Severe Thunderstorm Watch 535

Issued

Jul 28, 2012, 1:36 PM EDT (17:36 UTC)

Expired

Jul 28, 2012, 10:00 PM EDT

In force

8 hr

Issued by

the Storm Prediction Center

Largest hail expected

1.5 in

Strongest gust expected

60 kt

The Philadelphia radar (KDIX), 113 km from the middle of the area, began a volume at 17:36 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

10%

One or more EF2 to EF5 tornadoes

2%

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

5%

Six or more combined severe hail and wind reports

80%

• Mesoscale Discussion 1630Jul 28, 12:26 PM EDT
• Mesoscale Discussion 1635Jul 28, 4:18 PM EDT
• Mesoscale Discussion 1640Jul 28, 8:00 PM EDT

678 
WWUS20 KWNS 281743
SEL5
SPC WW 281743
CTZ000-DCZ000-DEZ000-MDZ000-NJZ000-NYZ000-PAZ000-VAZ000-WVZ000-CWZ00
0-290200-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 535
NWS STORM PREDICTION CENTER NORMAN OK
135 PM EDT SAT JUL 28 2012

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

       SOUTHWEST CONNECTICUT
       DISTRICT OF COLUMBIA
       DELAWARE
       CENTRAL AND EASTERN MARYLAND
       NEW JERSEY
       SOUTHEASTERN NEW YORK
       SOUTHERN AND EASTERN PENNSYLVANIA
       NORTHERN AND EASTERN VIRGINIA
       THE EASTERN WEST VIRGINIA PANHANDLE
       COASTAL WATERS

EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 135 PM UNTIL
1000 PM EDT.

HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 85
STATUTE MILES EAST AND WEST OF A LINE FROM 55 MILES NORTH OF
NEWARK NEW JERSEY TO 65 MILES SOUTHWEST OF PATUXENT RIVER
MARYLAND.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU5).

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR 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. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY
DO PRODUCE TORNADOES.

DISCUSSION...SFC HEATING AND CONTINUED ESE ADVANCE OF ERN OH/WRN PA
UPR IMPULSE EXPECTED TO FOSTER A GRADUAL INCREASE IN TSTM COVERAGE
AND  STRENGTH THROUGH EARLY TNGT OVER WW REGION. STORMS MAY BE MOST
CONCENTRATED ALONG AND E OF THE BLUE RIDGE...ALONG DIFFUSE LEE
TROUGH FROM SE PA/CNTRL MD SSW INTO VA...AND NEAR SHALLOW BACK-DOOR
BOUNDARY IN NJ/SE NY.  PREDOMINANT SVR THREAT SHOULD BE LOCALLY DMGG
WIND DUE TO RELATIVELY HIGH PW AND MODERATELY UNIDIRECTIONAL WSWLY
MID LVL FLOW...ESPECIALLY IN AREAS WHERE SFC HEATING WILL CONTINUE
TO OCCUR THROUGH MID AFTN. MARGINALLY SVR HAIL AND...IN NRN PART OF
WW...VERY HEAVY RAIN ALSO MAY OCCUR.  THE STORMS MAY MERGE INTO
SEVERAL LOOSELY ORGANIZED CLUSTERS/BANDS BY MID...WITH A DIMINISHING
SVR THREAT.

AVIATION...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 550. MEAN STORM
MOTION VECTOR 25025.


...CORFIDI

Severe Thunderstorm Watches in Virginia, 2012Severe Thunderstorm Watches in Maryland, 2012Severe Thunderstorm Watches in New Jersey, 2012Every severe thunderstorm watch in 2012

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.