Alert archive / New Jersey / Severe Thunderstorm Warnings in 2017
Severe Thunderstorm Warning 25, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Apr 29, 2017, 4:20 AM EDT for 4 counties in Pennsylvania; 6 counties in New Jersey. It was in force for 40 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
- Apr 29, 2017, 4:20 AM EDT (08:20 UTC)
- Expired
- Apr 29, 2017, 5:00 AM EDT
- In force
- 40 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Hail
- 0.75 in
- Wind
- 60.0 mph
Counties Burlington County, NJ, Hunterdon County, NJ, Mercer County, NJ, Middlesex County, NJ, Monmouth County, NJ, Somerset County, NJ, Bucks County, PA, Chester County, PA, Montgomery County, PA, Philadelphia County, PA
The radar
The Philadelphia radar (KDIX), 44 km from the middle of the area, began a volume at 08:22 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, 8.3 hours before the alert went out and 184 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1920 m above ground
- 0-6 km bulk shear
- 53 kt
- 0-1 km storm-relative helicity
- 215 m²/s²
- 0-3 km storm-relative helicity
- 229 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
915
WUUS51 KPHI 290820
SVRPHI
NJC005-019-021-023-025-035-PAC017-029-091-101-290900-
/O.NEW.KPHI.SV.W.0025.170429T0820Z-170429T0900Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
420 AM EDT SAT APR 29 2017
The National Weather Service in Mount Holly NJ has issued a
* Severe Thunderstorm Warning for...
Southeastern Hunterdon County in northwestern New Jersey...
Mercer County in central New Jersey...
Northern Burlington County in southern New Jersey...
Southwestern Somerset County in northern New Jersey...
Southwestern Monmouth County in central New Jersey...
Southwestern Middlesex County in northern New Jersey...
Montgomery County in southeastern Pennsylvania...
Bucks County in southeastern Pennsylvania...
Northeastern Chester County in southeastern Pennsylvania...
Northern Philadelphia County in southeastern Pennsylvania...
* Until 500 AM EDT
* At 419 AM EDT, severe thunderstorms were located along a line
extending from near Souderton to near Lansdale to King Of Prussia,
moving east at 65 mph.
HAZARD...60 mph wind gusts and penny size hail.
SOURCE...Radar indicated.
IMPACT...Expect damage to roofs, siding, and trees.
* Locations impacted include...
Philadelphia, Trenton, Bensalem, Ewing, Norristown, Willingboro,
Phoenixville, Lansdale, West Norriton, East Norriton, Princeton,
Florence, Burlington, Bristol, Perkasie, Doylestown, Riverside,
Conshohocken, Hatboro and Souderton.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
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.
Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.
&&
LAT...LON 4011 7450 4008 7455 4005 7453 4000 7456
4007 7551 4020 7560 4037 7553 4046 7466
4026 7441
TIME...MOT...LOC 0819Z 265DEG 56KT 4032 7537 4022 7532 4011 7538
HAIL...0.75IN
WIND...60MPH
$$
SFJ2 follow-up statements
525
WWUS51 KPHI 290834
SVSPHI
Severe Weather Statement
National Weather Service Mount Holly NJ
434 AM EDT SAT APR 29 2017
PAC029-290843-
/O.CAN.KPHI.SV.W.0025.000000T0000Z-170429T0900Z/
Chester PA-
434 AM EDT SAT APR 29 2017
...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN CHESTER COUNTY IS
CANCELLED...
The storms which prompted the warning have moved out of the warned
area. Therefore, the warning has been cancelled.
LAT...LON 4011 7450 4008 7455 4005 7453 4000 7456
4006 7532 4040 7527 4046 7466 4026 7441
TIME...MOT...LOC 0833Z 265DEG 56KT 4034 7511 4024 7506 4013 7512
$$
NJC005-019-021-023-025-035-PAC017-091-101-290900-
/O.CON.KPHI.SV.W.0025.000000T0000Z-170429T0900Z/
Hunterdon NJ-Mercer NJ-Burlington NJ-Somerset NJ-Monmouth NJ-
Middlesex NJ-Montgomery PA-Bucks PA-Philadelphia PA-
434 AM EDT SAT APR 29 2017
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 500 AM EDT
FOR SOUTHEASTERN HUNTERDON...MERCER...NORTHERN BURLINGTON...
SOUTHWESTERN SOMERSET...SOUTHWESTERN MONMOUTH...SOUTHWESTERN
MIDDLESEX...SOUTHEASTERN MONTGOMERY...BUCKS AND NORTHERN PHILADELPHIA
COUNTIES...
At 433 AM EDT, severe thunderstorms were located along a line
extending from Robesonia to near Ivyland to Abington, moving east at
65 mph.
HAZARD...60 mph wind gusts and penny size hail.
SOURCE...Radar indicated.
IMPACT...Expect damage to roofs, siding, and trees.
Locations impacted include...
Philadelphia, Trenton, Bensalem, Ewing, Willingboro, Lansdale, East
Norriton, Princeton, Florence, Burlington, Bristol, Doylestown,
Riverside, Conshohocken, Hatboro, Ambler, Hightstown, Jenkintown,
Chalfont and Bordentown.
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 4011 7450 4008 7455 4005 7453 4000 7456
4006 7532 4040 7527 4046 7466 4026 7441
TIME...MOT...LOC 0833Z 265DEG 56KT 4034 7511 4024 7506 4013 7512
HAIL...0.75IN
WIND...60MPH
$$
SFJ529
WWUS51 KPHI 290855
SVSPHI
Severe Weather Statement
National Weather Service Mount Holly NJ
455 AM EDT SAT APR 29 2017
NJC005-019-021-023-025-035-PAC017-091-101-290904-
/O.EXP.KPHI.SV.W.0025.000000T0000Z-170429T0900Z/
Hunterdon NJ-Mercer NJ-Burlington NJ-Somerset NJ-Monmouth NJ-
Middlesex NJ-Montgomery PA-Bucks PA-Philadelphia PA-
455 AM EDT SAT APR 29 2017
...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN HUNTERDON...
MERCER...NORTHERN BURLINGTON...SOUTHWESTERN SOMERSET...SOUTHWESTERN
MONMOUTH...SOUTHWESTERN MIDDLESEX...SOUTHEASTERN MONTGOMERY...BUCKS
AND NORTHERN PHILADELPHIA COUNTIES WILL EXPIRE AT 500 AM EDT...
The storms which prompted the warning have weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore the warning will be allowed to expire. However gusty winds
are still possible with these thunderstorms.
LAT...LON 4011 7450 4008 7455 4005 7453 4000 7456
4006 7532 4040 7527 4046 7466 4026 7441
TIME...MOT...LOC 0854Z 265DEG 56KT 4036 7476 4026 7471 4015 7477
$$
SFJThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 29, 3:12 AM EDT | Areal Flood Advisory | PHI | Berks | 4 hr |
| Apr 29, 3:20 AM EDT | Special Weather Statement | PHI | Berks, Lehigh, Northampton | 40 min |
| Apr 29, 3:51 AM EDT | Special Weather Statement | PHI | Berks, Bucks, Chester, Delaware, Montgomery | 39 min |
| Apr 29, 4:14 AM EDT | Special Weather Statement | PHI | Bucks | 46 min |
| Apr 29, 4:22 AM EDT | Special Weather Statement | PHI | Delaware, Philadelphia | 38 min |
| Apr 29, 4:29 AM EDT | Areal Flood Advisory | PHI | Bucks | 4 hr |
| Apr 29, 4:32 AM EDT | Severe Thunderstorm Warning | PHI | Bucks | 43 min |
| Apr 29, 2:54 AM EDT | Special Weather Statement | PHI | Burlington | 36 min |
| Apr 29, 4:56 AM EDT | Special Marine Warning | PHI | 64 min | |
| Apr 29, 4:56 AM EDT | Special Weather Statement | PHI | Burlington, Mercer, Monmouth, Ocean | 49 min |
| Apr 29, 5:16 AM EDT | Special Marine Warning | PHI | 29 min | |
| Apr 29, 6:16 AM EDT | Special Marine Warning | PHI | 29 min | |
| Apr 29, 7:04 AM EDT | Areal Flood Warning | PHI | Hunterdon, Somerset | 4 hr |
Nearby
Severe Thunderstorm Warnings in New Jersey, 2017Severe Thunderstorm Warnings in Pennsylvania, 2017Every 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.