Alert archive / New Jersey / Mesoscale Discussions in 2021
Mesoscale Discussion 1167
The Storm Prediction Center issued this mesoscale discussion at Jul 6, 2021, 5:25 PM EDT for 11 counties in New Jersey; 9 counties in New York; Carbon County, Monroe County, Northampton County, Pennsylvania. It was in force for 95 min.
The area
The outline as issued.
The facts
- Issued
- Jul 6, 2021, 5:25 PM EDT (21:25 UTC)
- Expired
- Jul 6, 2021, 7:00 PM EDT
- In force
- 95 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe thunderstorm watch 336
All 23 counties
Bergen County, NJ, Essex County, NJ, Hudson County, NJ, Hunterdon County, NJ, Middlesex County, NJ, Morris County, NJ, Passaic County, NJ, Somerset County, NJ, Sussex County, NJ, Union County, NJ, Warren County, NJ, Bronx County, NY, Kings County, NY, Nassau County, NY, New York County, NY, Orange County, NY, Queens County, NY, Richmond County, NY, Rockland County, NY, Westchester County, NY, Carbon County, PA, Monroe County, PA, Northampton County, PA
The radar
The Philadelphia radar (KDIX), 110 km from the middle of the area, began a volume at 21:25 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
Brookhaven, NY (KOKX), launched 12:00Z, 9.4 hours before the alert went out and 134 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
- 230 J/kg
- Mixed-layer CIN
- -195 J/kg
- Mixed-layer LCL
- 1202 m above ground
- 0-6 km bulk shear
- 19 kt
- 0-1 km storm-relative helicity
- 139 m²/s²
- 0-3 km storm-relative helicity
- 184 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
212
ACUS11 KWNS 062126
SWOMCD
SPC MCD 062125
NYZ000-CTZ000-NJZ000-PAZ000-062300-
Mesoscale Discussion 1167
NWS Storm Prediction Center Norman OK
0425 PM CDT Tue Jul 06 2021
Areas affected...portions of Northern New Jersey into the New York
City Metropolitan Area
Concerning...Severe Thunderstorm Watch 336...
Valid 062125Z - 062300Z
The severe weather threat for Severe Thunderstorm Watch 336
continues.
SUMMARY...A relatively concentrated swath of damaging gusts may
occur with an organizing line of thunderstorms across northern
portions of Severe Thunderstorm Watch 336. Brief instances of gusts
in the 65-75 mph range are possible with the stronger storms.
DISCUSSION...Latest MRMS mosaic radar data depicts an organizing
line of thunderstorms, with some forward bowing of the leading line
of higher reflectivity. KOKX and KDIX radars also show an
intensifying swath of higher inbound velocities at the 0.5 degree
scan, roughly 8 kft above ground level. Latest RAP forecast
soundings show 0-3km lapse rates exceeding 8 C/km (roughly at/below
8 kft), suggesting that efficient downward momentum transport of the
stronger winds in the 850-600 mb layer is likely. Combined with the
impacts of evaporative cooling in the sfc-500 mb layer (where
notable drying is present), a swath consisting of multiple damaging
gusts appear likely. Latest mesoanalysis shows 2000+ MLCAPE in
advance of this line, fueled by 90+ F surface temperatures and 70+ F
dewpoints. As such, locally higher damaging gust potential is
expected to accompany the line of storms to the Atlantic Seaboard,
including the New York City Metropolitan area within the next 2
hours.
..Squitieri/Hart.. 07/06/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...OKX...PHI...BGM...CTP...
LAT...LON 40817589 41287513 41437464 41457420 41317381 41097347
40777324 40437342 40407410 40497517 40817589SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 6, 12:33 PM EDT | Mesoscale Discussion | SPC | Atlantic, Bergen, Burlington, Camden, Essex, Gloucester and 13 more | 2 hr |
| Jul 6, 1:32 PM EDT | Severe Thunderstorm Watch | SPC | Atlantic, Bergen, Burlington, Camden, Cape May, Cumberland and 15 more | 8 hr |
| Jul 6, 4:23 PM EDT | Mesoscale Discussion | SPC | Atlantic, Bergen, Burlington, Camden, Cumberland, Essex and 14 more | 97 min |
| Jul 5, 9:14 PM EDT | Mesoscale Discussion | SPC | Cayuga, Jefferson, Lewis, Monroe, Oneida, Onondaga and 5 more | 2 hr |
| Jul 6, 1:13 PM EDT | Severe Thunderstorm Watch | SPC | Albany, Broome, Chemung, Chenango, Columbia, Cortland and 17 more | 7 hr |
Nearby
Mesoscale Discussions in New Jersey, 2021Mesoscale Discussions in New York, 2021Mesoscale Discussions in Pennsylvania, 2021Every mesoscale discussion in 2021
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.