Alert archive / Pennsylvania / Special Weather Statements in 2021

Special Weather Statement, NWS Philadelphia/Mount Holly

March 28, 2021Montgomery County, Pennsylvania

NWS Philadelphia/Mount Holly issued this special weather statement at Mar 28, 2021, 6:15 PM EDT for Montgomery County, Pennsylvania. It was in force for 30 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: Mar 28, 2021, 6:15 PM EDT (22:15 UTC)
Expired: Mar 28, 2021, 6:45 PM EDT
In force: 30 min
Issued by: NWS Philadelphia/Mount Holly

County Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 103 km from the middle of the area, began a volume at 22:17 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, 10.3 hours before the alert went out and 225 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: 666 m above ground
0-6 km bulk shear: 41 kt
0-1 km storm-relative helicity: 165 m²/s²
0-3 km storm-relative helicity: 285 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

605 
WWUS81 KPHI 282215
SPSPHI

Special Weather Statement
National Weather Service Mount Holly NJ
615 PM EDT Sun Mar 28 2021

NJZ007-009-PAZ061-062-101-103>106-282245-
Hunterdon-Warren-Lower Bucks-Upper Bucks-Lehigh-Eastern
Montgomery-Western Montgomery-Western Chester-Northampton-
615 PM EDT Sun Mar 28 2021

...A LINE OF SHOWERS WITH STRONG WINDS WILL AFFECT NORTHWESTERN 
HUNTERDON... SOUTHWESTERN WARREN...SOUTHEASTERN 
LEHIGH...NORTHWESTERN MONTGOMERY...NORTHWESTERN BUCKS...NORTHEASTERN 
CHESTER AND SOUTHEASTERN NORTHAMPTON COUNTIES...

At 615 PM EDT, radar indicated showers were located along a line
extending from Steuben to Pottstown. Movement was east at 40 mph.

Wind gusts up to 45 mph are possible with this line of showers.

Locations impacted include...
Allentown, Easton, Bethlehem, Pottstown, Lansdale, Forks, East
Norriton, Emmaus, Quakertown, Perkasie, Wilson, Souderton,
Bedminster, Washington, Hellertown, Nazareth, Collegeville,
Royersford, Chalfont and Tinicum.

This includes the following highways...
 Northeast Extension between mile markers 25 and 51.
 Interstate 78 in Pennsylvania between mile markers 59 and 76.
 Interstate 78 in New Jersey between mile markers 0 and 13.

If outdoors, consider seeking shelter inside a building.

LAT...LON 4029 7566 4044 7553 4047 7555 4073 7539
      4077 7489 4017 7524 4015 7575
TIME...MOT...LOC 2215Z 268DEG 37KT 4067 7538 4024 7562 

$$

Staarmann

The office that day

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

Issued	Product	Office	Counties	Lasted
Mar 28, 2:39 AM EDT	Gale Warning	PHI		35 hr
Mar 28, 6:21 PM EDT	Special Marine Warning	PHI		54 min
Mar 28, 6:43 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Mercer, Middlesex, Morris, Somerset, Warren	47 min
Mar 28, 6:47 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Camden, Gloucester, Mercer, Monmouth, Salem	43 min
Mar 28, 7:17 PM EDT	Severe Thunderstorm Warning	PHI	Mercer, Middlesex, Monmouth, Ocean, Somerset	60 min
Mar 28, 7:20 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Burlington, Camden, Gloucester, Monmouth, Ocean	70 min
Mar 28, 7:38 PM EDT	Special Marine Warning	PHI		111 min
Mar 28, 5:04 PM EDT	Special Weather Statement	PHI	Berks	41 min
Mar 28, 5:13 PM EDT	Special Weather Statement	PHI	Carbon	32 min
Mar 28, 5:45 PM EDT	Special Weather Statement	PHI	Berks, Lehigh	30 min
Mar 28, 6:02 PM EDT	Special Weather Statement	PHI	Chester	28 min
Mar 28, 6:12 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Delaware, Montgomery	48 min
Mar 28, 7:54 PM EDT	Special Weather Statement	PHI	Sussex	36 min

Nearby

Special Weather Statements in Pennsylvania, 2021 Every 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.