Alert archive / Maryland / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 207, NWS Baltimore/Washington

July 18, 2012Carroll County, Frederick County, Maryland

NWS Baltimore/Washington issued this severe thunderstorm warning at Jul 18, 2012, 3:15 PM EDT for Carroll County, Frederick County, Maryland. 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, 3:15 PM EDT (19:15 UTC)
Expired: Jul 18, 2012, 4:00 PM EDT
In force: 45 min
Issued by: NWS Baltimore/Washington
Area: Storm-based polygon

Counties Carroll County, MD, Frederick County, MD

The radar

The Sterling radar (KLWX), 65 km from the middle of the area, began a volume at 19:16 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

Washington/Dulle, VA (KIAD), launched 12:00Z, 7.3 hours before the alert went out and 65 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: 1864 J/kg
Mixed-layer CIN: -91 J/kg
Mixed-layer LCL: 1438 m above ground
0-6 km bulk shear: 14 kt
0-1 km storm-relative helicity: 38 m²/s²
0-3 km storm-relative helicity: 13 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, 3:04 PM EDT, 11 minutes earlier.

Area forecast discussion, Jul 18, 3:04 PM EDT, 11 minutes before

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Hazardous weather outlook, Jul 18, 1:25 PM EDT, 1 hour 50 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
125 PM EDT WED JUL 18 2012

ANZ530>543-DCZ001-MDZ006-007-011-013-014-016>018-VAZ052>057-
191100-
CHESAPEAKE BAY NORTH OF POOLES ISLAND MD-
CHESAPEAKE BAY FROM POOLES ISLAND TO SANDY POINT MD-
CHESAPEAKE BAY FROM SANDY POINT TO NORTH BEACH MD-
CHESAPEAKE BAY FROM NORTH BEACH TO DRUM POINT MD-
CHESAPEAKE BAY FROM DRUM POINT MD TO SMITH POINT VA-
TIDAL POTOMAC FROM KEY BRIDGE TO INDIAN HEAD MD-
TIDAL POTOMAC FROM INDIAN HEAD TO COBB ISLAND MD-
TIDAL POTOMAC FROM COBB ISLAND MD TO SMITH POINT VA-
PATAPSCO RIVER INCLUDING BALTIMORE HARBOR-
CHESTER RIVER TO QUEENSTOWN MD-EASTERN BAY-
CHOPTANK RIVER TO CAMBRIDGE MD AND THE LITTLE CHOPTANK RIVER-
PATUXENT RIVER TO BROOMES ISLAND MD-
TANGIER SOUND AND THE INLAND WATERS SURROUNDING BLOODSWORTH
ISLAND-DISTRICT OF COLUMBIA-NORTHERN BALTIMORE-HARFORD-
SOUTHERN BALTIMORE-PRINCE GEORGES-ANNE ARUNDEL-CHARLES-ST. MARYS-
CALVERT-PRINCE WILLIAM/MANASSAS/MANASSAS PARK-FAIRFAX-
ARLINGTON/FALLS CHURCH/ALEXANDRIA-STAFFORD-SPOTSYLVANIA-
KING GEORGE-
125 PM EDT WED JUL 18 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE MARYLAND PORTION OF THE
CHESAPEAKE BAY...TIDAL POTOMAC RIVER...AND ADJACENT COUNTIES IN
CENTRAL MARYLAND AND NORTHERN VIRGINIA AS WELL AS THE DISTRICT OF
COLUMBIA.

.DAY ONE...THIS AFTERNOON AND TONIGHT

A SEVERE THUNDERSTORM WATCH HAS BEEN ISSUED UNTIL 900 PM THIS
EVENING. SCATTERED THUNDERSTORMS ARE EXPECTED THIS AFTERNOON AND
EVENING. SOME OF THE STORMS MAY BE SEVERE...PRODUCING DAMAGING
WIND GUSTS AND LARGE HAIL. HEAVY RAINFALL COULD ALSO LEAD TO
LOCALIZED FLASH FLOODING.

AN EXCESSIVE HEAT WRNG IS IN EFFECT FROM 11 AM TO 9 PM FOR
BALTIMORE CITY AND ADJACENT SUBURBS...WHERE HEAT INDICES ARE
EXPECTED TO BE AROUND 110 DEGREES.

A HEAT ADVISORY IS IN EFFECT FROM 11 AM TO 9 PM TODAY FOR THE
REMAINDER OF THE AREA. HEAT INDICES AROUND 105 DEGREES ARE EXPECTED
DURING THE AFTERNOON.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

A FEW STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE THURSDAY
AFTERNOON AND EVENING. THE PRIMARY THREAT WILL BE DAMAGING WIND
GUSTS. LOCALLY HEAVY RAINFALL MAY LEAD TO FLASH FLOODING.

ISOLATED STRONG TO SEVERE THUNDERSTORMS MAY ALSO BE POSSIBLE
ACROSS LOWER SOUTHERN MARYLAND FRIDAY AFTERNOON.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS HAVE BEEN ACTIVATED. PLEASE RELAY SEVERE WEATHER REPORTS
TO THE NATIONAL WEATHER SERVICE.

MDZ003>005-009-010-501-502-VAZ025>031-036>040-042-050-051-501>504-
WVZ050>053-055-501>506-191100-
WASHINGTON-FREDERICK MD-CARROLL-MONTGOMERY-HOWARD-
EXTREME WESTERN ALLEGANY-CENTRAL AND EASTERN ALLEGANY-AUGUSTA-
ROCKINGHAM-SHENANDOAH-FREDERICK VA-PAGE-WARREN-CLARKE-NELSON-
ALBEMARLE-GREENE-MADISON-RAPPAHANNOCK-LOUDOUN-ORANGE-CULPEPER-
NORTHERN FAUQUIER-SOUTHERN FAUQUIER-WESTERN HIGHLAND-
EASTERN HIGHLAND-HAMPSHIRE-MORGAN-BERKELEY-JEFFERSON-HARDY-
WESTERN GRANT-EASTERN GRANT-WESTERN MINERAL-EASTERN MINERAL-
WESTERN PENDLETON-EASTERN PENDLETON-
125 PM EDT WED JUL 18 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR EASTERN WEST VIRGINIA...
NORTHERN AND CENTRAL VIRGINIA...AND CENTRAL AND WESTERN MARYLAND
WITH THE EXCEPTION OF GARRETT COUNTY.

.DAY ONE...THIS AFTERNOON AND TONIGHT

A SEVERE THUNDERSTORM WATCH HAS BEEN ISSUED UNTIL 900 PM THIS
EVENING. SCATTERED THUNDERSTORMS ARE EXPECTED THIS AFTERNOON AND
EVENING. SOME OF THE STORMS MAY BE SEVERE...PRODUCING DAMAGING
WIND GUSTS AND LARGE HAIL. HEAVY RAINFALL COULD ALSO LEAD TO
LOCALIZED FLASH FLOODING.

A HEAT ADVISORY IS IN EFFECT EAST OF THE BLUE RIDGE FROM 11 AM
TO 9 PM TODAY. HEAT INDICES AROUND 105 DEGREES ARE EXPECTED DURING
THE AFTERNOON.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

A FEW STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE THURSDAY
AFTERNOON AND EVENING. THE PRIMARY THREAT WILL BE DAMAGING WIND
GUSTS. LOCALLY HEAVY RAINFALL MAY ALSO LEAD TO FLASH FLOODING.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS HAVE BEEN ACTIVATED. PLEASE RELAY SEVERE WEATHER REPORTS
TO THE NATIONAL WEATHER SERVICE.

KONARIK

In the hours before

Local storm report, Jul 18, 2:36 PM EDT, 39 minutes before

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

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

0146 PM     TSTM WND DMG     3 S STEPHENSON          39.19N  78.10W
07/18/2012                   FREDERICK          VA   911 CALL CENTER

            MULTIPLE TREES DOWN ON 400 BLOCK OF WOODS MILL RD

&&

EVENT NUMBER LWX1200924

JRK

Special weather statement, Jul 18, 2:39 PM EDT, 36 minutes before

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

MDZ003-502-WVZ051-181915-
WASHINGTON MD-MORGAN WV-CENTRAL AND EASTERN ALLEGANY MD-
239 PM EDT WED JUL 18 2012

...STRONG THUNDERSTORM TO AFFECT WASHINGTON...MORGAN AND CENTRAL AND
EASTERN ALLEGANY COUNTIES...

AT 239 PM EDT...A STRONG THUNDERSTORM WAS LOCATED 3 MILES NORTH OF
BELLEGROVE...MOVING SOUTHEAST AT 10 MPH.

LOCATIONS IMPACTED INCLUDE FOREST PARK...HANCOCK...BERKELEY SPGS AND
BERRYVILLE.

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

&&

LAT...LON 3973 7813 3972 7813 3959 7824 3972 7853
      3973 7850 3973 7839
TIME...MOT...LOC 1839Z 298DEG 10KT 3975 7833

Local storm report, Jul 18, 2:41 PM EDT, 34 minutes before

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

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

0120 PM     TSTM WND DMG     2 SSW ALBIN             39.19N  78.22W
07/18/2012                   FREDERICK          VA   911 CALL CENTER

            TREE DOWN NEAR INTERSECTION OF ROUND HILL RD AND
            LIMESTONE LN

&&

EVENT NUMBER LWX1200925

JRK

Special weather statement, Jul 18, 2:43 PM EDT, 32 minutes before

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

MDZ003-004-VAZ042-WVZ053-181915-
FREDERICK MD-WASHINGTON MD-JEFFERSON WV-LOUDOUN VA-
243 PM EDT WED JUL 18 2012

...STRONG THUNDERSTORM TO AFFECT FREDERICK...WASHINGTON...JEFFERSON
AND LOUDOUN COUNTIES...

AT 243 PM EDT...A STRONG THUNDERSTORM WAS LOCATED OVER KNOXVILLE...
MOVING EAST AT 15 MPH.

LOCATIONS IMPACTED INCLUDE BRUNSWICK...POINT OF ROCKS...BRADDOCK
HEIGHTS AND BALLENGER CREEK.

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

&&

LAT...LON 3948 7745 3926 7742 3927 7777 3937 7779
TIME...MOT...LOC 1843Z 258DEG 13KT 3935 7767

Local storm report, Jul 18, 2:56 PM EDT, 19 minutes before

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

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

0228 PM     TSTM WND DMG     1 NNW GRAVEL SPRINGS    39.10N  78.45W
07/18/2012                   FREDERICK          VA   911 CALL CENTER

            TREE DOWN ON BACK CREEK RD AND WARDENSVILLE PIKE

&&

EVENT NUMBER LWX1200926

JRK

Special weather statement, Jul 18, 3:05 PM EDT, 10 minutes before

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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, 7:15 PM EDT	Severe Thunderstorm Warning	LWX	Augusta, Highland, Rockingham	45 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, 3:20 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 Maryland, 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.