Alert archive / New York / Mesoscale Discussions in 2021
Mesoscale Discussion 1365
The Storm Prediction Center issued this mesoscale discussion at Jul 27, 2021, 2:01 PM EDT for Berkshire County, Massachusetts; 35 counties in New York; Susquehanna County, Pennsylvania. It was in force for 89 min.
The area
The outline as issued.
The facts
- Issued
- Jul 27, 2021, 2:01 PM EDT (18:01 UTC)
- Expired
- Jul 27, 2021, 3:30 PM EDT
- In force
- 89 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe thunderstorm watch 395
All 37 counties
Berkshire County, MA, Albany County, NY, Allegany County, NY, Broome County, NY, Cattaraugus County, NY, Cayuga County, NY, Chemung County, NY, Chenango County, NY, Columbia County, NY, Cortland County, NY, Delaware County, NY, Dutchess County, NY, Fulton County, NY, Greene County, NY, Livingston County, NY, Madison County, NY, Monroe County, NY, Montgomery County, NY, Oneida County, NY, Onondaga County, NY, Ontario County, NY, Oswego County, NY, Otsego County, NY, Rensselaer County, NY, Saratoga County, NY, Schenectady County, NY, Schoharie County, NY, Schuyler County, NY, Seneca County, NY, Steuben County, NY, Tioga County, NY, Tompkins County, NY, Ulster County, NY, Wayne County, NY, Wyoming County, NY, Yates County, NY, Susquehanna County, PA
The radar
The Binghamton radar (KBGM), 60 km from the middle of the area, began a volume at 18:04 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, 6.0 hours before the alert went out and 184 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1464 m above ground
- 0-6 km bulk shear
- 44 kt
- 0-1 km storm-relative helicity
- 35 m²/s²
- 0-3 km storm-relative helicity
- 46 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
141
ACUS11 KWNS 271801
SWOMCD
SPC MCD 271801
MAZ000-VTZ000-CTZ000-NYZ000-PAZ000-271930-
Mesoscale Discussion 1365
NWS Storm Prediction Center Norman OK
0101 PM CDT Tue Jul 27 2021
Areas affected...Western/Central/Eastern NY...Southern
VT...Western/Central MA...Northern CT
Concerning...Severe Thunderstorm Watch 395...
Valid 271801Z - 271930Z
The severe weather threat for Severe Thunderstorm Watch 395
continues.
SUMMARY...Threat for damaging wind gusts continues across western
and central NY. A downstream watch across eastern NY and adjacent
areas will likely be needed soon.
DISCUSSION...Radar and visible satellite imagery show two lines of
convection pushing across western and central NY. The lead line
extends from RME southwestward to ITH. The second line extends from
FZY southwestward to OLE. While initially stronger, the lead line
has been on a weakening trend for the past half hour. In contract,
the second has seen a gradual increase in intensity. This increase
in intensity appears to be associated with a modest increase in
instability and decrease in convective inhibition ahead of the line.
Additionally, new development has recently occurred over Cattaraugus
and Allegany Counties as the second line intersects the outflow of
the leading convective line. Deep westerly flow aloft will result in
fast storm motion as well as the potential for damaging wind gusts
as these storms continue eastward.
Current estimated storm motion is about 45 kt with the north end of
the line. As a result, it is expected to reach the edge of Severe
Thunderstorm Watch 395 around or before 19Z. Given the recent
trends, a downstream watch will likely be needed across more of
eastern NY and adjacent southern VT, western/central MA, and
northern CT.
..Mosier.. 07/27/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...BOX...ALY...BGM...BUF...CTP...
LAT...LON 43247776 43567687 43567597 43427488 42897280 41707313
41767567 41857726 42167875 43247776SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 27, 2:47 PM EDT | Severe Thunderstorm Watch | SPC | Capitol Planning Region, Northwest Hills Planning Region, Northeastern Connecticut Planning Region | 6 hr |
| Jul 27, 4:36 PM EDT | Mesoscale Discussion | SPC | 84 min | |
| Jul 27, 6:09 PM EDT | Mesoscale Discussion | SPC | 96 min | |
| Jul 27, 10:33 AM EDT | Mesoscale Discussion | SPC | Allegany, Cattaraugus, Cayuga, Erie, Genesee, Livingston and 9 more | 117 min |
| Jul 27, 11:12 AM EDT | Severe Thunderstorm Watch | SPC | Allegany, Broome, Cattaraugus, Cayuga, Chautauqua, Chemung and 23 more | 7 hr |
Nearby
Mesoscale Discussions in New York, 2021Mesoscale Discussions in Connecticut, 2021Mesoscale Discussions in Massachusetts, 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.