High Level (Cirriform) Frequency of Occurrence (%) September (1954 - 1997) Day, Ship Observations Only Global Average: 38.4 Zonal Averages 15 zones Lat.N Average 85 56.5 75 42.2 65 44.8 55 43.6 45 43.6 35 39.4 25 39.3 15 50.1 5 52.0 -5 36.8 -15 26.5 -25 27.0 -35 32.2 -45 34.2 -55 38.3 Grid Box Averages 333 filled boxes Box # Lat.N Lon.E Average 1 85 60 49.3 2 85 180 59.3 3 85 300 62.4 4 75 20 39.4 5 75 60 36.9 6 75 100 33.8 7 75 140 37.9 8 75 180 44.7 9 75 220 50.2 10 75 260 51.3 11 75 300 43.8 12 75 340 41.8 13 65 10 43.9 14 65 30 39.1 15 65 50 34.9 20 65 150 30.7 21 65 170 32.4 22 65 190 38.6 23 65 210 57.3 25 65 250 55.6 26 65 270 53.3 27 65 290 50.9 28 65 310 46.4 29 65 330 46.9 30 65 350 45.0 31 55 10 45.3 32 55 30 39.3 37 55 130 43.4 38 55 150 37.3 39 55 170 40.0 40 55 190 43.7 41 55 210 46.3 42 55 230 48.4 44 55 270 50.4 45 55 290 48.8 46 55 310 41.4 47 55 330 41.1 48 55 350 50.9 49 45 5 42.6 50 45 15 32.5 51 45 25 20.5 52 45 35 18.3 53 45 45 22.7 54 45 55 20.0 62 45 135 37.5 63 45 145 40.0 64 45 155 44.8 65 45 165 47.4 66 45 175 47.1 67 45 185 46.7 68 45 195 47.9 69 45 205 49.0 70 45 215 47.6 71 45 225 41.3 72 45 235 38.2 77 45 285 42.5 78 45 295 43.3 79 45 305 44.3 80 45 315 46.0 81 45 325 42.9 82 45 335 42.2 83 45 345 42.7 84 45 355 43.6 85 35 5 34.1 86 35 15 23.7 87 35 25 12.7 88 35 35 8.3 90 35 55 21.6 96 35 115 30.2 97 35 125 38.6 98 35 135 50.9 99 35 145 52.2 100 35 155 49.3 101 35 165 48.8 102 35 175 46.3 103 35 185 46.8 104 35 195 44.1 105 35 205 42.7 106 35 215 36.6 107 35 225 28.5 108 35 235 23.5 109 35 245 18.8 112 35 275 48.2 113 35 285 45.3 114 35 295 44.1 115 35 305 44.5 116 35 315 43.3 117 35 325 38.6 118 35 335 36.0 119 35 345 29.3 120 35 355 35.8 124 25 35 14.8 125 25 45 5.7 126 25 55 9.4 127 25 65 22.4 128 25 75 40.4 129 25 85 63.2 131 25 105 54.0 132 25 115 49.2 133 25 125 47.9 134 25 135 53.8 135 25 145 52.1 136 25 155 45.3 137 25 165 44.5 138 25 175 43.6 139 25 185 41.4 140 25 195 33.5 141 25 205 30.4 142 25 215 27.7 143 25 225 27.5 144 25 235 29.5 145 25 245 33.6 146 25 255 54.5 147 25 265 53.3 148 25 275 57.2 149 25 285 52.0 150 25 295 47.6 151 25 305 43.5 152 25 315 36.9 153 25 325 29.4 154 25 335 25.1 155 25 345 24.4 160 15 35 21.6 161 15 45 22.5 162 15 55 21.5 163 15 65 37.3 164 15 75 56.6 165 15 85 58.0 166 15 95 63.8 167 15 105 62.6 168 15 115 62.8 169 15 125 63.3 170 15 135 64.8 171 15 145 65.6 172 15 155 58.3 173 15 165 51.8 174 15 175 52.1 175 15 185 49.0 176 15 195 44.8 177 15 205 43.0 178 15 215 40.5 179 15 225 39.4 180 15 235 42.0 181 15 245 50.0 182 15 255 66.2 183 15 265 71.0 184 15 275 65.2 185 15 285 57.7 186 15 295 51.4 187 15 305 45.2 188 15 315 40.0 189 15 325 36.7 190 15 335 35.6 191 15 345 43.8 193 5 5 49.1 197 5 45 27.9 198 5 55 33.3 199 5 65 50.2 200 5 75 61.0 201 5 85 68.7 202 5 95 73.0 203 5 105 66.2 204 5 115 70.7 205 5 125 67.5 206 5 135 68.0 207 5 145 66.2 208 5 155 66.6 209 5 165 62.3 210 5 175 58.8 211 5 185 49.3 212 5 195 48.2 213 5 205 46.7 214 5 215 49.5 215 5 225 36.8 216 5 235 40.3 217 5 245 44.7 218 5 255 45.7 219 5 265 55.3 220 5 275 65.1 221 5 285 65.0 223 5 305 45.9 224 5 315 34.2 225 5 325 28.9 226 5 335 38.4 227 5 345 46.2 228 5 355 33.6 229 -5 5 22.7 230 -5 15 25.6 232 -5 35 20.4 233 -5 45 23.9 234 -5 55 38.6 235 -5 65 60.3 236 -5 75 61.6 237 -5 85 69.9 238 -5 95 63.2 239 -5 105 57.3 240 -5 115 50.2 241 -5 125 43.0 242 -5 135 47.7 243 -5 145 63.2 244 -5 155 61.4 245 -5 165 56.4 246 -5 175 54.6 247 -5 185 42.8 248 -5 195 34.4 249 -5 205 30.1 250 -5 215 24.5 251 -5 225 12.6 252 -5 235 12.9 253 -5 245 17.9 254 -5 255 22.5 255 -5 265 24.7 256 -5 275 33.4 260 -5 315 22.8 261 -5 325 18.4 262 -5 335 15.8 263 -5 345 16.5 264 -5 355 15.8 265 -15 5 15.6 266 -15 15 17.5 268 -15 35 11.3 269 -15 45 13.0 270 -15 55 19.1 271 -15 65 24.1 272 -15 75 40.5 273 -15 85 38.8 274 -15 95 37.9 275 -15 105 30.3 276 -15 115 19.8 277 -15 125 22.1 278 -15 135 37.4 279 -15 145 28.7 280 -15 155 31.8 281 -15 165 37.3 282 -15 175 40.0 283 -15 185 37.4 284 -15 195 38.6 285 -15 205 30.3 286 -15 215 22.9 287 -15 225 17.9 288 -15 235 18.7 289 -15 245 19.3 290 -15 255 20.5 291 -15 265 21.2 292 -15 275 18.7 293 -15 285 22.4 297 -15 325 27.8 298 -15 335 22.6 299 -15 345 23.5 300 -15 355 22.3 301 -25 5 22.2 302 -25 15 22.5 304 -25 35 17.9 305 -25 45 17.0 306 -25 55 17.4 307 -25 65 20.6 308 -25 75 19.7 309 -25 85 16.1 310 -25 95 17.5 311 -25 105 17.4 312 -25 115 13.7 315 -25 145 15.4 316 -25 155 18.2 317 -25 165 22.8 318 -25 175 26.1 319 -25 185 30.1 320 -25 195 33.2 321 -25 205 38.8 322 -25 215 42.8 323 -25 225 44.5 324 -25 235 36.3 325 -25 245 33.3 326 -25 255 36.4 327 -25 265 22.5 328 -25 275 20.9 329 -25 285 20.1 332 -25 315 38.8 333 -25 325 33.7 334 -25 335 33.9 335 -25 345 32.4 336 -25 355 31.1 337 -35 5 35.2 338 -35 15 30.2 339 -35 25 36.6 340 -35 35 30.7 341 -35 45 30.5 342 -35 55 29.2 343 -35 65 29.8 344 -35 75 26.2 345 -35 85 28.1 346 -35 95 26.0 347 -35 105 24.1 348 -35 115 26.3 349 -35 125 33.0 350 -35 135 35.7 351 -35 145 39.4 352 -35 155 32.6 353 -35 165 31.7 354 -35 175 35.2 355 -35 185 31.0 356 -35 195 33.4 357 -35 205 34.1 358 -35 215 35.0 359 -35 225 34.6 360 -35 235 33.8 361 -35 245 38.5 364 -35 275 26.6 365 -35 285 25.3 367 -35 305 43.2 368 -35 315 36.2 369 -35 325 33.3 370 -35 335 30.9 371 -35 345 39.5 372 -35 355 38.9 379 -45 65 21.4 380 -45 75 19.9 384 -45 115 37.7 387 -45 145 36.4 388 -45 155 36.3 389 -45 165 38.0 390 -45 175 42.1 391 -45 185 44.7 392 -45 195 31.3 400 -45 275 25.1 401 -45 285 31.6 402 -45 295 49.2 403 -45 305 42.9 404 -45 315 38.3 405 -45 325 25.8 417 -55 170 42.0 423 -55 290 46.8 424 -55 310 35.9 425 -55 330 30.1