WxSim & NWS Forecast Comparison

National Weather Service (NW), Actual Observed (Act), WxSim Generated (WS)
Morning Forecasts
Updated: 12-21-24 at 5:00 am
Goal Forecast Day Day +1 Day +2 Day +3
± 2.0° F High Low High Low High Low High Low
Date NW Act WS NW Act WS NW Act WS NW Act WS NW Act WS NW Act WS NW Act WS NW Act WS
12-21-24 33   35 15   14 27   29 11   16 31   38 24   27 40   43 27   25
12-20-24 29 40.6 31 42 31.1 43 30   29 37   36 15   16 27   30 12   17 33   39
12-19-24 38 37.2 47 45 46.6 31 29 40.6 43 42 31.1 27 26   34 35   15 15   32 27   18
12-18-24 36 55.4 55 53 28.9 40 38 37.2 47 44 46.6 33 29 40.6 42 43 31.1 27 26   36 36   14
12-17-24 52 61.3 58 56 51.1 37 35 55.4 54 52 28.9 37 35 37.2 45 45 46.6 27 30 40.6 40 43 31.1 24
12-16-24 37 53.4 53 50 34.7 45 49 61.3 59 56 51.1 36 36 55.4 55 52 28.9 41 35 37.2 47 46 46.6 28
12-15-24 41 43.3 45 34 16.0 36 50 53.4 52 47 34.7 44 58 61.3 58 35 51.1 37 53 55.4 54 36 28.9 38
Results NW Act WS NW Act WS NW Act WS NW Act WS NW Act WS NW Act WS NW Act WS NW Act WS
# Succ 1 3 1 0 1 2 0 0 0 2 1 0 0 2 1 0
% Succ 16.7   50.0 16.7   0.0 20.0   40.0     0.0     50.0 25.0   0.0     66.7 33.3   0.0
Ave Error 10.0   4.2 12.5   13.8 9.7   3.5 10.8   10.0 9.1   3.2 13.2   12.5 5.1   3.9 6.5   11.6
Net Error -9.7   -0.4 11.9   3.9 -9.4   1.4 9.7   -3.1 -9.1   1.4 4.3   -6.4 -5.1   2.6 6.1   -5.5
Std Dev 6.0   3.9 7.3   2.1 6.3   3.0 6.6   3.2 1.2   0.9 0.6   4.2 0.0   0.0 0.0   0.0

Mid-Day Forecasts
Updated: 12-20-24 at 11:00 am
Goal Forecast Day Day +1 Day +2 Day +3
± 2.0° F High Low High Low High Low High Low
Date NW Act WS NW Act WS NW Act WS NW Act WS NW Act WS NW Act WS NW Act WS NW Act WS
12-20-24 41   44 27   28 35   35 14   17 26   29 11   17 32   37 23   28
12-19-24 46 46.6 50 29 31.1 31 42   45 26   29 35   35 15   15 27   30 12   19
12-18-24 53 55.4 58 38 37.2 40 44 46.6 47 29 31.1 32 43   43 26   28 36   36 13   13
12-17-24 56 61.3 59 35 28.9 38 52 55.4 55 35 37.2 38 45 46.6 46 30 31.1 27 43   41 25   27
12-16-24 50 53.4 52 49 51.1 44 56 61.3 58 36 28.9 36 52 55.4 55 35 37.2 37 46 46.6 47 26 31.1 31
12-15-24 41 43.3 44 34 34.7 35 50 53.4 52 47 51.1 44 58 61.3 58 35 28.9 37 53 55.4 55 36 37.2 37
12-14-24 34 37.0 39 18 16.0 27 40 43.3 43 32 34.7 34 49 53.4 53 43 51.1 45 57 61.3 59 34 28.9 36
Results NW Act WS NW Act WS NW Act WS NW Act WS NW Act WS NW Act WS NW Act WS NW Act WS
# Succ 1 3 3 2 0 4 0 3 1 3 1 1 1 2 1 2
% Succ 16.7   50.0 50.0   33.3     80.0     60.0 25.0   75.0 25.0   25.0 33.3   66.7 33.3   66.7
Ave Error 2.8   2.1 2.3   5.1 3.6   1.2 3.6   3.3 3.2   1.2 4.4   4.6 2.4   1.0 3.8   2.5
Net Error -2.8   0.8 0.7   2.7 -3.6   -1.0 -0.8   0.2 -3.2   -1.2 -1.3   -0.6 -2.4   -0.8 -0.4   2.3
Std Dev 1.4   0.9 1.8   3.5 0.9   1.1 1.8   2.3 0.8   0.3 1.6   0.3 0.0   0.0 0.0   0.0

Evening Forecasts
Updated: 12-20-24 at 5:00 pm
Goal Forecast Day Day +1 Day +2 Day +3
± 2.0° F Low High Low High Low High Low High
Date NW Act WS NW Act WS NW Act WS NW Act WS NW Act WS NW Act WS NW Act WS NW Act WS
12-20-24 28   27 32   35 16   15 27   29 14   17 34   38 23   27 40   42
12-19-24 29 31.1 31 42 46.6 44 30   29 37   34 15   15 27   30 12   18 33   39
12-18-24 53 37.2 39 39 55.4 46 46 31.1 32 30 46.6 44 42   29 27   35 36   13 14   29
12-17-24 61 28.9 37 35 61.3 55 50 37.2 40 36 55.4 47 44 31.1 31 29 46.6 40 42   26 27   35
12-16-24 51 51.1 46 48 53.4 58 57 28.9 36 35 61.3 53 52 37.2 38 35 55.4 45 46 31.1 27 30 46.6 39
12-15-24 37 34.7 36 50 43.3 53 49 51.1 45 59 53.4 58 36 28.9 37 52 61.3 55 35 37.2 38 46 55.4 46
12-14-24 20 16.0 23 42 37.0 43 33 34.7 35 50 43.3 53 44 51.1 46 57 53.4 59 34 28.9 38 54 61.3 56
Results NW Act WS NW Act WS NW Act WS NW Act WS NW Act WS NW Act WS NW Act WS NW Act WS
# Succ 1 3 0 0 1 2 0 0 0 2 0 0 0 1 0 0
% Succ 16.7   50.0     0.0 20.0   40.0     0.0     50.0     0.0     33.3     0.0
Ave Error 9.4   3.9 10.7   6.4 11.9   3.4 14.9   6.7 10.5   3.5 12.7   7.2 7.4   4.7 11.1   7.4
Net Error 8.7   2.2 -6.8   0.3 10.4   1.0 -10.0   -1.0 6.9   0.9 -10.9   -4.4 5.9   1.9 -11.1   -7.4
Std Dev 11.2   2.7 7.7   2.5 7.4   2.0 5.5   2.1 1.2   1.7 2.4   0.3 0.0   0.0 0.0   0.0

Nighttime Forecasts
Updated: 12-20-24 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 NW Act WS NW Act WS NW Act WS NW Act WS NW Act WS NW Act WS NW Act WS NW Act WS
12-20-24 28   28 32   36 16   16 27   29 14   17 34   39 23   28 40   45
12-19-24 29 31.1 31 42 46.6 43 30   29 37   36 15   16 27   30 12   17 33   39
12-18-24 39 37.2 40 46 55.4 47 30 31.1 32 42 46.6 44 27   30 36   35 14   12 27   30
12-17-24 35 28.9 34 50 61.3 54 36 37.2 39 44 55.4 47 29 31.1 31 42 46.6 42 27   27 35   35
12-16-24 51 51.1 48 57 53.4 58 35 28.9 38 52 61.3 54 35 37.2 38 46 55.4 44 30 31.1 27 43 46.6 39
12-15-24 37 34.7 33 50 43.3 52 49 51.1 44 59 53.4 58 36 28.9 36 52 61.3 54 35 37.2 39 46 55.4 45
12-14-24 19 16.0 15 42 37.0 45 33 34.7 36 50 43.3 52 44 51.1 45 57 53.4 58 34 28.9 37 54 61.3 55
Results NW Act WS NW Act WS NW Act WS NW Act WS NW Act WS NW Act WS NW Act WS NW Act WS
# Succ 2 3 0 0 3 3 0 0 0 2 0 0 1 1 0 0
% Succ 33.3   50.0     0.0 60.0   60.0     0.0     50.0     0.0 33.3   33.3     0.0
Ave Error 2.6   2.3 6.8   6.8 2.4   4.0 7.5   6.3 4.6   3.5 6.7   7.0 2.8   4.7 6.8   8.1
Net Error 1.8   0.3 -1.7   0.3 0.0   1.2 -2.6   -1.0 -1.1   0.4 -4.9   -4.7 0.6   1.9 -6.8   -8.1
Std Dev 1.8   1.5 2.7   1.9 1.8   2.8 2.3   2.0 1.3   1.7 1.1   1.2 0.0   0.0 0.0   0.0