Alert archive / New Jersey / Mesoscale Discussions in 2021

Mesoscale Discussion 972

June 14, 20214 states

The Storm Prediction Center issued this mesoscale discussion at Jun 14, 2021, 6:18 PM EDT for 4 states. It was in force for 117 min.

The area

The outline as issued.

The facts

Issued
Jun 14, 2021, 6:18 PM EDT (22:18 UTC)
Expired
Jun 14, 2021, 8:15 PM EDT
In force
117 min
Issued by
the Storm Prediction Center
Concerning
Severe thunderstorm watch 270
All 35 counties

New Castle County, DE, Atlantic County, NJ, Bergen County, NJ, Burlington County, NJ, Camden County, NJ, Cumberland County, NJ, Essex County, NJ, Gloucester County, NJ, Hudson County, NJ, Hunterdon County, NJ, Mercer County, NJ, Middlesex County, NJ, Monmouth County, NJ, Morris County, NJ, Ocean County, NJ, Passaic County, NJ, Salem County, NJ, Somerset County, NJ, Sussex County, NJ, Union County, NJ, Warren County, NJ, Bronx County, NY, Kings County, NY, New York County, NY, Queens County, NY, Richmond County, NY, Berks County, PA, Bucks County, PA, Chester County, PA, Delaware County, PA, Lancaster County, PA, Lehigh County, PA, Montgomery County, PA, Northampton County, PA, Philadelphia County, PA

The watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 10.3 hours before the alert went out and 203 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-pSkew-T log-p diagram, Brookhaven, NY at 12:00Z on 2021-06-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Brookhaven, NY at 12:00Z on 2021-06-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 48 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
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
687 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
48 m²/s²
0-3 km storm-relative helicity
88 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

As transmitted.

130 
ACUS11 KWNS 142219
SWOMCD
SPC MCD 142218 
NYZ000-NJZ000-PAZ000-DEZ000-MDZ000-150015-

Mesoscale Discussion 0972
NWS Storm Prediction Center Norman OK
0518 PM CDT Mon Jun 14 2021

Areas affected...Eastern Pennsylvania and New Jersey

Concerning...Severe Thunderstorm Watch 270...

Valid 142218Z - 150015Z

The severe weather threat for Severe Thunderstorm Watch 270
continues.

SUMMARY...The environment ahead of an approaching cold front will
remain supportive of strong to severe thunderstorms across WW 270
over the next few hours.

DISCUSSION...Surface analysis of observations across the
Mid-Atlantic show a cold front continuing to push eastward across
central to eastern PA. Ahead of this front temperatures remain in
the 80s with dewpoints in the mid to upper 60s. This warm/moist
boundary layer is supporting upwards of 1000-1500 J/kg MLCAPE with
limited inhibition per recent mesoanalysis estimates. Recent GOES
visible imagery shows agitated cumulus and a few convective towers
across eastern PA into northern NJ, which support the thermodynamic
estimates. Effective bulk shear values near 50 knots will help
organized any stronger updrafts that develop along the front, and
shear/boundary orientations suggest a mixture of embedded discrete
and linear clusters that will pose a hail/damaging wind threat over
the next few hours.

..Moore.. 06/14/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...OKX...PHI...CTP...LWX...

LAT...LON   40227660 40487610 40847528 41207483 41277422 41007383
            40517378 39967394 39447420 39257470 39327523 39517580
            39837646 40227660

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 14, 2:06 PM EDTSevere Thunderstorm WatchSPCNew Castle9 hr
Jun 14, 6:41 PM EDTMesoscale DiscussionSPCKent, New Castle, Sussex2 hr
Jun 14, 7:29 PM EDTSevere Thunderstorm WatchSPCKent, New Castle, Sussex6 hr
Jun 14, 1:40 PM EDTMesoscale DiscussionSPCBurlington, Camden, Gloucester, Hunterdon, Mercer, Middlesex and 3 more3 hr
Jun 14, 2:48 PM EDTMesoscale DiscussionSPCBroome, Chenango, Delaware, Fulton, Greene, Madison and 6 more2 hr
Jun 14, 11:31 AM EDTMesoscale DiscussionSPCAllegheny, Armstrong, Beaver, Bedford, Blair, Butler and 22 more89 min
Jun 14, 11:46 AM EDTSevere Thunderstorm WatchSPCAllegheny, Armstrong, Beaver, Bedford, Blair, Butler and 20 more6 hr
Jun 14, 3:25 PM EDTMesoscale DiscussionSPCFayette, Greene, Somerset, Washington, Westmoreland95 min

Nearby

Mesoscale Discussions in New Jersey, 2021Mesoscale Discussions in Pennsylvania, 2021Mesoscale Discussions in New York, 2021Every mesoscale discussion 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.