Alert archive / Maryland / Severe Thunderstorm Warnings in 2007

Severe Thunderstorm Warning 232, NWS Baltimore/Washington

August 5, 2007Saint Mary's County, Maryland

NWS Baltimore/Washington issued this severe thunderstorm warning at Aug 5, 2007, 3:56 PM EDT for Saint Mary's County, Maryland. It was in force for 54 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
Aug 5, 2007, 3:56 PM EDT (19:56 UTC)
Expired
Aug 5, 2007, 4:50 PM EDT
In force
54 min
Issued by
NWS Baltimore/Washington
Area
Counties, with a storm outline in the text

County Saint Mary's County, MD

The radar

The Dover AFB radar (KDOX), 116 km from the middle of the area, began a volume at 20:00 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

Wallops Is Stn, VA (KWAL), launched 12:00Z, 7.9 hours before the alert went out and 104 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, Wallops Is Stn, VA at 12:00Z on 2007-08-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2196 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, Wallops Is Stn, VA at 12:00Z on 2007-08-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 16 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
2196 J/kg
Mixed-layer CIN
-37 J/kg
Mixed-layer LCL
1142 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
16 m²/s²
0-3 km storm-relative helicity
68 m²/s²
Significant tornado parameter
0.2
Supercell composite
2.6

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 Aug 5, 3:12 PM EDT, 44 minutes earlier.

Area forecast discussion, Aug 5, 3:12 PM EDT, 44 minutes before
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Hazardous weather outlook, Aug 5, 2:55 PM EDT, 1 hour 1 minute before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
255 PM EDT SUN AUG 5 2007

ANZ530>537-DCZ001-MDZ003>007-009>011-013-014-016>018-501-502-
VAZ021-025>031-036>042-050>057-WVZ050>055-501>504-061000-
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-
DISTRICT OF COLUMBIA-WASHINGTON-FREDERICK MD-CARROLL-
NORTHERN BALTIMORE-HARFORD-MONTGOMERY-HOWARD-SOUTHERN BALTIMORE-
PRINCE GEORGES-ANNE ARUNDEL-CHARLES-ST. MARYS-CALVERT-
EXTREME WESTERN ALLEGANY-CENTRAL AND EASTERN ALLEGANY-HIGHLAND-
AUGUSTA-ROCKINGHAM-SHENANDOAH-FREDERICK VA-PAGE-WARREN-CLARKE-
NELSON-ALBEMARLE-GREENE-MADISON-RAPPAHANNOCK-FAUQUIER-LOUDOUN-
ORANGE-CULPEPER-PRINCE WILLIAM/MANASSAS/MANASSAS PARK-FAIRFAX-
ARLINGTON/FALLS CHURCH/ALEXANDRIA-STAFFORD-SPOTSYLVANIA-
KING GEORGE-HAMPSHIRE-MORGAN-BERKELEY-JEFFERSON-PENDLETON-HARDY-
WESTERN GRANT-EASTERN GRANT-WESTERN MINERAL-EASTERN MINERAL-
255 PM EDT SUN AUG 5 2007

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

.DAY ONE...LATE THIS AFTERNOON AND TONIGHT

SCATTERED TO NUMEROUS THUNDERSTORMS WILL DEVELOP LATE THIS AFTERNOON
AND EVENING ACROSS THE OUTLOOK AREA. SOME OF THE STORMS WILL PRODUCE
HEAVY RAINFALL. IN ADDITION...THERE IS A SLIGHT RISK OF SEVERE
THUNDERSTORMS IN AN AREA EAST OF FREDERICKSBURG AND SOUTH OF
ANNAPOLIS...INCLUDING LOWER SOUTHERN MARYLAND THE THE ADJACENT
WATERS OF THE TIDAL POTOMAC RIVER AND CHESAPEAKE BAY. THE MOST
LIKELY RISK IS LOCALLY DAMAGING WINDS BETWEEN 4 PM AND 9 PM.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SUNDAY

FROM MONDAY THROUGH WEDNESDAY...HEAT INDEX VALUES ARE EXPECTED TO BE
NEAR 100 DEGREES EACH DAY. TUESDAY IN PARTICULAR LOOKS TO BE THE
HOTTEST OF THOSE THREE DAYS...WITH HEAT INDICES RANGING FROM 100
TO 105 DEGREES ACROSS THE REGION.

SCATTERED THUNDERSTORMS ARE EXPECTED MONDAY. ISOLATED SEVERE
THUNDERSTORMS WILL BE POSSIBLE DURING THE AFTERNOON AND
EVENING...PRIMARILY IN AREAS INCLUDING AND NORTHEAST OF BALTIMORE.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED THIS EVENING.

ROGOWSKI/LEE

In the hours before

Special weather statement, Aug 5, 1:57 PM EDT, 1 hour 59 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
157 PM EDT SUN AUG 5 2007

DCZ001-MDZ013-014-016>018-VAZ054>057-060000-
DISTRICT OF COLUMBIA-PRINCE GEORGES-ANNE ARUNDEL-CHARLES-
ST. MARYS-CALVERT-ARLINGTON/FALLS CHURCH/ALEXANDRIA-STAFFORD-
SPOTSYLVANIA-KING GEORGE-
INCLUDING THE CITIES OF...WASHINGTON...ANNAPOLIS...WALDORF...
ST MARYS CITY...ALEXANDRIA...FALLS CHURCH...FREDERICKSBURG
157 PM EDT SUN AUG 5 2007

...SEVERE THUNDERSTORMS POSSIBLE LATE THIS AFTERNOON AND EVENING...

SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP LATE
THIS AFTERNOON AND EVENING IN AN AREA INCLUDING AND SOUTHEAST OF A
LINE FROM FREDERICKSBURG VIRGINIA...TO WASHINGTON DC...TO THE
CHESAPEAKE BAY BRIDGE. THIS AREA INCLUDES THE SOUTHEAST GREATER
WASHINGTON METROPOLITAN AREA...SOUTHERN MARYLAND...THE LOWER TIDAL
POTOMAC RIVER SOUTH OF THE ROUTE 301 BRIDGE...AND THE CHESAPEAKE
BAY FROM SANDY POINT MARYLAND TO SMITH POINT VIRGINIA. THERE IS
SUFFICIENT MOISTURE AND SPIN IN THE ATMOSPHERE TO ALLOW THESE
THUNDERSTORMS TO BECOME STRONG TO SEVERE...WITH THE PRIMARY RISK
OF LOCALLY DAMAGING WIND GUSTS.

THOSE PEOPLE WITH OUTDOOR ACTIVITIES SHOULD KEEP AN EYE TO THE
SKY AND MOVE INDOORS SHOULD THREATENING WEATHER APPROACH. BOATERS
SHOULD BE PARTICULARLY ALERT TO SEEK SAFE HARBOR BEFORE
THREATENING WEATHER OCCURS.

ROGOWSKI/LEE

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 5, 3:19 PM EDTSpecial Marine WarningLWX116 min
Aug 5, 3:52 PM EDTSpecial Marine WarningLWX113 min
Aug 5, 4:56 PM EDTSpecial Marine WarningLWX49 min
Aug 5, 6:10 PM EDTSpecial Marine WarningLWX95 min
Aug 5, 6:45 PM EDTSpecial Marine WarningLWX90 min
Aug 5, 7:07 PM EDTSpecial Marine WarningLWX113 min
Aug 5, 7:57 PM EDTSpecial Marine WarningLWX66 min
Aug 5, 3:30 PM EDTTornado WarningLWXSaint Mary's30 min
Aug 5, 4:12 PM EDTSevere Thunderstorm WarningLWXCalvert33 min
Aug 5, 4:55 PM EDTSevere Thunderstorm WarningLWXCharles65 min
Aug 5, 6:06 PM EDTSevere Thunderstorm WarningLWXPrince George's25 min

Nearby

Severe Thunderstorm Warnings in Maryland, 2007Every severe thunderstorm warning in 2007

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.