Alert archive / Massachusetts / Mesoscale Discussions in 2016

Mesoscale Discussion 1540

August 16, 20167 counties in Massachusetts; 4 counties in Rhode Island

The Storm Prediction Center issued this mesoscale discussion at Aug 16, 2016, 12:52 PM EDT for 7 counties in Massachusetts; 4 counties in Rhode Island. It was in force for 53 min.

The area

The outline as issued.

The facts

Issued
Aug 16, 2016, 12:52 PM EDT (16:52 UTC)
Expired
Aug 16, 2016, 1:45 PM EDT
In force
53 min
Issued by
the Storm Prediction Center
Chance of a watch
40%

Counties Bristol County, MA, Hampden County, MA, Hampshire County, MA, Middlesex County, MA, Norfolk County, MA, Suffolk County, MA, Worcester County, MA, Bristol County, RI, Kent County, RI, Providence County, RI, Washington County, RI

The radar

The Boston radar (KBOX), 83 km from the middle of the area, began a volume at 16:54 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, 4.9 hours before the alert went out and 129 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 2016-08-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1793 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 2016-08-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 69 square meters per square second.1939Sfc1 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
1793 J/kg
Mixed-layer CIN
-14 J/kg
Mixed-layer LCL
635 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
69 m²/s²
0-3 km storm-relative helicity
125 m²/s²
Significant tornado parameter
0.5
Supercell composite
3.5

Open this sounding in Storm Lab

The text

As transmitted.

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Nearby

Mesoscale Discussions in Massachusetts, 2016Mesoscale Discussions in Rhode Island, 2016Mesoscale Discussions in Connecticut, 2016Every mesoscale discussion in 2016

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.