Tornadoes
| Probability of 2 or more tornadoes |
Low (20%) |
| Probability of 1 or more strong (F2-F5) tornadoes |
Low (5%) |
Wind
| Probability of 10 or more severe wind events |
High (>95%) |
| Probability of 1 or more wind events > 65 knots |
High (70%) |
Hail
| Probability of 10 or more severe hail events |
Mod (30%) |
| Probability of 1 or more hailstones > 2 inches |
Low (<5%) |
Combined Severe Hail/Wind
| Probability of 6 or more combined severe hail/wind events |
High (>95%) |
DC
. DISTRICT OF COLUMBIA COUNTIES INCLUDED ARE
DISTRICT OF COLUMBIA
DE
. DELAWARE COUNTIES INCLUDED ARE
KENT NEW CASTLE SUSSEX
MD
. MARYLAND COUNTIES INCLUDED ARE
ALLEGANY ANNE ARUNDEL BALTIMORE
CALVERT CAROLINE CARROLL
CECIL CHARLES FREDERICK
HARFORD HOWARD KENT
MONTGOMERY PRINCE GEORGES QUEEN ANNE'S
ST. MARYS TALBOT WASHINGTON
MARYLAND INDEPENDENT CITIES INCLUDED ARE
BALTIMORE CITY
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URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 636
NWS STORM PREDICTION CENTER NORMAN OK
1215 PM EDT SAT SEP 8 2012
THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF
DISTRICT OF COLUMBIA
DELAWARE
MUCH OF MARYLAND
NEW JERSEY
EASTERN PENNSYLVANIA
NORTHERN VIRGINIA
THE EASTERN PANHANDLE OF WEST VIRGINIA
COASTAL WATERS
EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 1215 PM UNTIL
1000 PM EDT.
HAIL TO 1 INCH 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 100
STATUTE MILES EAST AND WEST OF A LINE FROM 50 MILES NORTH
NORTHWEST OF ALLENTOWN PENNSYLVANIA TO 55 MILES SOUTHWEST OF
WASHINGTON DISTRICT OF COLUM. FOR A COMPLETE DEPICTION OF THE
WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU6).
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.
OTHER WATCH INFORMATION...CONTINUE...WW 634...WW 635...
DISCUSSION...FRONTAL SQUALL LINE IS EXPECTED TO INTENSIFY THIS
AFTERNOON AS IT ENCOUNTERS THE AREA OF GREATER SURFACE
HEATING/INSTABILITY ACROSS ERN PA/MD/VA. INCREASING LOW-MIDLEVEL
FLOW WITH AN EJECTING SHORTWAVE TROUGH WILL LIKEWISE CONTRIBUTE TO
AN INCREASING RISK FOR WIDESPREAD DAMAGING WINDS THIS AFTERNOON THIS
AFTERNOON/EVENING.
AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS.
A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450. MEAN STORM MOTION
VECTOR 26040.
...THOMPSON
