Automatically generated forecasts

Some automatically generated forecasts are participating at the Berlin Weather Forecasting Contest for reference. This page gives a brief description of these forecast methods.

Moses

"Moses" is an automatic forecast based on the "model output statistics" (MOS) method.

Moses started its participation on 5.1.2001 with the equation following:

Moses = 0.5 * Dummschwätzer + 0.25 * Gatzen + 0.14 * Schmelzi + 0.11 * Frank

Persistency

the persistency forecast ("all parameters remain unchanged") participates for referency and statistical tests. We use the following observations:

TTn of friday 6 UTC
N, dd, ff, Wv, PPP, TTd of friday, 12 UTC
Wn, TTm of friday, 18 UTC
RR of saturday, 6 UTC.

Petrus

"Petrus" is the mean forecast of all participating contestants and methods of the weekend. These parameters are averaged arithmetically:

N, ff, PPP, TTm, TTn, TTd

For wind direction (dd) an average vector ist computed.

For precipitation amount (RR) a decision is made between dry cases and cases with observed precipitaion. Decisive is the majority of cases. In case of precipitation the arithmetic mean of all participants who forecasted measurable precipitaion is computed for RR. In case that the majority of forecasts are "dry", the forecast of Petrus will be RR = -3).

The weather conditions (Wv, Wn) are decided by majorities. The following decisions are taken in a row (in case of no majority the higher code number is taken):

Decision dry / not dry weather condtions (0, 4 vs. 5, 6, 7, 8, 9)

In first case simple decision between 0 and 4.

In second case decision stratiform vs. convective (5, 6, 7 vs. 8, 9)

In case of stratiform precipitation decision liquid vs. snow (5, 6 vs. 7), then decision between 5 and 6.

In case of convective precipitation simple decision between 8 and 9.