High Level (Cirriform) Frequency of Occurrence (%) October (1954 - 1997) Day, Ship Observations Only Global Average: 39.4 Zonal Averages 16 zones Lat.N Average 85 55.6 75 41.2 65 40.3 55 39.6 45 40.3 35 40.2 25 36.9 15 47.1 5 51.1 -5 38.1 -15 30.3 -25 33.0 -35 37.0 -45 36.7 -55 32.9 -65 50.7 Grid Box Averages 338 filled boxes Box # Lat.N Lon.E Average 1 85 60 50.1 2 85 180 60.5 3 85 300 56.0 4 75 20 33.0 5 75 60 32.5 6 75 100 34.2 7 75 140 38.4 8 75 180 53.7 9 75 220 47.7 10 75 260 46.2 11 75 300 48.2 12 75 340 35.1 13 65 10 39.1 14 65 30 36.1 15 65 50 32.9 20 65 150 32.3 21 65 170 32.4 22 65 190 29.4 23 65 210 44.9 26 65 270 52.0 27 65 290 49.7 28 65 310 40.7 29 65 330 43.0 30 65 350 40.0 31 55 10 42.5 32 55 30 39.3 37 55 130 24.6 38 55 150 31.9 39 55 170 36.0 40 55 190 38.6 41 55 210 41.3 42 55 230 48.1 45 55 290 49.4 46 55 310 38.4 47 55 330 38.9 48 55 350 46.9 49 45 5 47.0 50 45 15 40.1 51 45 25 28.1 52 45 35 23.3 53 45 45 26.4 54 45 55 28.8 62 45 135 27.5 63 45 145 31.5 64 45 155 38.7 65 45 165 41.0 66 45 175 39.5 67 45 185 39.6 68 45 195 39.8 69 45 205 43.5 70 45 215 45.4 71 45 225 45.0 72 45 235 44.3 77 45 285 36.5 78 45 295 37.1 79 45 305 38.8 80 45 315 40.3 81 45 325 42.3 82 45 335 42.7 83 45 345 43.2 84 45 355 43.7 85 35 5 41.9 86 35 15 36.4 87 35 25 26.6 88 35 35 21.1 90 35 55 34.0 96 35 115 22.9 97 35 125 29.4 98 35 135 37.5 99 35 145 43.8 100 35 155 44.5 101 35 165 44.9 102 35 175 41.8 103 35 185 42.0 104 35 195 43.0 105 35 205 43.2 106 35 215 42.7 107 35 225 37.5 108 35 235 30.9 109 35 245 28.9 112 35 275 39.7 113 35 285 39.0 114 35 295 41.0 115 35 305 44.9 116 35 315 45.6 117 35 325 42.8 118 35 335 41.5 119 35 345 38.3 120 35 355 42.0 124 25 35 14.8 125 25 45 17.6 126 25 55 11.4 127 25 65 11.6 128 25 75 35.5 129 25 85 43.5 131 25 105 33.8 132 25 115 32.4 133 25 125 34.5 134 25 135 40.9 135 25 145 39.9 136 25 155 38.3 137 25 165 36.6 138 25 175 36.5 139 25 185 37.2 140 25 195 37.4 141 25 205 35.6 142 25 215 33.8 143 25 225 35.7 144 25 235 32.2 145 25 245 31.1 146 25 255 40.0 147 25 265 40.8 148 25 275 43.3 149 25 285 45.6 150 25 295 46.0 151 25 305 45.3 152 25 315 40.7 153 25 325 36.7 154 25 335 33.5 155 25 345 32.6 160 15 35 16.3 161 15 45 16.9 162 15 55 19.1 163 15 65 31.9 164 15 75 52.3 165 15 85 52.0 166 15 95 55.2 167 15 105 49.1 168 15 115 48.7 169 15 125 54.9 170 15 135 56.5 171 15 145 55.7 172 15 155 51.8 173 15 165 46.9 174 15 175 45.0 175 15 185 41.7 176 15 195 48.8 177 15 205 45.5 178 15 215 46.2 179 15 225 47.4 180 15 235 39.1 181 15 245 47.4 182 15 255 53.6 183 15 265 61.5 184 15 275 59.5 185 15 285 55.5 186 15 295 48.7 187 15 305 47.7 188 15 315 45.0 189 15 325 43.9 190 15 335 42.1 191 15 345 44.0 193 5 5 45.4 197 5 45 25.5 198 5 55 25.6 199 5 65 46.1 200 5 75 60.0 201 5 85 64.4 202 5 95 70.9 203 5 105 65.7 204 5 115 68.0 205 5 125 65.0 206 5 135 71.2 207 5 145 67.8 208 5 155 66.3 209 5 165 62.7 210 5 175 56.5 211 5 185 52.6 212 5 195 48.7 213 5 205 42.1 214 5 215 48.3 215 5 225 36.9 216 5 235 34.3 217 5 245 38.2 218 5 255 46.2 219 5 265 47.3 220 5 275 60.1 221 5 285 62.9 223 5 305 49.5 224 5 315 43.1 225 5 325 35.5 226 5 335 44.1 227 5 345 45.6 228 5 355 34.5 229 -5 5 25.8 230 -5 15 30.6 232 -5 35 27.1 233 -5 45 20.9 234 -5 55 31.8 235 -5 65 53.8 236 -5 75 61.8 237 -5 85 71.1 238 -5 95 64.2 239 -5 105 65.5 240 -5 115 57.8 241 -5 125 49.4 242 -5 135 50.5 243 -5 145 63.3 244 -5 155 63.9 245 -5 165 59.0 246 -5 175 58.2 247 -5 185 50.5 248 -5 195 41.3 249 -5 205 37.5 250 -5 215 29.4 251 -5 225 15.2 252 -5 235 14.2 253 -5 245 15.6 254 -5 255 15.4 255 -5 265 16.4 256 -5 275 31.9 260 -5 315 31.7 261 -5 325 25.8 262 -5 335 20.4 263 -5 345 15.2 264 -5 355 15.5 265 -15 5 18.1 266 -15 15 23.0 268 -15 35 20.6 269 -15 45 22.0 270 -15 55 26.3 271 -15 65 34.0 272 -15 75 41.5 273 -15 85 41.9 274 -15 95 39.6 275 -15 105 31.1 276 -15 115 21.9 277 -15 125 25.4 278 -15 135 40.3 279 -15 145 30.5 280 -15 155 33.5 281 -15 165 37.4 282 -15 175 44.1 283 -15 185 45.6 284 -15 195 43.4 285 -15 205 39.6 286 -15 215 33.9 287 -15 225 26.2 288 -15 235 21.7 289 -15 245 19.3 290 -15 255 15.3 291 -15 265 22.9 292 -15 275 18.8 293 -15 285 30.6 297 -15 325 36.5 298 -15 335 28.7 299 -15 345 27.0 300 -15 355 19.6 301 -25 5 25.7 302 -25 15 26.5 304 -25 35 27.8 305 -25 45 30.0 306 -25 55 30.3 307 -25 65 26.7 308 -25 75 27.3 309 -25 85 22.1 310 -25 95 22.0 311 -25 105 22.9 312 -25 115 18.3 315 -25 145 17.5 316 -25 155 26.6 317 -25 165 31.3 318 -25 175 34.3 319 -25 185 37.5 320 -25 195 37.1 321 -25 205 38.5 322 -25 215 43.8 323 -25 225 48.2 324 -25 235 44.3 325 -25 245 35.9 326 -25 255 38.3 327 -25 265 34.5 328 -25 275 25.4 329 -25 285 19.4 332 -25 315 46.2 333 -25 325 40.9 334 -25 335 43.0 335 -25 345 40.3 336 -25 355 34.2 337 -35 5 41.9 338 -35 15 35.0 339 -35 25 38.9 340 -35 35 34.0 341 -35 45 38.4 342 -35 55 33.6 343 -35 65 33.6 344 -35 75 32.4 345 -35 85 34.7 346 -35 95 27.7 347 -35 105 27.4 348 -35 115 31.2 349 -35 125 35.8 350 -35 135 38.5 351 -35 145 40.2 352 -35 155 38.5 353 -35 165 35.8 354 -35 175 39.2 355 -35 185 36.6 356 -35 195 39.0 357 -35 205 36.8 358 -35 215 39.7 359 -35 225 38.2 360 -35 235 42.7 361 -35 245 41.8 363 -35 265 48.4 364 -35 275 32.0 365 -35 285 30.0 367 -35 305 44.7 368 -35 315 36.8 369 -35 325 35.5 370 -35 335 37.2 371 -35 345 42.3 372 -35 355 44.4 379 -45 65 24.9 380 -45 75 30.1 386 -45 135 31.1 387 -45 145 45.5 388 -45 155 36.5 389 -45 165 36.6 390 -45 175 44.5 391 -45 185 41.9 392 -45 195 40.2 393 -45 205 29.6 400 -45 275 36.7 401 -45 285 33.2 402 -45 295 47.4 403 -45 305 42.3 404 -45 315 37.0 405 -45 325 35.0 416 -55 150 24.2 417 -55 170 30.1 422 -55 270 26.9 423 -55 290 50.5 424 -55 310 42.6 425 -55 330 26.4 430 -65 70 56.6 432 -65 110 52.1 442 -65 310 45.0