Event Title

Development of springtime climate forecasting for the Intermountain West

Location

Eccles Conference Center

Event Website

http://water.usu.edu

Start Date

2-4-2014 1:15 PM

End Date

2-4-2014 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.

This document is currently not available here.

Share

COinS
 
Apr 2nd, 1:15 PM Apr 2nd, 1:30 PM

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.

http://digitalcommons.usu.edu/runoff/2014/2014Abstracts/53