Roque Vinicio Céspedes
May 3, 2013
MPO 524 - Applied Data Analysis
Spring 2013 Term Project
Professor Brian Mapes
Outline
What is a daily stochastic weather generator?
Motivations
 Application to modeling and climate change
What is WeaGETS?
Weather Generator École de Technologie Supérieure
(WeaGETS)
My own results
http://www.mathworks.com/matlabcentral/fileexchang
e/29136-stochastic-weather-generator-weagets
What is a daily stochastic weather
generator?
What is WeaGETS?
Weather Generator École de Technologie Supérieure
(WeaGETS) is a Matlab-based versatile stochastic daily
weather generator (WeaGETS) for producing time
series of unlimited length for daily precipitation at a
specific weather station site, plus maximum and
minimum temperatures.
WeaGETS can be used in climate change studies as a
downscaling tool by perturbing the parameters to
account for expected changes in precipitation and
temperature.
What is WeaGETS?
First, second and third-order Markov models are
provided to generate precipitation occurrence.
Exponential and gamma distributions are available to
produce daily precipitation quantity.
Precipitation generating parameters have options to
be smoothed using Fourier harmonics.
A spectral correction approach is included to correct
the well-known underestimation of monthly and
inter-annual variability associated with weather
generators.
What is WeaGETS?
My Data
National Oceanic and
Atmospheric
Administration (NOAA)
Climate Prediction
Center (CPC) 0.25 
0.25 Daily U.S.
UNIFIED Precipitation
Version 1 (1951-2000)
rain-gauge-based
precipitation
32
31
30
29
28
27
26
25
24
-88
-86
-84
-82
-80
-78
Florida Rainfall
Whole State - 25th Year
12
7-Day Running Mean (mm / day)
11
10
9
8
7
CPC Obs. (1975)
Generated
Corrected
6
5
4
3
2
1
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Month of the Year
Sep
Oct
Nov
Dec
Florida Rainfall
Whole State
50-Year Mean Seasonal Cycle
12
7-Day Running Mean (mm / day)
11
10
9
8
7
CPC Obs. (1951-2000)
Generated
Corrected
6
5
4
3
2
1
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Month of the Year
Sep
Oct
Nov
Dec
Florida Rainfall
Whole State
50-Year Standard Deviation
7-Day Running Mean (mm / day)
7
6.5
6
5.5
CPC Obs. (1951-2000)
Generated
Corrected
5
4.5
4
3.5
3
2.5
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Month of the Year
Sep
Oct
Nov
Dec
CPC Obs. (1951-2000)
Generated
12
1996
1991
11
10
46
41
9
1986
Corrected
12
11
10
46
41
9
36
8
1981
12
10
9
36
8
31
7
11
8
31
7
7
1976
6
26
6
26
6
1971
5
21
5
21
5
4
1966
4
16
3
1961
3
11
2
1956
1951
J F M A M J J A S O N D
1
0
4
16
3
11
2
6
1
J F M A M J J A S O N D
1
0
2
6
1
J F M A M J J A S O N D
1
0
CPC Obs. (1951-2000)
7000
Frequency
6000
5000
4000
3000
2000
1000
0
1
2
3
4
5
6
7
8
9
10
11
12
8
9
10
11
12
8
9
10
11
12
Precipitation Amount (mm / day)
First Generated 50 Years
7000
Frequency
6000
5000
4000
3000
2000
1000
0
1
2
3
4
5
6
7
Precipitation Amount (mm / day)
First Correted 50 Years
7000
Frequency
6000
5000
4000
3000
2000
1000
0
1
2
3
4
5
6
7
Precipitation Amount (mm / day)
Any question???