Weather and climate forecasts - Revision history

JeffreyJLukas: /* Additional Resources */

2024-10-31T20:44:25Z

Additional Resources

← Older revision		Revision as of 16:44, 31 October 2024
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	[https://wwa.colorado.edu/publications/reports/CRBreport/ColoRiver_StateOfScience_WWA_2020_Chapter_7.pdf Chapter 7] of the State of the Science report covers many aspects of Weather and climate forecasts in much greater detail.		[https://wwa.colorado.edu/publications/reports/CRBreport/ColoRiver_StateOfScience_WWA_2020_Chapter_7.pdf Chapter 7] of the State of the Science report covers many aspects of Weather and climate forecasts in much greater detail.

			===[https://www.zotero.org/groups/4274378/colorado_river_science_wiki/collections/2WJ74YUS Wiki Library: Weather and climate forecasts]===

			The Wiki library lists over 20 research publications on weather and climate forecasts that discuss forecast methods and products that are relevant to the Colorado River Basin.

JeffreyJLukas: /* Data and Tools */

2024-10-21T20:53:05Z

Data and Tools

← Older revision		Revision as of 16:53, 21 October 2024
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	====[https://www.cbrfc.noaa.gov/rmap/grid/index.php?type=qpf CBRFC Quantitative Precipitation Forecast (QPF) Grids]====		====[https://www.cbrfc.noaa.gov/rmap/grid/index.php?type=qpf CBRFC Quantitative Precipitation Forecast (QPF) Grids]====
	This is the QPF as used by CBRFC to drive their streamflow forecast model system. Days 2-7 are taken from the NWS WPC QPF product shown above; Day 1 comes from the very similar NWS National Blend of Models (NBM) QPF.		This is the QPF as used by CBRFC to drive their streamflow forecast model system. Days 2-7 are taken from the NWS WPC QPF product shown above; Day 1 comes from the very similar NWS National Blend of Models (NBM) QPF.

	~~====[https://www.emc.ncep.noaa.gov/users/meg/gefs_plumes/index.html?stationname=KASE GEFS Ensemble Plumes (for cumulative precipitation)]====~~
	This is another way of displaying a QPF (here, an 8-day ensemble forecast from the GFS weather model), for a single location. This URL shows the forecasted cumulative precipitation for KASE (Aspen, CO); zoom in on the map to select any other of ~20 locations within the Colorado River Basin. The plume shows the uncertainty in the forecast given our imperfect knowledge about the initial atmospheric conditions.

	===[https://www.cpc.ncep.noaa.gov/products/predictions/814day/index.php NWS CPC 8-14 day Temperature and Precipitation Outlooks]===		===[https://www.cpc.ncep.noaa.gov/products/predictions/814day/index.php NWS CPC 8-14 day Temperature and Precipitation Outlooks]===

JeffreyJLukas: /* Data and Tools */

2024-10-21T20:51:40Z

Data and Tools

← Older revision		Revision as of 16:51, 21 October 2024
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	===[https://www.cpc.ncep.noaa.gov/products/predictions/30day/ NWS CPC 1-month Temperature and Precipitation Outlooks]===		===[https://www.cpc.ncep.noaa.gov/products/predictions/30day/ NWS CPC 1-month Temperature and Precipitation Outlooks]===
	These monthly outlooks are issued for each full month (January, February, etc.) at two lead times: 0.5 months lead (i.e, issued in middle of prior month) and zero lead (end of prior month). Not surprisingly, the zero-lead monthly outlooks are more skillful since they incorporate short-term weather (0-14 days) forecast guidance, in addition to longer term guidance (equivalent to the Week 3-4 outlooks).		These monthly outlooks are issued for each full month (January, February, etc.) at two lead times: 0.5 months lead (i.e, issued in middle of prior month) and zero lead (end of prior month). Not surprisingly, the zero-lead monthly outlooks are more skillful since they incorporate short-term weather (0-14 days) forecast guidance, in addition to longer term guidance (equivalent to the Week 3-4 outlooks).

	~~===[https://hydro.rap.ucar.edu/s2s/ S2S Climate Outlooks for Watersheds]===~~
	~~''Since 29 June 2022, the forecasts on this tool have not been updated. It is not known when it will become operational again.''~~
	This interactive web tool, developed by NCAR and Reclamation, presents specific ("deterministic") forecasts of temperature and precipitation anomalies (departures from normal) from several weather/climate models, which can be viewed individually or as an 7-model ensemble ("NMME") average. These models are used as guidance for the NWS sub-seasonal outlooks listed above. The sub-seasonal forecasts available are for weeks 2-3 and 3-4 (CFSv2 only); and 1-month (all NMME models), at three lead times: zero, 1 month, and 2 months; the seasonal forecasts available are for 3-month seasons at three lead times: zero, 1 month, and 2 months.

	''Seasonal Climate Forecasts''		''Seasonal Climate Forecasts''

JeffreyJLukas: /* Additional Resources */

2024-10-21T20:51:06Z

Additional Resources

← Older revision		Revision as of 16:51, 21 October 2024
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	==Additional Resources==		==Additional Resources==

	===State of the Science ~~Report~~===		===[https://wwa.colorado.edu/resources/colorado-river-resources/CRBreport Colorado River Basin Climate and Hydrology: State of the Science report]===

	[https://wwa.colorado.edu/publications/reports/CRBreport/ColoRiver_StateOfScience_WWA_2020_Chapter_7.pdf Chapter 7] of the State of the Science report covers many aspects of Weather and climate forecasts in much greater detail.		[https://wwa.colorado.edu/publications/reports/CRBreport/ColoRiver_StateOfScience_WWA_2020_Chapter_7.pdf Chapter 7] of the State of the Science report covers many aspects of Weather and climate forecasts in much greater detail.

JeffreyJLukas: /* Weather forecasts */

2024-10-21T15:44:20Z

Weather forecasts

← Older revision		Revision as of 11:44, 21 October 2024
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	==Weather forecasts==		==Weather forecasts==
	[[File:5-dayQPF Feb2021.gif\|thumb\|700px\|Figure 2. 5-day Quantitative Precipitation Forecast (QPF) for February 12-17, 2021--the wettest period in ~~an otherwise forgettable~~ 2020-21 snow and runoff season for the Colorado River Basin. (Image: NOAA NWS Weather Prediction Center; https://www.wpc.ncep.noaa.gov/archives/qpf/get_qpf_images.php)]]		[[File:5-dayQPF Feb2021.gif\|thumb\|700px\|Figure 2. 5-day Quantitative Precipitation Forecast (QPF) for February 12-17, 2021, which turned out to be the wettest 5-day period in a in a drier-than-normal 2020-21 snow and runoff season for the Colorado River Basin. (Image: NOAA NWS Weather Prediction Center; https://www.wpc.ncep.noaa.gov/archives/qpf/get_qpf_images.php)]]

	Weather forecasts have relatively high skill, and continue to improve. In the Western U.S., a forecast of daily high temperature (Tmax) made 5 days in advance has a mean error of 3-4 °F, and the probability-of-precipitation (PoP) forecast at that same 5-day lead time is far more accurate than just assuming the average PoP for that season and location. In general, today's 5-day weather forecast is as skillful as the 4-day forecast was 10 years ago, or the 3-day forecast 20 years ago.		Weather forecasts have relatively high skill, and continue to improve. In the Western U.S., a forecast of daily high temperature (Tmax) made 5 days in advance has a mean error of 3-4 °F, and the probability-of-precipitation (PoP) forecast at that same 5-day lead time is far more accurate than just assuming the average PoP for that season and location. In general, today's 5-day weather forecast is as skillful as the 4-day forecast was 10 years ago, or the 3-day forecast 20 years ago.

JeffreyJLukas: /* Overview */

2023-10-18T20:23:04Z

Overview

← Older revision		Revision as of 16:23, 18 October 2023
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	Weather forecasts are routinely used by stakeholders across the basin for guiding short-term operational decision-making, such as in agriculture, recreation, and transportation, and water resource management. NOAA Colorado Basin River Forecast Center (CBRFC) incorporates weather forecasts (out to 10 days) into their short-term streamflow forecasts and peak runoff forecasts, and also into their [[Seasonal streamflow forecasts]].		Weather forecasts are routinely used by stakeholders across the basin for guiding short-term operational decision-making, such as in agriculture, recreation, and transportation, and water resource management. NOAA Colorado Basin River Forecast Center (CBRFC) incorporates weather forecasts (out to 10 days) into their short-term streamflow forecasts and peak runoff forecasts, and also into their [[Seasonal streamflow forecasts]].

	Climate forecasts and outlooks are frequently ''consulted'' by stakeholders, including agricultural producers and water managers, but because of their relatively low forecast ~~accuracy/~~skill, it is challenging to use them to support planning and decision-making ~~like how weather forecasts and seasonal streamflow forecasts are used~~. Reclamation and CBRFC are currently exploring ways to incorporate climate forecasts into basin runoff and reservoir outlooks. Most of the forecast error in April 1st seasonal streamflow forecasts is due to the weather during the April-July streamflow forecast period diverging from what is assumed in the ''most-probable'' streamflow forecast, which is the median trajectory of April-July temperature and precipitation in the recent past (1981-2015).		Climate forecasts and outlooks are frequently ''consulted'' by stakeholders, including agricultural producers and water managers, but because of their relatively low forecast skill, it is challenging to use them to support planning and decision-making. Reclamation and CBRFC are currently exploring ways to incorporate climate forecasts into seasonal basin runoff and reservoir outlooks. Most of the forecast error in April 1st seasonal streamflow forecasts is due to the weather during the April-July streamflow forecast period diverging from what is assumed in the ''most-probable'' streamflow forecast, which is the median trajectory of April-July temperature and precipitation in the recent past (1981-2015).

	==Weather forecasts==		==Weather forecasts==

JeffreyJLukas at 20:21, 18 October 2023

2023-10-18T20:21:33Z

← Older revision		Revision as of 16:21, 18 October 2023
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	[[File:Forecast_schematic.png\|thumb\|700px\|Figure 1. Schematic showing typical forecast skill relative to forecast range (or lead time), and main sources of predictability, for three types of weather and climate forecasts: short-range weather forecasts; sub-seasonal climate forecasts, and seasonal climate forecasts. (J. Lukas, modified from Lukas and Payton 2020, originally adapted from E. Gawthrop and T. Barnston, International Research Institute for Climate and Society)]]		[[File:Forecast_schematic.png\|thumb\|700px\|Figure 1. Schematic showing typical forecast skill relative to forecast range (or lead time), and main sources of predictability, for three types of weather and climate forecasts: short-range weather forecasts; sub-seasonal climate forecasts, and seasonal climate forecasts. (J. Lukas, modified from Lukas and Payton 2020, originally adapted from E. Gawthrop and T. Barnston, International Research Institute for Climate and Society)]]

	Weather and climate forecasts address our need to know what the weather will be like over the coming hours, days, weeks, and months. ''Weather'' forecasts refer to forecast periods of 14 days ahead or less, a time frame over which the evolution of the current atmospheric pattern can be more directly predicted, and specific and high-resolution (in time and space) predictions of weather variables can be made, at least for the first 7 days. Weather forecasts over mid-latitude continental areas like the Colorado River Basin have very high skill (~accuracy) for the first 1-3 day; skill is somewhat lower for the next 3-4 days, and then it drops off dramatically (Figure 1).		Weather and climate forecasts address our need to know what the weather will be like over the coming hours, days, weeks, and months.

			''Weather'' forecasts refer to forecast periods of 14 days ahead or less, a time frame over which the evolution of the current atmospheric pattern can be more directly predicted, and specific and high-resolution (in time and space) predictions of weather variables can be made, at least for the first 7 days. Weather forecasts over mid-latitude continental areas like the Colorado River Basin have very high skill (~accuracy) for the first 1-3 day; skill is somewhat lower for the next 3-4 days, and then it drops off dramatically (Figure 1).

	''Climate'' forecasts or outlooks are for longer periods (14 days to several months or more), and what is usually forecasted is tendencies towards anomalies (warmer/cooler temperatures; higher/lower precipitation) over weeks, months, or seasons, rather than specific quantities (Figure 1). The sources of predictability for climate forecasts are more diverse than for weather forecasts, which depend mainly on capturing the initial conditions and patterns of the atmosphere. The skill of climate forecasts is much lower than for weather forecasts in all parts of the world (Figure 1).		''Climate'' forecasts or outlooks are for longer periods (14 days to several months or more), and what is usually forecasted is tendencies towards anomalies (warmer/cooler temperatures; higher/lower precipitation) over weeks, months, or seasons, rather than specific quantities (Figure 1). The sources of predictability for climate forecasts are more diverse than for weather forecasts, which depend mainly on capturing the initial conditions and patterns of the atmosphere. The skill of climate forecasts is much lower than for weather forecasts in all parts of the world (Figure 1).

	Incomplete knowledge about future weather conditions is leads to uncertainty in streamflow forecasts at all time scales. Most of the forecast error in April 1st seasonal streamflow forecasts is due to the weather during the April-July streamflow forecast period diverging from what is assumed in the ''most-probable'' streamflow forecast, which is the median trajectory of April-July temperature and precipitation in the recent past (1981-2015).		Weather forecasts are routinely used by stakeholders across the basin for guiding short-term operational decision-making, such as in agriculture, recreation, and transportation, and water resource management. NOAA Colorado Basin River Forecast Center (CBRFC) incorporates weather forecasts (out to 10 days) into their short-term streamflow forecasts and peak runoff forecasts, and also into their [[Seasonal streamflow forecasts]].

	~~==Relevance==~~

	Weather forecasts ~~(out to 10 days)~~ are routinely used by stakeholders across the basin for guiding short-term operational decision-making, such as in agriculture, recreation, and transportation, and water resource management. NOAA Colorado Basin River Forecast Center (CBRFC) incorporates weather forecasts (out to 10 days) into their short-term streamflow forecasts and peak runoff forecasts, and also into their [[Seasonal streamflow forecasts]].

	Climate forecasts and outlooks are frequently ''consulted'' by stakeholders, including agricultural producers and water managers, but because of their relatively low ~~forecasts~~ accuracy/skill it is challenging to ~~actually~~ use them to support planning and decision-making like how weather forecasts and seasonal streamflow forecasts are used. Reclamation and CBRFC are currently exploring ways to incorporate climate forecasts into basin runoff and reservoir outlooks.		Climate forecasts and outlooks are frequently ''consulted'' by stakeholders, including agricultural producers and water managers, but because of their relatively low forecast accuracy/skill, it is challenging to use them to support planning and decision-making like how weather forecasts and seasonal streamflow forecasts are used. Reclamation and CBRFC are currently exploring ways to incorporate climate forecasts into basin runoff and reservoir outlooks. Most of the forecast error in April 1st seasonal streamflow forecasts is due to the weather during the April-July streamflow forecast period diverging from what is assumed in the ''most-probable'' streamflow forecast, which is the median trajectory of April-July temperature and precipitation in the recent past (1981-2015).

	==Weather forecasts==		==Weather forecasts==

JeffreyJLukas: /* S2S Climate Outlooks for Watersheds */

2023-02-02T22:41:40Z

S2S Climate Outlooks for Watersheds

← Older revision		Revision as of 18:41, 2 February 2023
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	===[https://hydro.rap.ucar.edu/s2s/ S2S Climate Outlooks for Watersheds]===		===[https://hydro.rap.ucar.edu/s2s/ S2S Climate Outlooks for Watersheds]===
	''Since 29 June 2022, the forecasts on this tool have not been updated. It is not known when it will become operational again.''		''Since 29 June 2022, the forecasts on this tool have not been updated. It is not known when it will become operational again.''
	This interactive web tool, developed by NCAR and Reclamation, presents specific ("deterministic") forecasts of temperature and precipitation anomalies (departures from normal) from several weather/climate models, which can be viewed individually or as an 7-model ensemble ("NMME") average. These models are used as guidance for the NWS sub-seasonal outlooks listed above. The sub-seasonal forecasts available are for weeks 2-3 and 3-4 (CFSv2 only); and 1-month (all NMME models), at three lead times: zero, 1 month, and 2 months; the seasonal forecasts available are for 3-month seasons at three lead times: zero, 1 month, and 2 months.		This interactive web tool, developed by NCAR and Reclamation, presents specific ("deterministic") forecasts of temperature and precipitation anomalies (departures from normal) from several weather/climate models, which can be viewed individually or as an 7-model ensemble ("NMME") average. These models are used as guidance for the NWS sub-seasonal outlooks listed above. The sub-seasonal forecasts available are for weeks 2-3 and 3-4 (CFSv2 only); and 1-month (all NMME models), at three lead times: zero, 1 month, and 2 months; the seasonal forecasts available are for 3-month seasons at three lead times: zero, 1 month, and 2 months.

	''Seasonal Climate Forecasts''		''Seasonal Climate Forecasts''

JeffreyJLukas: /* S2S Climate Outlooks for Watersheds */

2023-02-02T22:41:24Z

S2S Climate Outlooks for Watersheds

← Older revision		Revision as of 18:41, 2 February 2023
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	===[https://hydro.rap.ucar.edu/s2s/ S2S Climate Outlooks for Watersheds]===		===[https://hydro.rap.ucar.edu/s2s/ S2S Climate Outlooks for Watersheds]===
	This interactive web tool, developed by NCAR and Reclamation, presents specific ("deterministic") forecasts of temperature and precipitation anomalies (departures from normal) from several weather/climate models, which can be viewed individually or as an 7-model ensemble ("NMME") average. These models are used as guidance for the NWS sub-seasonal outlooks listed above. The sub-seasonal forecasts available are for weeks 2-3 and 3-4 (CFSv2 only); and 1-month (all NMME models), at three lead times: zero, 1 month, and 2 months; the seasonal forecasts available are for 3-month seasons at three lead times: zero, 1 month, and 2 months.		''Since 29 June 2022, the forecasts on this tool have not been updated. It is not known when it will become operational again.''
			This interactive web tool, developed by NCAR and Reclamation, presents specific ("deterministic") forecasts of temperature and precipitation anomalies (departures from normal) from several weather/climate models, which can be viewed individually or as an 7-model ensemble ("NMME") average. These models are used as guidance for the NWS sub-seasonal outlooks listed above. The sub-seasonal forecasts available are for weeks 2-3 and 3-4 (CFSv2 only); and 1-month (all NMME models), at three lead times: zero, 1 month, and 2 months; the seasonal forecasts available are for 3-month seasons at three lead times: zero, 1 month, and 2 months.

	''Seasonal Climate Forecasts''		''Seasonal Climate Forecasts''

	===[https://www.cpc.ncep.noaa.gov/products/predictions/90day/ NWS CPC Seasonal (3-month) Temperature and Precipitation Outlooks]===		===[https://www.cpc.ncep.noaa.gov/products/predictions/90day/ NWS CPC Seasonal (3-month) Temperature and Precipitation Outlooks]===
	These seasonal outlooks are issued monthly for overlapping 3-month periods (Jan-Mar, Feb-April, etc.) at lead times ranging from 0.5 months to 12.5 months. The shorter-lead outlooks are generally more skillful, but skill is relatively low for precipitation at all lead times. As with the CPC 8-14 day outlooks, the seasonal outlooks are probabilistic and based on 3 categories (above normal, near-normal, and below normal).		These seasonal outlooks are issued monthly for overlapping 3-month periods (Jan-Mar, Feb-April, etc.) at lead times ranging from 0.5 months to 12.5 months. The shorter-lead outlooks are generally more skillful, but skill is relatively low for precipitation at all lead times. As with the CPC 8-14 day outlooks, the seasonal outlooks are probabilistic and based on 3 categories (above normal, near-normal, and below normal).

JeffreyJLukas at 18:12, 3 November 2022

2022-11-03T18:12:34Z

← Older revision		Revision as of 14:12, 3 November 2022
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	[https://wwa.colorado.edu/publications/reports/CRBreport/ColoRiver_StateOfScience_WWA_2020_Chapter_7.pdf Chapter 7] of the State of the Science report covers many aspects of Weather and climate forecasts in much greater detail.		[https://wwa.colorado.edu/publications/reports/CRBreport/ColoRiver_StateOfScience_WWA_2020_Chapter_7.pdf Chapter 7] of the State of the Science report covers many aspects of Weather and climate forecasts in much greater detail.

	~~==New and Notable Research (2020-present)==~~