Alert archive / Massachusetts / Mesoscale Discussions in 2023

Mesoscale Discussion 2145

September 13, 20237 counties in Massachusetts; 5 counties in Rhode Island

The Storm Prediction Center issued this mesoscale discussion at Sep 13, 2023, 11:14 AM EDT for 7 counties in Massachusetts; 5 counties in Rhode Island. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Sep 13, 2023, 11:14 AM EDT (15:14 UTC)
Expired
Sep 13, 2023, 1:15 PM EDT
In force
2 hr
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch possible
Chance of a watch
40%

Counties Barnstable County, MA, Bristol County, MA, Dukes County, MA, Essex County, MA, Norfolk County, MA, Plymouth County, MA, Suffolk County, MA, Bristol County, RI, Kent County, RI, Newport County, RI, Providence County, RI, Washington County, RI

The radar

The Boston radar (KBOX), 21 km from the middle of the area, began a volume at 15:16 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, 3.2 hours before the alert went out and 168 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 2023-09-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 488 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, Brookhaven, NY at 12:00Z on 2023-09-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 150 square meters per square second.193958Sfc1 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
488 J/kg
Mixed-layer CIN
-16 J/kg
Mixed-layer LCL
876 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
150 m²/s²
0-3 km storm-relative helicity
157 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.2

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 13, 8:10 AM EDTMesoscale DiscussionSPC95 min
Sep 13, 4:00 PM EDTMesoscale DiscussionSPC90 min

Nearby

Mesoscale Discussions in Massachusetts, 2023Mesoscale Discussions in Rhode Island, 2023Mesoscale Discussions in Connecticut, 2023Every mesoscale discussion in 2023

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.