Alert archive / Virginia / Areal Flood Warnings in 2021

Areal Flood Warning 49, NWS Baltimore/Washington

June 15, 2021Fairfax County, Virginia

NWS Baltimore/Washington issued this areal flood warning at Jun 15, 2021, 2:05 AM EDT for Fairfax County, Virginia. It was in force for 4 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Jun 15, 2021, 2:05 AM EDT (06:05 UTC)
Expired
Jun 15, 2021, 6:01 AM EDT
In force
4 hr
Issued by
NWS Baltimore/Washington
Area
Storm-based polygon
Flood severity
None

County Fairfax County, VA

The radar

The Sterling radar (KLWX), 24 km from the middle of the area, began a volume at 06:08 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

Washington/Dulle, VA (KIAD), launched 00:00Z, 6.1 hours before the alert went out and 17 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-pSkew-T log-p diagram, Washington/Dulle, VA at 00:00Z on 2021-06-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 763 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 00:00Z on 2021-06-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 36 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
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
763 J/kg
Mixed-layer CIN
-21 J/kg
Mixed-layer LCL
1915 m above ground
0-6 km bulk shear
49 kt
0-1 km storm-relative helicity
36 m²/s²
0-3 km storm-relative helicity
130 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.4

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this areal flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Baltimore/Washington wrote its last area forecast discussion before this areal flood warning went out at Jun 14, 11:27 PM EDT, 2 hours 38 minutes earlier.

Area forecast discussion, Jun 14, 11:27 PM EDT, 2 hours 38 minutes before
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Hazardous weather outlook, Jun 15, 1:05 AM EDT, 1 hour before
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In the hours before

Local storm report, Jun 15, 12:11 AM EDT, 1 hour 54 minutes before
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Local storm report, Jun 15, 12:13 AM EDT, 1 hour 52 minutes before
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Local storm report, Jun 15, 12:17 AM EDT, 1 hour 48 minutes before
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Local storm report, Jun 15, 12:19 AM EDT, 1 hour 46 minutes before
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        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, Jun 15, 12:24 AM EDT, 1 hour 41 minutes before
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      <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.
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      <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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Local storm report, Jun 15, 12:29 AM EDT, 1 hour 36 minutes before
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      <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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The office that day

Everything else NWS Baltimore/Washington issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 14, 8:26 PM EDTSevere Thunderstorm WarningLWXFairfax, Loudoun, Prince William, City of Fairfax, City of Manassas, City of Manassas Park37 min
Jun 14, 9:01 PM EDTSpecial Marine WarningLWX46 min
Jun 14, 9:08 PM EDTSpecial Marine WarningLWX114 min
Jun 14, 9:55 PM EDTSevere Thunderstorm WarningLWXFairfax, Loudoun50 min
Jun 14, 10:07 PM EDTSpecial Marine WarningLWX83 min
Jun 14, 10:11 PM EDTSevere Thunderstorm WarningLWXArlington, Fairfax, Loudoun, Prince William, City of Alexandria, City of Fairfax49 min
Jun 14, 10:18 PM EDTSpecial Marine WarningLWX64 min
Jun 14, 10:25 PM EDTFlash Flood WatchLWXArlington, Fairfax, City of Alexandria, City of Fairfax, City of Falls Church4 hr
Jun 14, 10:30 PM EDTSevere Thunderstorm WarningLWXArlington, Fairfax, City of Falls Church45 min
Jun 14, 10:48 PM EDTSpecial Marine WarningLWX74 min
Jun 14, 10:49 PM EDTFlash Flood Warning Considerable damage threatLWXArlington, Fairfax, Prince William, City of Alexandria, City of Fairfax, City of Falls Church and 2 more3 hr
Jun 14, 11:11 PM EDTSpecial Marine WarningLWX36 min
Jun 15, 1:43 AM EDTAreal Flood WarningLWXArlington, Fairfax, City of Alexandria, City of Fairfax, City of Falls Church17 min
Jun 15, 1:53 AM EDTAreal Flood WarningLWXArlington, Fairfax, City of Alexandria, City of Fairfax, City of Falls Church4 hr
Jun 15, 6:08 AM EDTAreal Flood WarningLWXFairfax, City of Fairfax46 min
Jun 14, 9:02 PM EDTSevere Thunderstorm WarningLWXAnne Arundel, Baltimore, Carroll, Howard, City of Baltimore43 min
Jun 14, 9:22 PM EDTSevere Thunderstorm WarningLWXFrederick, Howard, Montgomery38 min
Jun 14, 9:29 PM EDTSevere Thunderstorm WarningLWXAnne Arundel, Baltimore, Harford, City of Baltimore46 min
Jun 14, 9:56 PM EDTSevere Thunderstorm WarningLWXAnne Arundel, Baltimore, Howard, City of Baltimore28 min
Jun 14, 10:05 PM EDTFlash Flood Warning Considerable damage threatLWXBaltimore, City of Baltimore2 hr
Jun 14, 10:12 PM EDTSevere Thunderstorm WarningLWXAnne Arundel, Baltimore, Harford33 min
Jun 14, 10:16 PM EDTSevere Thunderstorm WarningLWXAnne Arundel, Baltimore, City of Baltimore44 min
Jun 14, 11:23 PM EDTSevere Thunderstorm WarningLWXAnne Arundel24 min
Jun 15, 10:26 AM EDTAreal Flood WarningLWXPrince George's9 hr

Nearby

Areal Flood Warnings in Virginia, 2021Every areal flood warning in 2021

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.