On Saturday, the hourly temperature at the Des Moines Airport was unchanged or got colder with each successive hour. This is a somewhat rare occurrence with the last such day like it back on 27 November 2011. The featured map provides an analysis of station frequency of having such an occurrence since 1973. Setting aside some local climate effects, the map shows the general pattern of having the highest counts over northern US. For this type of event to occur, the cold air advection must be very robust to overwhelm any bit of warming that may happen during the day with sunshine present.

Voting:
Good = 16
Bad = 5
Abstain = 5

Tags:   cold