Alert archive / Connecticut / Mesoscale Discussions in 2024

Mesoscale Discussion 708

May 8, 20247 counties in Massachusetts; Dutchess County, Putnam County, Westchester County, New York; 5 counties in Rhode Island

The Storm Prediction Center issued this mesoscale discussion at May 8, 2024, 4:44 PM EDT for 7 counties in Massachusetts; Dutchess County, Putnam County, Westchester County, New York; 5 counties in Rhode Island. It was in force for 91 min.

The area

The outline as issued.

The facts

Issued
May 8, 2024, 4:44 PM EDT (20:44 UTC)
Expired
May 8, 2024, 6:15 PM EDT
In force
91 min
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch unlikely
Chance of a watch
20%

Counties Bristol County, MA, Hampden County, MA, Hampshire County, MA, Middlesex County, MA, Norfolk County, MA, Suffolk County, MA, Worcester County, MA, Dutchess County, NY, Putnam County, NY, Westchester County, NY, Bristol County, RI, Kent County, RI, Newport County, RI, Providence County, RI, Washington County, RI

The radar

The Brookhaven radar (KOKX), 93 km from the middle of the area, began a volume at 20:47 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, 8.7 hours before the alert went out and 93 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, Brookhaven, NY at 12:00Z on 2024-05-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 78 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Brookhaven, NY at 12:00Z on 2024-05-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 27 square meters per square second.19395878Sfc1 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
78 J/kg
Mixed-layer CIN
-106 J/kg
Mixed-layer LCL
791 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
27 m²/s²
0-3 km storm-relative helicity
81 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted.

437 
ACUS11 KWNS 082044
SWOMCD
SPC MCD 082044 
MAZ000-RIZ000-CTZ000-NYZ000-082215-

Mesoscale Discussion 0708
NWS Storm Prediction Center Norman OK
0344 PM CDT Wed May 08 2024

Areas affected...southern New England

Concerning...Severe potential...Watch unlikely 

Valid 082044Z - 082215Z

Probability of Watch Issuance...20 percent

SUMMARY...The threat for large hail and damaging wind gusts
continues across southern New England.

DISCUSSION...A large supercell has developed in southern
Massachusetts where temperatures have warmed into the mid 70s with
dewpoints in the mid 60s. This has yielded 500 to 750 J/kg MLCAPE.
Despite this relatively weak instability, storm organization due to
70 knots of 0-6km shear (per BOX VWP), has been sufficient for
supercell maintenance. This intense storm will continue to pose a
severe wind and large hail threat as it moves east and the
downstream environment continues to destabilize ahead of it. In
addition, some storms are starting to develop to the west of this
supercell on the trailing outflow. Given a similarly warm and
unstable environment, one or two more strong to severe storms may
form and move along this outflow boundary this afternoon/evening.

..Bentley/Smith.. 05/08/2024

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

ATTN...WFO...BOX...OKX...ALY...

LAT...LON   41887391 42287322 42597149 42417095 41847080 41447076
            41387114 41127173 41087259 41007341 41097377 41297399
            41887391

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 8, 2:23 PM EDTMesoscale DiscussionSPC2 hr

Nearby

Mesoscale Discussions in Connecticut, 2024Mesoscale Discussions in Massachusetts, 2024Mesoscale Discussions in Rhode Island, 2024Every mesoscale discussion in 2024

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.