY AND WEST CENTRAL BUCKS COUNTIES...
At 919 PM EDT, a severe thunderstorm was located over Dublin, or 20
miles southeast of Allentown, moving northeast at 35 mph. It will
not take as much wind to down some trees due to the saturated
ground.
HAZARD...60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Damage to roofs, siding, trees, and power lines is
possible.
Locations impacted include...
Lansdale, Perkasie, Doylestown, Souderton, Ambler, Chalfont,
Hatfield, Fricks, Telford, Sellersville, North Wales, New Britain,
Trumbauersville, Silverdale, Harleysville, Blue Bell, Brittany
Farms-Highlands, Spring House, Kulpsville and Montgomeryville.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4012 7526 4028 7543 4044 7540 4031 7509
TIME...MOT...LOC 0119Z 208DEG 30KT 4036 7522
HAIL...<.75IN
WIND...60MPH
$$
Gorse180
WWUS51 KPHI 140137
SVSPHI
Severe Weather Statement
National Weather Service Mount Holly NJ
937 PM EDT MON AUG 13 2018
PAC017-091-140146-
/O.EXP.KPHI.SV.W.0075.000000T0000Z-180814T0145Z/
Montgomery PA-Bucks PA-
937 PM EDT MON AUG 13 2018
...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL MONTGOMERY AND WEST
CENTRAL BUCKS COUNTIES WILL EXPIRE AT 945 PM EDT...
The storm which prompted the warning has moved out of the warned
area. Therefore, this warning will be allowed to expire.
LAT...LON 4012 7526 4028 7543 4044 7540 4031 7509
TIME...MOT...LOC 0136Z 205DEG 8KT 4039 7520
$$
GorseThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 13, 8:13 PM EDT | Special Weather Statement | PHI | Montgomery | 32 min |
| Aug 13, 8:16 PM EDT | Areal Flood Advisory | PHI | Chester, Delaware, Montgomery, Philadelphia | 3 hr |
| Aug 13, 9:00 PM EDT | Severe Thunderstorm Warning | PHI | Bucks, Montgomery, Philadelphia | 60 min |
| Aug 13, 9:16 PM EDT | Severe Thunderstorm Warning | PHI | Bucks | 44 min |
| Aug 14, 12:50 PM EDT | Areal Flood Advisory | PHI | Bucks, Lehigh, Northampton | 4 hr |
| Aug 14, 3:22 PM EDT | Special Weather Statement | PHI | Lehigh | 53 min |
| Aug 14, 3:58 PM EDT | Special Weather Statement | PHI | Montgomery | 47 min |
Nearby
Severe Thunderstorm Warnings in Pennsylvania, 2018Every severe thunderstorm warning in 2018
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.