High Level (Cirriform) Frequency of Occurrence (%) October (1954 - 1997) , Ship Observations Only Global Average: 34.0 Zonal Averages 16 zones Lat.N Average 85 54.4 75 36.1 65 31.9 55 32.5 45 33.2 35 33.0 25 30.6 15 39.8 5 43.9 -5 33.1 -15 25.5 -25 28.3 -35 32.8 -45 31.1 -55 29.4 -65 49.9 Grid Box Averages 347 filled boxes Box # Lat.N Lon.E Average 1 85 60 46.5 2 85 180 61.3 3 85 300 55.2 4 75 20 26.1 5 75 60 25.7 6 75 100 36.1 7 75 140 36.3 8 75 180 44.8 9 75 220 45.4 10 75 260 45.2 11 75 300 42.5 12 75 340 26.0 13 65 10 30.6 14 65 30 29.6 15 65 50 28.3 20 65 150 30.7 21 65 170 26.2 22 65 190 23.0 23 65 210 45.0 26 65 270 49.0 27 65 290 37.6 28 65 310 30.0 29 65 330 32.8 30 65 350 31.0 31 55 10 35.3 32 55 30 32.3 37 55 130 23.8 38 55 150 27.2 39 55 170 29.4 40 55 190 33.4 41 55 210 32.0 42 55 230 39.0 44 55 270 42.0 45 55 290 39.2 46 55 310 30.5 47 55 330 30.6 48 55 350 36.6 49 45 5 41.0 50 45 15 32.6 51 45 25 24.4 52 45 35 17.9 53 45 45 22.8 54 45 55 20.9 62 45 135 23.3 63 45 145 26.4 64 45 155 32.2 65 45 165 33.4 66 45 175 33.8 67 45 185 35.4 68 45 195 34.0 69 45 205 35.4 70 45 215 38.3 71 45 225 36.5 72 45 235 36.6 77 45 285 30.4 78 45 295 29.9 79 45 305 32.4 80 45 315 32.3 81 45 325 33.5 82 45 335 33.6 83 45 345 33.8 84 45 355 35.4 85 35 5 36.9 86 35 15 29.5 87 35 25 22.0 88 35 35 17.6 90 35 55 32.0 96 35 115 22.8 97 35 125 25.3 98 35 135 32.5 99 35 145 36.8 100 35 155 35.4 101 35 165 36.6 102 35 175 36.6 103 35 185 38.2 104 35 195 34.2 105 35 205 34.4 106 35 215 34.3 107 35 225 29.7 108 35 235 23.6 109 35 245 21.6 112 35 275 34.8 113 35 285 33.3 114 35 295 33.9 115 35 305 36.5 116 35 315 37.0 117 35 325 33.8 118 35 335 32.8 119 35 345 30.4 120 35 355 33.8 124 25 35 12.2 125 25 45 12.3 126 25 55 8.9 127 25 65 8.4 128 25 75 29.5 129 25 85 39.9 130 25 95 36.2 131 25 105 31.3 132 25 115 26.7 133 25 125 27.3 134 25 135 34.9 135 25 145 32.3 136 25 155 30.0 137 25 165 30.0 138 25 175 30.6 139 25 185 33.6 140 25 195 31.5 141 25 205 30.2 142 25 215 28.1 143 25 225 29.4 144 25 235 26.4 145 25 245 23.7 146 25 255 32.3 147 25 265 36.5 148 25 275 40.5 149 25 285 39.0 150 25 295 38.5 151 25 305 35.8 152 25 315 33.9 153 25 325 29.4 154 25 335 26.0 155 25 345 25.8 160 15 35 13.9 161 15 45 14.7 162 15 55 14.4 163 15 65 24.5 164 15 75 41.5 165 15 85 48.5 166 15 95 55.4 167 15 105 44.6 168 15 115 40.2 169 15 125 45.2 170 15 135 48.2 171 15 145 46.7 172 15 155 42.0 173 15 165 38.3 174 15 175 38.3 175 15 185 37.9 176 15 195 42.6 177 15 205 38.0 178 15 215 38.6 179 15 225 38.2 180 15 235 31.2 181 15 245 41.0 182 15 255 44.0 183 15 265 53.6 184 15 275 56.9 185 15 285 46.9 186 15 295 41.1 187 15 305 39.0 188 15 315 37.2 189 15 325 34.2 190 15 335 34.6 191 15 345 35.8 193 5 5 43.0 197 5 45 20.3 198 5 55 20.5 199 5 65 36.1 200 5 75 50.9 201 5 85 59.0 202 5 95 68.8 203 5 105 59.0 204 5 115 59.4 205 5 125 56.7 206 5 135 65.5 207 5 145 58.9 208 5 155 55.5 209 5 165 52.2 210 5 175 50.6 211 5 185 50.5 212 5 195 38.8 213 5 205 34.1 214 5 215 35.9 215 5 225 31.6 216 5 235 27.5 217 5 245 29.2 218 5 255 34.5 219 5 265 45.8 220 5 275 57.8 221 5 285 57.0 223 5 305 41.5 224 5 315 35.0 225 5 325 29.5 226 5 335 36.5 227 5 345 36.5 228 5 355 31.0 229 -5 5 25.2 230 -5 15 23.6 232 -5 35 25.5 233 -5 45 16.8 234 -5 55 25.6 235 -5 65 47.5 236 -5 75 52.2 237 -5 85 64.7 238 -5 95 61.3 239 -5 105 58.0 240 -5 115 50.9 241 -5 125 40.2 242 -5 135 43.5 243 -5 145 54.3 244 -5 155 51.8 245 -5 165 55.2 246 -5 175 53.4 247 -5 185 46.3 248 -5 195 34.1 249 -5 205 27.9 250 -5 215 24.6 251 -5 225 10.0 252 -5 235 11.2 253 -5 245 11.9 254 -5 255 12.4 255 -5 265 16.4 256 -5 275 33.7 257 -5 285 48.6 260 -5 315 26.6 261 -5 325 19.3 262 -5 335 15.1 263 -5 345 12.1 264 -5 355 13.8 265 -15 5 17.4 266 -15 15 20.5 268 -15 35 16.7 269 -15 45 17.3 270 -15 55 19.3 271 -15 65 24.6 272 -15 75 34.4 273 -15 85 40.1 274 -15 95 37.4 275 -15 105 23.8 276 -15 115 17.1 277 -15 125 21.2 278 -15 135 32.9 279 -15 145 26.5 280 -15 155 25.3 281 -15 165 33.0 282 -15 175 40.0 283 -15 185 40.4 284 -15 195 35.2 285 -15 205 31.7 286 -15 215 27.0 287 -15 225 19.7 288 -15 235 16.6 289 -15 245 13.7 290 -15 255 13.2 291 -15 265 22.3 292 -15 275 18.1 293 -15 285 28.9 297 -15 325 29.3 298 -15 335 23.4 299 -15 345 21.7 300 -15 355 19.3 301 -25 5 24.8 302 -25 15 23.5 304 -25 35 23.2 305 -25 45 24.2 306 -25 55 25.4 307 -25 65 23.8 308 -25 75 21.8 309 -25 85 20.1 310 -25 95 22.2 311 -25 105 20.3 312 -25 115 16.2 315 -25 145 14.7 316 -25 155 20.0 317 -25 165 25.5 318 -25 175 32.0 319 -25 185 34.7 320 -25 195 34.7 321 -25 205 28.9 322 -25 215 34.7 323 -25 225 40.9 324 -25 235 37.6 325 -25 245 26.1 326 -25 255 36.6 327 -25 265 26.5 328 -25 275 21.9 329 -25 285 18.2 332 -25 315 41.7 333 -25 325 33.6 334 -25 335 36.2 335 -25 345 34.2 336 -25 355 31.6 337 -35 5 40.3 338 -35 15 30.8 339 -35 25 30.2 340 -35 35 26.9 341 -35 45 32.5 342 -35 55 29.4 343 -35 65 28.3 344 -35 75 26.4 345 -35 85 31.1 346 -35 95 25.6 347 -35 105 26.4 348 -35 115 25.8 349 -35 125 28.6 350 -35 135 30.8 351 -35 145 32.5 352 -35 155 30.1 353 -35 165 29.5 354 -35 175 35.2 355 -35 185 33.4 356 -35 195 36.1 357 -35 205 28.3 358 -35 215 34.5 359 -35 225 32.4 360 -35 235 40.5 361 -35 245 40.8 362 -35 255 49.0 363 -35 265 51.6 364 -35 275 26.6 365 -35 285 24.1 367 -35 305 34.5 368 -35 315 30.1 369 -35 325 30.5 370 -35 335 30.8 371 -35 345 37.5 372 -35 355 39.7 379 -45 65 21.0 380 -45 75 26.6 384 -45 115 20.7 385 -45 125 18.9 386 -45 135 29.2 387 -45 145 36.1 388 -45 155 31.7 389 -45 165 27.6 390 -45 175 37.8 391 -45 185 36.6 392 -45 195 31.9 393 -45 205 27.2 394 -45 215 35.1 400 -45 275 37.2 401 -45 285 30.8 402 -45 295 38.4 403 -45 305 37.4 404 -45 315 36.0 405 -45 325 32.9 408 -45 355 32.8 415 -55 130 37.2 416 -55 150 23.1 417 -55 170 22.0 422 -55 270 23.9 423 -55 290 42.3 424 -55 310 37.9 425 -55 330 21.6 430 -65 70 54.1 432 -65 110 46.1 442 -65 310 48.8