Alert archive / Virginia / Tornado Warnings in 2001

Tornado Warning 11, NWS Baltimore/Washington

September 20, 2001Culpeper County, Virginia

NWS Baltimore/Washington issued this tornado warning at Sep 20, 2001, 7:29 PM EDT for Culpeper County, Virginia. It was in force for 16 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Sep 20, 2001, 7:29 PM EDT (23:29 UTC)
Expired
Sep 20, 2001, 7:45 PM EDT
In force
16 min
Issued by
NWS Baltimore/Washington
Area
Whole counties

County Culpeper County, VA

The radar

The Sterling radar (KLWX), 68 km from the middle of the area, began a volume at 23:31 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, 11.5 hours before the alert went out and 71 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 2001-09-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 76 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 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 2001-09-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 407 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
76 J/kg
Mixed-layer CIN
-41 J/kg
Mixed-layer LCL
611 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
407 m²/s²
0-3 km storm-relative helicity
432 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.

967 
WFUS51 KLWX 202330
TORLWX
VAC047-202345-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE BALTIMORE-WASHINGTON
729 PM EDT THU SEP 20 2001

THE NATIONAL WEATHER SERVICE IN STERLING VIRGINIA HAS ISSUED A

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

* UNTIL 745 PM EDT

* AT 726 PM EDT...EMERGENCY MANAGEMENT OFFICIALS REPORTED A TORNADO
  OVER CULPEPER...MOVING NORTHEAST AT 15 MPH.

* THE TORNADO IS EXPECTED TO BE...
NEAR ALANTHUS 735 PM
NEAR LAKOTA AT 740 PM

IF YOU ARE CAUGHT OUTSIDE...SEEK SHELTER IN A 
NEARBY REINFORCED BUILDING. AS A LAST RESORT...SEEK SHELTER IN A 
CULVERT...DITCH OR LOW SPOT AND COVER YOUR HEAD WITH YOUR HANDS.

THE SAFEST PLACE TO BE DURING A TORNADO IS IN A BASEMENT. GET UNDER A
WORKBENCH OR OTHER PIECE OF STURDY FURNITURE. IF NO BASEMENT IS
AVAILABLE...SEEK SHELTER ON THE LOWEST FLOOR OF THE BUILDING IN AN
INTERIOR HALLWAY OR ROOM SUCH AS A CLOSET. USE BLANKETS OR PILLOWS TO
COVER YOUR BODY AND ALWAYS STAY AWAY FROM WINDOWS.

IF IN MOBILE HOMES OR VEHICLES...EVACUATE THEM AND GET INSIDE A
SUBSTANTIAL SHELTER. IF NO SHELTER IS AVAILABLE...LIE FLAT IN THE
NEAREST DITCH OR OTHER LOW SPOT AND COVER YOUR HEAD WITH YOUR HANDS.

JA/BMW

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 20, 3:22 PM EDT, 4 hours 7 minutes earlier.

Area forecast discussion, Sep 20, 3:22 PM EDT, 4 hours 7 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE/WASHINGTON
322 PM EDT THU SEP 20 2001

LOW PRES IS LIFTING NE THIS AFTERNOON. THE WEAK COLD FRONT IS JUST
WEST OF CWA AND WILL MOVE ACROSS LATER TONIGHT. MOST OF PCPN IS
MOVING OFF TO THE NE WITH JUST SCATTERED STORMS WITH THE FRONT TO
THE WEST. WILL KEEP SOME CHANCE POPS BEFORE MIDNIGHT. THEN
DECREASING MID CLOUDS AND SOME FOG DEVELOPING.

ZONAL FLOW OVER THE NEXT 12 HOURS WITH PARTLY TO MOSTLY CLOUDY
SKIES. NEXT S/W WILL BRING US A CHANCE OF SHRA/TSTM FRI NIGHT.

SAT AND SUN IMPROVING CONDITIONS WITH PTCLOUDY AND WARMING TEMPS
TOWARDS 80 IN THE EAST AND MID 70S IN THE WEST.

NEXT SYSTEM WILL BE SLOW MOVING AND WILL BEGIN TO MOVE IN MON AND
HANG AROUND THROUGH TUESDAY WITH SHOWERS ACROSS THE AREA. IMPROVING
CONDITIONS WEDNESDAY AND THURSDAY.

FCSTID = 17
DCA   63  80  63  80 /  40  20  30  10
BWI   60  78  61  79 /  40  20  30  10
MRB   57  76  59  78 /  30  20  30  10
IAD   60  78  61  79 /  40  20  30  10
CHO   60  78  61  79 /  40  20  30  10
HGR   57  76  59  78 /  30  20  30  10
NHK   63  80  63  80 /  40  20  30  10
W99   55  75  55  75 /  30  20  30  10

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

Nearby

Tornado Warnings in Virginia, 2001Every tornado warning in 2001Tornadoes in 2001

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.