Storm Prediction Center Severe Thunderstorm Watch 646

Note: 
The expiration time in the watch graphic is amended if the watch is
replaced, cancelled or extended.
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   SEL6

   URGENT - IMMEDIATE BROADCAST REQUESTED
   Severe Thunderstorm Watch Number 646
   NWS Storm Prediction Center Norman OK
   455 PM EDT Wed Sep 2 2026

   The NWS Storm Prediction Center has issued a

   * Severe Thunderstorm Watch for portions of 
     Eastern Ohio
     Western and Central Pennsylvania
     The Far Northern West Virginia Panhandle

   * Effective this Wednesday afternoon from 455 PM until Midnight
     EDT.

   * Primary threats include...
     Scattered large hail and isolated very large hail events to 2
       inches in diameter possible
     Scattered damaging wind gusts to 70 mph possible
     A tornado or two possible

   SUMMARY...Robust thunderstorms have developed across eastern Ohio
   into northwest Pennsylvania in a favorable environment for severe
   hail and damaging winds. Current expectations are for this
   convection to spread generally east-southeastward through the late
   afternoon and into the evening. A tornado or two may also occur with
   any sustained supercell.

   The severe thunderstorm watch area is approximately along and 50
   statute miles north and south of a line from 25 miles west southwest
   of Youngstown OH to 45 miles northeast of State College PA. For a
   complete depiction of the watch see the associated watch outline
   update (WOUS64 KWNS WOU6).

   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 643...WW 644...WW 645...

   AVIATION...A few severe thunderstorms with hail surface and aloft to
   2 inches. Extreme turbulence and surface wind gusts to 60 knots. A
   few cumulonimbi with maximum tops to 550. Mean storm motion vector
   27030.

   ...Gleason

Note:
The Aviation Watch (SAW) product is an approximation to the watch area.
The actual watch is depicted by the shaded areas.

   SAW6 
   WW 646 SEVERE TSTM OH PA WV 022055Z - 030400Z
   AXIS..50 STATUTE MILES NORTH AND SOUTH OF LINE..
   25WSW YNG/YOUNGSTOWN OH/ - 45NE UNV/STATE COLLEGE PA/
   ..AVIATION COORDS.. 45NM N/S /38ESE CLE - 35ESE SLT/
   HAIL SURFACE AND ALOFT..2 INCHES. WIND GUSTS..60 KNOTS.
   MAX TOPS TO 550. MEAN STORM MOTION VECTOR 27030.

   LAT...LON 41838112 42037724 40597724 40398112

   THIS IS AN APPROXIMATION TO THE WATCH AREA.  FOR A
   COMPLETE DEPICTION OF THE WATCH SEE WOUS64 KWNS
   FOR WOU6.

Watch 646 Status Report Message has not been issued yet.

Note:
 Click for Complete Product Text.

Tornadoes

Wind

Hail

Combined Severe Hail/Wind

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.