Alert archive / Massachusetts / Mesoscale Discussions in 2014

Mesoscale Discussion 1300

July 7, 2014Cumberland County, Sagadahoc County, York County, Maine; 4 counties in Massachusetts; Rockingham County, New Hampshire

The Storm Prediction Center issued this mesoscale discussion at Jul 7, 2014, 5:42 PM EDT for Cumberland County, Sagadahoc County, York County, Maine; 4 counties in Massachusetts; Rockingham County, New Hampshire. It was in force for 63 min.

The area

The outline as issued.

The facts

Issued
Jul 7, 2014, 5:42 PM EDT (21:42 UTC)
Expired
Jul 7, 2014, 6:45 PM EDT
In force
63 min
Issued by
the Storm Prediction Center
Chance of a watch
20%

Counties Essex County, MA, Middlesex County, MA, Suffolk County, MA, Worcester County, MA, Cumberland County, ME, Sagadahoc County, ME, York County, ME, Rockingham County, NH

The radar

The Portland,ME radar (KGYX), 94 km from the middle of the area, began a volume at 21:42 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

Chatham, MA (KCHH), launched 12:00Z, 9.7 hours before the alert went out and 172 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, Chatham, MA at 12:00Z on 2014-07-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Chatham, MA at 12:00Z on 2014-07-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 55 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1151 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
55 m²/s²
0-3 km storm-relative helicity
60 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
Jul 7, 12:46 PM EDTMesoscale DiscussionSPCBerkshire, Franklin, Hampden, Hampshire, Middlesex, Worcester89 min
Jul 7, 4:44 PM EDTMesoscale DiscussionSPCBerkshire91 min
Jul 7, 6:41 PM EDTMesoscale DiscussionSPCBerkshire, Franklin, Hampden, Hampshire64 min

Nearby

Mesoscale Discussions in Massachusetts, 2014Mesoscale Discussions in Maine, 2014Mesoscale Discussions in New Hampshire, 2014Every mesoscale discussion in 2014

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.