Alert archive / Maryland / Areal Flood Advisories in 2015

Areal Flood Advisory 16, NWS Philadelphia/Mount Holly

May 18, 2015Queen Anne's County, Maryland

NWS Philadelphia/Mount Holly issued this areal flood advisory at May 18, 2015, 4:20 PM EDT for Queen Anne's County, Maryland. It was in force for 3 hr.

The area

The counties it named.

The facts

Issued: May 18, 2015, 4:20 PM EDT (20:20 UTC)
Expired: May 18, 2015, 7:15 PM EDT
In force: 3 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

County Queen Anne's County, MD

The radar

The Dover AFB radar (KDOX), 61 km from the middle of the area, began a volume at 20:04 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

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 8.3 hours before the alert went out and 48 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 615 J/kg
Mixed-layer CIN: -55 J/kg
Mixed-layer LCL: 962 m above ground
0-6 km bulk shear: 11 kt
0-1 km storm-relative helicity: 11 m²/s²
0-3 km storm-relative helicity: 32 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

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 May 18, 4:02 PM EDT, 18 minutes earlier.

Area forecast discussion, May 18, 4:02 PM EDT, 18 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>

Hazardous weather outlook, May 18, 4:04 PM EDT, 16 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>

In the hours before

Special weather statement, May 18, 2:25 PM EDT, 1 hour 55 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
225 PM EDT MON MAY 18 2015

DEZ003-181900-
INLAND SUSSEX-
225 PM EDT MON MAY 18 2015

...A STRONG THUNDERSTORM WILL AFFECT SOUTHWESTERN SUSSEX COUNTY...

AT 224 PM EDT...A STRONG THUNDERSTORM WAS OVER SYCAMORE...OR 10 MILES
SOUTHWEST OF GEORGETOWN. THE STORM WAS NEARLY STATIONARY.

WINDS IN EXCESS OF 40 MPH AND DIME SIZE HAIL ARE POSSIBLE WITH THIS
STORM.

LOCATIONS IMPACTED INCLUDE...
LAUREL AND SYCAMORE.

FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THIS STORM.
LIGHTNING CAN STRIKE 15 MILES AWAY FROM A THUNDERSTORM. SEEK A SAFE
SHELTER INSIDE A BUILDING OR VEHICLE.

LAT...LON 3860 7561 3868 7553 3854 7531 3845 7548
      3846 7548
TIME...MOT...LOC 1824Z 038DEG 3KT 3856 7550

Special weather statement, May 18, 3:28 PM EDT, 52 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
328 PM EDT MON MAY 18 2015

DEZ002-003-MDZ015-020-182030-
KENT-INLAND SUSSEX-CAROLINE-QUEEN ANNE'S-
328 PM EDT MON MAY 18 2015

...A STRONG THUNDERSTORM WILL AFFECT NORTHWESTERN SUSSEX...
SOUTHWESTERN KENT...NORTHEASTERN QUEEN ANNE'S AND NORTHEASTERN
CAROLINE COUNTIES...

AT 327 PM EDT...A STRONG THUNDERSTORM WAS OVER GOLDSBORO...OR 14
MILES EAST OF CENTERVILLE...MOVING EAST AT 10 MPH.

WINDS IN EXCESS OF 40 MPH AND HALF INCH HAIL ARE POSSIBLE WITH THIS
STORM.

LOCATIONS IMPACTED INCLUDE...
HARRINGTON...CAMDEN...GREENSBORO...GOLDSBORO...WOODSIDE...VIOLA...
ANDREWSVILLE...SANDTOWN...RISING SUN-LEBANON...RISING SUN...
HAZLETTVILLE...DOVER BASE HOUSING...WYOMING...FELTON...HENDERSON...
MARYDEL...TEMPLEVILLE...BARCLAY...RIVERVIEW AND WOODSIDE EAST.

TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THIS STORM...AND MAY CAUSE
LOCALIZED FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.

FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THIS STORM.
LIGHTNING CAN STRIKE 15 MILES AWAY FROM A THUNDERSTORM. SEEK A SAFE
SHELTER INSIDE A BUILDING OR VEHICLE.

LAT...LON 3909 7601 3919 7593 3911 7546 3883 7565
TIME...MOT...LOC 1927Z 281DEG 10KT 3904 7578

Special weather statement, May 18, 4:00 PM EDT, 20 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
May 18, 2:51 PM EDT	Areal Flood Advisory	PHI	Salem	3 hr
May 18, 2:01 PM EDT	Areal Flood Advisory	PHI	Chester	3 hr
May 18, 2:36 PM EDT	Areal Flood Advisory	PHI	Chester, Delaware	3 hr
May 18, 3:41 PM EDT	Areal Flood Advisory	PHI	Caroline	3 hr
May 18, 4:00 PM EDT	Special Weather Statement	PHI	Queen Anne's	30 min
May 18, 4:57 PM EDT	Areal Flood Advisory	PHI	Cecil, Kent	3 hr

Nearby

Areal Flood Advisories in Maryland, 2015 Every areal flood advisory in 2015

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.