NWS ILX in Lincoln, IL bringing up a blocking pattern taking place for Memorial Day weekend heading into next week.
Heading into next week, global deterministic models suggest the
development of a Rex block over the Plains. The progression of
the associated upper low will ultimately dictate rain and storm
potential through early next week. Current indications suggest
that areas south of I-72 are best positioned for rainfall as the
low portion of the block pivots up the Mississippi Valley while
the high-pressure side loiters over the Corn Belt. There is
stronger model agreement regarding temperatures, with mid-to-
upper 80s heat forecast to return by the middle of next week.