How well can an ensemble predict the uncertainty in the location of winter storm precipitation?

Fig. 1.

Notes: The forecast field (left) is the 24-h forecast of the 1-h accumulated precipitation starting at 0000 UTC 1 June 2005 and the verifying analysis field (right) is the 1-h accumulated Stage II precipitation analysis. In the left panel, the grey shades indicate the contours of the verifying precipitation field.

Fig. 2.

Notes: The values shown are based on randomly generated samples of 10, 000 realizations of $\mathit{r}$, ${\mathit{r}}_a$, ${\mathit{r}}_f^k,k=1,\dots ,K^{\prime }$, assuming a Gaussian random distribution with mean $\overline{\mathit{r}}=\mathbf{0}$. Because of the sampling fluctuations, the simulation is repeated 10 times for each value of K′ and the results are shown by scatter-plots.

Fig. 3.

Notes: The values shown are based on a randomly generated sample of 1000 realizations of $\mathit{r}$, ${\mathit{r}}_a$, ${\mathit{r}}_f^k,k=1,\dots ,100$, assuming a truncated Gaussian random distribution with mean $\overline{\mathit{r}}=\mathbf{0}$ in a one-dimensional search domain of size 2d. The values of Σ_loc on the x-axis are shown using the search radius d as unit, while the values of σ_loc and δ_loc on the y-axis are normalized by Σ_loc.

Fig. 4.

Fig. 5.

Fig. 6.

Fig. 7.

Fig. 8.