Several days ago, Andy Revkin did a nice post querying a number of weather forecasters and researchers about the relative merits of
the different forecast models [link], particularly since everyone seemed to be paying attention to the European model (ECMWF) rather than NOAA's GFS model.
Not exact matches
When the company auctions that oilfield drill, for example, the goal is for its pricing
model to
forecast demand in the near future based on
different factors, such as the price of oil, leaving Ritchie Bros. less vulnerable to market surprises.
Vlieghe told the committee: «I'm never confident of any
forecast, and I think the big thing that we risk missing here is that every time there is what we call a
forecast error — which means the outturn is
different from the central projection — to think that «Well if only we'd had a better
model we wouldn't have made that
forecast error.»
Third, the specifications of their econometric
models differ, thereby resulting in
different results, even if they used the same economic
forecasts and distributions.
Accordingly, the key difference between our DCF
model and others is that we calculate the value attributable to equity shareholders over multiple (100)
different forecast periods or what we call Growth Appreciation Periods (GAP)[1].
Our
models compare and contrast multiple
forecast scenarios so clients can assess the valuation impact of
different forecasts for revenue growth, margins and capital allocation strategies.
, Fabian Hollstein, Marcel Prokopczuk and Chardin Simen test effects of
different return sampling frequencies,
forecast adjustments and
model combinations on market beta prediction accuracy across the universe of U.S. stocks.
It considers a multitude of
different models,
forecasts and scenarios that all businesses should be considering in their long term planning.
It seems from one run of the
models to the next we keep getting a
different scenario and timing but generally I go back to my original
forecast that there is a good threat of rain during the race.
Complex
Forecasting Models: ElectionForecast.co.uk (Chris Hanretty) Electoral Calculus (main and local election forecast) Forecast UK UK - Elect PME Politics (Patrick English) Nigel Marriot (Uniform Regional Swing + Tactical Voting Model) Chris Prosser (GE vote shares from Local elections vote shares) Lord Ashcroft (3 models based on different turnout esti
Models: ElectionForecast.co.uk (Chris Hanretty) Electoral Calculus (main and local election
forecast)
Forecast UK UK - Elect PME Politics (Patrick English) Nigel Marriot (Uniform Regional Swing + Tactical Voting
Model) Chris Prosser (GE vote shares from Local elections vote shares) Lord Ashcroft (3
models based on different turnout esti
models based on
different turnout estimates)
Forecasters merged 480
different models for the 2007 California
forecast to produce a single
forecast with more clearly defined uncertainties.
We use
different computer
forecast models that feed initial conditions — including temperatures, humidity, wind speed and wind direction from around the United States and around the world, from the surface all the way up to the jet stream — into
different equations.
There are about 30 climate
models available today, and each has slightly
different physics, which means their
forecasts do not always match.
In a study set to come out in Nature tomorrow, an international group of scientists reports that they simulated atmospheric behavior using several
different models and used them to
forecast anthropogenically driven changes in average annual rainfall at
different latitudes from 1925 to 1999.
The researchers then turned to a
different framework using the Weather Research and
Forecasting regional
model to study the event in more detail.
The study used more than 40 scientific publications and Australian Institute of Marine Science monitoring data from 18 Australian reefs to build and validate a
model to
forecast the reef's future under
different conditions.
The researchers use computer
models to
forecast future ocean conditions such as surface temperatures, salinity, and currents, and project how the distribution of
different fish species could respond to climate change.
While reading James O'Shaughnessy's Predicting the Markets of Tomorrow (full review to come later), I came across an interesting section with three
different models used to
forecast the Standard & Poor's 500 Index.
These criteria provide useful metrics for us to compare
different alpha -
forecasting models.
Combining this value with the current dividend yield of 2.0 % results in a forward one - year expected yield of 3.5 %, not dramatically
different from the return
forecast by
Model 1.
Forecasting what may most likely happen with these factors over time (given the assumed fluctuations in the markets - which you can control every year by using
different rates of return on every investment for every year - including negative rates of return, and being able to change your income goal every year) is much more important to
model, than a one - dimensional probability number, to an actual investor's life.
Or said a
different way, a
model's value is in the collection of
forecasts it encompasses — that is, the system itself — and not in the individual
forecasts.
My local NOAA weather page, at the moment, reports that because two
models used give rather
different longrange results, the
forecast is:
Scenarios A, B, and C are the same
model, but with
different forcings (
different greenhouse gas emissions
forecasts).
The UK Met Office
forecast uses a very
different methodology than Gray, based upon climate
models rather than a statistical technique.
ECMWF, NCEP GFS, UK MetOffice Unified
Model, and Canadian GEM are the top global weather
models and each use somewhat
different methods to
forecast one atmosphere.
The breadth is inspiring: From novel bioactives for biotechnology and agri - tech, over autonomous and remote sensing for challenging environments, to
modelling for space weather
forecasts and sea - level rise our expertise can add value to many
different sectors of industry and society.
Both the accuracy of
forecast assumptions and
model performance are both important, but for
different reasons.
Careful calibration and judicious combination of ensembles of
forecasts from
different models into a larger ensemble can give higher skill than that from any single
model.
Different models are used for weather prediction versus climate
forecasts.
Also, some
models just aren't for
forecasting at all, or are for
forecasting different vectors than interest some readers.
Climate
modelling has a
different problem: based on
forecast and projection, it is by definition an inexact science, but one upon which concrete decisions must be based if governments and societies are to assess risks and plan ahead.
SWIF's performance was evaluated during disturbed conditions against standard
models (e.g., climatology and persistence) and other
forecasting models of
different philosophy such as the TSAR that is a purely autoregressive technique and the Geomagnetically Correlated Autoregression
Model — GCAM (Muhtarov et al. 2002) that is driven by the geomagnetic activity level by incorporating the cross-correlation between the foF2 and the Ap - index into the auto - correlation analysis (Tsagouri et al. 2009).
Understanding how these
different climate phenomena interact, how they are simulated in
models, and how they can be used for sub-seasonal to seasonal
forecasting is currently a major focus of research.
And that change can be
modelled in many ways which each leads to a
different forecast of future atmospheric CO2 concentration.
In our climate
modeling project we were trying to combine
different temperature
forecasts on a scale in which Africa was represented by about 600 grid boxes.
There are a wide range of sensitivities in the
models used in the IPCC reports yet the individual
model forecasts haven't separated themselves into
different temperature ranges based on their sensitivities yet, they're still all mixed together.
BBD If a book is written that uses
models to
forecast future conditions in the UK, but those same
models have been demonstrated to not be able to even reasonably accurately predict future rainfall at any specific location, what good is the analysis in the book that describes
different conditions based on changes in rainfall?
In this graph from the new paper, gray shading shows pollution levels
forecast by
different models if there were no clean - energy investment.
Various hydrologic
models with
different complexities have been developed to represent the characteristics of river basins, improve streamflow
forecasts such as seasonal volumetric flow predictions, and meet other demands from
different stakeholders.
[Poitou & Bréon] It is because the climate is a chaotic system that
models can
forecast the Climate for conditions very
different of todays.
They also show that some
forecast models are better than others at
different times of year.
They also recommend usage of
different independently devised
models to produce ensemble
forecasts, for better comparison and quicker
model improvements.
It's pretty funny that the GWPF is predicting no warming based on statistical analyses that can't agree whether warming stopped in 1998 or 2002, and pretty funny that the two
modeling techniques used deliver quite
different forecasts, making not one, not two, but four
different forecasts — all of which we are apparently supposed to take more seriously than anything that is based on, you know, physics.