Transcript Conceptual Graph - American Meteorological Society

Seasonal Forecasts
using
Objectively Chosen Analog Years
Seasonal Forecasts
using
Objectively Chosen Analog Years
•The Technique
•2011-12 Verification
•Analogs for Upcoming Winter
•The Forecast
Analog Seasonal Forecasting
• Look at this year so far…
Analog Seasonal Forecasting
• Look at this year so far…
• Look for past years that are similar to
this year …
Analog Seasonal Forecasting
• Look at this year so far…
• Look for past years that are similar to
this year …
• Use what subsequently happened in
those past years as a forecast for what
will happen this year.
Analog Seasonal Forecasting
• Look at this year so far…
• Look for past years that are similar to
this year …
• Use what subsequently happened in
those past years as a forecast for what
will happen this year.
Climate Indices
PNA (Pacific North American Index)
NAO (North Atlantic Oscillation)
Jones NAO
EPO (Eastern Pacific Oscillation)
TNH
ONI
NTA (North Tropical Atlantic Index)
CAR (Caribbean Index)
MEI
BEST
Nino 3
Nino 1+2
Nino 3+4
Nino 4
Pacific Warm Pool
Tropical Pacific SST EOF
TNA
TSA
WHWP WP (West Pacific Index)
QBO (Quasi-Biennial Oscillation)
PDO (Pacific Decadal Oscillation)
PMM (Pacific Meridional Mode)
NP (North Pacific Index)
NOI (Northern Oscillation Index)
AO (Arctic Oscillation)
AAO
TNI
Atlantic Tripole SST EOF
AMO
AMM (Atlantic Meridional Mode)
ACE (Atlantic Accumulated Cyclone
Intensities)
Solar Cycle (Flux)
Monthly Hurricane Total
MDR Hurricanes SST Anomaly
MDR - Tropics SST Anomaly
Central India Monsoon Precipitation
Sahel Rainfall
Brazil Rainfall
SW USA Monsoon
Global Mean Temperature
ESPI
Globally integrated angular
momentum
Automate the Process
• Compare each previous year to this
year…
• Compute a “Goodness of Fit”
number…
• Sort “Goodness of Fit”…
• Print/Save results…
• Do this for multiple indices…
• Find “Consensus” analog years
2011/12 Forecast Summary
Forecast:
Nov
Climate Division 2 – Willamette Valley
Dec
Jan
Feb
Mar
Apr
Above Near Near Below Near Below
Precip: Near
Near Above Near Below Near
Temp:
2011/12 Forecast Summary
Forecast:
Nov
Climate Division 2 – Willamette Valley
Dec
Jan
Feb
Mar
Apr
Above Near Near Below Near Below
Precip: Near
Near Above Near Below Near
Temp:
Observed:
Nov
Climate Division 2 – Willamette Valley
Dec
Jan
Feb
Mar
Apr
Below Below Near Near Below Below
Precip: Near Below Above Below Above Above
Temp:
2011/12 Forecast Summary
Forecast:
Climate Division 2 – Willamette Valley
Nov
Dec
Jan
P
P
Feb
Mar
Apr
P
Above Near Near Below Near Below
Precip: Near
Near Above Near Below Near
Temp:
P
Observed:
Nov
Climate Division 2 – Willamette Valley
Dec
Jan
Feb
Mar
Apr
Below Below Near Near Below Below
Precip: Near Below Above Below Above Above
Temp:
2011/12 Verification
• 4 “Hits”
• 6 One-category errors
• 2 Two-category errors
On to Next Winter…
On to Next Winter…
On to Next Winter…
Indices
CPC SOI, MEI, ONI,
BOM SOI, Nino 3.4 Anom,
Nino 3 Temps, Nino 4 Temps,
PNA, PDO, NAO, AO, WP,
and the QBO.
Composites
December…
Composites
January…
Composites
February…
Composites
March…
April
May
April
May
April
May
http://weather.jimlittle.net/2012 Winter Forecast Graphics
Portland/Willamette Valley
Month by Month…
Median
“Near”
Median
Summary
Climate Division 2 – Willamette Valley
Dec
Jan
Feb
Mar
Apr
May
Near Near Above Near Near Near
Precip: Below Above Below Near Above Near
Temp:
Cascades
Summary
Climate Division 4 – North Cascades
Dec
Jan
Feb
Mar
Apr
May
Near Near Near Near Below Near
Precip: Near Above Below Above Above Below
Temp:
Government Camp Snow
December
23d 24th 25th 26th 27th 28th 29th 30th 31st
2009 21
21
20
19
19
19
19
26
26
2001 56
56
54
52
50
50
50
50
48
1996 53
65
64
67
67
68
71
52
50
1986 6
8
8
8
7
6
6
11
11
1968 54
55
46
46
52
60
65
70
74
1963 8
7
8
9
8
6
6
5
3
Snow Depth in Inches
Government Camp Snow
December
23d 24th 25th 26th 27th 28th 29th 30th 31st
2009 21
21
20
19
19
19
19
26
26
2001 56
56
54
52
50
50
50
50
48
1996 53
65
64
67
67
68
71
52
50
1986 6
8
8
8
7
6
6
11
11
1968 54
55
46
46
52
60
65
70
74
1963 8
7
8
9
8
6
6
5
3
Snow Depth in Inches
Government Camp Snow
December
23d 24th 25th 26th 27th 28th 29th 30th 31st
2009 21
21
20
19
19
19
19
26
26
2001 56
56
54
52
50
50
50
50
48
1996 53
65
64
67
67
68
71
52
50
1986 6
8
8
8
7
6
6
11
11
1968 54
55
46
46
52
60
65
70
74
1963 8
7
8
9
8
6
6
5
3
Snow Depth in Inches
4 of 6 Years Great!
2 of 6 Marginal
Questions?
Climate Division 2 – Willamette Valley
Dec
Jan
Feb
Mar
Apr
May
Near Near Above Near Near Near
Precip: Below Above Below Near Above Near
Temp:
[email protected]
[email protected]
http://weather.jimlittle.net/2012 Winter Forecast Graphics