Alert archive / New Jersey / Mesoscale Discussions in 2021

Mesoscale Discussion 754

May 26, 20217 states

The Storm Prediction Center issued this mesoscale discussion at May 26, 2021, 6:34 PM EDT for 7 states. It was in force for 116 min.

The area

The outline as issued.

The facts

Issued
May 26, 2021, 6:34 PM EDT (22:34 UTC)
Expired
May 26, 2021, 8:30 PM EDT
In force
116 min
Issued by
the Storm Prediction Center
Concerning
Severe thunderstorm watch 205...206
All 63 counties

Kent County, DE, New Castle County, DE, Sussex County, DE, Anne Arundel County, MD, Baltimore County, MD, Calvert County, MD, Caroline County, MD, Carroll County, MD, Cecil County, MD, City of Baltimore, MD, Frederick County, MD, Harford County, MD, Howard County, MD, Kent County, MD, Montgomery County, MD, Prince George's County, MD, Queen Anne's County, MD, Talbot County, MD, Atlantic County, NJ, Bergen County, NJ, Burlington County, NJ, Camden County, NJ, Cape May 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, Union County, NJ, Bronx County, NY, Kings County, NY, New York County, NY, Richmond County, NY, Bucks County, PA, Chester County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA, Arlington County, VA, City of Alexandria, VA, City of Fairfax, VA, City of Falls Church, VA, City of Manassas, VA, City of Manassas Park, VA, City of Winchester, VA, Clarke County, VA, Fairfax County, VA, Fauquier County, VA, Frederick County, VA, Loudoun County, VA, Prince William County, VA, Rappahannock County, VA, Warren County, VA, Berkeley County, WV, Jefferson County, WV

The radar

The Dover AFB radar (KDOX), 107 km from the middle of the area, began a volume at 22:37 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

Washington/Dulle, VA (KIAD), launched 12:00Z, 10.6 hours before the alert went out and 117 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, Washington/Dulle, VA at 12:00Z on 2021-05-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 478 joules per kilogram.LCLLFCEL10008507005003002001001 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, Washington/Dulle, VA at 12:00Z on 2021-05-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 35 square meters per square second.193958Sfc1 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
478 J/kg
Mixed-layer CIN
-132 J/kg
Mixed-layer LCL
922 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
35 m²/s²
0-3 km storm-relative helicity
50 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

As transmitted.

055 
ACUS11 KWNS 262235
SWOMCD
SPC MCD 262234 
NYZ000-NJZ000-PAZ000-DEZ000-MDZ000-DCZ000-VAZ000-WVZ000-270030-

Mesoscale Discussion 0754
NWS Storm Prediction Center Norman OK
0534 PM CDT Wed May 26 2021

Areas affected...Portions of Mid-Atlantic

Concerning...Severe Thunderstorm Watch 205...206...

Valid 262234Z - 270030Z

The severe weather threat for Severe Thunderstorm Watch 205, 206
continues.

SUMMARY...Damaging wind gusts remain a concern with convection
nearing the Atlantic Coast. A few isolated storms near the Blue
Ridge and along the cold front may pose a low-end threat for strong
winds.

DISCUSSION...The most intense and organized convection near the
Atlantic Coast will impact portions or northern and central New
Jersey into western Long Island. Surface observations show much
cooler air in central and eastern Long Island. Parts of this
convective line will likely move offshore within the next hour. With
a narrow corridor of temperatures into the mid/upper 80s F, damaging
gusts will be possible in the short term. In Maryland and northern
Virginia, convection has been more of a broken line. A similar
hot/unstable airmass is ahead of a cluster now approaching the
Delmarva. Damaging gusts will be possible here for the next 1-1.5
hours. A small cluster has recently developed along the Blue Ridge
and is moving east. This may pose a threat for damaging gusts as
well, but stable air awaits this activity in the wake of early
convection and continued loss of boundary-layer heating. This threat
will be likely short-lived.

Farther north and west along the synoptic cold front, lingering
convection may persist this evening. With the boundary layer
stabilizing, isolated strong gusts would be the main threat before
this activity diminishes.

..Wendt.. 05/26/2021

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

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

LAT...LON   39357857 39547805 39637674 39877618 39897605 40607522
            41087479 41177428 40947381 40097397 39357445 38777493
            38587553 38517645 38497705 38487761 38637821 38907860
            39357857

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 26, 1:21 PM EDTMesoscale DiscussionSPCKent, New Castle, Sussex84 min
May 26, 2:48 PM EDTSevere Thunderstorm WatchSPCKent, New Castle, Sussex7 hr
May 26, 4:41 PM EDTMesoscale DiscussionSPCKent, New Castle64 min
May 26, 12:16 PM EDTMesoscale DiscussionSPCAlbany, Allegany, Broome, Cattaraugus, Cayuga, Chautauqua and 32 more119 min
May 26, 12:59 PM EDTSevere Thunderstorm WatchSPCAlbany, Broome, Chemung, Chenango, Columbia, Cortland and 23 more7 hr
May 26, 2:07 PM EDTMesoscale DiscussionSPCAlbany, Chenango, Cortland, Fulton, Greene, Madison and 6 more83 min

Nearby

Mesoscale Discussions in New Jersey, 2021Mesoscale Discussions in Maryland, 2021Mesoscale Discussions in Virginia, 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; radar from the NEXRAD Level II archive.