A 993 mb low will move across Iowa into Minnesota on April 20 - 21, 2023 swinging a cool front/dry line across the Mississippi River Valley and Eastern Arkansas River Valley. Hail, wind, and isolated tornadoes will all be possible with this system. Slight Non-polar CH4 release is expected from tree stems, and shallow water systems such as creeks, rivers, and lakes. Slight NO3 levels are expected from CAPE buildup and polar positive lightning strikes to develop a severe weather threat. NO3 will slightly tighten with soluble H20 to create a slight atmosphere for ground tornado development. Measurements of new information taken this morning indicate the slight potential for hail, wind, and isolated tornadoes April 20-21, 2023. Surface measurements are running .17, .17, .12, .12, and .11 which indicates a slim to a slight chance of tornadoes but this could change in the coming days. A new parameter of hail and wind threshold has been developed which indicates a hail and wind surface measurement of .15. This indicates hail and wind will be a better bet with severe storms on the next system. Measurements are still below the.25 threshold of dangerous tornado potential. Basically, EF-0 to EF-1 tornadoes could play out as of the latest measurements in an isolated fashion but the risk is slight. Check back tonight for more information on surface measurements and forecast updates.
Forecaster:
Climate Scientist Wayne Adams