Alert archive / Maryland / Tornado Watches in 2008

Tornado Watch 449

June 4, 20084 states

The Storm Prediction Center issued this tornado watch at Jun 4, 2008, 2:53 PM EDT for 4 states. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued: Jun 4, 2008, 2:53 PM EDT (18:53 UTC)
Expired: Jun 4, 2008, 7:58 PM EDT
In force: 5 hr
Issued by: the Storm Prediction Center
Largest hail expected: 2 in
Strongest gust expected: 70 kt

All 23 counties

Kent County, DE, New Castle County, DE, Sussex County, DE, Caroline County, MD, Cecil County, MD, Dorchester County, MD, Kent County, MD, Queen Anne's County, MD, Somerset County, MD, Talbot County, MD, Wicomico County, MD, Worcester County, MD, Atlantic County, NJ, Burlington County, NJ, Camden County, NJ, Cape May County, NJ, Cumberland County, NJ, Gloucester County, NJ, Ocean County, NJ, Salem County, NJ, Chester County, PA, Delaware County, PA, Philadelphia County, PA

The radar

The Dover AFB radar (KDOX), 48 km from the middle of the area, began a volume at 18:54 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.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes: 40%
One or more EF2 to EF5 tornadoes: 20%
Ten or more severe wind reports: 70%
One or more gusts of 65 knots or more: 40%
Ten or more severe hail reports: 50%
One or more hailstones of 2 inches or more: 30%
Six or more combined severe hail and wind reports: 95%

Warnings issued inside it

8 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

Issued	Product	Office	Counties	Lasted
Jun 4, 3:17 PM EDT	Severe Thunderstorm Warning	PHI	Caroline, Cecil, Kent, Queen Anne's, Talbot	58 min
Jun 4, 3:24 PM EDT	Severe Thunderstorm Warning	AKQ	Dorchester	81 min
Jun 4, 3:58 PM EDT	Tornado Warning	PHI	Caroline, Queen Anne's, Talbot	32 min
Jun 4, 3:59 PM EDT	Severe Thunderstorm Warning	PHI	Kent, New Castle, Sussex	76 min
Jun 4, 4:14 PM EDT	Severe Thunderstorm Warning	PHI	Caroline, Cecil, Kent, Queen Anne's, Talbot	61 min
Jun 4, 4:37 PM EDT	Severe Thunderstorm Warning	AKQ	Somerset, Wicomico	38 min
Jun 4, 5:20 PM EDT	Severe Thunderstorm Warning	AKQ	Worcester	31 min
Jun 4, 7:17 PM EDT	Severe Thunderstorm Warning	PHI	Caroline, Queen Anne's, Talbot	58 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 6.9 hours before the alert went out and 68 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: 27 J/kg
Mixed-layer CIN: -57 J/kg
Mixed-layer LCL: 622 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 157 m²/s²
0-3 km storm-relative helicity: 221 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000
WWUS20 KWNS 041853
SEL9  
SPC WW 041853
DEZ000-MDZ000-NJZ000-PAZ000-CWZ000-050000-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 449
NWS STORM PREDICTION CENTER NORMAN OK
255 PM EDT WED JUN 4 2008

THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF 

       DELAWARE
       EASTERN MARYLAND
       SOUTHERN NEW JERSEY
       SOUTHEAST PENNSYLVANIA
       COASTAL WATERS

EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 255 PM UNTIL
800 PM EDT.

TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 80 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 60 STATUTE
MILES EAST AND WEST OF A LINE FROM 20 MILES NORTH NORTHEAST OF
PHILADELPHIA PENNSYLVANIA TO 15 MILES EAST OF WALLOPS VIRGINIA. 
FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU9).

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS.

OTHER WATCH INFORMATION...CONTINUE...WW 446...WW 447...WW 448...

DISCUSSION...FAST-MOVING BOW ECHO CURRENTLY APPROACHING THE DC METRO
AREA WILL CONTINUE EASTWARD INTO THIS REGION IN THE NEXT FEW HOURS. 
A SIGNIFICANT THREAT FOR DAMAGING WINDS IS EXPECTED WITH THESE
STORMS...AS WELL AS ISOLATED TORNADOES ALONG THE LEADING EDGE. 
STRONG INSTABILITY WILL ALSO POSE A THREAT FOR ISOLATED THUNDERSTORM
DEVELOPMENT AHEAD OF AND SOUTH OF SQUALL LINE.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 70 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
500. MEAN STORM MOTION VECTOR 27045.


...HART

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 4, 7:13 PM EDT	Mesoscale Discussion	SPC	Kent, Sussex	62 min
Jun 4, 7:34 PM EDT	Tornado Watch	SPC	Kent, Sussex	5 hr
Jun 4, 12:18 AM EDT	Mesoscale Discussion	SPC	Calvert, Charles, Prince George's, Saint Mary's	87 min
Jun 4, 9:18 AM EDT	Tornado Watch	SPC	Garrett	7 hr
Jun 4, 11:51 AM EDT	Mesoscale Discussion	SPC	Allegany, Anne Arundel, Baltimore, Calvert, Carroll, Charles and 11 more	84 min
Jun 4, 12:49 PM EDT	Tornado Watch	SPC	Allegany, Anne Arundel, Baltimore, Calvert, Carroll, Charles and 8 more	7 hr
Jun 4, 2:01 PM EDT	Mesoscale Discussion	SPC	Charles	59 min
Jun 4, 4:04 PM EDT	Mesoscale Discussion	SPC	Charles	116 min

Nearby

Tornado Watches in Maryland, 2008 Tornado Watches in New Jersey, 2008 Tornado Watches in Delaware, 2008 Every tornado watch in 2008

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.