WMOD00502

• Title: Orographic Production of Supercooled Liquid Water and Precipitation over the Mogollon Rim of Arizona
• Date: 7/1/1990
• Weather Modification - Doc Type: Report

".

. .

studies will be examined to develop comprehensive
microphysical hypotheses of precipitation formation
and the effects of mesoscale orographic dynamics
that control the production of condensate and the
distribution of precipitation.

6. ACKNOWLEDGEMENTS:

The field investigation discussed in this report
was jointly supported by the Arizona Department
of Water Resources; Bureau of Reclamation, Lower
Colorado Region; Central Arizona Water Conservation

District; Maricopa Water District; and the Salt River
Project. Wayne Sand and George Bershinski of the
University of Wyoming capably managed the research
aircraft program and provided their skills as pilots and
scientists. Thanks go to Ed Holroyd who developed
the aircraft analysis software presented here. We also
appreciate the suggestions given by Robert Gall of the
University of Arizona and Terry Clark of NCAR.

7. REFERENCES:
Clark, T.L. and R.D. Farley, 1984: Severe downslope
windstorm calculations in two and three dimensions
using anelastic interactive grid nesting: A possible
mechanism for gustiness. J. Atmo". Sci., 41, 329-
350.
Clark, T.L. and W.D. Hall, 1990: Multi-domain
simulations of the time dependent Navier Stokes
equations: Benchmark error analysis of nesting
procedures. J. Comput. Phy"" (accepted for
publication).
Hobbs, P.V. and A.L. Rangno, 1985: Ice Particle
Concentration in Clouds. J. Atmo". Sci., 42,2523-
2549.
Koenig, L.R. and F.W. Murray, 1976: Ice-bearing
cumulus cloud evolution: Numerical simulations and
general comparison against observations. J. Appl.
Meteor., 15, 747-762.
Super, A.B., E.W. Holroyd,III, J.T. McPartland, 1989:
Winter Cloud Seeding Potential on the Mogollon
Rim, Final Report. R-89-02,Denver, CO 174 pp.

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Figure 1: Topography' of the Mogollon Rim region of
Arizona for domain 1. The contour interval is 100 m.
The brackets indicate domain 2 and the X marks the
location of HJK.

SWR-86 RRDRR DRTR
HAPPY JACK. RRIZONA

TIME-HEIGHT

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50
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35
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25
20
15
10
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-20
-25
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10.0 -35'
1.5 ~~ ~..~ ~I<...
2000 2200 2400

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.. .... ... 44.0

9

...... .._0" ...... 0"'" ..n. ...... ....... ...... ...... ....... ...... ...... 35.0

..................'101;1. ......n.... ...... ~~

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t

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.....! ...... ...... .-:..~ ...... ...... ...... ISO

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Figure 2: Radar time-height composite summary of
Range Height Indicator (RHI) observations parallel to
the wind toward the southwest from HJK, Arizona from
0000 to 2400 MST, 28 January 1987. Surface elevation
is 2.29 km MSL. The echo structure represents the cloud
development upwind and over the crest. Individual
aircraft passes are shown by dots within circles and by
base and topuotation.,

5

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Z(km [~

3 .

. ,

t

.. ..
caJllllIIUI .........

HJK

,....
. dl'!-:. ~

..

40 Ikml

Figure 3: Vertical composite cross-section of liquid
water content (g m-3) observed by the cloud physics
aircraft CSIRO King hotwire liquid water content
instrument from 0820 to 1010 MST on 28 January 1979.
Data observed within 20 km of the 2350 flight track
centered over HJK (HJK) are plotted along the track
at the ~ight altitude (km). The terrain within the
20 km zone is shown at the bottom of the figure. SLW
shows the supercooled liquid water production zone.
IPC shows the snow shower observed below cloud base.
Cloud top and base heights at the time of the flight are
indicated.