Alert archive / New York / Mesoscale Discussions in 2018

Mesoscale Discussion 355

May 4, 20187 states

The Storm Prediction Center issued this mesoscale discussion at May 4, 2018, 5:52 PM EDT for 7 states. It was in force for 83 min.

The area

The outline as issued.

The facts

Issued
May 4, 2018, 5:52 PM EDT (21:52 UTC)
Expired
May 4, 2018, 7:15 PM EDT
In force
83 min
Issued by
the Storm Prediction Center
Chance of a watch
95%
All 42 counties

Berkshire County, MA, Franklin County, MA, Hampden County, MA, Hampshire County, MA, Middlesex County, MA, Norfolk County, MA, Worcester County, MA, Cheshire County, NH, Hillsborough County, NH, Bergen County, NJ, Morris County, NJ, Passaic County, NJ, Sussex County, NJ, Warren County, NJ, Albany County, NY, Columbia County, NY, Delaware County, NY, Dutchess County, NY, Greene County, NY, Montgomery County, NY, Orange County, NY, Otsego County, NY, Putnam County, NY, Rensselaer County, NY, Rockland County, NY, Saratoga County, NY, Schenectady County, NY, Schoharie County, NY, Sullivan County, NY, Ulster County, NY, Westchester County, NY, Carbon County, PA, Lackawanna County, PA, Luzerne County, PA, Monroe County, PA, Pike County, PA, Susquehanna County, PA, Wayne County, PA, Wyoming County, PA, Providence County, RI, Bennington County, VT, Windham County, VT

The radar

The Albany radar (KENX), 80 km from the middle of the area, began a volume at 21:55 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Albany, NY (KALY), launched 12:00Z, 9.9 hours before the alert went out and 86 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, Albany, NY at 12:00Z on 2018-05-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 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, Albany, NY at 12:00Z on 2018-05-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 48 square meters per square second.19395878Sfc1 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
812 m above ground
0-6 km bulk shear
53 kt
0-1 km storm-relative helicity
48 m²/s²
0-3 km storm-relative helicity
147 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

<!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.

IssuedProductOfficeCountiesLasted
May 4, 6:20 PM EDTSevere Thunderstorm WatchSPCCapitol Planning Region, Northwest Hills Planning Region4 hr
May 4, 2:18 PM EDTMesoscale DiscussionSPCBelknap, Carroll, Cheshire, Coos, Grafton, Merrimack and 1 more87 min
May 4, 6:48 PM EDTMesoscale DiscussionSPCCoos, Grafton117 min
May 4, 7:54 PM EDTMesoscale DiscussionSPCBelknap, Carroll, Coos, Grafton, Strafford3 hr
May 4, 1:04 PM EDTMesoscale DiscussionSPCCattaraugus, Chautauqua, Erie, Genesee, Livingston, Monroe and 1 more86 min
May 4, 2:23 PM EDTMesoscale DiscussionSPCAllegany, Cattaraugus, Cayuga, Chemung, Cortland, Erie and 17 more97 min
May 4, 2:44 PM EDTSevere Thunderstorm WatchSPCAllegany, Broome, Cattaraugus, Cayuga, Chautauqua, Chemung and 23 more6 hr
May 4, 3:16 PM EDTTornado WatchSPCClinton, Essex, Franklin, Fulton, Hamilton, Herkimer and 5 more6 hr
May 4, 4:20 PM EDTMesoscale DiscussionSPCAllegany, Broome, Cattaraugus, Cayuga, Chautauqua, Chemung and 21 more55 min
May 4, 1:22 PM EDTSevere Thunderstorm WatchSPCCrawford, Erie5 hr

Nearby

Mesoscale Discussions in New York, 2018Mesoscale Discussions in Pennsylvania, 2018Mesoscale Discussions in Massachusetts, 2018Every mesoscale discussion in 2018

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.