Note:
The expiration time in the watch graphic is amended if the watch is
replaced, cancelled or extended.
Note: Click for
Watch Status Reports.
SEL9
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 459
NWS Storm Prediction Center Norman OK
530 PM EDT Thu Aug 27 2020
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Western and Central Pennsylvania
* Effective this Thursday afternoon from 530 PM until Midnight
EDT.
* Primary threats include...
Scattered damaging wind gusts to 70 mph possible
Isolated large hail events to 1.5 inches in diameter possible
A tornado or two possible
SUMMARY...Clusters of storms will move generally southeastward
across the region this evening with primary potential for damaging
winds and some severe hail.
The severe thunderstorm watch area is approximately along and 50
statute miles north and south of a line from 15 miles west of
Pittsburgh PA to 20 miles northeast of Harrisburg PA. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU9).
PRECAUTIONARY/PREPAREDNESS ACTIONS...
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 455...WW 456...WW
457...WW 458...
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 500. Mean storm motion vector
29025.
...Guyer
Note:
The Aviation Watch (SAW) product is an approximation to the watch area.
The actual watch is depicted by the shaded areas.
SAW9
WW 459 SEVERE TSTM PA 272130Z - 280400Z
AXIS..50 STATUTE MILES NORTH AND SOUTH OF LINE..
15W PIT/PITTSBURGH PA/ - 20NE CXY/HARRISBURG PA/
..AVIATION COORDS.. 45NM N/S /24SW EWC - 24ENE HAR/
HAIL SURFACE AND ALOFT..1.5 INCHES. WIND GUSTS..60 KNOTS.
MAX TOPS TO 500. MEAN STORM MOTION VECTOR 29025.
LAT...LON 41228051 41157657 39707657 39788051
THIS IS AN APPROXIMATION TO THE WATCH AREA. FOR A
COMPLETE DEPICTION OF THE WATCH SEE WOUS64 KWNS
FOR WOU9.
Watch 459 Status Report Messages:
STATUS REPORT #3 ON WW 459
VALID 280015Z - 280140Z
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 NW HLG TO
25 WSW LBE TO 25 SE LBE TO 35 SSW AOO TO 10 NW HGR TO 15 NE HGR
TO 10 S CXY TO 30 ENE CXY TO 25 W ABE TO 20 S AVP.
..JEWELL..08/28/20
ATTN...WFO...CTP...PBZ...
&&
STATUS REPORT FOR WS 459
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
MDC023-280140-
MD
. MARYLAND COUNTIES INCLUDED ARE
GARRETT
$$
PAC001-009-051-055-057-059-071-075-107-111-125-133-280140-
PA
. PENNSYLVANIA COUNTIES INCLUDED ARE
ADAMS BEDFORD FAYETTE
FRANKLIN FULTON GREENE
LANCASTER LEBANON SCHUYLKILL
SOMERSET WASHINGTON YORK
$$
WVC061-077-280140-
WV
. WEST VIRGINIA COUNTIES INCLUDED ARE
MONONGALIA PRESTON
$$
THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE
REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL
INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES
CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES.
$$
STATUS REPORT #2 ON WW 459
VALID 272340Z - 280040Z
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 N HLG TO
5 SW LBE TO 20 SW AOO TO 30 ESE AOO TO 25 N CXY TO 35 SW AVP.
FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1600
..JEWELL..08/27/20
ATTN...WFO...CTP...PBZ...
&&
STATUS REPORT FOR WS 459
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
PAC001-003-009-041-043-051-055-057-099-111-125-129-133-280040-
PA
. PENNSYLVANIA COUNTIES INCLUDED ARE
ADAMS ALLEGHENY BEDFORD
CUMBERLAND DAUPHIN FAYETTE
FRANKLIN FULTON PERRY
SOMERSET WASHINGTON WESTMORELAND
YORK
$$
THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE
REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL
INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES
CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES.
$$
STATUS REPORT #1 ON WW 459
VALID 272320Z - 280040Z
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 NW PIT TO
15 NW LBE TO 25 ENE LBE TO 10 N AOO TO 20 S UNV TO 15 ESE UNV TO
30 ESE IPT.
FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1600
..JEWELL..08/27/20
ATTN...WFO...CTP...PBZ...
&&
STATUS REPORT FOR WS 459
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
PAC001-003-007-009-013-021-041-043-051-055-057-061-067-087-093-
097-099-109-111-119-125-129-133-280040-
PA
. PENNSYLVANIA COUNTIES INCLUDED ARE
ADAMS ALLEGHENY BEAVER
BEDFORD BLAIR CAMBRIA
CUMBERLAND DAUPHIN FAYETTE
FRANKLIN FULTON HUNTINGDON
JUNIATA MIFFLIN MONTOUR
NORTHUMBERLAND PERRY SNYDER
SOMERSET UNION WASHINGTON
WESTMORELAND YORK
$$
THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE
REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL
INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES
CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES.
$$
Note:
Click for Complete Product Text.
Tornadoes
Probability of 2 or more tornadoes
|
Low (20%)
|
Probability of 1 or more strong (EF2-EF5) tornadoes
|
Low (5%)
|
Wind
Probability of 10 or more severe wind events
|
Mod (50%)
|
Probability of 1 or more wind events > 65 knots
|
Low (20%)
|
Hail
Probability of 10 or more severe hail events
|
Low (20%)
|
Probability of 1 or more hailstones > 2 inches
|
Low (20%)
|
Combined Severe Hail/Wind
Probability of 6 or more combined severe hail/wind events
|
High (70%)
|
For each watch, probabilities for particular events inside the watch
(listed above in each table) are determined by the issuing forecaster.
The "Low" category contains probability values ranging from less than 2%
to 20% (EF2-EF5 tornadoes), less than 5% to 20% (all other probabilities),
"Moderate" from 30% to 60%, and "High" from 70% to greater than 95%.
High values are bolded and lighter in color to provide awareness of
an increased threat for a particular event.
weather.gov 
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