Alert archive / Pennsylvania / Mesoscale Discussions in 2016

Mesoscale Discussion 1394

July 25, 20164 states

The Storm Prediction Center issued this mesoscale discussion at Jul 25, 2016, 12:41 PM EDT for 4 states. It was in force for 64 min.

The area

The outline as issued.

The facts

Issued
Jul 25, 2016, 12:41 PM EDT (16:41 UTC)
Expired
Jul 25, 2016, 1:45 PM EDT
In force
64 min
Issued by
the Storm Prediction Center
Chance of a watch
95%
All 52 counties

Allegany County, MD, Carroll County, MD, Frederick County, MD, Garrett County, MD, Washington County, MD, Adams County, PA, Allegheny County, PA, Armstrong County, PA, Beaver County, PA, Bedford County, PA, Berks County, PA, Blair County, PA, Butler County, PA, Cambria County, PA, Centre County, PA, Clarion County, PA, Clearfield County, PA, Clinton County, PA, Columbia County, PA, Cumberland County, PA, Dauphin County, PA, Fayette County, PA, Franklin County, PA, Fulton County, PA, Greene County, PA, Huntingdon County, PA, Indiana County, PA, Jefferson County, PA, Juniata County, PA, Lancaster County, PA, Lebanon County, PA, Mifflin County, PA, Montour County, PA, Northumberland County, PA, Perry County, PA, Schuylkill County, PA, Snyder County, PA, Somerset County, PA, Union County, PA, Washington County, PA, Westmoreland County, PA, York County, PA, Frederick County, VA, Berkeley County, WV, Brooke County, WV, Hampshire County, WV, Hancock County, WV, Jefferson County, WV, Mineral County, WV, Monongalia County, WV, Morgan County, WV, Preston County, WV

The radar

The State College radar (KCCX), 79 km from the middle of the area, began a volume at 16:43 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

Pittsburgh, PA (KAGC), launched 12:00Z, 4.7 hours before the alert went out and 133 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, Pittsburgh, PA at 12:00Z on 2016-07-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1271 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, Pittsburgh, PA at 12:00Z on 2016-07-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 54 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
1271 J/kg
Mixed-layer CIN
-42 J/kg
Mixed-layer LCL
1043 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
54 m²/s²
0-3 km storm-relative helicity
93 m²/s²
Significant tornado parameter
0.2
Supercell composite
1.4

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
Jul 25, 3:05 PM EDTMesoscale DiscussionSPCAnne Arundel, Baltimore, Calvert, Caroline, Charles, Dorchester and 12 more115 min
Jul 25, 3:30 PM EDTSevere Thunderstorm WatchSPCAllegany, Anne Arundel, Baltimore, Calvert, Caroline, Carroll and 13 more6 hr
Jul 25, 5:02 PM EDTMesoscale DiscussionSPCAllegany, Anne Arundel, Baltimore, Calvert, Caroline, Carroll and 13 more88 min
Jul 25, 7:06 PM EDTMesoscale DiscussionSPCAllegany, Anne Arundel, Baltimore, Calvert, Caroline, Carroll and 14 more84 min
Jul 25, 10:51 AM EDTMesoscale DiscussionSPCBradford, Cameron, Clarion, Clinton, Crawford, Elk and 13 more114 min
Jul 25, 12:43 PM EDTSevere Thunderstorm WatchSPCAdams, Armstrong, Bedford, Berks, Blair, Bradford and 51 more7 hr
Jul 25, 3:03 PM EDTMesoscale DiscussionSPCAdams, Allegheny, Armstrong, Bedford, Berks, Blair and 54 more57 min
Jul 25, 4:52 PM EDTMesoscale DiscussionSPCAdams, Allegheny, Armstrong, Bedford, Berks, Blair and 51 more83 min

Nearby

Mesoscale Discussions in Pennsylvania, 2016Mesoscale Discussions in West Virginia, 2016Mesoscale Discussions in Maryland, 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.