Alert archive / Massachusetts / Mesoscale Discussions in 2014

Mesoscale Discussion 1390

July 15, 20144 states

The Storm Prediction Center issued this mesoscale discussion at Jul 15, 2014, 1:51 PM EDT for 4 states. It was in force for 114 min.

The area

The outline as issued.

The facts

Issued: Jul 15, 2014, 1:51 PM EDT (17:51 UTC)
Expired: Jul 15, 2014, 3:45 PM EDT
In force: 114 min
Issued by: the Storm Prediction Center
Chance of a watch: 60%

All 23 counties

Barnstable County, MA, Bristol County, MA, Dukes County, MA, Essex County, MA, Franklin County, MA, Hampden County, MA, Hampshire County, MA, Middlesex County, MA, Norfolk County, MA, Plymouth County, MA, Suffolk County, MA, Worcester County, MA, Cheshire County, NH, Hillsborough County, NH, Merrimack County, NH, Rockingham County, NH, Sullivan County, NH, Suffolk County, NY, Bristol County, RI, Kent County, RI, Newport County, RI, Providence County, RI, Washington County, RI

The radar

The Boston radar (KBOX), 50 km from the middle of the area, began a volume at 17:51 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, 5.9 hours before the alert went out and 152 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 143 J/kg
Mixed-layer CIN: -132 J/kg
Mixed-layer LCL: 732 m above ground
0-6 km bulk shear: 19 kt
0-1 km storm-relative helicity: 54 m²/s²
0-3 km storm-relative helicity: 83 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.

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 15, 1:43 PM EDT	Severe Thunderstorm Watch	SPC	Greater Bridgeport Planning Region, Naugatuck Valley Planning Region	7 hr
Jul 15, 4:41 PM EDT	Mesoscale Discussion	SPC		94 min
Jul 15, 7:04 PM EDT	Mesoscale Discussion	SPC		56 min
Jul 15, 1:23 PM EDT	Mesoscale Discussion	SPC	Bronx, Kings, Nassau, New York, Queens, Richmond	97 min

Nearby

Mesoscale Discussions in Massachusetts, 2014 Mesoscale Discussions in Connecticut, 2014 Mesoscale Discussions in New Hampshire, 2014 Every 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.