Alert archive / Pennsylvania / Mesoscale Discussions in 2017
Mesoscale Discussion 1625
The Storm Prediction Center issued this mesoscale discussion at Sep 5, 2017, 5:00 PM EDT for 5 states. It was in force for 90 min.
The area
The outline as issued.
The facts
- Issued
- Sep 5, 2017, 5:00 PM EDT (21:00 UTC)
- Expired
- Sep 5, 2017, 6:30 PM EDT
- In force
- 90 min
- Issued by
- the Storm Prediction Center
All 27 counties
New Castle County, DE, Baltimore County, MD, Carroll County, MD, Cecil County, MD, City of Baltimore, MD, Harford County, MD, Howard County, MD, Kent County, MD, Montgomery County, MD, Hunterdon County, NJ, Mercer County, NJ, Warren County, NJ, Berks County, PA, Bucks County, PA, Carbon County, PA, Chester County, PA, Delaware County, PA, Lancaster County, PA, Lebanon County, PA, Lehigh County, PA, Monroe County, PA, Montgomery County, PA, Northampton County, PA, Philadelphia County, PA, Schuylkill County, PA, York County, PA, Loudoun County, VA
The radar
The Sterling radar (KLWX), 127 km from the middle of the area, began a volume at 20:59 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 12:00Z, 9.0 hours before the alert went out and 124 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
- 4 J/kg
- Mixed-layer CIN
- -324 J/kg
- Mixed-layer LCL
- 1529 m above ground
- 0-6 km bulk shear
- 40 kt
- 0-1 km storm-relative helicity
- 8 m²/s²
- 0-3 km storm-relative helicity
- 79 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
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.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 5, 2:31 PM EDT | Mesoscale Discussion | SPC | Carroll, Frederick, Howard, Montgomery, Washington | 59 min |
| Sep 5, 3:26 PM EDT | Severe Thunderstorm Watch | SPC | Baltimore, Carroll, Cecil, Frederick, Harford, Howard and 3 more | 5 hr |
| Sep 4, 10:26 PM EDT | Mesoscale Discussion | SPC | Erie | 64 min |
Nearby
Mesoscale Discussions in Pennsylvania, 2017Mesoscale Discussions in Maryland, 2017Mesoscale Discussions in New Jersey, 2017Every mesoscale discussion in 2017
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.