Alert archive / Virginia / Severe Thunderstorm Warnings in 2000

Severe Thunderstorm Warning 201, NWS Baltimore/Washington

July 16, 2000Fairfax County, Loudoun County, Virginia

NWS Baltimore/Washington issued this severe thunderstorm warning at Jul 16, 2000, 6:41 PM EDT for Fairfax County, Loudoun County, Virginia. It was in force for 49 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Jul 16, 2000, 6:41 PM EDT (22:41 UTC)
Expired
Jul 16, 2000, 7:30 PM EDT
In force
49 min
Issued by
NWS Baltimore/Washington
Area
Whole counties

Counties Fairfax County, VA, Loudoun County, VA

The radar

The Sterling radar (KLWX), 3 km from the middle of the area, began a volume at 22:42 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 was reported inside it

TimeReportWhereRemark
Jul 16, 7:05 PM EDTThunderstorm WindLeesburg, VATrees were downed onto White's Ferry Road.

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 10.7 hours before the alert went out and 5 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 2000-07-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 780 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 12:00Z on 2000-07-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -1 square meters per square second.1939Sfc1 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
780 J/kg
Mixed-layer CIN
-44 J/kg
Mixed-layer LCL
885 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
-1 m²/s²
0-3 km storm-relative helicity
53 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
WUUS51 KLWX 162242
SVRWBC
VAC059-107-162330-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE BALTIMORE-WASHINGTON
641 PM EDT SUN JUL 16 2000

THE NATIONAL WEATHER SERVICE IN STERLING VIRGINIA HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHERN FAIRFAX COUNTY IN NORTHERN VIRGINIA
  NORTHERN AND EASTERN LOUDOUN COUNTY IN NORTHERN VIRGINIA

* UNTIL 730 PM EDT

* AT 637 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM OVER HERNDON...MOVING NORTHEAST AT 10 MPH.

* THE SEVERE THUNDERSTORM WILL BE...
  4 MILES NORTHWEST OF GREAT FALLS AT 648 PM

IF SEVERE WEATHER APPROACHES YOUR AREA...GO INSIDE A STURDY SHELTER
AWAY FROM CREEK BEDS AND OTHER FLOOD-PRONE AREAS. REMEMBER...A SEVERE
THUNDERSTORM CAN PRODUCE LARGE DAMAGING HAIL...DAMAGING WINDS IN
EXCESS OF 55 MPH...DEADLY LIGHTNING...AND VERY HEAVY RAIN.

HAIL UP TO DIME SIZE HAS BEEN REPORTED WITH THIS STORM IN STERLING AT
635 PM. IF YOU ARE IN THE PATH OF THE STORM...PUT YOUR CAR IN A GARAGE 
AND MOVE TO A SUBSTANTIAL SHELTER.

AS THE STORM APPROACHES MOVE TO A PLACE OF SAFETY. TUNE INTO NOAA
WEATHER RADIO OR YOUR LOCAL RADIO OR TV STATION FOR THE LATEST
WEATHER INFORMATION.

JLW

What forecasters said that day

The local office's own words before this severe thunderstorm 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 severe thunderstorm warning went out at Jul 16, 2:40 PM EDT, 4 hours 1 minute earlier.

Area forecast discussion, Jul 16, 2:40 PM EDT, 4 hours 1 minute before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE/WASHINGTON
240 PM EDT SUN JUL 16 2000

SCATTERED SHOWERS AND THUNDERSTORMS ACROSS THE LWX CWA AT TIME... A
LITTLE STRONGER AND BETTER ORGANIZED OVER THE EAST THAN THE WEST. UPPER
LOW STILL ROTATING JUST TO OUR NORTHWEST... AND ASSOCIATED THERMAL
TROUGH SHOULD KEEP STORMS FIRING THROUGH THE EVENING HOURS. 12Z ETA/NGM
AND AVN ALL AGREE IN FILLING IN UPPER LOW A BIT... AND EJECTING IT OFF
TO THE ENE AS THE NIGHT GOES ON.  FEEL THAT PRECIP SHOULD COME TO AN
END BY THE MIDNIGHT HOUR FOR THE FAR WEST... AND OVERNIGHT FOR CHO AND
DCA.  NGM/AVN STILL HAVE 700 MB TROUGH OVER THE COUNTIES ALONG THE BAY
AT 12Z TOMORROW... SO WILL ADD A CHANCE OF EARLY MORNING SHOWERS FROM
BWI TO NHK.

W/NW FLOW BUILDING IN FOR A WHILE TOMORROW SHOULD DRY THINGS OUT A
LITTLE BIT AT THE SURFACE... WHILE INCREASING MID LEVEL TEMPS PUT A CAP
TO ANY AFTERNOON CONVECTION. EXPECTING A MOSTLY CLEAR NIGHT MONDAY
NIGHT.

A WEAK COLD FRONT WILL DROP DOWN THROUGH THE AREA LATE ON TUESDAY.
FWC/FAN GUIDANCE POPS RATHER LOW.. BUT MODEL SOUNDINGS INDICATE A
MODERATELY UNSTABLE ATMOSPHERE IN PLACE IN THE AFTERNOON... AT LEAST
UNSTABLE ENOUGH TO KEEP A MENTION OF SHOWERS AND STORMS ALONG WITH THE
COLD FRONT.

FWC TEMPS WARM PRETTY QUICKLY OVER THE NEXT COUPLE OF DAYS.. WHILE FAN
TEMPS A LITTLE LESS AGRESSIVE. WILL STICK CLOSER TO FAN TEMPS.

.LWX...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.

MARGRAF!

Nearby

Severe Thunderstorm Warnings in Virginia, 2000Every severe thunderstorm warning in 2000

Sources

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