From: elmore@rap.ucar.edu (Kim Elmore)
Subject: Aviation Weather (Was Re: ASRS CALLBACK # 163 (December, 1992))
Organization: NCAR, Research Application Program
Distribution: usa
Date: Wed, 6 Jan 1993 16:36:53 GMT

	In an e-mail response to my post about aviation weather,
Jordam Brown pointed out that what I posted about the aviation weather
system could be construed as saying that pilots won't need any weather
knowledge in the future; that it will all be done for them.  I didn't
mean to imply that pilots shouldn't be meteorologically aware and, now
that I think about it, such could implied from my post.  But the
system we currently have is simply inadequate and, frankly, not very
useful.  Certainly, pilots should have some knowledge of weather but
they should *not* be required to perform their own objective analysis
or optimal interpolation of data.

	I want to emphasize that I think the current aviation weather
system *stinks*.  It doesn't serve anyone very well and, because it
requires pilots to be meteorologists in many cases and knows very well
that this is unreasonable, we get the standard "VFR not recommended"
bucket of propwash.  Its also not very accurate and has a CYA tilt to
just about everything.

	An example of a small stride we've already made: The Terminal
Doppler Weather Radar (TDWR) system.  Not long ago, and still in many
places, if the anenmometer network around larger airports, called the
Low Level Wind Shear Alert System (LLWAS) went off, the pilot got an
earfull of wind vectors.  A'la "82T caution windshear alert
centerfield wind 120/10, north quadrant winds 270/15, northeast
quadrant winds 135/20, southeast quadrdant winds 180/17, southwest
quadrant winds 110/8, northwest quadranyt winds 130/12 cleared to
land".  That isn't useful to anyone in flight because it expects you
to draw a picture of the airport, put the anemometers on it and then
draw the wind vectors so you know what's happening; never mind that
there are five "quadrants".  I do stuff like that for a living (among
other things :-) and I can't perform that function and fly the
airplane.  What will we see with the TDWR system?  "82T caution
windshear alert, expect 20 kt loss on 2 mile final, cleared to land."
*THAT'S* what a pilot needs, not a mouthfull of data.  And it's
reliable, too: false alarm rates of less than 0.10 and probability of
detection around 0.93.  When?  The Atlanta TDWR facility will be
commissioned in early June this year, to be followed by about 45 more
in the next 2 years.

	Meteorological awareness needs to be stressed; pilots must
know how to read the data and need rulesets that help them make
decisions about whether or not to go and enough knowledge to recognize
unsavory situations in as they develop in flight.  But they should not
be expected to sit down with 10 pages of computer output and draw a
weather map!  We have the ability to do that for pilots and to do a
good job of it.  This isn't ultra-conservative
whatever-you-do-don't-go stuff.  It's real life,
verified-against-reality products.  Consider today's icing forecasts:
they're a joke!  They cover huge areas and everyone recognizes that
they are way too conservative.  How about a more believable product?
How about something that gives some detail, not just "freezing level
to 18,000 ft" crapola.  Imagine an icing product that's three
dimensional, with contours describing different icing severities
tailored to the aircraft the pilot specifies.  This exact product is
one of many we're working on right now.  How about pictures instead of
reams of data?  Sure, the data is available if you just have to
analyze it for yourself, but our job is to be as accurate as possible,
not cover-our-butts conservative.

	We have the technology to pull this off; there are significant
improvements in forecast model quality on the way with the latest
generation of numerical models and new supercomputers to run them on.
The eta model will be available operationally in the first quarter of
this year; the Forecast System Lab is working on the Mesoscale
Analysis and Prediction System (MAPS) product (nationwaide coverage)
as well as the Local Analysis and Prediction System (LAPS) model
(tuned to local regions).  For the first time, we'll get cloud-water
fields.  Explicit microphysics is now under investigation for the
large scale models.  Merging of IR satellite data, microwave satellite
radiometry, surface observations, NEXRAD and TDWR radar data,
profiling and acoustic sounding systems and ACARS data is being done
specifically for aviation products for the first time ever and will be
available experimentally this summer.  Even PIREPS are being included
in the database.  This is more *data* than any human can possibly
absorb or analyze, but if it's analyzed for us, then we can use it
all.

	What's required of the aviation weather system isn't more
gobbledy-gook data: it's a coherent, believable picture of the state
of the atmosphere, from the surface through the flight levels, along
with believable forecasts of the future state of the atmosphere.
Clearly, there's stuff out there that isn't available to pilots and
some products are still vaporware.  But they will be developed, and
they will be available in a coherent, verified and tested analyzed
products that can be dissected down to the individual observations
that make them up.  It's not pie-in-the-sky dreaming; we have
experimental consoles that display this stuff down the hall from me.
It is the only way we can possibly make use of the observation systems
at our disposal.

-- 

					Kim Elmore
					N5OP, PP ASEL/Glider 2232456
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