MMARY...THE TORNADO THREAT IS LIKELY INCREASING ACROSS NORTHERN
MINNESOTA AS THUNDERSTORMS DEVELOP WITHIN A FAVORABLE ENVIRONMENT.
DISCUSSION...GOES VISIBLE AND IR IMAGERY SHOW STEADY VERTICAL GROWTH
OF CONVECTION ACROSS NORTH-CENTRAL MN ALONG AND NORTH OF A WARM
FRONT AND TO THE WEST AHEAD OF A COLD FRONT. BASED ON RECENT RAP
FORECAST SOUNDINGS, AREAS THAT HAVE TEMPERATURES IN THE MID 70S OR
HIGHER WILL LIKELY SUPPORT SURFACE-BASED CONVECTION WITHIN THE WARM
FRONTAL ZONE WHERE BACKED LOW-LEVEL WINDS ARE YIELDING EFFECTIVE SRH
ON THE ORDER OF 200-250 M2/S2. INCREASING LOW TO MID-LEVEL ASCENT
ASSOCIATED WITH THE APPROACH OF AN UPSTREAM PERTURBATION AND WITHIN
THE WARM ADVECTION REGIME SHOULD PROMOTE CONTINUED STORM MATURATION
AND COVERAGE OVER THE NEXT COUPLE OF HOURS. GIVEN THAT THE NUMBER OF
CANDIDATE STORMS APPEARS TO BE INCREASING WITHIN THIS NARROW, BUT
VERY FAVORABLE ENVIRONMENT (BEST CHARACTERIZED BY STP VALUES BETWEEN
3-5), THE POTENTIAL FOR TORNADOES - INCLUDING STRONG TORNADOES - MAY
INCREASE IN THE COMING HOURS IF ONE OR MORE MATURE SUPERCELLS CAN
MAINTAIN SUFFICIENT RESIDENCE TIME WITHIN THIS CORRIDOR.
..MOORE.. 06/22/2025