VERIFICATION TO W.M.O. STANDARDS ---------------------------------------- N.C.E.P./U.S.A. AUGUST 2009 ------------------------------------------------ NORTH AMERICAN MODEL (NAM) ----------------------------------- # ** NCEP/USA NAM MODEL ** TABLE 4.1 NORTH AMERICA VERIFICATION AGAINST RADIOSONDES -------------------------------------------------- 850 HPA GEOPOTENTIAL HEIGHT AUGUST 2009 ------------------------------------------------ FORECAST MEAN ERROR RMSE PERIOD (M) (M) (HOURS) 00 GMT 12 GMT 00 GMT 12 GMT -------- ------ ------ ------ ------ 12 -2.17 0.30 7.80 8.06 24 -0.20 0.44 9.39 7.88 36 -2.07 0.50 10.05 10.05 48 -1.61 -0.88 12.32 11.44 60 -3.93 -1.51 13.71 13.99 72 -4.12 -2.13 16.04 15.53 84 -5.56 -1.79 19.03 18.58 TABLE 4.2 NORTH AMERICA VERIFICATION AGAINST RADIOSONDES -------------------------------------------------- 500 HPA GEOPOTENTIAL HEIGHT AUGUST 2009 ------------------------------------------------ FORECAST MEAN ERROR RMSE PERIOD (M) (M) (HOURS) 00 GMT 12 GMT 00 GMT 12 GMT -------- ------ ------ ------ ------ 12 -2.51 -1.30 8.69 9.36 24 -1.19 -1.95 10.19 10.21 36 -2.67 -1.55 11.99 12.47 48 -1.54 -2.88 14.68 14.38 60 -3.69 -2.70 17.31 17.84 72 -3.02 -3.07 21.69 20.76 84 -4.36 -2.18 24.84 25.09 TABLE 4.3 NORTH AMERICA VERIFICATION AGAINST RADIOSONDES -------------------------------------------------- 250 HPA GEOPOTENTIAL HEIGHT AUGUST 2009 ------------------------------------------------ FORECAST MEAN ERROR RMSE PERIOD (M) (M) (HOURS) 00 GMT 12 GMT 00 GMT 12 GMT -------- ------ ------ ------ ------ 12 7.25 6.52 14.22 13.76 24 8.87 7.39 17.98 15.87 36 10.38 8.79 21.34 20.71 48 12.68 10.33 27.27 24.49 60 12.00 11.46 30.51 30.43 72 13.92 11.58 38.42 35.84 84 13.72 14.10 43.16 43.36 # ** NCEP/USA NAM MODEL ** TABLE 4.4 NORTH AMERICA VERIFICATION AGAINST RADIOSONDES -------------------------------------------------- 850 HPA TEMPERATURE AUGUST 2009 ------------------------------------------------ FORECAST MEAN ERROR RMSE PERIOD (K) (K) (HOURS) 00 GMT 12 GMT 00 GMT 12 GMT -------- ------ ------ ------ ------ 12 0.29 -0.01 1.19 1.18 24 0.25 0.15 1.31 1.36 36 0.32 0.14 1.48 1.48 48 0.34 0.22 1.61 1.65 60 0.38 0.28 1.75 1.79 72 0.45 0.24 1.98 1.95 84 0.39 0.31 2.15 2.20 TABLE 4.5 NORTH AMERICA VERIFICATION AGAINST RADIOSONDES -------------------------------------------------- 500 HPA TEMPERATURE AUGUST 2009 ------------------------------------------------ FORECAST MEAN ERROR RMSE PERIOD (K) (K) (HOURS) 00 GMT 12 GMT 00 GMT 12 GMT -------- ------ ------ ------ ------ 12 0.29 0.25 0.88 0.87 24 0.27 0.20 0.96 0.95 36 0.31 0.23 1.05 1.08 48 0.37 0.26 1.22 1.15 60 0.37 0.30 1.31 1.32 72 0.42 0.29 1.51 1.44 84 0.44 0.36 1.62 1.66 TABLE 4.6 NORTH AMERICA VERIFICATION AGAINST RADIOSONDES -------------------------------------------------- 250 HPA TEMPERATURE AUGUST 2009 ------------------------------------------------ FORECAST MEAN ERROR RMSE PERIOD (K) (K) (HOURS) 00 GMT 12 GMT 00 GMT 12 GMT -------- ------ ------ ------ ------ 12 1.00 0.91 1.32 1.27 24 1.06 1.05 1.47 1.47 36 1.29 1.13 1.71 1.64 48 1.34 1.31 1.86 1.83 60 1.47 1.35 2.05 1.99 72 1.51 1.44 2.19 2.15 84 1.55 1.49 2.28 2.30 # ** NCEP/USA NAM MODEL ** TABLE 4.7 NORTH AMERICA VERIFICATION AGAINST RADIOSONDES -------------------------------------------------- 850 HPA WIND AUGUST 2009 ------------------------------------------------ FORECAST MEAN SPEED ERROR RMSEV PERIOD (M/S) (M/S) (HOURS) 00 GMT 12 GMT 00 GMT 12 GMT -------- ------ ------ ------ ------ 12 -0.40 -0.64 3.53 3.70 24 -0.45 -0.55 3.91 3.99 36 -0.34 -0.68 4.12 4.44 48 -0.44 -0.50 4.55 4.66 60 -0.38 -0.57 4.80 5.27 72 -0.43 -0.59 5.42 5.50 84 -0.40 -0.63 5.76 6.18 TABLE 4.8 NORTH AMERICA VERIFICATION AGAINST RADIOSONDES -------------------------------------------------- 500 HPA WIND AUGUST 2009 ------------------------------------------------ FORECAST MEAN SPEED ERROR RMSEV PERIOD (M/S) (M/S) (HOURS) 00 GMT 12 GMT 00 GMT 12 GMT -------- ------ ------ ------ ------ 12 -0.50 -0.28 3.85 3.87 24 -0.48 -0.25 4.23 4.21 36 -0.42 -0.34 4.62 4.85 48 -0.42 -0.30 5.26 5.21 60 -0.49 -0.44 5.72 5.95 72 -0.53 -0.41 6.51 6.28 84 -0.62 -0.48 7.01 7.17 TABLE 4.9 NORTH AMERICA VERIFICATION AGAINST RADIOSONDES -------------------------------------------------- 250 HPA WIND AUGUST 2009 ------------------------------------------------ FORECAST MEAN SPEED ERROR RMSEV PERIOD (M/S) (M/S) (HOURS) 00 GMT 12 GMT 00 GMT 12 GMT -------- ------ ------ ------ ------ 12 -0.25 -0.16 5.23 5.48 24 -0.51 -0.46 6.57 6.17 36 -0.68 -0.51 7.35 7.76 48 -0.93 -0.72 8.85 8.50 60 -1.04 -0.87 9.57 9.93 72 -1.24 -1.16 11.35 10.89 84 -1.49 -1.17 12.31 12.48