On Saturday, 31 December 2016 11:56:09 UTC, Norman Lynagh wrote:


A casual glance at the ensembles recently shows that beyond about 5 days there
is so much divergence that the situation is effectively unforecastable. The
operational runs of any model beyond about 5 days are getting into fantasy
land.

It all began with chaos and spin
Jive talkin', you're telling me lies, yeah
Jive talkin', you wear a disguise
Jive talkin', so misunderstood, yeah
Jive talkin', nope NWP no good

Some people will never know
Just what charts say
Is what the world does
They're gonna take away the energy

With all their
Jive talkin', they're not telling lies, yeah
Around t 72 all of those highs
Nobody believes what they say
It's just jive talkin' that gets in the way


With all your
Jive talkin', you're telling me lies, yeah
Jive talkin', you wear a disguise
Jive talkin', so misunderstood, yeah
Jive talkin', you just ain't no good

Unfortunately, it's not easy to build uncertainty into the apps
that are so prevalent these days.

Medium-range NWP output is a tool for meteorologists, not end-user material for
Joe Public.