UPPER AIR CALCULATIONS AND PLOTTING (Ver 5.52-LINUX-X11) Current filename: /home/data/upa/2025102800.upa.cvt Date: 0000Z 28 OCT 25 Searching for KREV... Searching the city database file for: KREV ... Date:0000Z 28 OCT 25 Station: KREV WMO ident: 72489 Latitude: 39.57 Longitude: -119.78 Elevation: 1516.00 ------------------------------------------------------------------------------- LEV PRES HGHT TEMP DEWP RH DD WETB DIR SPD THETA THE-V THE-W THE-E W mb m C C % C C deg knt K K K K g/kg ------------------------------------------------------------------------------- 0 1000 150 1 925 825 SFC 853 1516 14.6 2.6 44 12.0 8.1 75 5 301.1 302.1 287.9 317.4 5.41 3 850 1546 13.6 -2.4 33 16.0 5.8 65 9 300.4 301.1 285.9 311.8 3.77 4 841 1635 12.8 -1.2 38 14.0 5.8 62 8 300.5 301.2 286.4 313.0 4.16 5 780 2259 6.6 -3.4 49 10.0 2.0 52 1 300.4 301.0 286.0 311.9 3.81 6 766 2407 5.4 -5.6 45 11.0 0.5 11 0 300.6 301.2 285.5 310.6 3.28 7 758 2493 6.6 -8.4 33 15.0 0.3 344 1 302.8 303.3 285.7 311.1 2.67 8 751 2569 6.0 -10.0 31 16.0 -0.5 317 3 303.0 303.4 285.5 310.4 2.38 9 738 2711 4.8 -10.2 33 15.0 -1.2 268 7 303.2 303.6 285.5 310.6 2.38 10 714 2979 3.0 -25.0 11 28.0 -4.9 297 8 304.1 304.2 284.0 306.4 0.70 11 700 3139 1.6 -22.4 15 24.0 -5.5 305 9 304.3 304.4 284.2 307.2 0.90 12 684 3325 0.4 -24.6 13 25.0 -6.5 297 10 304.9 305.1 284.4 307.5 0.76 13 660 3610 -1.3 -17.3 28 16.0 -6.6 311 17 306.2 306.4 285.7 311.0 1.49 14 651 3719 -0.9 -14.9 34 14.0 -5.9 314 20 307.8 308.2 286.6 313.8 1.85 15 612 4209 -3.5 -10.5 58 7.0 -6.3 306 34 310.3 310.8 288.5 319.3 2.81 16 591 4484 -4.5 -15.5 42 11.0 -8.4 308 40 312.3 312.6 288.3 318.6 1.93 17 547 5088 -8.1 -15.1 57 7.0 -10.5 307 49 315.0 315.4 289.4 322.1 2.16 18 539 5203 -8.7 -15.7 57 7.0 -11.1 305 50 315.6 316.0 289.5 322.5 2.09 19 521 5465 -10.9 -15.9 67 5.0 -12.6 305 55 316.0 316.4 289.7 323.0 2.12 20 502 5749 -11.5 -19.5 52 8.0 -13.9 305 56 318.7 319.0 290.0 324.1 1.62 21 500 5780 -11.7 -19.7 51 8.0 -14.2 305 56 318.8 319.1 290.0 324.2 1.60 22 491 5919 -12.3 -20.3 51 8.0 -14.7 303 55 319.7 320.0 290.3 325.0 1.55 23 467 6302 -14.3 -25.3 39 11.0 -17.1 297 54 321.8 322.0 290.4 325.5 1.05 24 461 6400 -15.1 -25.1 42 10.0 -17.6 295 54 322.0 322.2 290.5 325.8 1.08 25 454 6516 -15.9 -26.9 38 11.0 -18.5 297 55 322.4 322.6 290.5 325.7 0.93 26 426 6993 -19.7 -29.7 41 10.0 -21.8 305 57 323.5 323.7 290.6 326.2 0.76 27 412 7241 -20.9 -31.9 37 11.0 -23.0 301 56 325.1 325.2 291.0 327.4 0.64 28 404 7386 -21.1 -34.1 30 13.0 -23.4 305 60 326.6 326.7 291.3 328.6 0.53 29 400 7460 -20.9 -34.9 27 14.0 -23.4 310 66 327.8 327.9 291.6 329.6 0.49 30 377 7895 -22.9 -38.9 22 16.0 -25.4 306 67 330.8 330.9 292.3 332.1 0.35 31 358 8271 -26.3 -41.3 23 15.0 -28.3 304 69 331.1 331.2 292.3 332.2 0.29 32 347 8495 -27.9 -43.9 20 16.0 -29.7 297 65 332.0 332.0 292.5 332.8 0.22 33 324 8983 -32.3 -45.3 26 13.0 -33.6 288 65 332.5 332.5 292.6 333.3 0.21 34 309 9315 -34.9 -45.9 32 11.0 -35.9 285 66 333.4 333.4 292.8 334.1 0.20 35 302 9474 -36.3 -47.3 31 11.0 -37.2 285 69 333.6 333.6 292.9 334.3 0.18 36 300 9520 -36.7 -47.7 31 11.0 -37.5 285 71 333.6 333.7 292.9 334.3 0.17 37 288 9800 -38.5 -51.5 24 13.0 -39.4 290 74 335.0 335.0 293.2 335.5 0.12 38 286 9848 -38.9 -51.9 24 13.0 -39.7 290 74 335.1 335.1 293.2 335.5 0.11 39 273 10164 -41.9 -53.9 26 12.0 -42.5 290 74 335.2 335.2 293.2 335.6 0.09 40 250 10750 -47.3 -56.3 35 9.0 -47.6 290 77 335.7 335.8 293.3 336.1 0.07 41 242 10965 -49.1 -59.1 30 10.0 -49.4 293 78 336.2 336.2 293.4 336.4 0.05 42 225 11440 -52.7 -62.7 29 10.0 -52.9 298 81 337.7 337.8 293.8 337.9 0.04 43 200 12190 -59.3 -67.3 35 8.0 -59.4 300 82 338.9 338.9 294.1 338.9 0.02 44 191 12477 -61.5 -68.5 39 7.0 -61.6 305 79 339.8 339.8 294.3 339.9 0.02 45 189 12542 -61.9 -69.9 34 8.0 -62.0 304 79 340.2 340.2 294.4 340.3 0.02 46 185 12675 -62.7 -69.7 38 7.0 -62.8 299 77 341.0 341.0 294.6 341.1 0.02 47 182 12775 -63.5 -70.5 38 7.0 -63.6 296 76 341.3 341.3 294.6 341.3 0.02 48 181 12809 -63.7 -70.7 38 7.0 -63.8 295 76 341.5 341.5 294.7 341.6 0.02 49 179 12878 -63.7 -70.7 38 7.0 -63.8 295 76 342.6 342.6 295.0 342.6 0.02 50 169 13231 -62.6 -71.6 29 9.0 -62.7 300 92 350.0 350.0 296.7 350.1 0.01 51 164 13417 -62.1 -72.1 25 10.0 -62.2 300 92 353.9 354.0 297.5 354.0 0.01 52 162 13493 -61.7 -71.7 25 10.0 -61.8 299 90 355.9 355.9 297.9 355.9 0.01 53 159 13609 -61.9 -71.9 25 10.0 -62.0 297 86 357.4 357.4 298.2 357.5 0.01 54 150 13970 -61.5 -73.5 19 12.0 -61.6 290 69 364.1 364.1 299.5 364.2 0.01 55 100 16430 -68.1 -87.1 5 19.0 -68.2 290 47 396.2 396.2 304.7 396.2 0.00 56 96 16674 -68.9 -87.9 5 19.0 -69.0 293 49 399.2 399.2 305.1 399.2 0.00 57 94 16800 -68.7 -87.7 5 19.0 -68.8 291 47 402.0 402.0 305.5 402.1 0.00 58 90 17060 -69.1 -89.1 4 20.0 -69.2 295 49 406.3 406.3 306.0 406.3 0.00 59 85 17402 -67.9 -88.9 3 21.0 -68.0 301 55 415.4 415.4 307.2 415.4 0.00 60 74 18241 -64.3 -89.3 2 25.0 -64.6 284 30 439.8 439.8 309.8 439.8 0.00 61 70 18580 -65.5 -90.5 2 25.0 -65.7 280 36 444.3 444.3 310.3 444.3 0.00 62 69 18667 -65.5 -90.5 2 25.0 -65.7 269 33 446.1 446.1 310.5 446.1 0.00 63 64 19122 -66.1 -90.1 2 24.0 -66.3 289 28 454.5 454.5 311.3 454.5 0.00 64 61 19412 -66.5 -90.5 2 24.0 -66.7 301 20 459.9 459.9 311.8 459.9 0.00 65 59 19613 -66.7 -90.7 2 24.0 -66.9 292 18 463.8 463.8 312.1 463.8 0.00 66 59 19613 -66.9 -90.9 2 24.0 -67.1 292 18 463.4 463.4 312.1 463.4 0.00 67 53 20263 -63.7 -88.7 2 25.0 -64.0 285 20 485.2 485.2 313.8 485.2 0.00 68 50 20620 -62.9 -87.9 2 25.0 -63.3 330 23 495.3 495.3 314.6 495.3 0.00 69 48 20871 -63.1 -88.1 2 25.0 -63.5 322 23 500.6 500.6 315.0 500.6 0.00 70 47 21001 -62.7 -87.7 2 25.0 -63.1 341 24 504.6 504.6 315.2 504.6 0.00 71 43 21546 -65.3 -89.3 2 24.0 -65.7 43 9 511.2 511.2 315.7 511.2 0.00 72 39 22144 -62.9 -87.9 2 25.0 -63.4 266 14 531.7 531.7 317.1 531.8 0.00 73 39 22144 -63.1 -88.1 2 25.0 -63.6 266 14 531.2 531.2 317.0 531.2 0.00 74 38 22304 -62.9 -86.9 3 24.0 -63.4 301 17 535.7 535.7 317.3 535.7 0.01 75 34 22995 -59.3 -85.3 2 26.0 -60.2 300 22 562.5 562.5 318.8 562.5 0.01 76 33 23183 -58.7 -84.7 2 26.0 -59.7 290 21 568.9 568.9 319.1 569.0 0.01 77 30 23780 -59.7 -84.7 2 25.0 -60.6 315 14 581.9 581.9 319.8 582.0 0.01 78 29 23992 -59.7 -84.7 2 25.0 -60.7 315 15 587.6 587.6 320.0 587.6 0.01 79 29 23992 -59.7 -84.7 2 25.0 -60.7 315 15 587.6 587.6 320.0 587.6 0.01 80 27 24440 -58.3 -84.3 2 26.0 -59.5 282 17 603.6 603.6 320.7 603.7 0.01 81 26 24677 -58.1 -83.1 3 25.0 -59.4 290 35 610.7 610.7 321.1 610.8 0.02 82 24 25182 -57.3 -83.3 2 26.0 -58.8 295 20 627.2 627.2 321.8 627.3 0.02 83 24 25182 -56.9 -82.9 2 26.0 -58.5 295 20 628.4 628.4 321.9 628.5 0.02 84 22 25731 -58.1 -83.1 3 25.0 -59.6 316 21 640.6 640.6 322.3 640.8 0.02 85 21 26024 -58.7 -83.7 3 25.0 -60.2 316 16 647.4 647.4 322.6 647.5 0.02 86 20 26330 -58.7 -83.7 3 25.0 -60.2 330 11 656.5 656.5 322.9 656.6 0.02 87 20 26330 -58.3 -83.3 3 25.0 -59.9 330 11 657.7 657.7 323.0 657.9 0.02 88 20 26330 -58.5 -83.5 3 25.0 -60.0 330 11 657.1 657.1 323.0 657.2 0.02 89 19 26652 -58.7 -83.7 3 25.0 -60.3 321 19 666.2 666.2 323.3 666.3 0.02 90 19 26652 -58.5 -83.5 3 25.0 -60.1 321 19 666.8 666.8 323.3 667.0 0.02 91 18 26993 -57.9 -82.9 3 25.0 -59.7 323 14 679.1 679.1 323.7 679.3 0.02 92 17 27354 -56.9 -81.9 3 25.0 -58.9 318 10 693.5 693.5 324.2 693.7 0.03 93 17 27354 -56.7 -81.7 3 25.0 -58.8 318 10 694.1 694.2 324.3 694.4 0.03 94 17 27354 -56.5 -81.5 3 25.0 -58.6 318 10 694.8 694.8 324.3 695.0 0.03 95 16 27739 -56.5 -81.5 3 25.0 -58.7 291 9 706.9 707.0 324.7 707.2 0.03 96 16 27739 -56.5 -81.5 3 25.0 -58.7 291 9 706.9 707.0 324.7 707.2 0.03 TRP 181 12809 -63.7 -70.7 38 7.0 -63.8 295 76 341.5 341.5 294.7 341.6 0.02 WND 169 13231 -62.6 -71.6 29 9.0 -62.7 300 92 350.0 350.0 296.7 350.1 0.01 Sounding variables and indices 1000-500 mb thick: 5630.00 m Freezing level: 678.35 mb = 3391.64 m = 11127.29 ft Wetbulb zero: 755.66 mb = 2517.98 m = 8261.00 ft Precipitable water: 0.39 inches Sfc-500 mean rel hum: 41.39 % Est. max temperature: 17.55 C = 63.58 F Sfc-Lift cond lev (LCL): 711.62 mb = 3006.20 m = 9862.76 ft T: 2.76 C 700-500 lapse rate: 5.04 C/km ThetaE index: 5.55 C Layer 850.0- 841.0 mb Conv cond level (CCL): 545.38 mb = 5111.54 m = 16769.95 ft Mean mixing ratio: 3.78 g/kg Conv temperature: 27.93 C = 82.28 F Cap Strength: 9.28 C Lifted Index: 9.29 C Risk: None Lifted Index @300 mb: 15.55 C Lifted Index @700 mb: 3.24 C Showalter Index: 9.49 C Risk: None Total Totals Index: 34.60 C Risk: None Vertical Totals Index: 25.30 C Cross Totals Index: 9.30 C K Index: -1.10 Risk: None Sweat Index: 74.00 Risk: None Energy Index: 2.51 Risk: None Parcel Indices Parcel: using 100 mb layer CAPE (B+): 6.97 J/kg Max Up Vert Vel: 3.73 m/s Conv Inhibition (B-): 39016.87 J/kg Cap Strength: 9.06 C Lift Cond Lev (LCL): 664.27 mb = 3558.21 m = 11673.77 ft Lev Free Conv (LFC): -1.00 mb = -9999.00 m = -9999.00 ft Wind level data Storm motion: 335 at 26 knt ---------------------------------------------------------- TRUE/GROUND REL | STORM REL LEV P H DIR SPD U V | DIR SPD U V mb m knt m/s | knt m/s ---------------------------------------------------------- 0 853 1516 75 5 -4.8 -1.3 | 144 27 -15.8 21.8 1 850 1546 65 9 -8.2 -3.8 | 135 27 -19.1 19.3 2 821 1829 55 6 -4.9 -3.4 | 141 25 -15.9 19.7 3 791 2134 85 2 -2.0 -0.2 | 151 26 -13.0 22.9 4 762 2438 0 0 -0.0 -0.0 | 155 26 -11.0 23.1 5 735 2743 255 8 7.7 2.1 | 173 25 -3.2 25.2 6 708 3048 310 8 6.1 -5.1 | 165 19 -4.8 18.0 7 700 3139 305 9 7.4 -5.2 | 169 18 -3.6 17.9 8 681 3353 295 10 9.1 -4.2 | 174 19 -1.9 18.9 9 655 3658 315 18 12.7 -12.7 | 190 11 1.8 10.4 10 606 4267 305 36 29.5 -20.6 | 262 19 18.5 2.4 11 583 4572 310 42 32.2 -27.0 | 280 22 21.2 -3.9 12 561 4877 310 48 36.8 -30.9 | 287 27 25.8 -7.8 13 540 5182 305 50 41.0 -28.7 | 281 31 30.0 -5.6 14 519 5486 305 55 45.1 -31.5 | 284 35 34.1 -8.4 15 500 5780 305 56 45.9 -32.1 | 284 36 34.9 -9.0 16 499 5791 305 56 45.9 -32.1 | 284 36 34.9 -9.0 17 479 6096 300 53 45.9 -26.5 | 276 35 34.9 -3.4 18 460 6401 295 54 48.9 -22.8 | 270 38 38.0 0.3 19 425 7010 305 57 46.7 -32.7 | 285 37 35.7 -9.6 20 408 7315 300 55 47.6 -27.5 | 277 37 36.7 -4.4 21 400 7460 310 66 50.6 -42.4 | 296 44 39.6 -19.3 22 391 7620 310 68 52.1 -43.7 | 297 46 41.1 -20.6 23 375 7925 305 67 54.9 -38.4 | 289 47 43.9 -15.3 24 359 8230 305 69 56.5 -39.6 | 290 48 45.6 -16.5 25 344 8534 295 64 58.0 -27.0 | 275 47 47.0 -3.9 26 330 8839 290 66 62.0 -22.6 | 269 51 51.1 0.5 27 316 9144 285 64 61.8 -16.6 | 263 51 50.9 6.5 28 303 9449 285 68 65.7 -17.6 | 264 55 54.7 5.5 29 300 9520 285 71 68.6 -18.4 | 265 58 57.6 4.7 30 290 9754 290 74 69.5 -25.3 | 272 59 58.6 -2.2 31 277 10058 290 75 70.5 -25.7 | 272 60 59.5 -2.6 32 265 10363 290 73 68.6 -25.0 | 272 58 57.6 -1.9 33 253 10668 290 76 71.4 -26.0 | 273 61 60.4 -2.9 34 250 10750 290 77 72.4 -26.3 | 273 61 61.4 -3.2 35 220 11582 300 82 71.0 -41.0 | 287 63 60.0 -17.9 36 210 11887 300 83 71.9 -41.5 | 287 64 60.9 -18.4 37 200 12190 300 82 71.0 -41.0 | 287 63 60.0 -17.9 38 190 12497 305 79 64.7 -45.3 | 292 58 53.7 -22.2 39 181 12809 295 76 68.9 -32.1 | 279 59 57.9 -9.0 40 172 13106 295 76 68.9 -32.1 | 279 59 57.9 -9.0 41 169 13231 300 92 79.7 -46.0 | 288 72 68.7 -22.9 42 164 13411 300 92 79.7 -46.0 | 288 72 68.7 -22.9 43 156 13716 295 83 75.2 -35.1 | 281 65 64.3 -12.0 44 150 13970 290 69 64.8 -23.6 | 271 54 53.9 -0.5 45 149 14021 295 74 67.1 -31.3 | 278 57 56.1 -8.2 46 141 14326 290 70 65.8 -23.9 | 271 55 54.8 -0.8 47 135 14630 285 66 63.8 -17.1 | 263 53 52.8 6.0 48 128 14935 285 65 62.8 -16.8 | 263 52 51.8 6.3 49 122 15240 285 66 63.8 -17.1 | 263 53 52.8 6.0 50 116 15545 290 70 65.8 -23.9 | 271 55 54.8 -0.8 51 110 15850 285 56 54.1 -14.5 | 259 44 43.1 8.6 52 105 16154 290 49 46.0 -16.8 | 260 36 35.1 6.3 53 100 16430 290 47 44.2 -16.1 | 258 34 33.2 7.0 54 100 16459 300 54 46.8 -27.0 | 276 36 35.8 -3.9 55 95 16764 290 47 44.2 -16.1 | 258 34 33.2 7.0 56 90 17069 295 49 44.4 -20.7 | 266 34 33.4 2.4 57 86 17374 300 56 48.5 -28.0 | 277 38 37.5 -4.9 58 77 17983 310 38 29.1 -24.4 | 274 18 18.1 -1.3 59 73 18288 280 29 28.6 -5.0 | 224 25 17.6 18.1 60 70 18580 280 36 35.5 -6.3 | 235 30 24.5 16.8 61 70 18593 265 33 32.9 2.9 | 220 34 21.9 26.0 62 66 18898 280 34 33.5 -5.9 | 233 28 22.5 17.2 63 60 19507 305 18 14.7 -10.3 | 196 13 3.8 12.8 64 57 19812 270 17 17.0 -0.0 | 195 24 6.0 23.1 65 52 20422 290 21 19.7 -7.2 | 209 18 8.8 15.9 66 50 20620 330 23 11.5 -19.9 | 189 3 0.5 3.2 67 49 20726 300 22 19.1 -11.0 | 214 15 8.1 12.1 68 47 21031 345 24 6.2 -23.2 | 89 5 -4.8 -0.1 69 45 21336 350 21 3.6 -20.7 | 108 8 -7.3 2.4 70 42 21641 65 4 -3.6 -1.7 | 146 26 -14.6 21.4 71 40 21946 165 6 -1.6 5.8 | 157 31 -12.5 28.9 72 38 22250 310 17 13.0 -10.9 | 190 12 2.1 12.2 73 37 22555 270 17 17.0 -0.0 | 195 24 6.0 23.1 74 35 22860 310 23 17.6 -14.8 | 219 11 6.7 8.3 75 33 23165 290 21 19.7 -7.2 | 209 18 8.8 15.9 76 32 23470 295 22 19.9 -9.3 | 213 16 9.0 13.8 77 30 23774 320 11 7.1 -8.4 | 165 15 -3.9 14.7 78 30 23780 315 14 9.9 -9.9 | 175 13 -1.1 13.2 79 29 24079 315 15 10.6 -10.6 | 178 12 -0.4 12.5 80 27 24384 280 13 12.8 -2.3 | 185 21 1.8 20.8 81 26 24689 290 36 33.8 -12.3 | 245 25 22.9 10.8 82 25 24994 295 20 18.1 -8.5 | 206 16 7.2 14.6 83 24 25298 295 20 18.1 -8.5 | 206 16 7.2 14.6 84 22 25603 310 25 19.2 -16.1 | 229 11 8.2 7.0 85 21 25908 325 16 9.2 -13.1 | 170 10 -1.8 10.0 86 20 26213 300 15 13.0 -7.5 | 187 16 2.0 15.6 87 20 26330 330 11 5.5 -9.5 | 158 15 -5.5 13.6 88 19 26518 320 20 12.9 -15.3 | 194 8 1.9 7.8 89 17 26822 325 10 5.7 -8.2 | 161 16 -5.2 14.9 90 16 27127 285 9 8.7 -2.3 | 174 21 -2.3 20.8 91 14 27432 270 12 12.0 -0.0 | 183 23 1.0 23.1 92 13 27737 260 19 18.7 3.3 | 196 28 7.7 26.4 Wind Parameters Mean winds (0-6000m): 304.6 at 34.1 knts Storm direction: 334.6 at 25.6 knts Shear (0-3000m) pos: 3.5 neg: 4.1 tot: 7.6 10-3/s Storm rel Dir Shear (0-3000m): 133.3 deg Storm rel helicity (0-3000m) pos: 199.4 neg: -36.7 tot: 162.7 m^2/s^2 ave: 54.2 10^-3 m/s^2 rel: 0.56 Storm rel vorticity (0-3000m) horiz: 11.0 stream: 6.1 10^-3/s Energy-Hel index: 0.01 Bulk Rich Number: 0.04 Bulk Shear: 185.81 m/s Storm Parameters ------------------------------------------------------------------------------- Depth Mean Inflow| Shear | Helicity | Vorticity AGL Dir Spd Dir Spd| Pos Neg Tot| Pos Neg Tot Ave Rel | Hor Strm m knt knt| 10^-3/s | m^2/s^2 m/s^2 | 10^-3/s ------------------------------------------------------------------------------- 500 62 6 140 26| 0.0 1.5 1.5| 32.3 -24.9 7.4 14.9 0.13| 9.1 1.2 1000 63 4 146 26| 0.0 3.0 3.0| 56.2 -24.9 31.3 31.3 0.32| 7.6 2.4 1500 9 5 147 22| 0.0 4.1 4.1|100.0 -36.7 63.3 42.2 0.35| 9.6 3.4 2000 317 6 160 20| 1.6 3.1 4.7|122.5 -36.7 85.8 42.9 0.41| 9.2 3.8 2500 314 9 166 17| 4.2 2.4 6.7|155.7 -36.7 119.0 47.6 0.52| 10.5 5.4 3000 310 14 178 14| 3.5 4.1 7.6|199.4 -36.7 162.7 54.2 0.56| 11.0 6.1 4000 308 23 217 11| 2.7 4.9 7.6|235.3 -55.6 179.6 44.9 0.48| 10.4 5.0 5000 305 29 244 14| 2.1 4.0 6.2|253.7-141.5 112.2 22.4 0.34| 9.6 3.2 6000 305 34 258 17| 3.1 3.4 6.5|479.0-191.4 287.6 47.9 0.39| 10.5 4.1 Wrote GIF file: /home/apache/climate/data/raob//KREV/skewt/KREV.skewt.20251028.00.gif