Alert archive / Virginia / Flash Flood Warnings in 2000

Flash Flood Warning 35, NWS Baltimore/Washington

September 3, 2000Arlington County, City of Alexandria, City of Falls Church, Virginia

NWS Baltimore/Washington issued this flash flood warning at Sep 3, 2000, 6:04 PM EDT for Arlington County, City of Alexandria, City of Falls Church, Virginia. It was in force for 56 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties.

The facts

Issued: Sep 3, 2000, 6:04 PM EDT (22:04 UTC)
Expired: Sep 3, 2000, 7:00 PM EDT
In force: 56 min
Issued by: NWS Baltimore/Washington
Area: Whole counties; the outline is the Mesonet’s reconstruction

Counties Arlington County, VA, City of Alexandria, VA, City of Falls Church, VA

The radar

The Sterling radar (KLWX), 40 km from the middle of the area, began a volume at 22:04 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

Washington/Dulle, VA (KIAD), launched 12:00Z, 10.1 hours before the alert went out and 31 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: 643 J/kg
Mixed-layer CIN: -31 J/kg
Mixed-layer LCL: 658 m above ground
0-6 km bulk shear: 8 kt
0-1 km storm-relative helicity: 18 m²/s²
0-3 km storm-relative helicity: 39 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 
WGUS51 KLWX 032205
FFWLWX
DCC001-VAC013-510-610-032300-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE BALTIMORE-WASHINGTON
604 PM EDT SUN SEP 3 2000

THE NATIONAL WEATHER SERVICE IN STERLING VIRGINIA HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  DISTRICT OF COLUMBIA
  ARLINGTON COUNTY IN NORTHERN VIRGINIA
  CITY OF ALEXANDRIA IN NORTHERN VIRGINIA
  CITY OF FALLS CHURCH IN NORTHERN VIRGINIA

* UNTIL 700 PM EDT

* AT 558 PM EDT...WEATHER SERVICE DOPPLER RADAR INDICATED
  THUNDERSTORMS WITH VERY HEAVY RAINFALL OVER ALEXANDRIA...MOVING
  NORTH AT 5 MPH.

TORRENTIAL RAINFALL IN THE WARNED AREA WILL CAUSE FLASH FLOODING
ACROSS THE AREA. FLOODING IS ALREADY OCCURRING ON LOWER KING STREET
IN ALEXANDRIA.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING.
IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND IMMEDIATELY.
RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE IMMEDIATE
PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO CROSS
SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY
AUTOMOBILE. IF YOUR VEHICLE STALLS, ABANDON IT IMMEDIATELY AND SEEK
HIGHER GROUND.

TO REPORT SEVERE WEATHE=R TO THE NATIONAL WEATHER SERVICE FORECAST
OFFICE IN STERLING VIRGINIA.

LAT...LON 3874 7711 3875 7701 3900 7694 3888 7721

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 Sep 3, 3:15 AM EDT, 14 hours 49 minutes earlier.

Area forecast discussion, Sep 3, 3:15 AM EDT, 14 hours 49 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE/WASHINGTON
315 AM EDT SUN SEP 3 2000

KLWX RADAR SHOWING A LARGE AREA OF SHOWERS AND THUNDERSTORMS OVER
SOUTH CENTRAL VA... MOVING NNE TOWARD THE NORTHERN NECK AND FAR
SOUTHERN MD.  OTHER SHOWERS BEGINNING TO BREAK OUT JUST TO THE SOUTH
OF IAD AREA. SKIES MAINLY CLOUDY... WITH A FEW THIN SPOTS SHOWING UP
ON THE IR LOOP OVER CENTRAL AND WESTERN MD.

MODELS IN GENERAL AGREEMENT WITH OVERALL PATTERN TODAY AND TONIGHT.
WEAK SHORT WAVE SHOWING UP OVER NC AND SOUTHERN VA ON LATEST WV
IMAGE. 00Z ETA AND 06Z RUC HAVE PICKED UP THIS WAVE... AND THEY BOTH
ROTATE IT SLOWLY SLOW THE AREA THIS AFTERNOON. LOW LEVEL CONVERGENCE
BOUNDARY SETTING UP OVER NWRN EDGE OF CWA... WITH MOIST
SOUTHEASTERLY FLOW CONTINUING OVER THE AREA. SHORT WAVE SHOULD HELP
FOCUS SHOWER AND THUNDERSTORM ACTIVITY OVER OUR CWA TODAY...
ESPECIALLY THE SOUTHEASTERN HALF. EXPECTING PRECIP TO BE MORE
WIDESPREAD TODAY THAN IT HAS BEEN THE PAST COUPLE OF DAYS BECAUSE OF
THIS FEATURE. AMS STILL RATHER MOIST.. WITH ETA FORECAST PW VALUES
BETWEEN 1.75 AND 2.00 INCHES TODAY. STEERING FLOW REMAINS RATHER
LIGHT.. SO WHERE SHOWERS AND STORMS DO DEVELOP THEY HAVE THE
POTENTIAL TO PRODUCE SOME HEAVY RAINFALL. 1-HOUR FFG VALUES STILL
OVER 2 INCHES FOR MOST OF THE AREA.. SO THREAT OF WIDESPREAD FLASH
FLOODING APPEARS MINIMAL. EXCEPTION TO THIS IS THE CENTRAL
SHENANDOAH VALLEY... WHERE FFG VALUES ARE BETWEEN 0.9 AND 1.5
INCHES. WILL ISSUE FFA TODAY AND TONIGHT FOR THE FAR SW CORNER OF
THE CWA.. WHERE FFG VALUES ARE LOWER.

LIGHT WESTERLY/NORTHWESTERLY FLOW BEGINNING TO MIX DOWN OVER THE
AREA ON MONDAY... AND THIS SHOULD BRING ENOUGH DRY AIR DOWN TO THE
SURFACE TO KEEP POPS IN CHANCE CATEGORY. SURFACE FRONT EXPECTED TO
MOVE THROUGH THE AREA MONDAY NIGHT SHOULD BRING AN END TO THE PRECIP
FOR A FEW DAYS. ETA/NGM ARE 6-12 HOURS SLOWER AT USHERING IN COOLER
AIR THAN AVN... AND PLAN TO STICK TO WARMER ETA/NGM FOR MONDAY NIGHT
AND TUESDAY FORECAST TEMPS.

.LWX...
DC...NONE.
MD...NONE.
VA...FLASH FLOOD WATCH TODAY AND TONIGHT VAZ021-025>026-036>039.
WV...FLASH FLOOD WATCH TODAY AND TONIGHT WVZ054.

MARGRAF!

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 3, 10:59 AM EDT	Flash Flood Warning	LWX	Albemarle	2 hr
Sep 3, 5:03 PM EDT	Flash Flood Warning	LWX	Spotsylvania, Stafford, City of Fredericksburg	117 min

Nearby

Flash Flood Warnings in Virginia, 2000 Flash Flood Warnings in District of Columbia, 2000 Every flash flood 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.