IEM Daily Feature
Tuesday, 23 April 2013
Tuesday, 23 April 2013
Weather Phases
Posted: 23 Apr 2013 05:38 AM
With snow once again visiting the state, our recent stretch of weather
has certainly been on the wet and cold side of average. How did we get
to this point? The featured chart is sometimes called a phase plot and
is often used to explain business cycles. Is this context, the line
traces a time-series of 14 day temperature and precipitation departures
since November 2012. There is a nice property of these plots as they
tend to make loops as physical processes in our atmosphere interact on
timescales longer than one day (think passing series of storm systems
and air mass regime changes). By normalizing the axes to standard
deviation departures from average, the time-series is constrained and
will nicely oscillate around within the plot as temperature and
precipitation departures somewhat correlated. Anyway, you can see the
large jump we have recently taken to over 4.0 SD on precipitation and
-1.5 SD on temperature! From here, we have to loop back to somewhere
at least drier (we are currently at a precipitation extreme) and
hopefully warmer. Thankfully, the forecast is hinting at just that with
warmer weather for this weekend and less rain.
Voting:
Good = 58
Bad = 11
Tags: phase
Voting:
Good = 58
Bad = 11
Tags: phase