Alert archive / Virginia / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 217, NWS Baltimore/Washington

July 18, 2012Augusta County, Highland County, Rockingham County, Virginia; Pendleton County, West Virginia

NWS Baltimore/Washington issued this severe thunderstorm warning at Jul 18, 2012, 7:15 PM EDT for Augusta County, Highland County, Rockingham County, Virginia; Pendleton County, West Virginia. It was in force for 45 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: Jul 18, 2012, 7:15 PM EDT (23:15 UTC)
Expired: Jul 18, 2012, 8:00 PM EDT
In force: 45 min
Issued by: NWS Baltimore/Washington
Area: Storm-based polygon

Counties Augusta County, VA, Highland County, VA, Rockingham County, VA, Pendleton County, WV

The radar

The Sterling radar (KLWX), 163 km from the middle of the area, began a volume at 23:17 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 watch it was issued in

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

Issued	Product	Office	Lasted
Jul 18, 12:41 PM EDT	Severe Thunderstorm Watch	SPC	8 hr

The nearest sounding before it

Roanoke, VA (KRNK), launched 12:00Z, 11.3 hours before the alert went out and 139 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: 804 J/kg
Mixed-layer CIN: -89 J/kg
Mixed-layer LCL: 1062 m above ground
0-6 km bulk shear: 4 kt
0-1 km storm-relative helicity: 18 m²/s²
0-3 km storm-relative helicity: 2 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

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 18, 6:44 PM EDT, 31 minutes earlier.

Area forecast discussion, Jul 18, 6:44 PM EDT, 31 minutes before

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Hazardous weather outlook, Jul 18, 6:52 PM EDT, 23 minutes before

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In the hours before

Special weather statement, Jul 18, 6:03 PM EDT, 1 hour 12 minutes before

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Special weather statement, Jul 18, 6:06 PM EDT, 1 hour 9 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
606 PM EDT WED JUL 18 2012

VAZ042-052-053-182245-
PRINCE WILLIAM/MANASSAS/MANASSAS PARK VA-LOUDOUN VA-FAIRFAX VA-
606 PM EDT WED JUL 18 2012

...STRONG THUNDERSTORM TO AFFECT PRINCE WILLIAM/MANASSAS/MANASSAS
PARK...LOUDOUN AND FAIRFAX COUNTIES...

AT 606 PM EDT...A STRONG THUNDERSTORM WAS LOCATED OVER CENTREVILLE...
MOVING EAST AT 15 MPH.

LOCATIONS IMPACTED INCLUDE DULLES INTERNATIONAL AIRPORT...
CHANTILLY...HERNDON...OAKTON...RESTON...VIENNA...WOLF TRAP...
MERRIFIELD AND MANTUA.

WIND GUSTS OF 40 TO 50 MPH CAN BE EXPECTED WITH THIS STORM.

&&

LAT...LON 3904 7733 3881 7717 3878 7753 3887 7759
TIME...MOT...LOC 2206Z 252DEG 13KT 3885 7746

BJL

Special weather statement, Jul 18, 6:23 PM EDT, 52 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
623 PM EDT WED JUL 18 2012

VAZ503-504-WVZ505-506-182300-
EASTERN HIGHLAND VA-EASTERN PENDLETON WV-WESTERN HIGHLAND VA-
WESTERN PENDLETON WV-
623 PM EDT WED JUL 18 2012

...STRONG THUNDERSTORM TO AFFECT EASTERN HIGHLAND...EASTERN
PENDLETON...WESTERN HIGHLAND AND WESTERN PENDLETON COUNTIES...

AT 623 PM EDT...A STRONG THUNDERSTORM WAS LOCATED 2 MILES WEST OF
BRANDYWINE...MOVING EAST AT 10 MPH.

LOCATIONS IMPACTED INCLUDE BRANDYWINE AND OAK FLAT.

WIND GUSTS OF 40 TO 50 MPH AND SMALL HAIL CAN BE EXPECTED WITH THIS
STORM.

&&

LAT...LON 3852 7967 3857 7967 3861 7963 3867 7963
      3876 7953 3871 7909 3867 7909 3866 7913
      3850 7921 3842 7928 3841 7932 3838 7931
      3836 7934 3847 7970 3849 7970
TIME...MOT...LOC 2223Z 281DEG 7KT 3863 7928

BJL

Special weather statement, Jul 18, 6:28 PM EDT, 47 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
628 PM EDT WED JUL 18 2012

VAZ026-027-029-WVZ055-501-502-505-506-182300-
SHENANDOAH VA-PAGE VA-EASTERN PENDLETON WV-HARDY WV-WESTERN GRANT WV-
EASTERN GRANT WV-WESTERN PENDLETON WV-ROCKINGHAM VA-
628 PM EDT WED JUL 18 2012

...STRONG THUNDERSTORMS TO AFFECT SHENANDOAH...PAGE...EASTERN
PENDLETON...HARDY...WESTERN GRANT...EASTERN GRANT...WESTERN PENDLETON
AND ROCKINGHAM COUNTIES...

AT 626 PM EDT...STRONG THUNDERSTORMS WERE LOCATED ACROSS THE POTOMAC
HIGHLANDS INTO THE SHENANDOAH VALLEY. THUNDERSTORMS WERE MOVING
SOUTHEAST AT 10 MPH.

LOCATIONS IMPACTED INCLUDE ROUGH RUN...SENECA
ROCKS...YANKEETOWN...AND BROADWAY.

WIND GUSTS OF 40 TO 50 MPH AND SMALL HAIL CAN BE EXPECTED WITH THIS
ACTIVITY.

&&

LAT...LON 3889 7952 3890 7946 3892 7947 3894 7945
      3893 7938 3905 7931 3907 7931 3909 7936
      3916 7934 3919 7944 3919 7943 3894 7848
      3849 7867 3875 7954 3878 7952 3882 7954
TIME...MOT...LOC 2226Z 297DEG 8KT 3899 7926

BJL

Local storm report, Jul 18, 6:30 PM EDT, 45 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
630 PM EDT WED JUL 18 2012

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

0558 PM     FLOOD            1 SW EDMONSTON          38.94N  76.94W
07/18/2012                   PRINCE GEORGES     MD   TRAINED SPOTTER

            WATER ABOUT 18 INCHES DEEP PONDED ON UPSHUR ST BETWEEN
            KENILWORTH AVE AND ALT. RT. 1 IN BLADENSBURG

&&

EVENT NUMBER LWX1200934

KLW

Local storm report, Jul 18, 6:36 PM EDT, 39 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
636 PM EDT WED JUL 18 2012

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

0530 PM     TSTM WND DMG     1 E CAPE ST. CLAIRE     39.04N  76.42W
07/18/2012                   ANNE ARUNDEL       MD   PUBLIC

            TWO SNAPPED TREES AND LARGE BRANCH DOWN AT A RESIDENCE

&&

EVENT NUMBER LWX1200935

KWIDELSKI

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 18, 10:50 AM EDT	Special Weather Statement	LWX	Highland	25 min
Jul 18, 12:11 PM EDT	Special Weather Statement	LWX	Augusta	34 min
Jul 18, 12:13 PM EDT	Special Weather Statement	LWX	City of Harrisonburg	32 min
Jul 18, 12:14 PM EDT	Severe Thunderstorm Warning	LWX	Augusta	46 min
Jul 18, 12:21 PM EDT	Special Weather Statement	LWX	City of Harrisonburg	24 min
Jul 18, 12:33 PM EDT	Special Weather Statement	LWX	Frederick	27 min
Jul 18, 12:37 PM EDT	Special Weather Statement	LWX	Shenandoah	23 min
Jul 18, 12:55 PM EDT	Special Weather Statement	LWX	Augusta, City of Staunton, City of Waynesboro	35 min
Jul 18, 12:56 PM EDT	Special Weather Statement	LWX	Rockingham	34 min
Jul 18, 1:00 PM EDT	Special Weather Statement	LWX	Frederick, City of Winchester	30 min
Jul 18, 1:05 PM EDT	Special Weather Statement	LWX	Frederick, City of Winchester	25 min
Jul 18, 1:15 PM EDT	Severe Thunderstorm Warning	LWX	Page, Rockingham, Shenandoah	45 min
Jul 18, 1:19 PM EDT	Severe Thunderstorm Warning	LWX	Clarke, Frederick, Shenandoah, Warren, City of Winchester	41 min
Jul 18, 1:34 PM EDT	Severe Thunderstorm Warning	LWX	Clarke, Frederick	41 min
Jul 18, 1:42 PM EDT	Severe Thunderstorm Warning	LWX	Frederick, Shenandoah, Warren	48 min
Jul 18, 2:10 PM EDT	Special Weather Statement	LWX	Nelson	35 min
Jul 18, 2:13 PM EDT	Severe Thunderstorm Warning	LWX	Frederick, Shenandoah, Warren	47 min
Jul 18, 2:37 PM EDT	Severe Thunderstorm Warning	LWX	Frederick, Shenandoah	38 min
Jul 18, 2:56 PM EDT	Flash Flood Warning	LWX	Frederick, Shenandoah	94 min
Jul 18, 2:57 PM EDT	Severe Thunderstorm Warning	LWX	Loudoun	48 min
Jul 18, 3:05 PM EDT	Special Weather Statement	LWX	Frederick	25 min
Jul 18, 3:10 PM EDT	Severe Thunderstorm Warning	LWX	Frederick, City of Winchester	50 min
Jul 18, 3:24 PM EDT	Severe Thunderstorm Warning	LWX	Loudoun	30 min
Jul 18, 3:45 PM EDT	Special Marine Warning	LWX		2 hr
Jul 18, 3:48 PM EDT	Special Weather Statement	LWX		27 min
Jul 18, 4:05 PM EDT	Severe Thunderstorm Warning	LWX	Augusta, Highland, Rockingham	40 min
Jul 18, 4:17 PM EDT	Special Marine Warning	LWX		88 min
Jul 18, 4:17 PM EDT	Special Weather Statement	LWX	Arlington, Fairfax, City of Alexandria, City of Fairfax, City of Falls Church, City of Manassas and 1 more	28 min
Jul 18, 4:19 PM EDT	Severe Thunderstorm Warning	LWX	Arlington, Fairfax, City of Falls Church	41 min
Jul 18, 4:49 PM EDT	Special Marine Warning	LWX		106 min
Jul 18, 4:53 PM EDT	Severe Thunderstorm Warning	LWX	Arlington	52 min
Jul 18, 4:55 PM EDT	Special Marine Warning	LWX		95 min
Jul 18, 5:02 PM EDT	Severe Thunderstorm Warning	LWX	Arlington	20 min
Jul 18, 5:05 PM EDT	Special Weather Statement	LWX	Rockingham	40 min
Jul 18, 5:27 PM EDT	Severe Thunderstorm Warning	LWX	Augusta, Rockingham, City of Harrisonburg	30 min
Jul 18, 5:29 PM EDT	Flash Flood Warning	LWX	Rockingham	2 hr
Jul 18, 5:37 PM EDT	Special Marine Warning	LWX		57 min
Jul 18, 5:52 PM EDT	Special Marine Warning	LWX		2 hr
Jul 18, 6:03 PM EDT	Special Weather Statement	LWX	Rockingham	27 min
Jul 18, 6:06 PM EDT	Special Weather Statement	LWX	Fairfax, City of Fairfax	39 min
Jul 18, 6:28 PM EDT	Special Weather Statement	LWX	Shenandoah	32 min
Jul 18, 6:33 PM EDT	Special Marine Warning	LWX		87 min
Jul 18, 6:34 PM EDT	Severe Thunderstorm Warning	LWX	Augusta, Highland, Rockingham, Shenandoah	41 min
Jul 18, 7:39 PM EDT	Special Marine Warning	LWX		96 min
Jul 18, 1:17 PM EDT	Excessive Heat Warning	LWX	Baltimore, City of Baltimore	3 hr
Jul 18, 2:04 PM EDT	Severe Thunderstorm Warning	LWX	Washington	41 min
Jul 18, 2:43 PM EDT	Special Weather Statement	LWX	Frederick	32 min
Jul 18, 2:50 PM EDT	Severe Thunderstorm Warning	LWX	Washington	40 min
Jul 18, 3:15 PM EDT	Severe Thunderstorm Warning	LWX	Carroll, Frederick	45 min
Jul 18, 3:20 PM EDT	Severe Thunderstorm Warning	LWX	Allegany	40 min
Jul 18, 3:43 PM EDT	Special Weather Statement	LWX	Harford	47 min
Jul 18, 4:03 PM EDT	Special Weather Statement	LWX	Carroll	27 min
Jul 18, 4:06 PM EDT	Special Weather Statement	LWX	Prince George's	24 min
Jul 18, 4:29 PM EDT	Severe Thunderstorm Warning	LWX	Anne Arundel, Howard, Montgomery, Prince George's	46 min
Jul 18, 5:00 PM EDT	Flash Flood Warning	LWX	Montgomery, Prince George's	96 min
Jul 18, 1:37 PM EDT	Special Weather Statement	LWX	Hardy	38 min
Jul 18, 1:47 PM EDT	Severe Thunderstorm Warning	LWX	Grant, Hampshire, Hardy, Mineral	43 min
Jul 18, 2:32 PM EDT	Special Weather Statement	LWX	Berkeley	28 min
Jul 18, 2:39 PM EDT	Special Weather Statement	LWX	Morgan	36 min
Jul 18, 2:51 PM EDT	Severe Thunderstorm Warning	LWX	Berkeley, Morgan	39 min
Jul 18, 3:34 PM EDT	Special Weather Statement	LWX	Berkeley	26 min
Jul 18, 4:02 PM EDT	Special Weather Statement	LWX	Berkeley, Morgan	28 min
Jul 18, 5:29 PM EDT	Special Weather Statement	LWX	Hardy	31 min
Jul 18, 6:23 PM EDT	Special Weather Statement	LWX	Pendleton	37 min
Jul 18, 7:40 PM EDT	Flash Flood Warning	LWX	Pendleton	100 min

Nearby

Severe Thunderstorm Warnings in Virginia, 2012 Severe Thunderstorm Warnings in West Virginia, 2012 Every severe thunderstorm warning in 2012

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.