This proposal recommends a comprehensive radar system for Paducah, KY to monitor storms. It describes Paducah's climate with frequent convective storms covering large areas, though isolated cells are common. The system aims to observe fast-moving storms with high resolution while seeing distant storms. It proposes one S-band radar to scan 250km and detect distant storms, and two C-band radars near Paducah scanning 87.5km with higher resolution to observe storm evolution and winds over the city. The temporal resolution is 5 minutes to track rapid storm changes.

1. Proposal for a Comprehensive Radar System in Paducah, KY
Cobalt: Rachel Bobyak, Spencer Rhodes and Charlon Wright
Department of Marine, Earth and Atmospheric Sciences
I. Climatology
Paducah is located in the far western tip of Kentucky in a region of flood
plains with low hills. Almost all of the precipitation during the months of
April, May, and June falls as rain and is associated with convective
thunderstorms and/or synoptic frontal passages. Storms tend to cover a
large area (Fig. 1a), with much smaller cells often embedded in some
larger system associated with a frontal boundary. Isolated cells are not
uncommon (Fig. 1b), however the majority of cases with isolated
convection often evolve into more congested cells of precipitation, which
can also cover a substantial area. Severe weather such as high winds
and hail is common, with tornadoes occurring occasionally.
II. Design Objectives
III. Radar Hardware
IV. Scan Strategy
Fig. 1a) Example of
widespread precipitation in
the region. These types of
quasi-linear systems are
typically associated with
frontal boundaries. This
particular radar image is
from a warm frontal
passage.
Fig. 1b)
Example of isolated
convective cells near
Paducah, KY. These
convective cells do
eventually merge into a
broader mesoscale
convective system.
 Optimal for observing fast-moving, quickly evolving storms
 Dual polarization for identifying hail and rapidly intensifying storms
 C-band has smaller resolution volume for maximum detail
 S-band has larger range to see approaching storms from any direction
 Combination of C-band and S-band allows view of large storm areas
with minimal attenuation
 Displacement of C-band radars relative to Paducah allows for
calculation of true winds over the city
− Dual polarization requires frequent calibration
− Lack of coverage at long distances due to bending of beam and large
resolution volumes
V. Strengths and Weaknesses
Our objective is to design a radar system that encompasses the
large area of observed storms, yet is able to resolve small
differences in the radial velocity and reflectivity fields. As such, we
are proposing one S-Band radar that scans to a maximum
unambiguous range of 250 km, and two C-Band radars close to the
city that scan out to 87.5 km. Based on these ranges, the S-Band
radar will have a horizontal resolution of 2.2 km, while the C-Band
radars’ horizontal resolution will be 0.57 km. The temporal
resolution necessary for precipitation is determined by the fastest
storm evolution of 5 minutes.
Radars #1 S-band #2 C-band #3 C-band
Wavelength 10 cm 7 cm 7 cm
Beam width 1° .75° .75°
Antenna Size 7 m 6.5 m 6.5 m
Points Spent
Total = 21
(1 + 8) = 9 (1 + 5) = 6 (1 + 5) = 6
VCP Type S-Band Precip
Degrees/sec 14.4
Pulses/degree 41.67
PRF 600 Hz
V max 15 m/s
R max 250 km
Elevation angle
range
0.5°-16°
# of angles to be
scanned
12 (Repeated base
scan)
VCP Type C-Band Precip
Degrees/sec 16.8
Pulses/degree 102.0
PRF 1714 Hz
V max 30 m/s
R max 87.5 km
Elevation angle
range
0.5°-18°
# of angles to be
scanned
14 (Repeated base
scan)
VCP Type C-Band Clear Air
Degrees/sec 4.8
Pulses/degree 357.1
PRF 1714 Hz
V max 30 m/s
R max 87.5 km
Elevation angle
range
0.5°-4.25°
# of angles to be
scanned
8 (Repeat lowest 2
elevation angles)Key Climatological Values Average Value Maximum Value
Temperature (°𝐶) 20.9 31.1
Precipitation (𝑐𝑚) 3.99 14.2
Freezing Level Height (𝑘𝑚) 3.8 4.4
Area of Storms (𝑘𝑚2) 119,886 274,133
Echo Intensity (𝑑𝐵𝑍) 34.6 67.0
Mean Echo Top (𝑘𝑚) 10.6 14.6
Mean Radial Velocity (𝑚𝑠−1
) 10.7 28.7
Storm Motion (𝑚𝑠−1) 16.0 25.2
Storm Evolution (𝑚𝑖𝑛) 11.5 21.0
= Mean Freezing Level Height = Mean Echo Top Height
Acknowledgements: Dr. Sandra Yuter, Nicole Corbin, Jessica King, NOAA, Kentucky State Climate
Office, NCDC, Google, ESRI, Matlab, University of Wyoming, MS PowerPoint