Alert archive / Pennsylvania / Areal Flood Advisories in 2020
Areal Flood Advisory 174, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this areal flood advisory at Sep 10, 2020, 3:07 PM EDT for Berks County, Lehigh County, Montgomery County, Pennsylvania. It was in force for 3 hr.
The area
The counties it named.
The facts
- Issued
- Sep 10, 2020, 3:07 PM EDT (19:07 UTC)
- Expired
- Sep 10, 2020, 6:26 PM EDT
- In force
- 3 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
Counties Berks County, PA, Lehigh County, PA, Montgomery County, PA
The radar
The Philadelphia radar (KDIX), 116 km from the middle of the area, began a volume at 19:08 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
Wallops Is Stn, VA (KWAL), launched 12:00Z, 7.1 hours before the alert went out and 277 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
- 1088 J/kg
- Mixed-layer CIN
- -15 J/kg
- Mixed-layer LCL
- 575 m above ground
- 0-6 km bulk shear
- 31 kt
- 0-1 km storm-relative helicity
- 142 m²/s²
- 0-3 km storm-relative helicity
- 167 m²/s²
- Significant tornado parameter
- 0.5
- Supercell composite
- 3.9
What forecasters said that day
The local office's own words before this areal flood advisory went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Philadelphia/Mount Holly wrote its last area forecast discussion before this areal flood advisory went out at Sep 10, 10:53 AM EDT, 4 hours 14 minutes earlier.
Area forecast discussion, Sep 10, 10:53 AM EDT, 4 hours 14 minutes before
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</html>Hazardous weather outlook, Sep 10, 3:40 AM EDT, 11 hours 27 minutes before
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<link rel="stylesheet" href="index.css">
</head>
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<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.
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<p class="small" id="detail">
If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
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</html>The office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 10, 4:39 AM EDT | Areal Flood Advisory | PHI | Atlantic, Cape May | 2 hr |
| Sep 10, 2:48 PM EDT | Small Craft Advisory | PHI | 6 days | |
| Sep 10, 4:08 PM EDT | Areal Flood Advisory | PHI | Camden, Cumberland, Gloucester, Salem | 4 hr |
| Sep 10, 5:04 PM EDT | Areal Flood Advisory | PHI | Hunterdon, Somerset | 3 hr |
| Sep 10, 7:31 PM EDT | Areal Flood Advisory | PHI | Mercer, Middlesex, Somerset | 101 min |
Nearby
Areal Flood Advisories in Pennsylvania, 2020Every areal flood advisory in 2020
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.