You don't say what your current values are, nor where you got the 'extremes' from. You don't say which is correct !.. and if I select with extreme cumulus 1050-950 forecast says the same thing but if I select cumulus forecast and put in my area extremes 1035-985 now says: "Becoming fine", it is necessary to adjust the values of extreme pressure in my area?
If find the Zambretti forecast very inaccurate try shortening the 'extreme' ranges by taking say 10hPa from the 'top' and adding 10hPa to the bottom. (or do the opposite with 5hPa to any all-time measurements you may have) If your Zambretti forecast starts "Exceptional weather ..." you have gone above (Clear / fine) or below (stormy) the range you have set.
You can try conditions outside of Cumulus at: Zambretti Forecaster
Although ...
Point #2 ..
The Canaries have micro climates within it's own micro-climate ! No generic forecast softare is going to cope with that.
eg.
I THINK the Davis uses a variation of the Sager forcasting system, which appears to place more importance on the wind direction and any direction change than on barometer (although of course still taken into account)Tips on predicting the weather in Gran Canaria based upon the wind direction
If the winds are gusty north-westerly or northerly (i.e. winds from the north-west or north), then the warmest location would be on the southeastern and southern coastlines and adjacent inland regions. The north westerly winds indicate that a cool air has arrived and so expect showery weather on the windward side of Gran Canaria. Day and night-time temperatures may be 2-3°C cooler that what it's normally like for that time of year.
If there's moderately gusty winds blowing in from the south west, this means the weather in Gran Canaria is warmer than usual and that cooler air is on the way. During this time, the eastern and north-eastern parts of Gran canaria will record the highest temperatures. Generally, the south-westerly winds indicate that there is an anticyclone over North Africa.
If there is quite gusty south-easterly winds (i.e. winds from the south-east) then expect daytime temperatures to rise at least 3-6°C above the average day and night-time temperature for that time of the year. The south-eastern coastline generally records the highest daytime temperatures during this time. You may notice some dust in the air and this typically occurs in February and March. The locals call this dusty dry and warm wind the calima.
... again you don't say if the Zambretti gets it right ?
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