One additional precipitation maximum of 80 mm, not present at any lower resolution, is simulated in west-central Kansas. This plot shows an east-west elongated primary region centered over central Iowa with a maximum contour of 127 mm. To the west of the primary center, in central Nebraska, a second closed contour is simulated to have a maximum of about 38 mm. A third east-west elongated region centered in central Minnesota has maximum of about 25 mm. The simulations presented are our first results and are subject to modification as our experience increases.
Total precipitation produced by the model also is far below the observed amount.
Marked improvement in defining major precipitation regions and 24 hour accumulated amounts is realized by increasing the resolution to 90 km. Secondary regions resembling observed locations of maxima are resolved. A large amount of precipitation seems to be produced at a single grid point not within the observed heavy precipitation region. Increase of the resolution to 60 km modestly refines the primary precipitation region and the location of its maximum. Oddly enough, a secondary precipitation region has its precipitation reduced from 30 mm to less than 20 mm.