ATMOSPHERIC BLOCKING TRACKING SYSTEM

Quick links to sections :

Link to simulated blockings from ERA5 reanalyses
Link to the atmospheric blocking forecast with GEPS

Atmospheric blocking is a term used by meteorologists referring to weather situations in which the normal zonal flow is temporarily suppressed in an area by a strong persistent meridional flow (e.g., Treidl et al., 1981). Blocking events are typically associated with persistent high pressure systems that interrupt the prevailing mid- and high-latitude westerlies, and thus slow or even block the normal eastward propagation of extratropical storm systems (Ionita et al., 2016; Pfahl et al., 2012; Schwierz et al., 2004).

Blocking events have a significant impact on surface weather (Scherrer et al., 2006; Wazneh et al., 2021), and are an important component of extratropical intraseasonal variability and cause climate anomalies over mid- and high-latitude regions (Carrera et al., 2004). The methodology for calculating these blocking features is derived from the approach developed by Barriopedro et al. (2006) and is repeated and detailed in the recent work of Wazneh et al. (2021). This is used in the present work and the blocking characteristics (occurrence, duration, intensity and extension) are calculated from the ERA5 reanalyses over the entire period from 1950 to 2020.

Animation

The last 15 days of blocking calculation are shown here. The monthly animations are available below, please select the month and the year.

Atmospheric blocking list

The last two years atmospheric blockings are listed below. You can download the CSV file by clicking on "download as CSV".

30-day forecast of atmospheric blocking

The 30-day atmospheric blocking forecast is obtained with GEPS data (Global Ensemble Prediction System, Data GEPS website)

The forecast up to 16 days is updated every day at 7:30 am. The forecast between 16 days and 30 days is updated every Thursday at 7:30 am.

List of forecasted atmospheric blockings for the next 30 days

Number of forecasted atmospheric blockings for the next 30 days:

You can download the CSV file by clicking on "download as CSV".

References

1. Barriopedro, D., García-Herrera, R., Lupo, A. R., & Hernández, E. , A Climatology of Northern Hemisphere Blocking, Journal of Climate, 19(6), 1042-1063., (2006)

2. Carrera, M. L., R. W. Higgins, and V. E. Kousky, Downstream weather impacts associated with atmospheric blocking over the northeast Pacific, J. Climate, 17, 4823–4839, doi:10.1175/JCLI-3237.1., (2004)

3. Ionita, M., Scholz, P., Lohmann, G. et al., Linkages between atmospheric blocking, sea ice export through Fram Strait and the Atlantic Meridional Overturning Circulation., Sci Rep 6, 32881. https://doi.org/10.1038/srep32881, (2016)

4. Pfahl, S., and H. Wernli, Quantifying the relevance of atmospheric blocking for co-located temperature extremes in the Northern Hemisphere on (sub-)daily time scales.,Geophys.Res. Lett., 39, L12807, doi:10.1029/2012GL052261., (2012)

5. Scherrer SC, Croci-Maspoli M, Schwierz C, Appenzeller C , Two-dimensional indices of atmospheric blocking and their statistical relationship with winter climate patterns in the Euro-Atlantic region, Int J Climatol 26(2):233–249., (2006)

6. Schwierz, C., Croci-Maspoli, M., and Davies, H. C. , Perspicacious indicators of atmospheric blocking, Geophys. Res. Lett., 31, L06125, doi:10.1029/2003GL019341., (2004)

7. Tibaldi and Molteni, On the operational predictability of blocking, Geophysical Research Letters, (1990)

8. Treidl RA, Birch EC, Sajecki P, Blocking action in the northern hemisphere: a climatological study, Atmos Ocean , (1981)

9. Wazneh, H., Gachon, P., Laprise, R. et al, Atmospheric blocking events in the North Atlantic: trends and links to climate anomalies and teleconnections., Clim Dyn 56, 2199–2221, https://doi.org/10.1007/s00382-020-05583-x (2021)

10. Wiedenmann, J. M., Lupo, A. R., Mokhov, I. I., & Tikhonova, E. A., The Climatology of Blocking Anticyclones for the Northern and Southern Hemispheres: Block Intensity as a Diagnostic, Journal of Climate, 15(23), 3459-3473, (2002)