Alert archive / Pennsylvania / Special Weather Statements in 2021
Special Weather Statement, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this special weather statement at Feb 18, 2021, 5:46 AM EST for Mercer County, New Jersey; Chester County, Montgomery County, Pennsylvania. It was in force for 89 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
- Feb 18, 2021, 5:46 AM EST (10:46 UTC)
- Expired
- Feb 18, 2021, 7:15 AM EST
- In force
- 89 min
- Issued by
- NWS Philadelphia/Mount Holly
Counties Mercer County, NJ, Chester County, PA, Montgomery County, PA
The radar
The Philadelphia radar (KDIX), 63 km from the middle of the area, began a volume at 10:46 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, 10.8 hours before the alert went out and 201 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
- 2319 m above ground
- 0-6 km bulk shear
- 87 kt
- 0-1 km storm-relative helicity
- -130 m²/s²
- 0-3 km storm-relative helicity
- 165 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
048
WWUS81 KPHI 181046
SPSPHI
Special Weather Statement
National Weather Service Mount Holly NJ
546 AM EST Thu Feb 18 2021
NJZ012-015-PAZ070-071-101>104-106-181215-
Middlesex-Mercer-Lower Bucks-Eastern Montgomery-Western
Montgomery-Delaware-Western Chester-Eastern Chester-Philadelphia-
546 AM EST Thu Feb 18 2021
...A BAND OF HEAVY SNOW WILL AFFECT MERCER...SOUTHWESTERN
MIDDLESEX...MONTGOMERY...SOUTHERN BUCKS...CHESTER...NORTHERN
PHILADELPHIA AND NORTHERN DELAWARE COUNTIES...
At 540 AM EST, a band of heavy snow was located from about central
Chester County northeastward across the lower portions of Montgomery
and Bucks counties then into southern Mercer County in New Jersey.
This band is lifting northeastward.
Snowfall rates of around an inch per hour will be common within this
band. Given temperatures in the 20s and the cold ground, road
conditions are rapidly deteriorating. In addition, the visibility
will be reduced to one quarter of a mile within the heavy snow.
Be prepared for snow covered roads. Slow down and allow extra time
when traveling.
Locations impacted include...
Philadelphia, Trenton, West Chester, Bensalem, Ewing, Norristown,
Pottstown, Phoenixville, Lansdale, West Norriton, East Norriton,
Coatesville, Princeton, Westtown, Bristol, Doylestown, Downingtown,
Conshohocken, Hatboro and Ambler.
This includes the following highways...
New Jersey Turnpike between exits 8 and 9.
Pennsylvania Turnpike between mile markers 300 and 359.
Northeast Extension between mile markers 21 and 32.
Interstate 95 in Pennsylvania between mile markers 34 and 40.
Interstate 76 in Pennsylvania between mile markers 327 and 340.
Interstate 195 in New Jersey between mile markers 0 and 7.
Interstate 295 in New Jersey between mile markers 60 and 76.
Interstate 476 in Pennsylvania between mile markers 8 and 19.
LAT...LON 4027 7441 4018 7461 4016 7461 4018 7471
4010 7484 3975 7607 3987 7599 4011 7594
4022 7574 4030 7529 4026 7522 4032 7517
4036 7496 4034 7489 4036 7432
TIME...MOT...LOC 1040Z 240DEG 49KT 4005 7569
$$
GorseThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Feb 18, 5:58 AM EST | Special Weather Statement | PHI | Monmouth | 77 min |
| Feb 18, 7:24 AM EST | Special Weather Statement | PHI | Mercer, Middlesex, Monmouth | 51 min |
| Feb 18, 8:24 AM EST | Special Weather Statement | PHI | Mercer, Middlesex, Monmouth | 66 min |
| Feb 18, 10:43 AM EST | Special Weather Statement | PHI | Hunterdon, Mercer, Middlesex, Monmouth, Somerset | 62 min |
| Feb 18, 12:06 PM EST | Special Weather Statement | PHI | Burlington, Hunterdon, Mercer, Middlesex, Monmouth, Ocean and 1 more | 54 min |
Nearby
Special Weather Statements in Pennsylvania, 2021Special Weather Statements in New Jersey, 2021Every special weather statement in 2021
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.