Storm Prediction Center Severe Thunderstorm Watch 621

Note: 
The expiration time in the watch graphic is amended if the watch is
replaced, cancelled or extended.
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   SEL1

   URGENT - IMMEDIATE BROADCAST REQUESTED
   Severe Thunderstorm Watch Number 621
   NWS Storm Prediction Center Norman OK
   400 PM MDT Sun Aug 23 2026

   The NWS Storm Prediction Center has issued a

   * Severe Thunderstorm Watch for portions of 
     Southwest North Dakota

   * Effective this Sunday afternoon and evening from 400 PM until
     900 PM MDT.

   * Primary threats include...
     Scattered large hail and isolated very large hail events to 2
       inches in diameter possible
     Isolated significant damaging wind gusts to 75 mph possible

   SUMMARY...A few supercells with large hail up to 2 inches in
   diameter and isolated severe outflow gusts of 60-75 mph will be
   possible into this evening.

   The severe thunderstorm watch area is approximately along and 60
   statute miles east and west of a line from 55 miles north of
   Dickinson ND to 30 miles west of Lemmon SD. For a complete depiction
   of the watch see the associated watch outline update (WOUS64 KWNS
   WOU1).

   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 617...WW 618...WW
   619...WW 620...

   AVIATION...A few severe thunderstorms with hail surface and aloft to
   2 inches. Extreme turbulence and surface wind gusts to 65 knots. A
   few cumulonimbi with maximum tops to 500. Mean storm motion vector
   32015.

   ...Thompson

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

   SAW1 
   WW 621 SEVERE TSTM ND 232200Z - 240300Z
   AXIS..60 STATUTE MILES EAST AND WEST OF LINE..
   55N DIK/DICKINSON ND/ - 30W Y22/LEMMON SD/
   ..AVIATION COORDS.. 50NM E/W /44N DIK - 56S DIK/
   HAIL SURFACE AND ALOFT..2 INCHES. WIND GUSTS..65 KNOTS.
   MAX TOPS TO 500. MEAN STORM MOTION VECTOR 32015.

   LAT...LON 47590151 45920155 45920404 47590409

   THIS IS AN APPROXIMATION TO THE WATCH AREA.  FOR A
   COMPLETE DEPICTION OF THE WATCH SEE WOUS64 KWNS
   FOR WOU1.

Watch 621 Status Report Messages:

STATUS REPORT #1 ON WW 621

VALID 232245Z - 232340Z

THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA.

FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 2105

..WEINMAN..08/23/26

ATTN...WFO...BIS...

&&

STATUS REPORT FOR WS 621 

SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS 

NDC001-007-011-025-033-037-041-053-057-059-065-085-087-089-
232340-

ND 
.    NORTH DAKOTA COUNTIES INCLUDED ARE

ADAMS		     BILLINGS		 BOWMAN 	     
DUNN		     GOLDEN VALLEY	 GRANT		     
HETTINGER	     MCKENZIE		 MERCER 	     
MORTON		     OLIVER		 SIOUX		     
SLOPE		     STARK		 
$$


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

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.