High Level (Cirriform) Frequency of Occurrence (%) June (1954 - 1997) Night, Ship Observations Only Global Average: 28.7 Zonal Averages 15 zones Lat.N Average 85 48.3 75 50.2 65 43.2 55 41.6 45 39.0 35 35.5 25 29.4 15 35.1 5 42.8 -5 28.4 -15 18.5 -25 19.5 -35 20.5 -45 19.7 -55 18.4 Grid Box Averages 307 filled boxes Box # Lat.N Lon.E Average 1 85 60 35.2 2 85 180 54.4 3 85 300 57.7 4 75 20 40.0 5 75 60 42.8 8 75 180 53.4 9 75 220 65.0 10 75 260 50.2 11 75 300 54.5 12 75 340 44.4 13 65 10 39.0 14 65 30 44.5 15 65 50 41.9 20 65 150 49.5 21 65 170 36.4 22 65 190 43.8 23 65 210 35.3 28 65 310 51.4 29 65 330 46.9 30 65 350 39.3 31 55 10 40.4 32 55 30 45.6 37 55 130 37.9 38 55 150 41.5 39 55 170 38.4 40 55 190 43.1 41 55 210 43.0 42 55 230 41.4 46 55 310 42.0 47 55 330 40.0 48 55 350 44.1 49 45 5 36.7 50 45 15 37.9 51 45 25 34.9 52 45 35 23.1 53 45 45 22.9 54 45 55 19.9 62 45 135 36.8 63 45 145 31.8 64 45 155 40.6 65 45 165 41.1 66 45 175 40.6 67 45 185 41.2 68 45 195 46.9 69 45 205 46.3 70 45 215 42.4 71 45 225 31.9 72 45 235 26.6 77 45 285 46.9 78 45 295 50.5 79 45 305 44.5 80 45 315 40.3 81 45 325 30.9 82 45 335 36.8 83 45 345 38.8 84 45 355 37.0 85 35 5 28.2 86 35 15 26.1 87 35 25 15.6 88 35 35 9.4 96 35 115 27.0 97 35 125 42.7 98 35 135 51.9 99 35 145 45.1 100 35 155 41.8 101 35 165 48.0 102 35 175 45.0 103 35 185 44.2 104 35 195 47.7 105 35 205 42.6 106 35 215 34.4 107 35 225 22.9 108 35 235 17.9 109 35 245 14.0 112 35 275 44.2 113 35 285 48.9 114 35 295 45.5 115 35 305 34.8 116 35 315 29.1 117 35 325 26.1 118 35 335 24.1 119 35 345 20.7 120 35 355 25.7 124 25 35 9.9 125 25 45 9.9 126 25 55 10.7 127 25 65 19.9 131 25 105 56.3 132 25 115 43.4 133 25 125 45.6 134 25 135 49.8 135 25 145 40.0 136 25 155 34.8 137 25 165 33.9 138 25 175 34.9 139 25 185 28.6 140 25 195 30.0 141 25 205 24.8 142 25 215 19.7 143 25 225 18.8 144 25 235 17.3 145 25 245 18.1 146 25 255 26.2 147 25 265 35.4 148 25 275 41.9 149 25 285 50.1 150 25 295 38.7 151 25 305 26.5 152 25 315 21.8 153 25 325 17.6 154 25 335 13.4 155 25 345 14.9 160 15 35 19.4 161 15 45 24.3 162 15 55 23.8 163 15 65 30.7 164 15 75 47.8 165 15 85 57.7 166 15 95 67.6 167 15 105 59.0 168 15 115 47.6 169 15 125 44.4 170 15 135 44.0 171 15 145 38.9 172 15 155 32.6 173 15 165 28.9 174 15 175 34.1 175 15 185 36.4 176 15 195 33.3 177 15 205 25.2 178 15 215 27.8 179 15 225 19.2 180 15 235 14.4 181 15 245 27.7 182 15 255 44.1 183 15 265 61.1 184 15 275 57.0 185 15 285 49.7 186 15 295 34.6 187 15 305 28.2 188 15 315 22.8 189 15 325 26.4 190 15 335 21.5 191 15 345 25.0 193 5 5 45.6 197 5 45 31.9 198 5 55 30.4 199 5 65 43.0 200 5 75 46.5 201 5 85 57.7 202 5 95 70.0 203 5 105 57.2 204 5 115 57.8 205 5 125 58.0 206 5 135 62.1 207 5 145 49.5 208 5 155 46.5 209 5 165 38.6 210 5 175 52.6 211 5 185 46.3 212 5 195 41.7 213 5 205 31.6 214 5 215 27.3 215 5 225 33.6 216 5 235 30.2 217 5 245 34.0 218 5 255 37.2 219 5 265 49.2 220 5 275 62.5 221 5 285 62.0 223 5 305 36.9 224 5 315 31.7 225 5 325 25.9 226 5 335 28.2 227 5 345 32.2 228 5 355 31.7 229 -5 5 21.9 230 -5 15 10.6 233 -5 45 21.4 234 -5 55 35.7 235 -5 65 42.8 236 -5 75 44.7 237 -5 85 53.5 238 -5 95 56.2 239 -5 105 42.0 240 -5 115 29.1 241 -5 125 32.3 242 -5 135 34.5 243 -5 145 39.1 244 -5 155 36.9 245 -5 165 39.7 246 -5 175 40.1 247 -5 185 44.5 248 -5 195 27.7 249 -5 205 22.9 250 -5 215 15.5 251 -5 225 7.5 252 -5 235 8.3 253 -5 245 10.0 254 -5 255 15.6 255 -5 265 20.9 256 -5 275 35.5 260 -5 315 29.8 261 -5 325 17.9 262 -5 335 14.4 263 -5 345 10.5 264 -5 355 16.0 265 -15 5 12.1 266 -15 15 9.3 268 -15 35 5.7 269 -15 45 9.4 270 -15 55 14.3 271 -15 65 17.5 272 -15 75 20.9 273 -15 85 22.3 274 -15 95 34.5 275 -15 105 20.2 276 -15 115 17.8 277 -15 125 13.6 278 -15 135 16.1 279 -15 145 17.0 280 -15 155 20.9 281 -15 165 29.3 282 -15 175 30.3 283 -15 185 38.1 284 -15 195 24.3 285 -15 205 18.9 286 -15 215 17.5 287 -15 225 13.5 288 -15 235 12.2 289 -15 245 8.3 290 -15 255 10.8 291 -15 265 17.5 292 -15 275 18.7 293 -15 285 23.7 297 -15 325 23.7 298 -15 335 8.0 299 -15 345 12.8 300 -15 355 12.2 301 -25 5 15.3 302 -25 15 10.4 304 -25 35 8.1 305 -25 45 8.8 306 -25 55 9.5 307 -25 65 13.6 308 -25 75 14.1 309 -25 85 8.1 310 -25 95 10.8 311 -25 105 15.8 312 -25 115 12.7 316 -25 155 15.6 317 -25 165 21.1 318 -25 175 26.0 319 -25 185 32.0 320 -25 195 23.5 321 -25 205 28.9 322 -25 215 31.3 323 -25 225 28.4 324 -25 235 24.6 325 -25 245 16.9 328 -25 275 14.8 329 -25 285 25.1 332 -25 315 29.9 333 -25 325 24.9 334 -25 335 27.3 335 -25 345 20.8 336 -25 355 16.0 337 -35 5 26.4 338 -35 15 19.9 339 -35 25 20.8 340 -35 35 13.2 341 -35 45 15.0 342 -35 55 21.5 343 -35 65 17.9 344 -35 75 12.0 345 -35 85 11.3 346 -35 95 11.3 347 -35 105 12.4 348 -35 115 14.0 349 -35 125 23.5 350 -35 135 25.5 351 -35 145 26.6 352 -35 155 22.6 353 -35 165 22.6 354 -35 175 19.0 355 -35 185 20.6 356 -35 195 23.8 357 -35 205 27.7 358 -35 215 25.0 364 -35 275 14.5 365 -35 285 21.8 367 -35 305 31.7 368 -35 315 25.1 369 -35 325 28.3 370 -35 335 23.6 371 -35 345 28.9 372 -35 355 22.1 387 -45 145 31.7 389 -45 165 16.5 390 -45 175 17.3 398 -45 255 15.4 400 -45 275 12.9 402 -45 295 28.4 403 -45 305 20.1 423 -55 290 21.5 424 -55 310 26.1 425 -55 330 8.2