Alert archive / New York / Mesoscale Discussions in 2021
Mesoscale Discussion 1488
The Storm Prediction Center issued this mesoscale discussion at Aug 11, 2021, 4:57 PM EDT for 5 states. It was in force for 93 min.
The area
The outline as issued.
The facts
- Issued
- Aug 11, 2021, 4:57 PM EDT (20:57 UTC)
- Expired
- Aug 11, 2021, 6:30 PM EDT
- In force
- 93 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch unlikely
- Chance of a watch
- 5%
All 36 counties
Berkshire County, MA, Franklin County, MA, Hampden County, MA, Hampshire County, MA, Middlesex County, MA, Worcester County, MA, Belknap County, NH, Cheshire County, NH, Grafton County, NH, Hillsborough County, NH, Merrimack County, NH, Sullivan County, NH, Albany County, NY, Columbia County, NY, Dutchess County, NY, Essex County, NY, Greene County, NY, Orange County, NY, Putnam County, NY, Rensselaer County, NY, Rockland County, NY, Saratoga County, NY, Ulster County, NY, Washington County, NY, Westchester County, NY, Providence County, RI, Addison County, VT, Bennington County, VT, Caledonia County, VT, Chittenden County, VT, Lamoille County, VT, Orange County, VT, Rutland County, VT, Washington County, VT, Windham County, VT, Windsor County, VT
The radar
The Albany radar (KENX), 66 km from the middle of the area, began a volume at 20:59 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
Albany, NY (KALY), launched 12:00Z, 9.0 hours before the alert went out and 52 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
- 112 J/kg
- Mixed-layer CIN
- -115 J/kg
- Mixed-layer LCL
- 839 m above ground
- 0-6 km bulk shear
- 25 kt
- 0-1 km storm-relative helicity
- 230 m²/s²
- 0-3 km storm-relative helicity
- 261 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.7
The text
As transmitted.
533
ACUS11 KWNS 112057
SWOMCD
SPC MCD 112057
NHZ000-MAZ000-RIZ000-VTZ000-CTZ000-NYZ000-NJZ000-112230-
Mesoscale Discussion 1488
NWS Storm Prediction Center Norman OK
0357 PM CDT Wed Aug 11 2021
Areas affected...Portions of the Northeast
Concerning...Severe potential...Watch unlikely
Valid 112057Z - 112230Z
Probability of Watch Issuance...5 percent
SUMMARY...Isolated storms capable of mostly damaging wind are
expected to persist into the evening.
DISCUSSION...Isolated storms have formed along a weak wind shift
where temperatures are in the upper 80s to low 90s with dewpoints in
the low 70s. This yields MLCAPE around 2500 J/kg per SPC
mesoanalysis. The KCXX and KENX VWP show around 25 to 30 knots of
effective shear. This should be sufficient for some multicell
clusters to develop. Despite a mostly weak wind profile, any
multicell clusters could pose a threat for damaging winds given the
favorable thermodynamic environment featuring DCAPE around 2500
J/kg.
The isolated nature of the threat should preclude the need for a
watch.
..Bentley/Thompson.. 08/11/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...GYX...BOX...BTV...OKX...ALY...PHI...BGM...
LAT...LON 41597454 42737391 44397376 44847202 43147118 41537168
41067354 41157436 41597454SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 11, 6:44 PM EDT | Mesoscale Discussion | SPC | Bronx, Kings, New York, Orange, Putnam, Queens and 3 more | 91 min |
Nearby
Mesoscale Discussions in New York, 2021Mesoscale Discussions in Vermont, 2021Mesoscale Discussions in Connecticut, 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.