Alert archive / Pennsylvania / Mesoscale Discussions in 2011
Mesoscale Discussion 2017
The Storm Prediction Center issued this mesoscale discussion at Aug 19, 2011, 12:43 PM EDT for 15 counties in New Jersey; 16 counties in New York; 37 counties in Pennsylvania. It was in force for 62 min.
The area
The outline as issued.
The facts
- Issued
- Aug 19, 2011, 12:43 PM EDT (16:43 UTC)
- Expired
- Aug 19, 2011, 1:45 PM EDT
- In force
- 62 min
- Issued by
- the Storm Prediction Center
All 68 counties
Bergen County, NJ, Camden 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, Passaic County, NJ, Somerset County, NJ, Sussex County, NJ, Union County, NJ, Warren County, NJ, Albany County, NY, Bronx County, NY, Columbia County, NY, Delaware County, NY, Dutchess County, NY, Greene County, NY, Kings County, NY, New York County, NY, Orange County, NY, Putnam County, NY, Richmond County, NY, Rockland County, NY, Schoharie County, NY, Sullivan County, NY, Ulster County, NY, Westchester County, NY, Adams County, PA, Berks County, PA, Blair County, PA, Bucks County, PA, Carbon County, PA, Chester County, PA, Columbia County, PA, Cumberland County, PA, Dauphin County, PA, Delaware County, PA, Franklin County, PA, Fulton County, PA, Huntingdon County, PA, Juniata County, PA, Lackawanna County, PA, Lancaster County, PA, Lebanon County, PA, Lehigh County, PA, Luzerne County, PA, Lycoming County, PA, Mifflin County, PA, Monroe County, PA, Montgomery County, PA, Montour County, PA, Northampton County, PA, Northumberland County, PA, Perry County, PA, Philadelphia County, PA, Pike County, PA, Schuylkill County, PA, Snyder County, PA, Sullivan County, PA, Susquehanna County, PA, Union County, PA, Wayne County, PA, Wyoming County, PA, York County, PA
The radar
The Binghamton radar (KBGM), 117 km from the middle of the area, began a volume at 16:45 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 watches that followed
Watches SPC issued over any of the same counties within four hours of this discussion.
The nearest sounding before it
Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 4.7 hours before the alert went out and 190 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
- 146 J/kg
- Mixed-layer CIN
- -154 J/kg
- Mixed-layer LCL
- 1250 m above ground
- 0-6 km bulk shear
- 19 kt
- 0-1 km storm-relative helicity
- 359 m²/s²
- 0-3 km storm-relative helicity
- 370 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
707
ACUS11 KWNS 191643
SWOMCD
SPC MCD 191643
MAZ000-CTZ000-NYZ000-NJZ000-PAZ000-DEZ000-MDZ000-191745-
MESOSCALE DISCUSSION 2017
NWS STORM PREDICTION CENTER NORMAN OK
1143 AM CDT FRI AUG 19 2011
AREAS AFFECTED...PARTS OF CNTRL/ERN PA...SRN NY...NJ
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 191643Z - 191745Z
TRENDS ARE BEING MONITORED FOR THE POSSIBILITY OF A SEVERE THREAT
THAT COULD REQUIRE A WATCH.
SCATTERED STORM DEVELOPMENT IS NOW WELL UNDERWAY ACROSS MUCH OF THE
NORTHEAST...BENEATH GENERALLY LIGHT...BROADLY CYCLONIC MID/UPPER
FLOW. A MID-LEVEL COLD POCKET WITHIN THIS REGIME APPEARS TO PROVIDE
THE FOCUS FOR ONE CLUSTERING OF STORMS NOW SPREADING INTO/THROUGH
THE NORTHERN ALLEGHENY MOUNTAINS AREA OF PENNSYLVANIA. EAST OF THIS
ACTIVITY...AND IN FACT THROUGH MUCH OF THE NORTHEAST...A MOIST
BOUNDARY LAYER CONTINUES TO GRADUALLY DESTABILIZE...WITH LOW-LEVEL
LAPSE RATES STEEPENING IN RESPONSE TO INSOLATION...AND MIXED LAYER
CAPE BECOMING MODERATELY LARGE. THIS SHOULD CONTINUE TO SUPPORT
INCREASING/INTENSIFYING THUNDERSTORM ACTIVITY THROUGH THE AFTERNOON
HOURS. THERMODYNAMIC PROFILES MAY BE SUFFICIENT FOR SOME HAIL AND
LOCALIZED DOWNBURSTS IN STRONGER STORMS...BUT VERY WEAK DEEP LAYER
MEAN FLOW AND SHEAR WILL PROBABLY MINIMIZE THE RISK FOR ORGANIZED
SEVERE STORMS. IT MAY BE POSSIBLE THAT CONSOLIDATING COLD POOLS
COULD SUPPORT UPSCALE CONVECTIVE GROWTH ACROSS THE REMAINDER OF
CENTRAL AND EASTERN PENNSYLVANIA INTO NEW JERSEY AND PORTIONS OF THE
LOWER HUDSON VALLEY BY THE 21-22Z TIME FRAME. IF THIS OCCURS
...THERE MAY BE SOME POTENTIAL FOR BROADER SCALE STRONG WINDS ALONG
A DEVELOPING GUST FRONT. BUT PEAK WINDS MAY GENERALLY REMAIN BELOW
SEVERE CRITERIA...EXCEPT PERHAPS WHERE LOCALLY ACCELERATED BY
TERRAIN FEATURES.
..KERR.. 08/19/2011
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...BOX...OKX...ALY...PHI...BGM...CTP...LWX...
LAT...LON 40477839 41117757 41597670 42217565 42587486 42627366
42197295 41067354 40167425 39577523 39927823 40477839SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 19, 1:04 PM EDT | Severe Thunderstorm Watch | SPC | Greater Bridgeport Planning Region, Northwest Hills Planning Region | 8 hr |
| Aug 19, 6:42 PM EDT | Mesoscale Discussion | SPC | 63 min | |
| Aug 19, 7:44 PM EDT | Mesoscale Discussion | SPC | Atlantic, Burlington, Camden, Cumberland, Essex, Gloucester and 8 more | 61 min |
Nearby
Mesoscale Discussions in Pennsylvania, 2011Mesoscale Discussions in New York, 2011Mesoscale Discussions in New Jersey, 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.