Alert archive / New Jersey / Mesoscale Discussions in 2012

Mesoscale Discussion 1937

September 8, 20125 states

The Storm Prediction Center issued this mesoscale discussion at Sep 8, 2012, 4:22 PM EDT for 5 states. It was in force for 53 min.

The area

The outline as issued.

The facts

Issued
Sep 8, 2012, 4:22 PM EDT (20:22 UTC)
Expired
Sep 8, 2012, 5:15 PM EDT
In force
53 min
Issued by
the Storm Prediction Center
All 37 counties

Kent County, DE, New Castle County, DE, Sussex County, DE, Anne Arundel County, MD, Calvert County, MD, Caroline County, MD, Cecil County, MD, Charles County, MD, Dorchester County, MD, Kent County, MD, Prince George's County, MD, Queen Anne's County, MD, Saint Mary's County, MD, Talbot County, MD, Wicomico County, MD, Atlantic 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, Salem County, NJ, Somerset County, NJ, Union County, NJ, Richmond County, NY, Bucks County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Dover AFB radar (KDOX), 73 km from the middle of the area, began a volume at 20:23 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, 8.4 hours before the alert went out and 167 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 2012-09-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 252 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 12:00Z on 2012-09-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 150 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
252 J/kg
Mixed-layer CIN
-81 J/kg
Mixed-layer LCL
638 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
150 m²/s²
0-3 km storm-relative helicity
140 m²/s²
Significant tornado parameter
0.1
Supercell composite
1.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 8, 12:15 PM EDTSevere Thunderstorm WatchSPCKent, New Castle, Sussex9 hr
Sep 8, 2:12 PM EDTMesoscale DiscussionSPCKent, New Castle93 min
Sep 8, 5:00 AM EDTMesoscale DiscussionSPCAllegany, Garrett60 min
Sep 8, 11:38 AM EDTMesoscale DiscussionSPCAllegany, Baltimore, Carroll, Frederick, Howard, Montgomery and 2 more97 min
Sep 8, 1:48 PM EDTSevere Thunderstorm WatchSPCDorchester, Somerset, Wicomico, Worcester7 hr
Sep 8, 3:25 PM EDTMesoscale DiscussionSPCSaint Mary's, Somerset65 min
Sep 8, 10:39 AM EDTMesoscale DiscussionSPCBergen, Hudson, Passaic2 hr
Sep 8, 11:18 AM EDTTornado WatchSPCBergen, Essex, Hudson, Passaic, Union10 hr
Sep 8, 1:30 PM EDTMesoscale DiscussionSPCBergen, Hudson60 min
Sep 8, 12:57 AM EDTMesoscale DiscussionSPCChautauqua2 hr
Sep 8, 8:42 AM EDTMesoscale DiscussionSPCBroome, Cayuga, Chemung, Chenango, Cortland, Herkimer and 13 more93 min
Sep 8, 10:03 AM EDTSevere Thunderstorm WatchSPCAllegany, Cattaraugus, Cayuga, Chemung, Franklin, Genesee and 16 more5 hr
Sep 8, 12:40 PM EDTTornado WatchSPCAlbany, Broome, Chenango, Clinton, Columbia, Cortland and 22 more7 hr
Sep 8, 2:46 PM EDTMesoscale DiscussionSPCAlbany, Clinton, Columbia, Delaware, Dutchess, Essex and 14 more59 min
Sep 8, 3:55 PM EDTMesoscale DiscussionSPCColumbia, Rensselaer, Washington65 min
Sep 8, 6:17 PM EDTMesoscale DiscussionSPCSuffolk58 min

Nearby

Mesoscale Discussions in New Jersey, 2012Mesoscale Discussions in Maryland, 2012Mesoscale Discussions in Pennsylvania, 2012Every mesoscale discussion in 2012

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.