Alert archive / Virginia / Flash Flood Warnings in 2018

Flash Flood Warning 86, NWS Baltimore/Washington

October 11, 2018Culpeper County, Orange County, Spotsylvania County, Virginia

NWS Baltimore/Washington issued this flash flood warning at Oct 11, 2018, 4:35 PM EDT for Culpeper County, Orange County, Spotsylvania County, Virginia. It was in force for 5 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
Oct 11, 2018, 4:35 PM EDT (20:35 UTC)
Expired
Oct 11, 2018, 9:15 PM EDT
In force
5 hr
Issued by
NWS Baltimore/Washington
Area
Storm-based polygon
Flood severity
None

Counties Culpeper County, VA, Orange County, VA, Spotsylvania County, VA

The radar

The Sterling radar (KLWX), 82 km from the middle of the area, began a volume at 20:36 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, 8.6 hours before the alert went out and 83 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 12:00Z on 2018-10-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 435 joules per kilogram.LCLEL10008507005003002001001 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 12:00Z on 2018-10-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 177 square meters per square second.193958Sfc1 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
435 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
461 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
177 m²/s²
0-3 km storm-relative helicity
187 m²/s²
Significant tornado parameter
0.3
Supercell composite
2.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this flash 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 flash flood warning went out at Oct 11, 3:33 PM EDT, 1 hour 2 minutes earlier.

Area forecast discussion, Oct 11, 3:33 PM EDT, 1 hour 2 minutes before
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Hazardous weather outlook, Oct 11, 9:18 AM EDT, 7 hours 17 minutes before
Hazardous Weather Outlook
National Weather Service Baltimore MD/Washington DC
918 AM EDT Thu Oct 11 2018

ANZ530>543-DCZ001-MDZ011-013-014-016>018-508-VAZ052>057-121000-
Chesapeake Bay north of Pooles Island MD-
Chesapeake Bay from Pooles Island to Sandy Point MD-
Chesapeake Bay from Sandy Point to North Beach MD-
Chesapeake Bay from North Beach to Drum Point MD-
Chesapeake Bay from Drum Point MD to Smith Point VA-
Tidal Potomac from Key Bridge to Indian Head MD-
Tidal Potomac from Indian Head to Cobb Island MD-
Tidal Potomac from Cobb Island MD to Smith Point VA-
Patapsco River including Baltimore Harbor-
Chester River to Queenstown MD-Eastern Bay-
Choptank River to Cambridge MD and the Little Choptank River-
Patuxent River to Broomes Island MD-
Tangier Sound and the inland waters surrounding Bloodsworth
Island-District of Columbia-Southern Baltimore-Prince Georges-
Anne Arundel-Charles-St. Marys-Calvert-Southeast Harford-
Prince William/Manassas/Manassas Park-Fairfax-
Arlington/Falls Church/Alexandria-Stafford-Spotsylvania-
King George-
918 AM EDT Thu Oct 11 2018

This Hazardous Weather Outlook is for the Maryland portion of the
Chesapeake Bay, Tidal Potomac River, and adjacent counties in
central Maryland and northern Virginia as well as the District of
Columbia.

.DAY ONE...Today and Tonight

A Flash Flood Watch is in effect for areas near and east of
Interstate 95 this afternoon and tonight. Isolated instances of
flooding are possible outside the watch area during this time.

A Wind Advisory is in effect for Saint Mary's and Calvert Counties
in southern Maryland tonight.

A Storm Warning is in effect for the lower tidal Potomac and lower
Maryland portion of the Chesapeake Bay tonight. A Gale Warning is
in effect for the remainder of the waters during this time.

An isolated tornado or waterspout is possible over far southern
Maryland this afternoon and this evening.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday

A Gale Warning is in effect for the waters Friday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

MDZ003>006-501>507-VAZ025>031-036>040-050-051-501>508-WVZ050>053-
055-501>506-121000-
Washington-Frederick MD-Carroll-Northern Baltimore-
Extreme Western Allegany-Central and Eastern Allegany-
Northwest Montgomery-Central and Southeast Montgomery-
Northwest Howard-Central and Southeast Howard-Northwest Harford-
Augusta-Rockingham-Shenandoah-Frederick VA-Page-Warren-Clarke-
Nelson-Albemarle-Greene-Madison-Rappahannock-Orange-Culpeper-
Northern Fauquier-Southern Fauquier-Western Highland-
Eastern Highland-Western Loudoun-Eastern Loudoun-
Northern Virginia Blue Ridge-Central Virginia Blue Ridge-
Hampshire-Morgan-Berkeley-Jefferson-Hardy-Western Grant-
Eastern Grant-Western Mineral-Eastern Mineral-Western Pendleton-
Eastern Pendleton-
918 AM EDT Thu Oct 11 2018

This Hazardous Weather Outlook is for eastern West Virginia,
northern and central Virginia, and central and western Maryland
with the exception of Garrett County.

.DAY ONE...Today and Tonight

A Flash Flood Watch is in effect for portions of central Virginia
this afternoon and tonight. Isolated instances of flooding are
possible outside the watch area during this time.

A Wind Advisory is in effect for the northern and central Virginia
Blue Ridge mountains tonight.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

In the hours before

Local storm report, Oct 11, 3:52 PM EDT, 43 minutes before
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The office that day

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

IssuedProductOfficeCountiesLasted
Oct 10, 8:29 PM EDTCoastal Flood AdvisoryLWXArlington, City of Alexandria, City of Falls Church4 hr
Oct 11, 2:49 AM EDTStorm WarningLWX25 hr
Oct 11, 3:12 AM EDTWind AdvisoryLWXAlbemarle, Amherst, Arlington, Augusta, Fairfax, Fauquier and 15 more29 hr
Oct 11, 1:52 PM EDTSmall Craft AdvisoryLWX36 hr
Oct 11, 2:56 PM EDTFlash Flood WarningLWXAlbemarle, Augusta, Nelson, City of Charlottesville, City of Waynesboro6 hr
Oct 11, 3:39 PM EDTSevere Thunderstorm WarningLWXCulpeper, Fauquier, Orange, Spotsylvania, Stafford34 min
Oct 11, 5:47 PM EDTAreal Flood WarningLWXPrince William4 hr
Oct 11, 6:23 PM EDTFlash Flood WarningLWXKing George, Prince William, Spotsylvania, Stafford, City of Fredericksburg3 hr
Oct 11, 6:51 PM EDTAreal Flood WarningLWXFairfax, City of Alexandria2 hr
Oct 11, 2:27 PM EDTCoastal Flood AdvisoryLWXBaltimore, City of Baltimore9 hr
Oct 11, 7:59 PM EDTAreal Flood WarningLWXCharles, Prince George's24 hr

Nearby

Flash Flood Warnings in Virginia, 2018Every flash flood warning in 2018

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.