Alert archive / New York / Mesoscale Discussions in 2021

Mesoscale Discussion 1873

October 16, 2021Berkshire County, Massachusetts; 13 counties in New York; 11 counties in Vermont

The Storm Prediction Center issued this mesoscale discussion at Oct 16, 2021, 2:55 PM EDT for Berkshire County, Massachusetts; 13 counties in New York; 11 counties in Vermont. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued
Oct 16, 2021, 2:55 PM EDT (18:55 UTC)
Expired
Oct 16, 2021, 4:30 PM EDT
In force
95 min
Issued by
the Storm Prediction Center
Concerning
Severe thunderstorm watch 529
All 25 counties

Berkshire County, MA, Albany County, NY, Columbia County, NY, Delaware County, NY, Dutchess County, NY, Greene County, NY, Rensselaer County, NY, Saratoga County, NY, Schenectady County, NY, Schoharie County, NY, Sullivan County, NY, Ulster County, NY, Warren County, NY, Washington County, NY, Addison County, VT, Bennington County, VT, Chittenden County, VT, Franklin County, VT, Grand Isle 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), 87 km from the middle of the area, began a volume at 18:57 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, 6.9 hours before the alert went out and 71 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.

Skew-T log-pSkew-T log-p diagram, Albany, NY at 12:00Z on 2021-10-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 50 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Albany, NY at 12:00Z on 2021-10-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 279 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
50 J/kg
Mixed-layer CIN
-197 J/kg
Mixed-layer LCL
735 m above ground
0-6 km bulk shear
49 kt
0-1 km storm-relative helicity
279 m²/s²
0-3 km storm-relative helicity
291 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.4

Open this sounding in Storm Lab

The text

As transmitted.

718 
ACUS11 KWNS 161856
SWOMCD
SPC MCD 161855 
VTZ000-MAZ000-CTZ000-NYZ000-PAZ000-162030-

Mesoscale Discussion 1873
NWS Storm Prediction Center Norman OK
0155 PM CDT Sat Oct 16 2021

Areas affected...Western NY...Much of VT...Far Western MA...Far
Western CT

Concerning...Severe Thunderstorm Watch 529...

Valid 161855Z - 162030Z

The severe weather threat for Severe Thunderstorm Watch 529
continues.

SUMMARY...Threat for damaging wind gusts and maybe a brief tornado
will continue across the region for the next hour or two.

DISCUSSION...Shallow convective line extending from the northernmost
NY/VT border to the NY Hudson Valley continues to move
east-northeastward at about 30-35 kt. Only modest changes in the
thermodynamic environment preceding the line have occurred over the
past hour or so, with much of the area still characterized by
temperatures in the mid/upper 70s and dewpoints in the low/mid 60s.
A pocket of somewhat higher low-level moisture exists across far
northern VT, where mesoanalysis estimated MLCAPE is around 500 J/kg.
Additionally, the wind profile across the region remains supportive
of low-level rotation, particularly across northern VT. Recent VAD
from CXX sampled over 350 m2/s2 of 0-1 km storm-relative helicity
and over 500 m2/s2 of 0-3 km storm-relative helicity. These
conditions suggest the threat for damaging wind gusts and maybe even
a brief tornado will continue for the next hour or two before
limited instability likely leads to a diminished threat across New
England.

..Mosier.. 10/16/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...BOX...BTV...OKX...ALY...BGM...

LAT...LON   42127506 43137423 43787377 44507356 44797362 44997319
            44977252 44297228 42247291 41597341 41437527 42127506

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Oct 16, 12:35 PM EDTSevere Thunderstorm WatchSPCNorthwest Hills Planning Region6 hr
Oct 16, 5:39 PM EDTMesoscale DiscussionSPC2 hr
Oct 16, 12:09 PM EDTMesoscale DiscussionSPCBerkshire2 hr
Oct 16, 11:06 AM EDTMesoscale DiscussionSPCBroome, Chenango, Cortland, Delaware, Madison, Otsego and 2 more114 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.