Alert archive / Pennsylvania / Mesoscale Discussions in 2011
Mesoscale Discussion 656
The Storm Prediction Center issued this mesoscale discussion at Apr 28, 2011, 3:32 AM EDT for Hunterdon County, Sussex County, Warren County, New Jersey; 21 counties in New York; 31 counties in Pennsylvania. It was in force for 28 min.
The area
The outline as issued.
The facts
- Issued
- Apr 28, 2011, 3:32 AM EDT (07:32 UTC)
- Expired
- Apr 28, 2011, 4:00 AM EDT
- In force
- 28 min
- Issued by
- the Storm Prediction Center
All 55 counties
Hunterdon County, NJ, Sussex County, NJ, Warren County, NJ, Albany County, NY, Broome County, NY, Chenango County, NY, Delaware County, NY, Fulton County, NY, Greene County, NY, Hamilton County, NY, Herkimer County, NY, Madison County, NY, Montgomery County, NY, Orange County, NY, Otsego County, NY, Rensselaer County, NY, Saratoga County, NY, Schenectady County, NY, Schoharie County, NY, Sullivan County, NY, Tioga County, NY, Ulster County, NY, Warren County, NY, Washington County, NY, Adams County, PA, Berks County, PA, Bradford County, PA, Bucks County, PA, Carbon County, PA, Chester County, PA, Columbia County, PA, Cumberland County, PA, Dauphin County, PA, Juniata County, PA, Lackawanna County, PA, Lancaster County, PA, Lebanon County, PA, Lehigh County, PA, Luzerne County, PA, Lycoming County, PA, Monroe County, PA, Montgomery 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, Susquehanna County, PA, Union County, PA, Wayne County, PA, Wyoming County, PA, York County, PA
The radar
The Binghamton radar (KBGM), 60 km from the middle of the area, began a volume at 07:31 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
Albany, NY (KALY), launched 00:00Z, 7.5 hours before the alert went out and 165 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
- 108 J/kg
- Mixed-layer CIN
- -95 J/kg
- Mixed-layer LCL
- 777 m above ground
- 0-6 km bulk shear
- 41 kt
- 0-1 km storm-relative helicity
- 307 m²/s²
- 0-3 km storm-relative helicity
- 401 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 2.8
The text
As transmitted, in the capitals the NWS used until 2016.
881
ACUS11 KWNS 280733
SWOMCD
SPC MCD 280732
VTZ000-NYZ000-NJZ000-PAZ000-280800-
MESOSCALE DISCUSSION 0656
NWS STORM PREDICTION CENTER NORMAN OK
0232 AM CDT THU APR 28 2011
AREAS AFFECTED...CNTRL/ERN PA/NY...NWRN NJ
CONCERNING...SEVERE THUNDERSTORM WATCH 244...246...
VALID 280732Z - 280800Z
THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
244...246...CONTINUES.
WITH WW 244 SCHEDULED TO EXPIRE AT 08Z...A REDEFINITION OF THIS WW
ALONG WITH POSSIBLY WW 246 WILL BE COORDINATED SHORTLY WITH AFFECTED
WFOS. OVERALL SCENARIO DESCRIBED PREVIOUSLY IN MCD 0652 REMAINS
VALID WITH RISKS OF ISOLATED DAMAGING WINDS AND BRIEF TORNADOES
PERSISTING /REF POSSIBLE TORNADO DAMAGE REPORT IN CHEMUNG COUNTY NY
AT 0622Z/. THE QLCS ACROSS CNTRL PA HAS SHOWN A RECENT TREND FOR
NEWD ACCELERATION IN THE PAST HOUR. AS SUCH...THE WW REDEFINITION
WILL LIKELY INCLUDE PARTS OF ERN PA NEWD INTO THE HUDSON VALLEY NOT
CURRENTLY COVERED BY A WW.
..GRAMS.. 04/28/2011
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...BTV...OKX...ALY...PHI...BGM...CTP...
LAT...LON 39887770 41357710 42757587 43627503 44027464 43947395
43547335 42797332 40507480 39837573 39757632 39887770SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 27, 8:15 PM EDT | Severe Thunderstorm Watch | SPC | Hunterdon, Mercer, Morris, Passaic, Somerset, Sussex and 1 more | 8 hr |
| Apr 28, 4:05 AM EDT | Severe Thunderstorm Watch | SPC | Camden, Cape May, Cumberland, Gloucester, Hunterdon, Salem and 2 more | 6 hr |
| Apr 28, 6:21 AM EDT | Mesoscale Discussion | SPC | Bergen, Burlington, Camden, Cumberland, Gloucester, Hunterdon and 7 more | 54 min |
| Apr 28, 9:45 AM EDT | Severe Thunderstorm Watch | SPC | Atlantic, Bergen, Burlington, Camden, Cape May, Cumberland and 15 more | 6 hr |
| Apr 28, 10:44 AM EDT | Mesoscale Discussion | SPC | Salem | 61 min |
| Apr 28, 11:49 AM EDT | Mesoscale Discussion | SPC | Atlantic, Bergen, Burlington, Camden, Cape May, Cumberland and 15 more | 56 min |
| Apr 27, 9:03 PM EDT | Mesoscale Discussion | SPC | Cayuga, Chemung, Tioga, Tompkins | 57 min |
| Apr 27, 10:45 PM EDT | Mesoscale Discussion | SPC | Albany, Broome, Chenango, Delaware, Essex, Franklin and 15 more | 60 min |
| Apr 28, 2:20 AM EDT | Mesoscale Discussion | SPC | Broome, Chemung, Chenango, Cortland, Delaware, Fulton and 13 more | 55 min |
| Apr 27, 11:50 PM EDT | Severe Thunderstorm Watch | SPC | Adams, Bedford, Blair, Cambria, Cameron, Centre and 26 more | 7 hr |
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.