Alert archive / New Jersey / Mesoscale Discussions in 2011

Mesoscale Discussion 628

April 27, 20115 states

The Storm Prediction Center issued this mesoscale discussion at Apr 27, 2011, 3:55 PM EDT for 5 states. It was in force for 65 min.

The area

The outline as issued.

The facts

Issued
Apr 27, 2011, 3:55 PM EDT (19:55 UTC)
Expired
Apr 27, 2011, 5:00 PM EDT
In force
65 min
Issued by
the Storm Prediction Center
All 44 counties

Kent County, DE, New Castle County, DE, Sussex County, DE, Caroline County, MD, Cecil County, MD, Dorchester County, MD, Harford County, MD, Kent County, MD, Queen Anne's County, MD, Somerset County, MD, Talbot County, MD, Wicomico County, MD, Camden County, NJ, Cumberland County, NJ, Essex County, NJ, Gloucester County, NJ, Hunterdon County, NJ, Mercer County, NJ, Morris County, NJ, Passaic County, NJ, Salem County, NJ, Somerset County, NJ, Sussex County, NJ, Union County, NJ, Warren County, NJ, Albany County, NY, Columbia County, NY, Dutchess County, NY, Greene County, NY, Orange County, NY, Putnam County, NY, Rockland County, NY, Sullivan County, NY, Ulster County, NY, Berks County, PA, Bucks County, PA, Chester County, PA, Delaware County, PA, Lehigh County, PA, Monroe County, PA, Montgomery County, PA, Northampton County, PA, Philadelphia County, PA, Pike County, PA

The radar

The Philadelphia radar (KDIX), 81 km from the middle of the area, began a volume at 19:55 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

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 7.9 hours before the alert went out and 150 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, Phillips Aaf/Abe, MD at 12:00Z on 2011-04-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 139 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, Phillips Aaf/Abe, MD at 12:00Z on 2011-04-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 77 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
139 J/kg
Mixed-layer CIN
-57 J/kg
Mixed-layer LCL
640 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
77 m²/s²
0-3 km storm-relative helicity
84 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

469 
ACUS11 KWNS 271956
SWOMCD
SPC MCD 271955
CTZ000-MAZ000-NYZ000-NJZ000-PAZ000-DEZ000-MDZ000-VAZ000-272100-

MESOSCALE DISCUSSION 0628
NWS STORM PREDICTION CENTER NORMAN OK
0255 PM CDT WED APR 27 2011

AREAS AFFECTED...PORTIONS OF THE DELMARVA...NJ...ERN PA...SERN NY

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 271955Z - 272100Z

ISOLATED TO SCATTERED THUNDERSTORMS DEVELOPING ACROSS PORTIONS OF
DELMARVA...NJ...ERN PA AND SERN NY WILL POSE A MARGINAL SVR WEATHER
THREAT. WW DOES NOT APPEAR LIKELY ATTM.

PARTIAL SUNSHINE THIS AFTERNOON IS AIDING IN WARMING/DESTABILIZING
BOUNDARY LAYER FROM DELMARVA N-NEWD INTO SERN NY. WITH TEMPERATURES
IN THE UPPER 70S/LOW 80S AND DEWPOINTS IN THE 60S...MLCAPE VALUES
HAVE INCREASED TO AROUND 500-1000 J/KG. IN ADDITION...AREA VWP/S AND
RUC FORECAST SOUNDINGS SHOW VEERING WIND PROFILES...WHICH COULD AID
IN BRIEF STORM ORGANIZATION AS ACTIVITY TRACKS NEWD ACROSS THE AREA.
THOUGH ISOLATED DAMAGING WIND GUSTS OR MARGINALLY SVR HAIL WILL BE
POSSIBLE...THE ENVIRONMENT DOES NOT APPEAR TO SUPPORT A WW ATTM.

..GARNER.. 04/27/2011

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

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

LAT...LON   39277646 40477608 42627404 42467337 41737348 40757425
            37627585 39277646

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 27, 1:23 PM EDTTornado WatchSPCAllegany, Anne Arundel, Baltimore, Calvert, Carroll, Charles and 8 more5 hr
Apr 27, 1:24 PM EDTMesoscale DiscussionSPCAllegany, Garrett96 min
Apr 27, 3:10 PM EDTTornado WatchSPCGarrett7 hr
Apr 27, 4:39 PM EDTMesoscale DiscussionSPCAllegany, Anne Arundel, Baltimore, Calvert, Carroll, Charles and 10 more66 min
Apr 27, 6:00 PM EDTMesoscale DiscussionSPCAnne Arundel, Baltimore, Calvert, Carroll, Charles, Frederick and 9 more60 min
Apr 27, 6:15 PM EDTTornado WatchSPCAllegany, Anne Arundel, Baltimore, Calvert, Carroll, Charles and 8 more6 hr
Apr 27, 6:50 PM EDTMesoscale DiscussionSPCCarroll, Harford, Washington55 min
Apr 27, 7:55 PM EDTMesoscale DiscussionSPCAnne Arundel, Baltimore, Calvert, Carroll, Charles, Harford and 8 more65 min

Nearby

Mesoscale Discussions in New Jersey, 2011Mesoscale Discussions in Pennsylvania, 2011Mesoscale Discussions in Maryland, 2011Every mesoscale discussion in 2011

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.