Page History

...

The weekly anomaly charts (2m temperature, surface temperature, total precipitation, mean sea level pressure) display the anomaly between the forecast weekly mean and the corresponding weekly mean in the ER-M-climate.  The charts are "clickable".   Clicking the mouse over any location on HRES or ENS charts the ensemble charts will produce probability information in diagrammatic form.  Diagrams available:

...

The weekly anomaly probability charts (2m temperature, surface temperature, total precipitation, mean sea level pressure) display the probability that the weekly mean anomalies are greater than zero (i.e. the proportion of ensemble members warmer or wetter etc than ER-M-climate).  A particular consideration when using the precipitation charts is that the range of colours available for "below average" anomalies (red brown colours) is constrained by the local climatology in the ER-M-climate.  For example if all ENS members showed a dry week, the mean (-ve) anomaly could be no larger in magnitude than the mean in the ER-M-climate.  So in some locations the strongest dry signal one can ever see will only be in the first or the second of the red brown shades.

White on the plot means that eithereither:

• the proportion of members above the ER-M-climate mean is between 40 and 60%,
• or that that proportion, whatever it is, is not statistically significant.

The plot structure circumvents the fact that some ER-M-Climate distributions will be skewed , wherein (i.e. the climatological probability of seeing more than the mean is far from 50%).

Clicking the mouse over any location on HRES or ENS charts will produce probability information in diagrammatic form.  Diagrams available:

...

Clicking the mouse over any location on HRES or ENS the ensemble charts will produce probability information in diagrammatic form.  Diagrams available:

...

Clicking the mouse over any location on HRES or ENS the ensemble charts will produce probability information in diagrammatic form.  Diagrams available:

...

The weather regime cluster products are based on a method of regime clustering for the ENS.  The weekly mean 500hPa geopotential forecast by each ensemble member is assigned to the closest pattern.  The display indicates the number of members that fall within the same cluster and shows the averaged 500hPa geopotential pattern of these ensemble members.  This product is not bias-corrected.
The weather regime graphical time series shows the probability of each regime (as measured by the proportion of ENS members in each cluster) in diagram form.  This shows the distribution of regime probability at weekly intervals as the forecast progresses.

...

Hovmöller diagram or Time-Longitudes diagram - Extended range forecast 

Hovmoeller Hovmöller or Time-Longitudes diagrams show the time evolution of the ensemble mean anomaly of a parameter (past above and forecast below the horizontal line).  The x-axis represents the longitude, the y-axis represents the time evolution (time increasing downwards).  

The northern mid-latitude Hovmoeller Hovmöller diagrams show the time evolution of the ensemble mean anomaly of geopotential height at 500hPa or 1000hPa, averaged over the latitude band 35N-60N (Northern Extratropics) or 25S-50S (Southern Extratropics).  The anomaly has been computed by averaging all the members of the real-time forecast and subtracting the mean of the ER-M-climate.   Contours are plotted every 1.5dam.  Since it is an ensemble mean, the structures shown are much more detailed in the first days of the forecast (top part) than in the last days (bottom part).   Shaded areas represent the ensemble spread and are displayed only when the amplitude of the anomaly exceeds 2dam.  On average spread will naturally increase with forecast lead time, though occasionally, when moving to longer lead times, there can be a reduction.

The Madden-Julian Oscillation (MJO) Hovmoeller  Hovmöller diagrams show the ensemble mean anomalies of outgoing long wave radiation, zonal wind at 850hPa, and velocity potential at 200hPa averaged over a tropical band (15N-15S). 

The Madden-Julian Oscillation (MJO) Postage Stamp charts show the Hovmoeller Hovmöller sections of anomalies of outgoing long wave radiation, zonal wind at 850hPa and velocity potential at 200hPa averaged over a tropical band (15N-15S) for each ensemble member (51 stamps).

...

Clicking the mouse over any location on HRES or ENS the ensemble charts will produce probability information in diagrammatic form.  Diagrams available:

...