Alert archive / Pennsylvania / Dense Fog Advisories in 2025

Dense Fog Advisory 1, NWS Philadelphia/Mount Holly

January 1, 20254 counties in New Jersey; 5 counties in Pennsylvania; New Castle County, Delaware

NWS Philadelphia/Mount Holly issued this dense fog advisory at Jan 1, 2025, 2:28 AM EST for 4 counties in New Jersey; 5 counties in Pennsylvania; New Castle County, Delaware. It was in force for 3 hr.

The area

The counties it named.

The facts

Issued: Jan 1, 2025, 2:28 AM EST (07:28 UTC)
Expired: Jan 1, 2025, 5:32 AM EST
In force: 3 hr
Issued by: NWS Philadelphia/Mount Holly

Counties New Castle County, DE, Burlington County, NJ, Camden County, NJ, Gloucester County, NJ, Salem County, NJ, Bucks County, PA, Chester County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 72 km from the middle of the area, began a volume at 07:28 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.

What forecasters said that day

The local office's own words before this dense fog 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 dense fog advisory went out at Jan 1, 1:30 AM EST, 58 minutes earlier.

Area forecast discussion, Jan 1, 1:30 AM EST, 58 minutes before

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In the hours before

Local storm report, Dec 31, 8:54 PM EST, 5 hours 34 minutes before

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<body>
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    <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.
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Local storm report, Dec 31, 9:01 PM EST, 5 hours 27 minutes before

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<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>
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Local storm report, Dec 31, 9:02 PM EST, 5 hours 26 minutes before

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<head>
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  <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>

Local storm report, Dec 31, 9:54 PM EST, 4 hours 34 minutes before

<!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>

The office that day

Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Dec 31, 7:06 PM EST	Special Marine Warning	PHI		54 min
Dec 31, 8:03 PM EST	Special Marine Warning	PHI		57 min
Dec 31, 8:54 PM EST	Special Marine Warning	PHI		66 min
Dec 31, 9:52 PM EST	Special Marine Warning	PHI		21 min
Dec 31, 7:15 PM EST	Severe Thunderstorm Warning	PHI	Kent, New Castle, Sussex	22 min

Nearby

Dense Fog Advisories in Pennsylvania, 2025 Dense Fog Advisories in New Jersey, 2025 Dense Fog Advisories in Delaware, 2025 Every dense fog advisory in 2025

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; radar from the NEXRAD Level II archive.