Alert archive / Virginia / Tornado Warnings in 1987

Tornado Warning 2, NWS Baltimore/Washington

July 12, 1987Fairfax County, Loudoun County, Virginia

NWS Baltimore/Washington issued this tornado warning at Jul 12, 1987, 4:15 PM EDT for Fairfax County, Loudoun County, Virginia. It was in force for 60 min.

The area

The counties it named.

The facts

Issued
Jul 12, 1987, 4:15 PM EDT (20:15 UTC)
Expired
Jul 12, 1987, 5:15 PM EDT
In force
60 min
Issued by
NWS Baltimore/Washington
Area
Whole counties

Counties Fairfax County, VA, Loudoun County, VA

The radar

The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 8.3 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 1987-07-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1116 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 1987-07-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 13 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
1116 J/kg
Mixed-layer CIN
-97 J/kg
Mixed-layer LCL
1025 m above ground
0-6 km bulk shear
13 kt
0-1 km storm-relative helicity
13 m²/s²
0-3 km storm-relative helicity
7 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 
TTAA00 KWBC 122015
TORWBC
VAC059-107-122115-

BULLETIN - IMMEDIATE BROADCAST REQUESTED/EBS ACTIVATION REQUESTED 
TORNADO WARNING
NATIONAL WEATHER SERVICE WASHINGTON DC
415 PM EDT SUN JUL 12 1987

THE NATIONAL WEATHER SERVICE HAS ISSUED A TORNADO WARNING 
EFFECTIVE UNTIL 515 PM EDT FOR PEOPLE IN THE FOLLOWING COUNTIES OF

VIRGINIA...WESTERN FAIRFAX AND SOUTHERN LOUDOUN

A TORNADO HAS CAUSED EXTENSIVE DAMAGE AT ARCOLA IN LOUDON

COUNTY. THE STORM ON RADAR IS MOVING SLOWLY SOUTHWARD.

IF YOU ARE IN THE PATH OF A TORNADO..GO TO A BASEMENT SHELTER
OR A CENTRAL INTERIOR ROOM ON THE LOWEST FLOOR. ABANDON CARS AND
MOBILE HOMES FOR REENFORCED BUILDINGS.

PLEASE REPORT ALL SEVERE WEATHER TO YOUR LOCAL LAW ENFO RCEMENT
OFFICIALS AND ASK THEM TO PASS THE REPORT ALONG TO A WEATHER
SERVICE OFFICE.

 KERCHER

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.

In the hours before

Special weather statement, Jul 12, 1:15 PM EDT, 3 hours before
-WBCSPSBWI
NATIONAL WEATHER SERVICE BALTIMORE MD
SPECIAL WEATHER STATEMENT
 110 PM SUN JULY 12 1987

 ...THUNDERSTORMS DEVELOPING RAPIDLY...

AS TEMPERATURES APPROACH 90 DEGREES AROUND THE REGION THUNDERSTORMS
HAVE BEEN DEVELOPING RAPIDLY.

AT 1 PM THE NATIONAL WEATHER SERVICE WAS DETECTING A VERY HEAVY
THUNDERSTORM OVER THE EASTERN SHORE...ABOUT 5 MILES NE OF CAMBRIDGE.
THIS STORM WAS MOVING SLOWLY TOWARD THE SSW AND WILL LIKELY PRODUCE
VERY HEAVY RAIN ALONG ITS PATH. OTHER THUNDERSTORMS WERE NOTED IN
CENTRAL MARYLAND AND NORTHERN VIRGINIA.

THE FREQUENCY OF THE THUNDERSTORM ACTIVITY WILL INCREASE THIS AFTERNOON
IN THE MOIST UNSTABLE AIRMASS WHICH IS OVER US. THERE WILL BE THE
POTENTIAL FOR VERY HEAVY DOWNPOURS IN THESE SLOW MOVING THUNDERSTORMS
WHICH WILL PRODUCE LOCAL FLOODING. ALL THUNDERSTORMS ARE POTENTIALLY
DANGEROUS...BE ON THE LOOKOUT THIS AFTERNOON. END/RNN

                          %                                                   [
Special weather statement, Jul 12, 3:09 PM EDT, 1 hour 6 minutes before
-WBCSPSBWI
NATIONAL WEATHER SERVICE BALTIMORE MD
SPECIAL WEATHER STATEMENT
 3PM SUN JULY 12 1987

 ...HEAVY THUNDERSTORMS DEVELOPING OVER THE REGION...

THUNDERSTORM ACTIVITY IS BUILDING RAPIDY OVER THE AREA WITH THE
AREAL COVERAGE INCREASING. SCATTERED THUNDERSTORMS ARE OVER THE ENTIRE
MID ATLANTIC REGION.

MOVEMENT OF THE STORMS HAS BEEEN VERY SLOW...THEREFORE HEAVY CONTINUOUS
DOWNPOURS CAN BE EXPECTD WHICH WILL PRODUCE FLOODING...ESPECIALLY IN
THE AREAS SUBJECT TO FLOODING SUCH AS LOW LYING AREAS...UNDERPASSES...
AND AREAS WITH A HISTORY OF POOR DRAINAGE.

IN ADDITION...DANGEROUS LIGHTNING...HAIL...AND GUSTY WINDS CAN BE
EXPECTED WITH THESE STORMS. PEOPLE ENGAGED IN OUTDOOR ACTIVITIES
SHOULD BE ALERT TO THESE STORMS AND BE PREPARED TO SEEK COVER.

                                                                             [
Special weather statement, Jul 12, 4:13 PM EDT, 2 minutes before
-WBCSPSBWI
NATIONAL WEATHER SERVICE BALTIMORE MD
SPECIAL WEATHER STATEMENT
 410 PM SUN JULY 12 1987

 ...SMALL STREAM AND URBAN FLOODING...

AT 4 PM A BAND OF HEAVY THUNDERSTORMS EXTENDED FRON NORTHERN DELAWARE
SOUTHWEST THROUGH NORTHEAST MARYLAND INTO NORTHERN VIRGINIA. ELSEWHERE
THERE WERE HEAVY THUNDERSTORMS OVER CENTRAL DELAWARE...AT THE MARYLAND
LINE AND THE LOWER EASTERN SHORE.

THE HEAVIEST STORMS  WERE INDICATED OVER SOUTHERN HOWARD COUNTY...
NORTHERN BALTIMORE COUNTY AND HARFORD AND CECIL COUNTIES.

THE STORMS HAVE BEEN MOVING VERY SLOWLY WITH VERY HEAVY RAINS BEING
REPORTED...THEREFORE SMALL STREAM AND URBAN FLOODING CAN BE EXPECTED IN
THE AREAS OF HEAVY RAIN.

END/RN



Nearby

Tornado Warnings in Virginia, 1987Every tornado warning in 1987Tornadoes in 1987

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.