Alert archive / Virginia / Tornado Warnings in 2004

Tornado Warning 55, NWS Baltimore/Washington

September 17, 2004Loudoun County, Virginia

NWS Baltimore/Washington issued this tornado warning at Sep 17, 2004, 5:55 PM EDT for Loudoun County, Virginia. It was in force for 65 min. 3 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Sep 17, 2004, 5:55 PM EDT (21:55 UTC)
Expired: Sep 17, 2004, 7:00 PM EDT
In force: 65 min
Issued by: NWS Baltimore/Washington
Area: Counties, with a storm outline in the text

County Loudoun County, VA

The radar

The Sterling radar (KLWX), 19 km from the middle of the area, began a volume at 21:58 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

Time	Report	Where	Remark
Sep 17, 6:12 PM EDT	TORNADO	Dulles International Ai, VA	ON GROUND.
Sep 17, 6:12 PM EDT	TORNADO	Dulles International Ai, VA	ON GROUND.
Sep 17, 6:30 PM EDT	TORNADO	Lovettsville, VA	JOHN WOLFORD AT ASH GEORGE TREES BLOCKING BRIDGE. RICKARD ROAD NORTH OF MILLTOWN ROAD BLOCKED BY DOWNED TREES.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

Did it verify

Verified. The Iowa Environmental Mesonet's Cow matched 2 storm reports to this tornado warning; the first came 17 minutes after it went out.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Sep 17, 3:50 PM EDT	Tornado Watch	SPC	4 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 9.9 hours before the alert went out and 26 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: 105 J/kg
Mixed-layer CIN: -89 J/kg
Mixed-layer LCL: 687 m above ground
0-6 km bulk shear: 49 kt
0-1 km storm-relative helicity: 74 m²/s²
0-3 km storm-relative helicity: 150 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 
WFUS51 KLWX 172155
TORLWX
VAC107-172300-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
554 PM EDT FRI SEP 17 2004

THE NATIONAL WEATHER SERVICE IN STERLING VIRGINIA HAS ISSUED A

* TORNADO WARNING FOR...
  LOUDOUN COUNTY IN NORTHERN VIRGINIA

* UNTIL 700 PM EDT

* AT 552 PM EDT...RADAR INDICATED A TORNADO AND SPOTTERS CONFIRMED
  DANGEROUS TORNADIC THUNDERSTORMS TO AFFECT LOUDOUN COUNTY. ONE STORM
  WAS REPORTED 7 MILES NORTHEAST OF PURCELLVILLE AND THE SECOND WAS
  MOVING WAS 8 MILES SOUTH OF DULLES INTERNATIONAL AIRPORT. BOTH WERE 
  MOVING NORTH AT 25 MPH. TORNADOES ARE ON THE GROUND THIS IS A LIFE
  THREATENING SITUATION...TAKE COVER NOW

* SOME LOCATIONS NEAR THE PATH OF THIS TORNADO INCLUDE...ASHBURN...
  COUNTRYSIDE...LEESBURG...PURCELLVILLE...ARCOLA AND DULLES
  INTERNATIONAL AIRPORT.

A TORNADO HAS BEEN CONFIRMED IF YOU ARE NEAR THE PATH OF THIS
TORNADO...TAKE COVER NOW IF NO UNDERGROUND SHELTER IS AVAILABLE MOVE
TO AN INTERIOR ROOM ON THE LOWEST FLOOR. MOBILE HOMES AND VEHICLES
SHOULD BE ABANDONED FOR MORE SUBSTANTIAL SHELTER. AVOID WINDOWS

DO NOT TAKE SHELTER UNDER HIGHWAY OVERPASSES THEY OFFER NO
PROTECTION FROM VIOLENT WINDS. BLOCKING THE ROAD WILL PREVENT OTHERS
FROM REACHING SAFE SHELTER.

LAT...LON 3917 7778 3885 7752 3904 7735 3912 7753
      3923 7748 3932 7769

$$

DM/CS

What forecasters said that day

The local office's own words before this tornado 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 tornado warning went out at Sep 17, 4:06 PM EDT, 1 hour 49 minutes earlier.

Area forecast discussion, Sep 17, 4:06 PM EDT, 1 hour 49 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
406 PM EDT FRI SEP 17 2004

HONESTLY THIS HAS BEEN AN XTRMLY REACTIONARY SHIFT - HV SPENT MOST
OF DAY ISSUING PRODUCTS/GIVING BRIEFINGS/DOING INTERVIEWS. HVG BEEN
ON FOR THE PAST SVRL DAYS I HV AN UNDERSTANDING OF THE SYNOPTICS
BEHIND WHAT IS HAPPENING ATTM. XPCT WELL BE ISSUING MR TORS DURG
THE NEXT SVRL HRS. ALTHO WE HV NOT RCVD MUCH RAFL SO FAR STILL BLV
THAT IN TRPCL ENVIRONMENT LARGE AMTS OF RA COULD FALL IN SHORT AMT
OF TIME. WE HV DROPPED THE PSBL TOTALS TO 3-5.

IT LOOKS LK PCPN THREAT SHOULD BEGIN TO WANE IN THE NW SXN OF CWA
DURG SAT AFTN...BCMG BRZY AS WIND TURNS NRLY.

WOODY
&&

.LONG TERM (SAT NIGHT-FRI)

THERE WILL BE A TASTE OF FALL IN THE AIR EARLY NEXT WEEK AS CANADIAN
HIGH BUILDS IN. OVERNIGHT TEMPS EARLY NEXT WEEK WILL DROP INTO THE
40S IN SOME SPOTS OUT WEST WITH 50S MORE COMMON EAST. SKIES EXPECTED
TO CLEAR RAPIDLY SAT NIGHT AS MUCH DRIER AIR ADVECTS IN GUSTY NRLY
WINDS. DONT HAVE ANY MENTION OF PRECIP IN THE EXTENDED. WILL ONLY
HAVE TO DEAL WITH ANY RIVER FLOODING THAT MAY BE ONGOING.

ROSA
&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...FLOOD WATCH UNTIL 800 PM EDT SATURDAY FOR ZONE DCZ001.

TORNADO WATCH UNTIL 800 PM EDT FRIDAY FOR ZONE DCC001.

MD...FLOOD WATCH UNTIL 800 PM EDT SATURDAY FOR ZONES MDZ002>007...
MDZ009>011...MDZ013>014...MDZ016>018.

TORNADO WATCH UNTIL 800 PM EDT FRIDAY FOR ZONES MDC003...MDC009...
MDC017...MDC031...MDC033...MDC037.

TORNADO WATCH UNTIL 800 PM EDT FRIDAY FOR ZONES MDC005...MDC013...
MDC021...MDC025...MDC027...MDC043.

VA...TORNADO WARNING UNTIL 415 PM EDT FRIDAY FOR ZONES VAC113...
VAC157.

FLOOD WATCH UNTIL 800 PM EDT SATURDAY FOR ZONES
VAZ021...VAZ025>031...VAZ036>042...VAZ050>057.

WV...FLOOD WATCH UNTIL 800 PM EDT SATURDAY FOR ZONES WVZ048>055.

&&

Hazardous weather outlook, Sep 17, 11:29 AM EDT, 6 hours 26 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1129 AM EDT FRI SEP 17 2004

DCZ001-MDZ002>007-009>011-013-014-016>018-VAZ021-025>031-036>042-
050>057-WVZ048>055-180800-
ALBEMARLE VA-ALLEGANY MD-ANNE ARUNDEL MD-
ARLINGTON/FALLS CHURCH/ALEXANDRIA VA-AUGUSTA VA-BERKELEY WV-
CALVERT MD-CARROLL MD-CHARLES MD-CLARKE VA-CULPEPER VA-
DISTRICT OF COLUMBIA DC-FAIRFAX VA-FAUQUIER VA-FREDERICK VA-
FREDERICK MD-GRANT WV-GREENE VA-HAMPSHIRE WV-HARDY WV-HARFORD MD-
HIGHLAND VA-HOWARD MD-JEFFERSON WV-KING GEORGE VA-LOUDOUN VA-
MADISON VA-MINERAL WV-MONTGOMERY MD-MORGAN WV-NELSON VA-
NORTHERN BALTIMORE MD-ORANGE VA-PAGE VA-PENDLETON WV-
PRINCE GEORGES MD-PRINCE WILLIAM/MANASSAS/MANASSAS PARK VA-
RAPPAHANNOCK VA-ROCKINGHAM VA-SHENANDOAH VA-SOUTHERN BALTIMORE MD-
SPOTSYLVANIA VA-ST. MARYS MD-STAFFORD VA-WARREN VA-WASHINGTON MD-
1129 AM EDT FRI SEP 17 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR MARYLAND WEST OF THE CHESAPEAKE
BAY AND EAST OF GARRETT COUNTY...EASTERN WEST VIRGINIA...NORTHERN AND
CENTRAL VIRGINIA AND WASHINGTON DC.

.DAY ONE...
A FLOOD WATCH IS IN EFFECT FOR NORTHERN VIRGINIA...MARYLAND...THE
PANHANDLE OF WEST VIRGINIA...AND THE DISTRICT OF COLUMBIA. RAINFALL
ASSOCIATED WITH THE REMNANTS OF IVAN WILL MOVE INTO THE AREA
THROUGH SATURDAY. TOTAL RAINFALL AMOUNTS OF 3 TO 5 INCHES WILL BE
POSSIBLE. THIS COULD LEAD TO THE FLOODING OF LOW LYING AREAS...SMALL
STREAMS AND CREEKS.

.DAYS TWO THROUGH SEVEN...
THE FLOOD WATCH WILL REMAIN IN EFFECT THROUGH SATURDAY. AS THE
RAIN CONTINUES...SIGNIFICANT RISES ON THE POTOMAC RIVER WILL BE
POSSIBLE...WITH SEVERAL LOCATIONS EXCEEDING FLOOD STAGE ON SUNDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED.

In the hours before

Local storm report, Sep 17, 5:29 PM EDT, 26 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
529 PM EDT FRI SEP 17 2004

..TIME...   ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE...   ....MAG....     ..COUNTY LOCATION...ST.. ...SOURCE....
            ..REMARKS..

0529 PM     TORNADO          WOODBRIDGE              38.64N 77.26W
09/17/2004                   PRINCE WILLIAM     VA   AMATEUR RADIO

            TORNADO REPORTED ON GROUND TRAVELLING NORTH-NORTHWEST.
            HOADLEY ROAD AND ROUTE 234.

&&

CS

Local storm report, Sep 17, 5:37 PM EDT, 18 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
537 PM EDT FRI SEP 17 2004

..TIME...   ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE...   ....MAG....     ..COUNTY LOCATION...ST.. ...SOURCE....
            ..REMARKS..

0535 PM     TORNADO          HUGHESVILLE             39.10N 77.66W
09/17/2004                   LOUDOUN            VA   EMERGENCY MNGR

            TORNADO ON GROUND NEAR HARMONY CHURCH ROAD.

&&

CS

Local storm report, Sep 17, 5:41 PM EDT, 14 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
541 PM EDT FRI SEP 17 2004

..TIME...   ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE...   ....MAG....     ..COUNTY LOCATION...ST.. ...SOURCE....
            ..REMARKS..

0540 PM     TORNADO          2 S MANASSAS            38.72N 77.49W
09/17/2004                   PRINCE WILLIAM     VA   AMATEUR RADIO

&&

CS

Local storm report, Sep 17, 5:45 PM EDT, 10 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
545 PM EDT FRI SEP 17 2004

..TIME...   ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE...   ....MAG....     ..COUNTY LOCATION...ST.. ...SOURCE....
            ..REMARKS..

0544 PM     TORNADO          2 S MANASSAS            38.72N 77.49W
09/17/2004                   PRINCE WILLIAM     VA   AMATEUR RADIO

&&

CS

Local storm report, Sep 17, 5:46 PM EDT, 9 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
546 PM EDT FRI SEP 17 2004

..TIME...   ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE...   ....MAG....     ..COUNTY LOCATION...ST.. ...SOURCE....
            ..REMARKS..

0546 PM     TORNADO          MIDDLETOWN              39.03N 78.28W
09/17/2004                   FREDERICK          VA   EMERGENCY MNGR

            WAYSTATION WAS HIT.

&&

CS

Local storm report, Sep 17, 5:52 PM EDT, 3 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
552 PM EDT FRI SEP 17 2004

..TIME...   ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE...   ....MAG....     ..COUNTY LOCATION...ST.. ...SOURCE....
            ..REMARKS..

0552 PM     TORNADO          HAMILTON                39.13N 77.66W
09/17/2004                   LOUDOUN            VA   EMERGENCY MNGR

            DAMAGE IN HAMILTON AND PURCELLVILLE.

&&

CS

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 17, 2:46 PM EDT	Tornado Warning	LWX	Nelson	44 min
Sep 17, 2:59 PM EDT	Tornado Warning	LWX	Albemarle, City of Charlottesville	61 min
Sep 17, 3:07 PM EDT	Tornado Warning	LWX	Spotsylvania, City of Fredericksburg	53 min
Sep 17, 3:12 PM EDT	Tornado Warning	LWX	Madison, Rappahannock	63 min
Sep 17, 3:19 PM EDT	Tornado Warning	LWX	Orange	41 min
Sep 17, 3:32 PM EDT	Tornado Warning	LWX	Culpeper	28 min
Sep 17, 3:42 PM EDT	Flash Flood Warning	LWX	Albemarle, City of Charlottesville	3 hr
Sep 17, 3:44 PM EDT	Tornado Warning	LWX	Warren	46 min
Sep 17, 3:50 PM EDT	Severe Thunderstorm Warning	LWX	Greene	40 min
Sep 17, 3:55 PM EDT	Tornado Warning	LWX	Fauquier	65 min
Sep 17, 3:59 PM EDT	Tornado Warning	LWX	Greene	46 min
Sep 17, 4:06 PM EDT	Tornado Warning	LWX	Madison	54 min
Sep 17, 4:20 PM EDT	Tornado Warning	LWX	Spotsylvania, Stafford, City of Fredericksburg	55 min
Sep 17, 4:31 PM EDT	Tornado Warning	LWX	Frederick, City of Winchester	59 min
Sep 17, 4:36 PM EDT	Tornado Warning	LWX	Page	39 min
Sep 17, 4:39 PM EDT	Severe Thunderstorm Warning	LWX	Albemarle, City of Charlottesville	51 min
Sep 17, 4:44 PM EDT	Tornado Warning	LWX	Prince William, City of Manassas, City of Manassas Park	61 min
Sep 17, 4:58 PM EDT	Tornado Warning	LWX	Fauquier, Loudoun	62 min
Sep 17, 5:09 PM EDT	Tornado Warning	LWX	Stafford	36 min
Sep 17, 5:11 PM EDT	Severe Thunderstorm Warning	LWX	Greene	49 min
Sep 17, 5:14 PM EDT	Tornado Warning	LWX	Orange	31 min
Sep 17, 5:15 PM EDT	Tornado Warning	LWX	Greene	30 min
Sep 17, 5:23 PM EDT	Severe Thunderstorm Warning	LWX	Madison	52 min
Sep 17, 5:26 PM EDT	Severe Thunderstorm Warning	LWX	Page	64 min
Sep 17, 5:30 PM EDT	Tornado Warning	LWX	Frederick, City of Winchester	45 min
Sep 17, 5:32 PM EDT	Tornado Warning	LWX	Culpeper	43 min
Sep 17, 5:38 PM EDT	Tornado Warning	LWX	Fairfax, City of Fairfax	52 min
Sep 17, 5:44 PM EDT	Tornado Warning	LWX	Prince William, City of Manassas, City of Manassas Park	16 min
Sep 17, 5:49 PM EDT	Flash Flood Warning	LWX	Madison	3 hr
Sep 17, 6:05 PM EDT	Tornado Warning	LWX	Fauquier	55 min
Sep 17, 6:16 PM EDT	Tornado Warning	LWX	Frederick	29 min
Sep 17, 6:19 PM EDT	Tornado Warning	LWX	King George	56 min
Sep 17, 6:22 PM EDT	Special Marine Warning	LWX		113 min
Sep 17, 6:36 PM EDT	Flash Flood Warning	LWX	Frederick, City of Winchester	3 hr
Sep 17, 7:00 PM EDT	Tornado Warning	LWX	Clarke	60 min
Sep 17, 7:09 PM EDT	Tornado Warning	LWX	Culpeper	66 min
Sep 17, 7:11 PM EDT	Tornado Warning	LWX	Fairfax, Prince William, City of Fairfax, City of Falls Church	64 min
Sep 17, 7:21 PM EDT	Flash Flood Warning	LWX	Clarke, Culpeper, Fauquier, Orange, Rappahannock, Warren	3 hr
Sep 17, 7:54 PM EDT	Severe Thunderstorm Warning	LWX	Stafford	51 min

Nearby

Tornado Warnings in Virginia, 2004 Every tornado warning in 2004 Tornadoes in 2004

Sources

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