VERIFICATION TO W.M.O. STANDARDS ---------------------------------------- N.C.E.P./U.S.A. APRIL 2009 ------------------------------------------------ NORTH AMERICAN MODEL (NAM) ----------------------------------- # ** NCEP/USA NAM MODEL ** TABLE 4.1 NORTH AMERICA VERIFICATION AGAINST RADIOSONDES -------------------------------------------------- 850 HPA GEOPOTENTIAL HEIGHT APRIL 2009 ------------------------------------------------ FORECAST MEAN ERROR RMSE PERIOD (M) (M) (HOURS) 00 GMT 12 GMT 00 GMT 12 GMT -------- ------ ------ ------ ------ 12 -1.96 -1.02 8.76 7.92 24 -1.11 -1.36 9.48 9.62 36 -1.73 -0.97 11.64 11.25 48 -1.68 -1.36 13.98 13.88 60 -2.08 -2.20 16.73 17.01 72 -2.84 -1.96 19.86 19.13 84 -3.20 -2.07 22.53 22.66 TABLE 4.2 NORTH AMERICA VERIFICATION AGAINST RADIOSONDES -------------------------------------------------- 500 HPA GEOPOTENTIAL HEIGHT APRIL 2009 ------------------------------------------------ FORECAST MEAN ERROR RMSE PERIOD (M) (M) (HOURS) 00 GMT 12 GMT 00 GMT 12 GMT -------- ------ ------ ------ ------ 12 -4.50 -2.57 11.05 9.78 24 -3.83 -3.93 11.95 12.74 36 -4.75 -3.35 15.87 14.63 48 -3.62 -3.52 18.86 18.91 60 -4.66 -4.08 23.48 23.85 72 -5.75 -3.99 27.60 27.90 84 -5.90 -4.69 33.41 32.48 TABLE 4.3 NORTH AMERICA VERIFICATION AGAINST RADIOSONDES -------------------------------------------------- 250 HPA GEOPOTENTIAL HEIGHT APRIL 2009 ------------------------------------------------ FORECAST MEAN ERROR RMSE PERIOD (M) (M) (HOURS) 00 GMT 12 GMT 00 GMT 12 GMT -------- ------ ------ ------ ------ 12 2.66 4.27 13.82 12.84 24 6.88 5.56 17.93 17.78 36 8.25 9.49 22.08 22.76 48 11.27 10.84 28.33 27.54 60 11.28 10.64 32.61 33.27 72 10.83 12.32 38.22 38.37 84 12.27 10.98 45.35 43.35 # ** NCEP/USA NAM MODEL ** TABLE 4.4 NORTH AMERICA VERIFICATION AGAINST RADIOSONDES -------------------------------------------------- 850 HPA TEMPERATURE APRIL 2009 ------------------------------------------------ FORECAST MEAN ERROR RMSE PERIOD (K) (K) (HOURS) 00 GMT 12 GMT 00 GMT 12 GMT -------- ------ ------ ------ ------ 12 -0.24 -0.15 1.39 1.42 24 -0.24 -0.33 1.45 1.61 36 -0.40 -0.35 1.69 1.72 48 -0.39 -0.45 1.77 1.93 60 -0.53 -0.47 1.97 2.11 72 -0.57 -0.58 2.18 2.35 84 -0.69 -0.64 2.48 2.58 TABLE 4.5 NORTH AMERICA VERIFICATION AGAINST RADIOSONDES -------------------------------------------------- 500 HPA TEMPERATURE APRIL 2009 ------------------------------------------------ FORECAST MEAN ERROR RMSE PERIOD (K) (K) (HOURS) 00 GMT 12 GMT 00 GMT 12 GMT -------- ------ ------ ------ ------ 12 0.15 0.19 0.87 0.89 24 0.22 0.18 1.01 1.05 36 0.26 0.32 1.17 1.24 48 0.33 0.35 1.36 1.42 60 0.39 0.38 1.58 1.62 72 0.43 0.45 1.78 1.81 84 0.46 0.43 2.01 1.98 TABLE 4.6 NORTH AMERICA VERIFICATION AGAINST RADIOSONDES -------------------------------------------------- 250 HPA TEMPERATURE APRIL 2009 ------------------------------------------------ FORECAST MEAN ERROR RMSE PERIOD (K) (K) (HOURS) 00 GMT 12 GMT 00 GMT 12 GMT -------- ------ ------ ------ ------ 12 0.79 0.80 1.29 1.27 24 0.94 0.88 1.56 1.50 36 1.02 1.03 1.77 1.76 48 1.18 1.03 1.98 1.98 60 1.12 1.15 2.11 2.15 72 1.17 1.13 2.31 2.28 84 1.17 1.17 2.46 2.45 # ** NCEP/USA NAM MODEL ** TABLE 4.7 NORTH AMERICA VERIFICATION AGAINST RADIOSONDES -------------------------------------------------- 850 HPA WIND APRIL 2009 ------------------------------------------------ FORECAST MEAN SPEED ERROR RMSEV PERIOD (M/S) (M/S) (HOURS) 00 GMT 12 GMT 00 GMT 12 GMT -------- ------ ------ ------ ------ 12 -0.24 -0.51 3.91 4.00 24 -0.13 -0.16 4.20 4.41 36 -0.04 -0.15 4.59 4.77 48 -0.14 -0.15 4.96 5.17 60 -0.07 -0.22 5.27 5.64 72 -0.22 -0.24 5.78 6.05 84 -0.21 -0.39 6.14 6.70 TABLE 4.8 NORTH AMERICA VERIFICATION AGAINST RADIOSONDES -------------------------------------------------- 500 HPA WIND APRIL 2009 ------------------------------------------------ FORECAST MEAN SPEED ERROR RMSEV PERIOD (M/S) (M/S) (HOURS) 00 GMT 12 GMT 00 GMT 12 GMT -------- ------ ------ ------ ------ 12 -0.38 -0.46 4.25 4.23 24 -0.26 -0.23 4.80 4.94 36 -0.36 -0.33 5.56 5.57 48 -0.34 -0.40 6.19 6.41 60 -0.48 -0.32 6.79 7.06 72 -0.35 -0.49 7.61 7.65 84 -0.68 -0.39 8.56 8.63 TABLE 4.9 NORTH AMERICA VERIFICATION AGAINST RADIOSONDES -------------------------------------------------- 250 HPA WIND APRIL 2009 ------------------------------------------------ FORECAST MEAN SPEED ERROR RMSEV PERIOD (M/S) (M/S) (HOURS) 00 GMT 12 GMT 00 GMT 12 GMT -------- ------ ------ ------ ------ 12 -0.48 -0.25 5.45 5.33 24 -0.41 -0.43 6.42 6.43 36 -0.66 -0.29 7.55 7.48 48 -0.59 -0.59 8.56 8.30 60 -0.84 -0.75 9.68 9.55 72 -0.88 -0.90 10.65 10.32 84 -1.02 -0.73 11.76 11.19