Transcript Hail Threat Standardisation

Hail Threat Standardisation
Gennaro Cappelluti, Paul Field & Will Hand
Atmospheric Processes & Parametrizations
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Hail Threat
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• kinetic energy
• diameter
• thickness
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Ice Water Path 12h 2004-8
AMSU-B
NOAA15, 16, 17
89, 150, 183 GHz
830 km, 101 min,
16 km
hail, graupel, snow, anvil ice, sea ice, desert sand
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Diurnal Cycle of Flash Density
PDD
photodiode detector
FORTE satellite
non imaging
1200 km
WWLLN
em energy sensors
28 stations world wide
5/28 stations
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Flash Density 12h Climatology
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NASA Global Hydrology and Climate Center
Hail Water Path 12h 2004-8
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HWP(s,t) = IWP(s,t) · H · FD(s,t) / FDmax(s)
HWP Peak Hour 2004-8
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Convective Diagnosis Procedure
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USA
NSSL observations peak over Oklahoma (9 hail days per
year) with almost no hail precipitation over the West; the
CDP data show New Mexico and Arizona as the areas with
the highest density of hail days (20 hail days per year).
Hail days per year (1980-1999) from NSSL
The NSSL point
climatologies show
a constant increase
of hail days over
the years, probably
due to increasingly
higher accuracy in
the observations.
Point hail climatology from NSSL
according to day of year
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normalised
hail days
density
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
0.008751
0.018296
0.037923
0.094807
0.146797
0.173180
0.174934
0.165147
0.112504
0.051991
0.015671
0.000000
Canada
Mean annual hail day frequency in China 1961-2005
(Zhang et al., 2008).
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The 30 year hail climatology for
Canada points out a peak of 5 hail
days per year between May and
September over the Rockies, while
the CDP analysis highlights a peak
of 8 hail days per year in the same
period, the mean being 2.
New South Wales
Total number of hailstorms and hail days
occurring in each month in NSW from 1791
to 2003. The solid line is the monthly
average number of hailstorms and the
dashed line is the monthly average number
of hail days (Schuster et al, 2005).
ma=538
me=70
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JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
ma=100
me=17
normalised
hail days
density
scaled
hail days
number
model
hail days
number
hail days
density
0.124273
0.142917
0.075451
0.055035
0.046780
0.017056
0.015876
0.022192
0.055035
0.110958
0.151347
0.183081
156
180
95
69
58
21
20
27
69
139
190
230
2385
2500
1448
1022
898
316
304
426
1022
2130
2811
3514
0.361290
0.415493
0.219355
0.160000
0.136000
0.049587
0.046154
0.064516
0.160000
0.322581
0.440000
0.532258
ma=43
me=2
ma=247
me=51
Africa
Mean annual frequency of hail over Africa
(10 year record).
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max = 183 hail days / year
Europe
max = 22 hail days / year
Preliminary climatology of large hail (> 2cm) over
Europe showing average number of reports per
year per 10000 km2 in the period 2000-2007
(http://www.essl.org/research/).
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The CDP data show high densities of hail days over
the Alps, Italy, Romania, ex Yugoslavia and Greece,
while the ESSL over Germany and Romania, with
lack of record over Italy and ex Yugoslavia. As the
ESSL data are biased over Germany due to a very
dense observing network prior to 2005, the CDP
peak areas matches broadly the ESSL, over Romania
and the Pyrenees.
United Kingdom
normalised
hail days
density
Mean number of days
of thunder in the British
Isles (1971-2000). Key:
black = 15–19 days,
dark grey = 10–14
days, light grey = 5–9
days, white = under 5
days (Webb et al.,
2008).
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Number of hailstorms
(per 1000 km2 per 100
years) containing hail
reaching or exceeding
1.5 cm diameter, for
counties of England and
Wales, 1930-2004
(Webb et al., 2008).
Monthly percentage distribution
of hail storms with hail
diameter greater than 1.5 cm
over the British Isles in the
period 1930-2004 (Webb et al.,
2008).
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
0.000000
0.000000
0.047675
0.049078
0.139950
0.151694
0.215308
0.186887
0.052973
0.156435
0.000000
0.000000
Summary
• HWP climatology
• Peak hour analysis
• Hail days climatology
• Local climatologies
• Aircraft material and dimensions
• Aircraft routes
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