WxSim Forecast Comparison to Actual Observations
Columns: Actual Observed (Act), Differenceħ (Diff), Station-WxSim Generated (WS)

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Morning Forecast(06:00)
Updated: 14-05-26 at 6:00 am
Goal Forecast Day Day +1 Day +2 Day +3
± 2.0° F High Low High Low High Low High Low
Date Act Diff WS Act Diff WS Act Diff WS Act Diff WS Act Diff WS Act Diff WS Act Diff WS Act Diff WS
14-05-26     24     17     23     17     23     17     23     17
13-05-26 27.2 -1.2 26 16.6 -0.6 16     23     18     23     17     23     17
12-05-26 29.1 -3.1 26 19.3 -1.3 18 27.2 -1.2 26 16.6 0.4 17     23     17     21     17
11-05-26 23.4 2.6 26 17.2 -0.2 17 29.1 -2.1 27 19.3 -1.3 18 27.2 -1.2 26 16.6 0.4 17     24     16
10-05-26 24.8 1.2 26 17.4 -0.4 17 23.4 2.6 26 17.2 0.8 18 29.1 -2.1 27 19.3 -1.3 18 27.2 -1.2 26 16.6 -0.6 16
09-05-26 22.1 1.9 24 17.7 -0.7 17 24.8 1.2 26 17.4 0.6 18 23.4 2.6 26 17.2 0.8 18 29.1 -2.1 27 19.3 -1.3 18
08-05-26 19.2 1.8 21 15.4 0.6 16 22.1 1.9 24 17.7 -0.7 17 24.8 1.2 26 17.4 0.6 18 23.4 1.6 25 17.2 0.8 18
07-05-26 21.6 -1.6 20 16.3 -4.3 12 19.2 4.8 24 15.4 -1.4 14 22.1 1.9 24 17.7 -2.7 15 24.8 0.2 25 17.4 -0.4 17
06-05-26 22.8 -2.8 20 16.3 -4.3 12 21.6 2.4 24 16.3 -2.3 14 19.2 4.8 24 15.4 -0.4 15 22.1 2.9 25 17.7 -0.7 17
05-05-26 25.2 -5.2 20 15.8 -3.8 12 22.8 1.2 24 16.3 -2.3 14 21.6 2.4 24 16.3 -1.3 15 19.2 5.8 25 15.4 1.6 17
04-05-26 19.6 0.4 20 14.2 -2.2 12 25.2 -1.2 24 15.8 -1.8 14 22.8 1.2 24 16.3 -1.3 15 21.6 3.4 25 16.3 0.7 17
03-05-26 18.6 -2.6 16 11.3 -0.3 11 19.6 0.4 20 14.2 -2.2 12 25.2 -2.2 23 15.8 -1.8 14 22.8 1.2 24 16.3 0.7 17
02-05-26 17.1 -0.1 17 10.3 -1.3 9 18.6 -3.6 15 11.3 -1.3 10 19.6 0.4 20 14.2 -3.2 11 25.2 -1.2 24 15.8 -1.8 14
01-05-26 14.4 1.6 16 9.7 0.3 10 17.1 -1.1 16 10.3 -0.3 10 18.6 -2.6 16 11.3 -0.3 11 19.6 -0.6 19 14.2 -2.2 12
Results Act Diff WS Act Diff WS Act Diff WS Act Diff WS Act Diff WS Act Diff WS Act Diff WS Act Diff WS
# Succ   8   9   7   9   5   9   6   9
% Succ     61.5     69.2     58.3     75.0     45.5     81.8     60.0     90.0
Ave Error   2.0     1.6     2.0     1.3     2.1     1.3     2.0     1.1  
Net Error   -0.5     -1.4     0.4     -1.0     0.6     -1.0     1.0     -0.3  
Std Dev   1.3     1.5     1.1     0.6     1.0     0.6     1.4     0.4  

Mid Day Forecast(12:00)
Updated: 13-05-26 at 12:00 pm
Goal Forecast Day Day +1 Day +2 Day +3
± 2.0° F High Low High Low High Low High Low
Date Act Diff WS Act Diff WS Act Diff WS Act Diff WS Act Diff WS Act Diff WS Act Diff WS Act Diff WS
13-05-26     26     18     23     18     24     18     24     17
12-05-26 29.1 -2.1 27 19.3 -1.3 18     26     17     24     17     21     17
11-05-26 23.4 1.6 25 17.2 0.8 18 29.1 -2.1 27 19.3 -1.3 18     25     17     24     16
10-05-26 24.8 2.2 27 17.3 0.7 18 23.4 2.6 26 17.2 0.8 18 29.1 -2.1 27 19.3 -2.3 17     25     17
09-05-26 22.1 -0.1 22 17.3 -1.3 16 24.8 0.2 25 17.3 -0.3 17 23.4 1.6 25 17.2 -0.2 17 29.1 -2.1 27 19.3 -2.3 17
08-05-26 19.2 0.8 20 15.4 0.6 16 22.1 0.9 23 17.3 -0.3 17 24.8 1.2 26 17.3 -0.3 17 23.4 2.6 26 17.2 0.8 18
07-05-26 21.6 1.4 23 16.3 0.7 17 19.2 1.8 21 15.4 0.6 16 22.1 1.9 24 17.3 -0.3 17 24.8 1.2 26 17.3 -0.3 17
06-05-26 22.8 -2.8 20 16.3 -4.3 12 21.6 2.4 24 16.3 -2.3 14 19.2 4.8 24 15.4 -0.4 15 22.1 2.9 25 17.3 -0.3 17
05-05-26 25.2 -5.2 20 15.8 -3.8 12 22.8 1.2 24 16.3 -2.3 14 21.6 2.4 24 16.3 -1.3 15 19.2 5.8 25 15.4 1.6 17
04-05-26 19.6 0.4 20 14.2 -2.2 12 25.2 -1.2 24 15.8 -1.8 14 22.8 1.2 24 16.3 -1.3 15 21.6 3.4 25 16.3 0.7 17
03-05-26 18.6 -1.6 17 10.8 0.2 11 19.6 0.4 20 14.2 -2.2 12 25.2 -2.2 23 15.8 -1.8 14 22.8 1.2 24 16.3 -0.3 16
02-05-26 17.1 -0.1 17 9.9 -0.9 9 18.6 -2.6 16 10.8 0.2 11 19.6 -0.6 19 14.2 -2.2 12 25.2 -1.2 24 15.8 -1.8 14
01-05-26 14.4 1.6 16 9.4 0.6 10 17.1 -0.1 17 9.9 1.1 11 18.6 -2.6 16 10.8 1.2 12 19.6 -0.6 19 14.2 -2.2 12
30-04-26 21.7 0.3 22 9.3 0.7 10 14.4 0.6 15 9.4 1.6 11 17.1 -0.1 17 9.9 2.1 12 18.6 -1.6 17 10.8 1.2 12
Results Act Diff WS Act Diff WS Act Diff WS Act Diff WS Act Diff WS Act Diff WS Act Diff WS Act Diff WS
# Succ   9   10   8   9   6   8   5   8
% Succ     69.2     76.9     66.7     75.0     54.5     72.7     50.0     80.0
Ave Error   1.6     1.4     1.3     1.2     1.9     1.2     2.3     1.2  
Net Error   -0.3     -0.7     0.3     -0.5     0.5     -0.6     1.2     -0.3  
Std Dev   1.3     1.2     0.8     0.8     1.0     0.7     1.2     0.6  

Evening Forecast(18:00)
Updated: 13-05-26 at 6:00 pm
Goal Forecast Day Day +1 Day +2 Day +3
± 2.0° F Low High Low High Low High Low High
Date Act Diff WS Act Diff WS Act Diff WS Act Diff WS Act Diff WS Act Diff WS Act Diff WS Act Diff WS
13-05-26     18     23     18     23     17     24     17     23
12-05-26 19.3 -0.3 19 29.1 -3.1 26     18     23     17     23     17     23
11-05-26 17.2 0.8 18 23.4 1.6 25 19.3 -1.3 18 29.1 -4.1 25     17     23     16     20
10-05-26 17.3 -0.3 17 24.8 0.2 25 17.2 0.8 18 23.4 2.6 26 19.3 -2.3 17 29.1 -4.1 25     17     23
09-05-26 17.3 -0.3 17 22.1 2.9 25 17.3 -0.3 17 24.8 1.2 26 17.2 0.8 18 23.4 3.6 27 19.3 -2.3 17 29.1 -3.1 26
08-05-26 15.4 0.6 16 19.2 3.8 23 17.3 -0.3 17 22.1 3.9 26 17.3 0.7 18 24.8 1.2 26 17.2 0.8 18 23.4 3.6 27
07-05-26 16.3 0.7 17 21.6 -0.6 21 15.4 0.6 16 19.2 3.8 23 17.3 -0.3 17 22.1 2.9 25 17.3 -0.3 17 24.8 0.2 25
06-05-26 16.3 3.7 20 22.8 -10.8 12 16.3 7.7 24 21.6 -7.6 14 15.4 8.6 24 19.2 -4.2 15 17.3 7.7 25 22.1 -5.1 17
05-05-26 25.2 -5.2 20 15.8 -3.8 12 16.3 7.7 24 22.8 -8.8 14 16.3 7.7 24 21.6 -6.6 15 15.4 9.6 25 19.2 -2.2 17
04-05-26 19.6 0.4 20 14.2 -2.2 12 25.2 -1.2 24 15.8 -1.8 14 16.3 7.7 24 22.8 -7.8 15 16.3 8.7 25 21.6 -4.6 17
03-05-26 18.6 -6.6 12 10.8 10.2 21 19.6 -6.6 13 14.2 8.8 23 25.2 -10.2 15 15.8 9.2 25 16.3 -0.3 16 22.8 1.2 24
02-05-26 9.9 -0.9 9 17.1 -2.1 15 18.6 -7.6 11 10.8 8.2 19 19.6 -7.6 12 14.2 8.8 23 25.2 -11.2 14 15.8 6.2 22
01-05-26 9.4 -0.4 9 14.4 1.6 16 9.9 0.1 10 17.1 -0.1 17 18.6 -7.6 11 10.8 9.2 20 19.6 -8.6 11 14.2 8.8 23
30-04-26 9.3 -0.3 9 21.7 -7.7 14 9.4 0.6 10 14.4 1.6 16 9.9 1.1 11 17.1 -0.1 17 18.6 -6.6 12 10.8 8.2 19
Results Act Diff WS Act Diff WS Act Diff WS Act Diff WS Act Diff WS Act Diff WS Act Diff WS Act Diff WS
# Succ   10   4   8   4   4   2   3   2
% Succ     76.9     30.8     66.7     33.3     36.4     18.2     30.0     20.0
Ave Error   1.6     3.9     2.9     4.4     5.0     5.2     5.6     4.3  
Net Error   -0.6     -0.8     0.0     0.6     -0.1     1.1     -0.3     1.3  
Std Dev   2.0     3.2     3.0     2.7     3.3     2.2     3.0     1.6  

Night Forecast(23:00)
Updated: 13-05-26 at 11:00 pm
Goal Forecast Day Day +1 Day +2 Day +3
± 2.0° F Low High Low High Low High Low High
Date Act Diff WS Act Diff WS Act Diff WS Act Diff WS Act Diff WS Act Diff WS Act Diff WS Act Diff WS
13-05-26     18     24     17     24     18     25     17     24
12-05-26 19.1 -0.1 19 29.1 -2.1 27     18     24     18     24     18     24
11-05-26 23.8 -5.8 18 23.4 2.6 26 19.1 -1.1 18 29.1 -3.1 26     17     24     17     21
10-05-26 19.3 -2.3 17 24.8 0.2 25 23.8 -5.8 18 23.4 3.6 27 19.1 -1.1 18 29.1 -3.1 26     17     22
09-05-26 19.4 -2.4 17 22.1 3.9 26 19.3 -1.3 18 24.8 1.2 26 23.8 -5.8 18 23.4 3.6 27 19.1 -1.1 18 29.1 -3.1 26
08-05-26 18.3 -3.3 15 19.2 4.8 24 19.4 -2.4 17 22.1 3.9 26 19.3 -2.3 17 24.8 1.2 26 23.8 -6.8 17 23.4 3.6 27
07-05-26 15.8 1.2 17 21.6 -0.6 21 18.3 -1.3 17 19.2 4.8 24 19.4 -2.4 17 22.1 3.9 26 19.3 -1.3 18 24.8 1.2 26
06-05-26 18.8 1.2 20 22.8 -10.8 12 15.8 8.2 24 21.6 -7.6 14 18.3 5.7 24 19.2 -4.2 15 19.4 5.6 25 22.1 -5.1 17
05-05-26 25.2 -5.2 20 18.1 -6.1 12 18.8 5.2 24 22.8 -8.8 14 15.8 8.2 24 21.6 -6.6 15 18.3 6.7 25 19.2 -2.2 17
04-05-26 19.6 0.4 20 20.1 -8.1 12 25.2 -1.2 24 18.1 -4.1 14 18.8 5.2 24 22.8 -7.8 15 15.8 9.2 25 21.6 -4.6 17
03-05-26 18.6 -6.6 12 16.7 4.3 21 19.6 -6.6 13 20.1 3.9 24 25.2 -10.2 15 18.1 5.9 24 18.8 -2.8 16 22.8 1.2 24
02-05-26 14.2 -3.2 11 17.1 -0.1 17 18.6 -7.6 11 16.7 3.3 20 19.6 -7.6 12 20.1 2.9 23 25.2 -11.2 14 18.1 5.9 24
01-05-26 11.9 -0.9 11 14.4 2.6 17 14.2 -4.2 10 17.1 -1.1 16 18.6 -8.6 10 16.7 3.3 20 19.6 -8.6 11 20.1 2.9 23
30-04-26 11.2 -1.2 10 21.7 -5.7 16 11.9 -1.9 10 14.4 1.6 16 14.2 -4.2 10 17.1 -0.1 17 18.6 -7.6 11 16.7 3.3 20
Results Act Diff WS Act Diff WS Act Diff WS Act Diff WS Act Diff WS Act Diff WS Act Diff WS Act Diff WS
# Succ   6   3   5   3   1   2   2   2
% Succ     46.2     23.1     41.7     25.0     9.1     18.2     20.0     20.0
Ave Error   2.6     4.0     3.9     3.9     5.6     3.9     6.1     3.3  
Net Error   -2.2     -1.2     -1.7     -0.2     -2.1     -0.1     -1.8     0.3  
Std Dev   2.0     3.0     2.5     2.0     2.5     1.8     2.4     1.0  

Here, we will try to compare WxSim produced forecasts with the actual values recorded by meteothes.gr weather station. There is a comparison table for each one of the four forecasts issued(*) daily at 06:00, 12:00, 18:00 and 23:00 hours. The software reads right after each forecast the values and updates the corresponding table. Then, after the end of each day, updates the tables with the actual values and compares them.

(*)Uploaded 30 minutes later, 06:30, 12:30, 18:30, 23:30.

The current goal, is to achieve forecast values not more than +- 2 degrees C than the actual ones! So, if the forecat values are between that range, the colour of WxSim cell turns green, otherwise remains white(no colour). In the rows beneath the values, there are statistics about the comparison.

Our goal, is to achieve a difference not more than one degree C with the actual values! We keep trying all the time to adjust WxSim and make it more accurate for our location, the Historical Center of Thessaloniki!