Alert archive / Pennsylvania / Mesoscale Discussions in 2014
Mesoscale Discussion 1493
The Storm Prediction Center issued this mesoscale discussion at Jul 27, 2014, 9:39 PM EDT for 5 states. It was in force for 66 min.
The area
The outline as issued.
The facts
- Issued
- Jul 27, 2014, 9:39 PM EDT (01:39 UTC)
- Expired
- Jul 27, 2014, 10:45 PM EDT
- In force
- 66 min
- Issued by
- the Storm Prediction Center
All 59 counties
Allegany County, MD, Frederick County, MD, Washington County, MD, Hunterdon County, NJ, Sussex County, NJ, Warren County, NJ, Adams County, PA, Bedford County, PA, Berks County, PA, Blair County, PA, Bradford County, PA, Bucks County, PA, Cambria County, PA, Cameron County, PA, Carbon County, PA, Centre County, PA, Chester County, PA, Clearfield County, PA, Clinton County, PA, Columbia County, PA, Cumberland County, PA, Dauphin County, PA, Elk County, PA, Franklin County, PA, Fulton County, PA, Huntingdon County, PA, Juniata County, PA, Lackawanna County, PA, Lancaster County, PA, Lebanon County, PA, Lehigh County, PA, Luzerne County, PA, Lycoming County, PA, McKean County, PA, Mifflin County, PA, Monroe County, PA, Montgomery County, PA, Montour County, PA, Northampton County, PA, Northumberland County, PA, Perry County, PA, Pike County, PA, Potter County, PA, Schuylkill County, PA, Snyder County, PA, Somerset County, PA, Sullivan County, PA, Susquehanna County, PA, Tioga County, PA, Union County, PA, Wayne County, PA, Wyoming County, PA, York County, PA, Frederick County, VA, Berkeley County, WV, Hampshire County, WV, Hardy County, WV, Jefferson County, WV, Morgan County, WV
The radar
The State College radar (KCCX), 102 km from the middle of the area, began a volume at 01:39 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
Washington/Dulle, VA (KIAD), launched 00:00Z, 1.7 hours before the alert went out and 140 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.
- Mixed-layer CAPE
- 1013 J/kg
- Mixed-layer CIN
- -35 J/kg
- Mixed-layer LCL
- 1007 m above ground
- 0-6 km bulk shear
- 43 kt
- 0-1 km storm-relative helicity
- 67 m²/s²
- 0-3 km storm-relative helicity
- 103 m²/s²
- Significant tornado parameter
- 0.3
- Supercell composite
- 2.7
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 27, 11:28 PM EDT | Mesoscale Discussion | SPC | Calvert, Caroline, Charles, Dorchester, Queen Anne's, Saint Mary's and 3 more | 2 hr |
| Jul 27, 8:49 PM EDT | Mesoscale Discussion | SPC | Allegheny, Armstrong, Beaver, Butler, Clarion, Crawford and 9 more | 86 min |
| Jul 27, 8:00 PM EDT | Tornado Watch | SPC | Buchanan, Dickenson, Lee, Russell, Scott, Washington and 3 more | 5 hr |
| Jul 27, 9:28 PM EDT | Tornado Watch | SPC | Albemarle, Alleghany, Augusta, Bath, Greene, Highland and 13 more | 4 hr |
Nearby
Mesoscale Discussions in Pennsylvania, 2014Mesoscale Discussions in West Virginia, 2014Mesoscale Discussions in Maryland, 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.