MESOSCALE DISCUSSION 1392
NWS STORM PREDICTION CENTER NORMAN OK
1139 PM CDT FRI JUN 20 2025
AREAS AFFECTED...PORTIONS OF EASTERN NORTH DAKOTA INTO NORTHWESTERN
MINNESOTA
CONCERNING...TORNADO WATCH 449...
VALID 210439Z - 210545Z
THE SEVERE WEATHER THREAT FOR TORNADO WATCH 449 CONTINUES.
SUMMARY...A DERECHO MAY CONTINUE FOR A FEW MORE HOURS, WITH SEVERE
WINDS REMAINING WIDESPREAD, AND 75-100 MPH GUSTS STILL POSSIBLE IN
THE SHORT TERM. SEVERAL QLCS TORNADOES MAY ALSO OCCUR.
DISCUSSION...A DERECHO-PRODUCING BOW-ECHO MCS CONTINUES TO RAPIDLY
PROPAGATE EASTWARD, ACCOMPANIED BY A WIDESPREAD/HIGH-END SEVERE WIND
SWATH. GIVEN THE PERSEVERANCE OF A STRONG REAR-INFLOW JET AND LARGE,
LINE-END MESOVORTEX, PROLONGED SEVERE WINDS REMAIN POSSIBLE WELL
INTO THE TRAILING PRECIPITATION REGION OF THE PARENT BOW-ECHO MCS,
BEHIND THE LEADING LINE. TO THE EAST, TORNADIC SUPERCELLS PERSIST,
WITH RECENT EVIDENCE OF STRONG TORNADOES. OVER THE NEXT COUPLE OF
HOURS, THE BOW-ECHO WILL MERGE WITH THESE SUPERCELLS, AND THE
SUPERCELLS WILL PERSIST FOR SOME TIME BEFORE GRADUALLY MORPHING INTO
PRONOUNCED, DEEP MESOVORTICES EMBEDDED IN THE LINE. THROUGH THIS
ENTIRE PHASE, SEVERE WINDS AND LINE-EMBEDDED TORNADOES WILL REMAIN A
CONCERN. 75-100 MPH GUSTS AND EF2+ TORNADOES WILL BE MOST LIKELY IN
THE EARLY MERGING PROCESS. A FEW HOURS FROM NOW, MAINLY 65-75 MPH
WINDS WILL BE LIKELY, THOUGH A FEW EMBEDDED 75+ MPH GUSTS AND/OR
QLCS TORNADOES WILL REMAIN POSSIBLE.