Alert archive / New York / Mesoscale Discussions in 2011
Mesoscale Discussion 809
The Storm Prediction Center issued this mesoscale discussion at May 19, 2011, 10:47 AM EDT for 12 counties in New Jersey; 28 counties in New York; 15 counties in Pennsylvania. It was in force for 88 min.
The area
The outline as issued.
The facts
- Issued
- May 19, 2011, 10:47 AM EDT (14:47 UTC)
- Expired
- May 19, 2011, 12:15 PM EDT
- In force
- 88 min
- Issued by
- the Storm Prediction Center
All 55 counties
Bergen County, NJ, Essex County, NJ, Hudson County, NJ, Hunterdon County, NJ, Mercer County, NJ, Middlesex County, NJ, Morris County, NJ, Passaic County, NJ, Somerset County, NJ, Sussex County, NJ, Union County, NJ, Warren County, NJ, Albany County, NY, Broome County, NY, Chenango County, NY, Columbia County, NY, Cortland County, NY, Delaware County, NY, Dutchess County, NY, Fulton County, NY, Greene County, NY, Herkimer County, NY, Madison County, NY, Montgomery County, NY, Oneida County, NY, Onondaga County, NY, Orange County, NY, Otsego County, NY, Putnam County, NY, Rensselaer County, NY, Richmond County, NY, Rockland County, NY, Saratoga County, NY, Schenectady County, NY, Schoharie County, NY, Sullivan County, NY, Tioga County, NY, Tompkins County, NY, Ulster County, NY, Washington County, NY, Berks County, PA, Bradford County, PA, Bucks County, PA, Carbon County, PA, Lackawanna County, PA, Lehigh County, PA, Luzerne County, PA, Monroe County, PA, Montgomery County, PA, Northampton County, PA, Pike County, PA, Schuylkill County, PA, Susquehanna County, PA, Wayne County, PA, Wyoming County, PA
The radar
The Binghamton radar (KBGM), 95 km from the middle of the area, began a volume at 14:48 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 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 12:00Z, 2.8 hours before the alert went out and 148 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
- 11 J/kg
- Mixed-layer CIN
- -44 J/kg
- Mixed-layer LCL
- 491 m above ground
- 0-6 km bulk shear
- 34 kt
- 0-1 km storm-relative helicity
- 99 m²/s²
- 0-3 km storm-relative helicity
- 103 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
954
ACUS11 KWNS 191448
SWOMCD
SPC MCD 191447
NYZ000-NJZ000-PAZ000-191615-
MESOSCALE DISCUSSION 0809
NWS STORM PREDICTION CENTER NORMAN OK
0947 AM CDT THU MAY 19 2011
AREAS AFFECTED...PARTS OF CENTRAL/ERN NY...ERN PA...AND CENTRAL/NRN
NJ
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 191447Z - 191615Z
SEVERE TSTM WATCH ISSUANCE MAY BE NEEDED BY EARLY AFTERNOON ACROSS
PARTS OF ERN PA...NRN NJ INTO PORTIONS OF CENTRAL AND ERN NY. HAIL
IS EXPECTED TO BE THE PRIMARY THREAT.
A SLIGHT RISK AREA WILL BE ADDED TO THE DAY 1 CONVECTIVE OUTLOOK FOR
THIS MESOSCALE DISCUSSION AREA.
VISIBLE SATELLITE IMAGERY SHOWED BREAKS IN CLOUDINESS ACROSS NORTH
CENTRAL-NERN PA...NJ AND INTO MUCH OF NY...WITH SURFACE HEATING ALSO
EXPECTED IN THE WAKE OF CONVECTION CURRENTLY TRACKING NWD THROUGH
SRN/CENTRAL NY. OBJECTIVE ANALYSES SHOWED THE AIR MASS FROM
DELMARVA/MID ATLANTIC REGION NWD INTO NY DESTABILIZING /MUCAPE
500-1000 J/KG/...GIVEN SURFACE HEATING BENEATH MIDLEVEL LAPSE RATES
CLOSE TO 7 C/KM. ALTHOUGH MIDLEVEL WINDS SHOULD TEND TO WEAKEN WITH
THE APPROACH THE MIDLEVEL CLOSED LOW FROM THE UPPER OH VALLEY...
EFFECTIVE BULK SHEAR OF 25-30 KT WILL BE SUFFICIENT FOR MULTICELLS
AND LINE SEGMENTS. FORCING FOR ASCENT ATTENDANT TO A MIDLEVEL
IMPULSE TRACKING NWD FROM ERN VA AND THE CLOSED LOW ITSELF IS
EXPECTED TO SUPPORT NEW TSTM DEVELOPMENT ACROSS ERN PA BY EARLY
AFTERNOON...WITH ACTIVITY SPREADING INTO NJ AND PARTS OF CENTRAL/ERN
NY. COLD MIDLEVEL TEMPERATURES PER AREA 12Z SOUNDINGS /-18 TO -20 C
AT 500 MB/ ADVECTING OVER THIS REGION AND STEEPENING LAPSE RATES
WILL SUPPORT HAIL AS THE PRIMARY SEVERE WEATHER THREAT.
11Z WRF-HRRR AND 00Z 4 KM WRF-ARW/WRF-NMM SUPPORT THE CONVECTIVE
SCENARIO SHOWING ONE OR MORE CLUSTERS/BROKEN LINES OF CONVECTION
DEVELOPING OVER ERN PA AND SPREADING INTO NJ/NY.
..PETERS.. 05/19/2011
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...OKX...ALY...PHI...BGM...BUF...CTP...
LAT...LON 40167435 40227583 40617623 42227674 42737676 43537595
43687417 43317341 41557368 40677402 40167435SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 19, 12:20 PM EDT | Severe Thunderstorm Watch | SPC | Bergen, Burlington, Camden, Essex, Gloucester, Hudson and 9 more | 8 hr |
| May 19, 2:17 PM EDT | Mesoscale Discussion | SPC | Atlantic, Bergen, Burlington, Camden, Cumberland, Essex and 12 more | 58 min |
| May 19, 5:02 PM EDT | Mesoscale Discussion | SPC | Bergen, Burlington, Camden, Essex, Gloucester, Hudson and 9 more | 58 min |
Nearby
Mesoscale Discussions in New York, 2011Mesoscale Discussions in Pennsylvania, 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.