A new view of seasonal forecast skill: bounding boxes from the DEMETER ensemble forecasts

A. Weisheimer, L.A. Smith, Kevin Judd

Research output: Contribution to journalArticle

16 Citations (Scopus)

Abstract

Insight into the likely weather several months in advance would be of great economic and societal value. The DEMETER project has made coordinated multi-model, multi-initial-condition simulations of the global weather as observed over the last 40 years; transforming these model simulations into forecasts is non-trivial. One approach is to extract merely a single forecast (e.g. best-first-guess) designed to minimize some measure of forecast error. A second approach would be to construct a full probability forecast. This paper explores a third option, namely to see how often this collection of simulations can be said to capture the target value, in the sense that the target lies within the bounding box of the forecasts. The DEMETER forecast system is shown to often capture the 2-m temperature target in this sense over continental areas at lead times up to six months. The target is captured over 95% of the time at over a third of the grid points and maintains a bounding box range less than that of the local climatology. Such information is of immediate value from a user's perspective. Implications for the minimum ensemble size as well as open foundational issues in translating a set of multi-model multi-initial-condition simulations into a forecast are discussed; in particular, those involving 'bias correction' are considered.
Original languageEnglish
Pages (from-to)265-279
JournalTellus Series A : Dynamic Meteorology and Oceanography
Volume57
Issue number3
DOIs
Publication statusPublished - 2005

Fingerprint

DEMETER
simulation
weather
forecast
climatology
economics

Cite this

@article{46b0afe6e77747cab8ca985d163731fc,
title = "A new view of seasonal forecast skill: bounding boxes from the DEMETER ensemble forecasts",
abstract = "Insight into the likely weather several months in advance would be of great economic and societal value. The DEMETER project has made coordinated multi-model, multi-initial-condition simulations of the global weather as observed over the last 40 years; transforming these model simulations into forecasts is non-trivial. One approach is to extract merely a single forecast (e.g. best-first-guess) designed to minimize some measure of forecast error. A second approach would be to construct a full probability forecast. This paper explores a third option, namely to see how often this collection of simulations can be said to capture the target value, in the sense that the target lies within the bounding box of the forecasts. The DEMETER forecast system is shown to often capture the 2-m temperature target in this sense over continental areas at lead times up to six months. The target is captured over 95{\%} of the time at over a third of the grid points and maintains a bounding box range less than that of the local climatology. Such information is of immediate value from a user's perspective. Implications for the minimum ensemble size as well as open foundational issues in translating a set of multi-model multi-initial-condition simulations into a forecast are discussed; in particular, those involving 'bias correction' are considered.",
author = "A. Weisheimer and L.A. Smith and Kevin Judd",
year = "2005",
doi = "10.1111/j.1600-0870.2005.00106.x",
language = "English",
volume = "57",
pages = "265--279",
journal = "Tellus Series A : Dynamic Meteorology and Oceanography",
issn = "0280-6495",
publisher = "Co-Action Publishing",
number = "3",

}

A new view of seasonal forecast skill: bounding boxes from the DEMETER ensemble forecasts. / Weisheimer, A.; Smith, L.A.; Judd, Kevin.

In: Tellus Series A : Dynamic Meteorology and Oceanography, Vol. 57, No. 3, 2005, p. 265-279.

Research output: Contribution to journalArticle

TY - JOUR

T1 - A new view of seasonal forecast skill: bounding boxes from the DEMETER ensemble forecasts

AU - Weisheimer, A.

AU - Smith, L.A.

AU - Judd, Kevin

PY - 2005

Y1 - 2005

N2 - Insight into the likely weather several months in advance would be of great economic and societal value. The DEMETER project has made coordinated multi-model, multi-initial-condition simulations of the global weather as observed over the last 40 years; transforming these model simulations into forecasts is non-trivial. One approach is to extract merely a single forecast (e.g. best-first-guess) designed to minimize some measure of forecast error. A second approach would be to construct a full probability forecast. This paper explores a third option, namely to see how often this collection of simulations can be said to capture the target value, in the sense that the target lies within the bounding box of the forecasts. The DEMETER forecast system is shown to often capture the 2-m temperature target in this sense over continental areas at lead times up to six months. The target is captured over 95% of the time at over a third of the grid points and maintains a bounding box range less than that of the local climatology. Such information is of immediate value from a user's perspective. Implications for the minimum ensemble size as well as open foundational issues in translating a set of multi-model multi-initial-condition simulations into a forecast are discussed; in particular, those involving 'bias correction' are considered.

AB - Insight into the likely weather several months in advance would be of great economic and societal value. The DEMETER project has made coordinated multi-model, multi-initial-condition simulations of the global weather as observed over the last 40 years; transforming these model simulations into forecasts is non-trivial. One approach is to extract merely a single forecast (e.g. best-first-guess) designed to minimize some measure of forecast error. A second approach would be to construct a full probability forecast. This paper explores a third option, namely to see how often this collection of simulations can be said to capture the target value, in the sense that the target lies within the bounding box of the forecasts. The DEMETER forecast system is shown to often capture the 2-m temperature target in this sense over continental areas at lead times up to six months. The target is captured over 95% of the time at over a third of the grid points and maintains a bounding box range less than that of the local climatology. Such information is of immediate value from a user's perspective. Implications for the minimum ensemble size as well as open foundational issues in translating a set of multi-model multi-initial-condition simulations into a forecast are discussed; in particular, those involving 'bias correction' are considered.

U2 - 10.1111/j.1600-0870.2005.00106.x

DO - 10.1111/j.1600-0870.2005.00106.x

M3 - Article

VL - 57

SP - 265

EP - 279

JO - Tellus Series A : Dynamic Meteorology and Oceanography

JF - Tellus Series A : Dynamic Meteorology and Oceanography

SN - 0280-6495

IS - 3

ER -