Alert archive / Pennsylvania / Mesoscale Discussions in 2015
Mesoscale Discussion 970
The Storm Prediction Center issued this mesoscale discussion at Jun 11, 2015, 2:47 PM EDT for 4 states. It was in force for 118 min.
The area
The outline as issued.
The facts
- Issued
- Jun 11, 2015, 2:47 PM EDT (18:47 UTC)
- Expired
- Jun 11, 2015, 4:45 PM EDT
- In force
- 118 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 20%
All 56 counties
Bergen County, NJ, Essex County, NJ, Hudson County, NJ, Hunterdon County, NJ, Morris County, NJ, Passaic County, NJ, Somerset County, NJ, Sussex County, NJ, Union County, NJ, Warren County, NJ, New York County, NY, Richmond County, NY, Rockland County, NY, Westchester County, NY, Columbiana County, OH, Mahoning County, OH, Portage County, OH, Trumbull County, OH, Allegheny County, PA, Armstrong County, PA, Beaver County, PA, Berks County, PA, Blair County, PA, Butler County, PA, Cambria County, PA, Carbon County, PA, Centre County, PA, Clarion County, PA, Clearfield County, PA, Clinton County, PA, Columbia County, PA, Dauphin County, PA, Huntingdon County, PA, Indiana County, PA, Jefferson County, PA, Juniata County, PA, Lackawanna County, PA, Lawrence County, PA, Lebanon County, PA, Lehigh County, PA, Luzerne County, PA, Lycoming County, PA, Mercer County, PA, Mifflin County, PA, Monroe County, PA, Montour County, PA, Northampton County, PA, Northumberland County, PA, Perry County, PA, Pike County, PA, Schuylkill County, PA, Snyder County, PA, Sullivan County, PA, Union County, PA, Westmoreland County, PA, Wyoming County, PA
The radar
The State College radar (KCCX), 23 km from the middle of the area, began a volume at 18:48 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
Pittsburgh, PA (KAGC), launched 12:00Z, 6.8 hours before the alert went out and 163 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.
- Mixed-layer CAPE
- 48 J/kg
- Mixed-layer CIN
- -154 J/kg
- Mixed-layer LCL
- 1348 m above ground
- 0-6 km bulk shear
- 25 kt
- 0-1 km storm-relative helicity
- 37 m²/s²
- 0-3 km storm-relative helicity
- 56 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
081
ACUS11 KWNS 111847
SWOMCD
SPC MCD 111847
NYZ000-NJZ000-PAZ000-WVZ000-OHZ000-112045-
MESOSCALE DISCUSSION 0970
NWS STORM PREDICTION CENTER NORMAN OK
0147 PM CDT THU JUN 11 2015
AREAS AFFECTED...PARTS OF NE OHIO...THE MIDDLE TIER OF
PENNSYLVANIA...NRN NEW JERSEY...AND SERN NEW YORK...INCLUDING
PORTIONS OF THE GREATER NEW YORK CITY AREA
CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY
VALID 111847Z - 112045Z
PROBABILITY OF WATCH ISSUANCE...20 PERCENT
SUMMARY...THE NEED FOR A SEVERE WEATHER WATCH FOR LATE THIS
AFTERNOON STILL APPEARS UNLIKELY DUE TO POTENTIALLY LIMITED STORM
COVERAGE. BUT CONVECTIVE TRENDS WILL CONTINUE TO BE MONITORED FOR
THE POSSIBILITY OF INCREASING SEVERE WEATHER POTENTIAL...MAINLY IN
THE FORM OF POTENTIALLY DAMAGING WIND GUSTS.
DISCUSSION...LOW-LEVEL CONVERGENCE...AND MID/UPPER FORCING FOR
ASCENT...APPEAR WEAK...BUT MODERATELY STRONG BOUNDARY LAYER
DESTABILIZATION IS UNDERWAY ALONG A STALLED/SLOW MOVING FRONTAL ZONE
ACROSS THE UPPER OHIO VALLEY INTO NORTHERN MID ATLANTIC COAST AND
SOUTHERN NEW ENGLAND. INHIBITION FOR THE MIXED LAYER /NOW
CHARACTERIZED BY CAPE ON THE ORDER OF 2000 J PER KG/ CONTINUES TO
ERODE WITH DAYTIME HEATING...AND THIS IS RESULTING IN SCATTERED
DEEPENING CONVECTIVE DEVELOPMENT. AT LEAST SOME OF THIS IS EXPECTED
TO CONTINUE TO INTENSIFY...WITH ISOLATED TO WIDELY SCATTERED STORM
DEVELOPMENT INCREASINGLY LIKELY THROUGH 21-23Z. SUSTAINED STORMS
PROBABLY WILL BE AUGMENTED/ENHANCED BY BY MODEST WEST NORTHWESTERLY
DEEP LAYER MEAN FLOW AND SHEAR /30-40 KT/...ON THE SOUTHERN FRINGE
OF THE SEASONABLY STRONG MID/UPPER JET STREAK NOW BEGINNING TO NOSE
EAST OF THE NORTHERN MID ATLANTIC COAST. THE EVOLUTION OF ONE OR
TWO SMALL ORGANIZED STORM CLUSTERS MAY NOT BE OUT OF THE
QUESTION...WITH ASSOCIATED EAST SOUTHEASTWARD ADVANCING COLD POOLS
ACCOMPANIED BY THE RISK FOR POTENTIALLY DAMAGING WIND GUSTS.
..KERR/HART.. 06/11/2015
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...OKX...PHI...BGM...CTP...PBZ...CLE...
LAT...LON 41028186 41318078 41348007 41277808 41577609 41317359
40517413 40317552 40147781 40137868 40588074 41028186SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 10, 9:02 PM EDT | Severe Thunderstorm Watch | SPC | Cayuga, Chenango, Cortland, Hamilton, Herkimer, Jefferson and 10 more | 4 hr |
| Jun 10, 10:53 PM EDT | Mesoscale Discussion | SPC | Cayuga, Hamilton, Herkimer, Jefferson, Lewis, Oneida and 6 more | 67 min |
| Jun 11, 4:52 PM EDT | Mesoscale Discussion | SPC | Defiance, Hancock, Henry, Paulding, Putnam, Van Wert and 1 more | 113 min |
Nearby
Mesoscale Discussions in Pennsylvania, 2015Mesoscale Discussions in New Jersey, 2015Mesoscale Discussions in New York, 2015Every mesoscale discussion in 2015
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.