Alert archive / Connecticut / Mesoscale Discussions in 2013

Mesoscale Discussion 759

May 21, 2013Washington County, Rhode Island

The Storm Prediction Center issued this mesoscale discussion at May 21, 2013, 6:09 PM EDT for Washington County, Rhode Island. It was in force for 66 min.

The area

The outline as issued.

The facts

Issued
May 21, 2013, 6:09 PM EDT (22:09 UTC)
Expired
May 21, 2013, 7:15 PM EDT
In force
66 min
Issued by
the Storm Prediction Center
Chance of a watch
20%

County Washington County, RI

The radar

The Brookhaven radar (KOKX), 62 km from the middle of the area, began a volume at 22:09 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, 10.2 hours before the alert went out and 62 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 2013-05-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 267 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 2013-05-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 59 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
267 J/kg
Mixed-layer CIN
-122 J/kg
Mixed-layer LCL
734 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
59 m²/s²
0-3 km storm-relative helicity
64 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 21, 12:54 PM EDTMesoscale DiscussionSPC66 min
May 21, 1:40 PM EDTSevere Thunderstorm WatchSPCNorthwest Hills Planning Region10 hr
May 21, 2:03 PM EDTSevere Thunderstorm WatchSPCCapitol Planning Region, Northeastern Connecticut Planning Region7 hr
May 21, 4:37 PM EDTMesoscale DiscussionSPC53 min

Nearby

Mesoscale Discussions in Connecticut, 2013Mesoscale Discussions in Rhode Island, 2013Every mesoscale discussion in 2013

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.