OCR Text |
Show ALTA 2 1 Bate Condi- of tion Fall 1 2 3 4 6 5 AVALANCHE 8 7 9 10 HAZARD 11 12 Temp. Visi- Field Hew Weather Wild Snow Present Forecast bility Test Forc< "Dir. Stable or 12"* Any 100* Aay ctd Stora 100 yd Aay Storm or less Unsta. Type wt. Any .80* .60.80 Any Any 60** Any Storm My 18"24* Severe Storm Condi tion Aay Aay Aay 12* 14* 16-* Any .07 to .09 40* 50 to 60* A N N M N N • tt N N N 3 .40- Aay 4 .60* Dry s 5 4a 6 7 8 9 w Breaks Below Ln Stoza Below Storm 32° N tt tt Aay N it a a • N „ „ N N U TL M tt I< H * H HW H SW s IE NE 50*- Any H X .60* - dur. stoza N Aver age 12 Any u Dry " " 13 Old settled Aay j High hazard on Rustler Face, Stonecrusher A W. Rustler. 14* Borderline conditions. Field testing A observation important. 6* Aay Unsta. Any Unsta. 10-* Aay 14" Same as Condition 3* Aay Any 10" Close highway A high int. hazard areas until thunderstorm has passed. If nearby cloee lifts. 14" Same as Condition 4. Any Umta. Fair to Good Becoming Aay Stable H H N a a « • H tt M H a N Cloudy Cloudy a Rapidly Clear Clear Good a a a M tt a A a 60** Any NV& Clear m Any Any Clear & Cold Good II N Clear M HE AKJW- Above 320 M 2 nts.in succee. & Warm Close highway A high int. iuuard areas. Protective skiing ln all other areas. Highly unstable snow condition. Unless sloughing is continuous, use max. protective measures after 12*. Aay Sridaooe of Slab Below 10° u High hazard to traffic area. Prepare to cloee. 10* a Any 40*- ii High int. hasard areas closed. Field testing A observation important. a a Any Entire area closed until storm breaks. Protective skiing in minimum A low int. hasard & explosives control in high int. hasard areas necessary before reopening. Prepare to close highway A clear area of day ricitors. Cloee high int. hasard areas to skiing. Highway closed except convoys during breaks. Protective skiing necessary. Highway closed A skiing restricted to minima* hasard area unless slough cycle takes place. Protective skiing. Explosive control in high int. hasard areas. Fair to Poor tt Any Blizzard condition, highway closed & area clear of day visitors. Skiing restricted to min. hasard area. High hazard to ski area. Closa high int. hasard slopes. Protective skiing. Explosives control. H tt 13 Action 12" N 6o** Unsta. 12* • it - iI -1 14-* Any N Rising r~ Any ctd 3 torn Poor Hear 32° • •11* 50** Any steady a , M rising Below N Any Dry 20° Any . 0 5 - Any Any Hear Breaks Damp 320 ln Aay .40- or dry Any Uo*- Aay Falling Storm Damp Thnd. 4 Aay Aay Aay Any Lghtn. Any Any Aay See Daap Hear .60* CLaks or .11* 50** Cond. ctd Stora 32° Storm 4 Steady Mixed Rising Storm W & Any Fair A«y Aay Any vari- Slowly lading able N n Con dition federate torn £ Damp .50* Gran orPel tt 10 Any SW & V SW & s N2 & I GUIDE Depending on what closures in effect reopen low int. hazard area after protective skiing. Reopen high int. hazard areas after explosives control. Reopen hwy. when avalanche oycle has taken place or field testing shows • tithle, Warn touring parties of slab danger on northerly exposures. Warn touring parties of slab danger on northerly exposures. Explosives control before reopening aay slope on or overlooked by Ruetler. Becom. N Stable Little danger of fair weather slides. Unst.on sunbe&tc Small sunslides. Slopes M 32-16" Medium sunslides. Large sunslides. Close hwy. during danger period on N 16** Superior. Close hi«h int. hazard slopes when suabeaten. Wind hacked 1 0 " * Slab conditions likely on lee slopes. Protective skiing A explosives. Unsta. 12"* a 16"* Deep Thaw Column 1. An old snow depth of 24" or more is assumed. Delayed action slab or slab A dry avalanches likely. Warn touring parties protective skiing A explo. Delayed action dry avalanches likely. See Condition 12. Spring avalanche condition. See Condition 10 Column 10. Visibility is extremely important for observer making on the spot decisions. Svery break in the storm should be utilized to see what has taken place in hazard areas too distant for direct inspection. Column 2. Measured in inches per hour. Column 4. Inches of water per inch of snow. Column 11. Indications of unstable snow: Snow ring or ski penetrate deeply and easily; enow sifts into the track behind ekis; slides easy to start in test plots; new snov is brittle and cracks extensively when run over by skis on either hard or soft surface. Snow is tacky, balls up tinder skis and breaks away easily from undersurface; snow is slushy and rotten and skis occasionally break through. Column 5. Per cent of time wind is at or above 10 mph. Column 9. Weather forecast by Weather Bureau and observer' s instruments. Salt Lake forecasts are not too accurate for Alta. -50- |