Tornado Watch 377

Issued

Jun 27, 2013, 1:58 PM EDT (17:58 UTC)

Expired

Jun 27, 2013, 9:26 PM EDT

In force

7 hr

Issued by

the Storm Prediction Center

Largest hail expected

1.5 in

Strongest gust expected

60 kt

The Philadelphia radar (KDIX), 140 km from the middle of the area, began a volume at 17:59 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.

Two or more tornadoes

30%

One or more EF2 to EF5 tornadoes

20%

Ten or more severe wind reports

50%

One or more gusts of 65 knots or more

10%

Ten or more severe hail reports

20%

One or more hailstones of 2 inches or more

10%

Six or more combined severe hail and wind reports

80%

• Mesoscale Discussion 1266Jun 27, 1:04 PM EDT
• Mesoscale Discussion 1270Jun 27, 3:57 PM EDT
• Mesoscale Discussion 1274Jun 27, 6:58 PM EDT

861 
WWUS20 KWNS 271804
SEL7  
SPC WW 271804
DCZ000-DEZ000-MDZ000-NJZ000-PAZ000-VAZ000-CWZ000-280200-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 377
NWS STORM PREDICTION CENTER NORMAN OK
200 PM EDT THU JUN 27 2013

THE NWS STORM PREDICTION CENTER HAS ISSUED A

* TORNADO WATCH FOR PORTIONS OF 
  DISTRICT OF COLUMBIA
  DELAWARE
  CENTRAL AND EASTERN MARYLAND
  NEW JERSEY
  SOUTH CENTRAL AND SOUTHEASTERN PENNSYLVANIA
  NORTHERN VIRGINIA
  COASTAL WATERS

* EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 200 PM UNTIL
  1000 PM EDT.

* PRIMARY THREATS INCLUDE...
  SEVERAL TORNADOES POSSIBLE
  SEVERAL DAMAGING WIND GUSTS TO 70 MPH POSSIBLE
  A FEW LARGE HAIL EVENTS TO 1.5 INCHES IN DIAMETER POSSIBLE

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 75 STATUTE
MILES EAST AND WEST OF A LINE FROM 40 MILES NORTHWEST OF
ALLENTOWN PENNSYLVANIA TO 50 MILES SOUTH OF DOVER DELAWARE.  FOR
A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU7).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 376...

DISCUSSION...STRONG/SEVERE STORM DEVELOPMENT IS NOW UNDERWAY ALONG
AND TO THE EAST OF THE NORTH CENTRAL APPALACHIANS.  ACTIVITY IS
EXPECTED TO CONTINUE TO INCREASE AND INTENSIFY...AHEAD OF THE
MID-LEVEL TROUGH SHIFTING TOWARD NORTHERN MID ATLANTIC COASTAL
AREAS.  DEEP LAYER FLOW AND SHEAR ARE SOMEWHAT MODEST...BUT HIGH
BOUNDARY LAYER MOISTURE CONTENT AND HUMIDITY...COUPLED WITH AMBIENT
VERTICAL VORTICITY...MAY CONTRIBUTE TO THE RISK FOR A FEW...AT LEAST
WEAK...TORNADOES IN DISCRETE STORMS.  PRECIPITATION LOADING WITHIN
CONSOLIDATING CONVECTION WILL ALSO CONTRIBUTE TO THE RISK FOR
POTENTIALLY DAMAGING WIND GUSTS.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
500. MEAN STORM MOTION VECTOR 24025.


...KERR

Tornado Watches in Pennsylvania, 2013Tornado Watches in Maryland, 2013Tornado Watches in New Jersey, 2013Every tornado watch in 2013

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.