Radar Imagery

October 2004

Let us begin with a satellite image…

17 October 2004 2230Z  
Note the huge parallelogram opened across the Great Salt Lake
extending into southern Idaho.  A big clear square zone
devoid of clouds and forecast rainfall.  A big bust for
a showery day forecast.

Base Reflectivity1 Scan Oct 17, 2004
2235Z/4:35pm Local

This is 15 minutes later when compared to the above
satellite image. Not much rainfall making the ground; the
showers do line up to the grid. We have to learn to recognize
that more unnatural forces drive our weather than natural;
this dictates a change in our paradigm of understanding of
the operational unnatural meteorological world around us.

 

Composite Reflectivity Scan Oct 17,
2004 2230Z/4:30 Local

This scan includes the ‘brightest’ echoes. the extra
data/levels helps us see the squares right-angle bends somewhat
easier.

Discovering scalar signatures in clouds is
fairly easy, then seeing how those shapes translates into
rain and snowfall becomes just another part of understanding
this grand project.  Just as with clouds, there are hot
zones where the rain is allowed to fall, and others where
it is not. During this past year some impressive storms have
worked through the Northern Rockies yet rainfall has not measured
up to what is expected; thus continuing our drought. While
doing a post mortem of these storms it became evident that
large chunks of what should be a storm’s rain or snow shield
are simply large squares, or semi circle voids, large voids
where the moisture is simply not allowed to condense into
anything more than deck of mid or high-level clouds. One storm,
last May 28th 2004, as the storm advanced inland we were well
into the warm advection rain shield expecting the rains to
begin at any moment… suddenly, the entire Snake River plain
was cleared out as cloud cohesion was lost; greater than half
of that storms potential was stolen from us.  These warm
‘IR holes’ as I like to call them, show up nicely below on
the composite reflectivity and very clearly on Base Ref 1
tilt scans and IR satellite loops.  Weathermen, start
looking for them!

There is much work yet to be done in matching
specific satellite signatures with showers actually reaching
the ground. more time and interns would be great! 

 

 
 

 

Sunday evening September 19, 2004
7:26pm Mountain eastern Idaho

An exceptionally potent storm worked across the Northern
Rockies this day, we received about 1/5 the rainfall as compared
to model forecast of the storm potential.  One look at
this radar image and it is easy to see why. What should have
been a 100 to 125 mile wide rain band accompanying the front
what cut into much smaller, much weaker, 20 mile wide meager
rain zones. This was stolen rainfall, from what should have
been an impressive and memorable storm, it was cut down to
‘normal.’   This is what happens to a storm, that
is greater than three standard deviations from normal, so
it doesn’t garner too much attention. Oh, and it happens all
the time much to my frustration.

 

This is the area (radar data)where I have
done the least amount of work. Archiving radar imagery just
plain stinks, until I can streamline this process my energies
will be directed elsewhere. Much work needs to be done.