VERIFICATION TO W.M.O. STANDARDS ---------------------------------------- N.C.E.P./U.S.A. SEPTEMBER 2011 ------------------------------------------------ NORTH AMERICAN MODEL (NAM) ----------------------------------- # ** NCEP/USA NAM MODEL ** TABLE 4.1 NORTH AMERICA VERIFICATION AGAINST RADIOSONDES -------------------------------------------------- 850 HPA GEOPOTENTIAL HEIGHT SEPTEMBER 2011 ------------------------------------------------ FORECAST MEAN ERROR RMSE PERIOD (M) (M) (HOURS) 00 GMT 12 GMT 00 GMT 12 GMT -------- ------ ------ ------ ------ 12 -2.76 -0.37 7.51 7.44 24 -0.99 -0.63 8.37 8.24 36 -3.75 -2.77 10.61 11.44 48 -4.39 -4.62 12.92 13.18 60 -5.77 -5.12 15.07 16.18 72 -6.04 -6.23 18.25 19.60 84 -6.86 -5.14 20.88 20.33 TABLE 4.2 NORTH AMERICA VERIFICATION AGAINST RADIOSONDES -------------------------------------------------- 500 HPA GEOPOTENTIAL HEIGHT SEPTEMBER 2011 ------------------------------------------------ FORECAST MEAN ERROR RMSE PERIOD (M) (M) (HOURS) 00 GMT 12 GMT 00 GMT 12 GMT -------- ------ ------ ------ ------ 12 -4.89 -3.44 9.77 9.50 24 -3.52 -4.28 10.50 11.06 36 -6.79 -7.02 13.84 15.00 48 -7.58 -8.76 17.65 17.90 60 -8.83 -9.30 20.08 21.56 72 -8.92 -10.68 23.75 25.85 84 -9.35 -8.72 27.57 27.57 TABLE 4.3 NORTH AMERICA VERIFICATION AGAINST RADIOSONDES -------------------------------------------------- 250 HPA GEOPOTENTIAL HEIGHT SEPTEMBER 2011 ------------------------------------------------ FORECAST MEAN ERROR RMSE PERIOD (M) (M) (HOURS) 00 GMT 12 GMT 00 GMT 12 GMT -------- ------ ------ ------ ------ 12 1.53 3.61 11.39 11.62 24 5.29 4.27 15.11 14.79 36 4.06 3.96 18.82 20.36 48 4.83 3.77 25.53 24.57 60 3.29 4.40 29.47 30.64 72 6.64 3.09 35.59 36.05 84 5.10 7.91 41.41 42.93 # ** NCEP/USA NAM MODEL ** TABLE 4.4 NORTH AMERICA VERIFICATION AGAINST RADIOSONDES -------------------------------------------------- 850 HPA TEMPERATURE SEPTEMBER 2011 ------------------------------------------------ FORECAST MEAN ERROR RMSE PERIOD (K) (K) (HOURS) 00 GMT 12 GMT 00 GMT 12 GMT -------- ------ ------ ------ ------ 12 0.09 -0.16 1.14 1.20 24 0.03 -0.14 1.22 1.32 36 0.02 -0.22 1.37 1.41 48 -0.05 -0.17 1.49 1.58 60 -0.02 -0.23 1.68 1.77 72 -0.04 -0.21 1.93 1.93 84 -0.01 -0.20 2.11 2.22 TABLE 4.5 NORTH AMERICA VERIFICATION AGAINST RADIOSONDES -------------------------------------------------- 500 HPA TEMPERATURE SEPTEMBER 2011 ------------------------------------------------ FORECAST MEAN ERROR RMSE PERIOD (K) (K) (HOURS) 00 GMT 12 GMT 00 GMT 12 GMT -------- ------ ------ ------ ------ 12 0.11 0.10 0.82 0.86 24 0.11 0.06 0.96 0.94 36 0.09 0.08 1.08 1.12 48 0.15 0.09 1.29 1.25 60 0.11 0.10 1.42 1.42 72 0.21 0.07 1.57 1.59 84 0.12 0.12 1.70 1.76 TABLE 4.6 NORTH AMERICA VERIFICATION AGAINST RADIOSONDES -------------------------------------------------- 250 HPA TEMPERATURE SEPTEMBER 2011 ------------------------------------------------ FORECAST MEAN ERROR RMSE PERIOD (K) (K) (HOURS) 00 GMT 12 GMT 00 GMT 12 GMT -------- ------ ------ ------ ------ 12 0.85 0.89 1.21 1.23 24 0.97 1.03 1.39 1.44 36 1.11 1.19 1.63 1.66 48 1.25 1.26 1.90 1.85 60 1.29 1.41 2.00 2.10 72 1.44 1.49 2.27 2.28 84 1.45 1.61 2.40 2.51 # ** NCEP/USA NAM MODEL ** TABLE 4.7 NORTH AMERICA VERIFICATION AGAINST RADIOSONDES -------------------------------------------------- 850 HPA WIND SEPTEMBER 2011 ------------------------------------------------ FORECAST MEAN SPEED ERROR RMSEV PERIOD (M/S) (M/S) (HOURS) 00 GMT 12 GMT 00 GMT 12 GMT -------- ------ ------ ------ ------ 12 -0.40 -0.57 3.51 3.70 24 -0.49 -0.47 3.77 4.03 36 -0.52 -0.49 4.16 4.46 48 -0.44 -0.49 4.56 4.80 60 -0.57 -0.60 4.97 5.40 72 -0.57 -0.61 5.39 5.96 84 -0.53 -0.73 5.75 6.20 TABLE 4.8 NORTH AMERICA VERIFICATION AGAINST RADIOSONDES -------------------------------------------------- 500 HPA WIND SEPTEMBER 2011 ------------------------------------------------ FORECAST MEAN SPEED ERROR RMSEV PERIOD (M/S) (M/S) (HOURS) 00 GMT 12 GMT 00 GMT 12 GMT -------- ------ ------ ------ ------ 12 -0.47 -0.46 3.92 3.90 24 -0.37 -0.33 4.25 4.36 36 -0.54 -0.41 4.78 4.89 48 -0.41 -0.41 5.40 5.35 60 -0.58 -0.46 6.10 6.05 72 -0.56 -0.61 6.65 6.91 84 -0.64 -0.88 7.22 7.29 TABLE 4.9 NORTH AMERICA VERIFICATION AGAINST RADIOSONDES -------------------------------------------------- 250 HPA WIND SEPTEMBER 2011 ------------------------------------------------ FORECAST MEAN SPEED ERROR RMSEV PERIOD (M/S) (M/S) (HOURS) 00 GMT 12 GMT 00 GMT 12 GMT -------- ------ ------ ------ ------ 12 -0.31 -0.26 5.04 5.00 24 -0.57 -0.64 6.03 6.09 36 -0.59 -0.60 7.07 7.38 48 -0.49 -0.76 8.50 8.38 60 -0.70 -0.80 9.52 9.91 72 -0.78 -0.76 11.10 11.02 84 -0.95 -1.15 11.70 12.26