Alert archive / New York / Mesoscale Discussions in 2021
Mesoscale Discussion 1712
The Storm Prediction Center issued this mesoscale discussion at Sep 8, 2021, 4:40 AM EDT for Erie County, Niagara County, New York. It was in force for 3 hr.
The area
The outline as issued.
The facts
- Issued
- Sep 8, 2021, 4:40 AM EDT (08:40 UTC)
- Expired
- Sep 8, 2021, 7:15 AM EDT
- In force
- 3 hr
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch unlikely
- Chance of a watch
- 5%
Counties Erie County, NY, Niagara County, NY
The radar
The Buffalo radar (KBUF), 23 km from the middle of the area, began a volume at 08:42 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
Buffalo Intl Airport, NY (KBUF), launched 00:00Z, 8.7 hours before the alert went out and 25 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
- -10 J/kg
- Mixed-layer LCL
- 1665 m above ground
- 0-6 km bulk shear
- 44 kt
- 0-1 km storm-relative helicity
- 140 m²/s²
- 0-3 km storm-relative helicity
- 201 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.1
The text
As transmitted.
444
ACUS11 KWNS 080841
SWOMCD
SPC MCD 080840
NYZ000-081115-
Mesoscale Discussion 1712
NWS Storm Prediction Center Norman OK
0340 AM CDT Wed Sep 08 2021
Areas affected...Portions of western NY
Concerning...Severe potential...Watch unlikely
Valid 080840Z - 081115Z
Probability of Watch Issuance...5 percent
SUMMARY...An isolated strong/gusty wind threat may exist with storms
moving eastward early this morning. Watch issuance is not expected.
DISCUSSION...A broken, low-topped line of storms should continue to
move east-northeastward from southern Ontario and Lake Erie across
parts of western NY over the next few hours. Strong low/mid-level
flow preceding an upper trough is present over this region, with
recent VWPs from KBUF showing southwesterly winds rapidly
strengthening to around 50 kt only 1 km AGL. Latest surface
observations along/near the shore of Lake Erie have shown an
increase in temperatures into the low to mid 70s, with low 60s
surface dewpoints also present. Modifying a RAP forecast sounding
for current conditions at KBUF suggests a narrow, skinny CAPE
profile exists in the boundary layer. Given the strength of the
low-level flow and the presence of weak MLCAPE, there may be some
potential for isolated strong/gusty downdraft winds associated with
the broken line to reach the surface. Even so, this wind threat is
expected to remain quite isolated through the early morning hours,
and watch issuance is not expected.
..Gleason/Edwards.. 09/08/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...BUF...
LAT...LON 42357938 42417952 42597924 42827901 43227913 43367893
43437831 43207827 42827844 42477899 42357938SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 8, 4:15 PM EDT | Mesoscale Discussion | SPC | Albany, Delaware, Greene, Orange, Schoharie, Sullivan and 1 more | 2 hr |
| Sep 8, 6:30 PM EDT | Mesoscale Discussion | SPC | Saratoga, Washington | 90 min |
| Sep 8, 7:54 PM EDT | Severe Thunderstorm Watch | SPC | Columbia, Dutchess, Greene, Orange, Putnam, Rockland and 2 more | 4 hr |
Nearby
Mesoscale Discussions in New York, 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.