Development of springtime climate forecasting for the Intermountain West
Location
Eccles Conference Center
Event Website
http://water.usu.edu
Start Date
4-2-2014 1:15 PM
End Date
4-2-2014 1:30 PM
Description
Persistently wet and dry climate anomalies during spring are known to be associated with a meandering jet stream. Embedded within the jet stream is a guide for short Rossby waves, i.e planetary waves that can affect precipitation extremes in regions afar. Filtering these planetary waves to reveal a zonal wavenumber 5 structure, isolates a synoptic structure know as the Circumglobal Teleconnection (CGT) and it has been linked to regional climate extremes of the midlatudes. The influence of these short Rossby waves/CGT is independent from the forcing of prominent climate oscillations such as ENSO, making seasonal prediction difficult. This study proposes using the NCEP Climate Forecast System Version 2 (CFSv2) to make synoptic predictions of the CGT out to one month. The idea is to apply the semi-stationary circulation anomalies (or short waves) as a proxy for long-term precipitation anomalies, which remains a challenge for models to capture. To test the veracity of this secondary precipitation estimate, the complete Reforecast of CFS version 2, over the 29-year period (1982-2010) was analyzed. With the goal of obtaining an improved monthly precipitation estimate, skill scores using this mechanism were obtained for the targeted regions including Utah. The results indicate varying degrees of improvement and will be presented at the conference.
Development of springtime climate forecasting for the Intermountain West
Eccles Conference Center
Persistently wet and dry climate anomalies during spring are known to be associated with a meandering jet stream. Embedded within the jet stream is a guide for short Rossby waves, i.e planetary waves that can affect precipitation extremes in regions afar. Filtering these planetary waves to reveal a zonal wavenumber 5 structure, isolates a synoptic structure know as the Circumglobal Teleconnection (CGT) and it has been linked to regional climate extremes of the midlatudes. The influence of these short Rossby waves/CGT is independent from the forcing of prominent climate oscillations such as ENSO, making seasonal prediction difficult. This study proposes using the NCEP Climate Forecast System Version 2 (CFSv2) to make synoptic predictions of the CGT out to one month. The idea is to apply the semi-stationary circulation anomalies (or short waves) as a proxy for long-term precipitation anomalies, which remains a challenge for models to capture. To test the veracity of this secondary precipitation estimate, the complete Reforecast of CFS version 2, over the 29-year period (1982-2010) was analyzed. With the goal of obtaining an improved monthly precipitation estimate, skill scores using this mechanism were obtained for the targeted regions including Utah. The results indicate varying degrees of improvement and will be presented at the conference.
https://digitalcommons.usu.edu/runoff/2014/2014Abstracts/53