Weather Flashback

July 2021 - An Upper Midwest Dryline (August 7, 2015)


I captured this scene on the evening of 7 August 2015 near the Crookston Airport in Minnesota. On this day, a closed area of low-pressure moved east from Saskatchewan to Manitoba. To the south of the low, a weak, south and east -ward moving cold front was evident early in the day across the Dakotas. Clear skies and strong (sensible) heating behind the front result in the development of a deep, dry adiabatic (vertical) layer by afternoon. The leading edge of this shallow, south and east -ward moving warm, dry air impinged on moist air near the surface across western Minnesota. The evidence for higher moisture to the south and east of this Upper Midwest dryline is in convective cloudiness shown. While these types of drylines are not as frequent or as well-studied as drylines in the southern Plains, they can be noteworthy features in meso or synoptic -scale analyses.

Plate 1. An Upper Midwest Dryline. Captured on August 7, 2015 at 8:34pm CDT. Looking northwest from 47.84°, -96.61°.