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<br />20
<br />
<br />FLOODS IN COLORADO
<br />
<br />Along the Front Range back of the foothills the precipitation was
<br />generally leSll, except at Silver Lake where a total of 10.88 inches
<br />was reported. The following table shows the precipitation in that area.
<br />
<br />RainJaU, in inches, along the Front Range back of the foothills, June S-7, 1921
<br />
<br /> AUI- lun'
<br />Btation tude Total
<br /> (feet) . . . . . 7
<br /> - - - - - - -
<br />Bouth 'Platte Ri1'1lI' Basin:
<br />Frrs Ra.ncb__h___.__~.___n__._._u___h'._ 7,500 0.&7 no. 0." 0.10 0.70 1.71
<br />Estes PBrk_.________.n__u_.____u..n~____ 8,000 0." .OS 1.12 ... .,. .,. 2."
<br />Near Longs Peak_____.on__ .__nnnO...nO 8,956 ... .25 1." 1... .35 .30 3,9S
<br />SllVl'cf Lako..___.__._ ....._..u....._n...___ lO,:IlO ..., .IS 1.30 o'Oon 2." .... 16.88
<br />Georgetown___._...____....________.____._._ 8,550 --:i.- ... ... d:OO- .76 u:20- 1,91
<br />Ark~~O :r::'i8Siii;--..--------_----n-h-... 7,6'13 .,. 1.16 .3'l 2.51
<br />La Veta PMlL__n___...___________d________ 9,242 .hn. ... .59 .hn_ .,. --~42' 2.07
<br />CUch8l1l CalIlPB__..uun.____._.n_________ 8,'" --_00. "ioo' .88 .21 .12 1.61
<br />North Lake__.___~_.._.~~_____.~_.._..hd__ 8,700 -----~ .55 .18 -~:io- .53 ~26
<br />Madrid_____ ~~__.. n ~___.._ _ ~ - -...~ -~ - ---.~ - ~ 6,3M _nU~ .23 ... ... .25 1.76
<br />
<br />I RslnCaU. June 8, Inl, <f inOOM reported. making a total of 10.88 inches for ~e storm period.
<br />
<br />II
<br />
<br />The Pikes Peak uplift not only was responsible for the highest
<br />recorded precipitation, but by its practically isolated position it de-
<br />flected the moist air currents into the upper basin of the Arkansas
<br />River east of Canon City, where the storm took the form of a series
<br />of cloudbursts in a small area. These cloudbursts were the sole cause
<br />of the flood of June 3-5, 1921, on the Arkansas River," as the river
<br />above Canon City was not at high stage, and the footbill region did
<br />not contain any appreciable amount of snow.
<br />A few days later the highest flood of record on the upper South
<br />Platte River occurred; with floods on its principal mountffin tribu-
<br />taries. These floods were caused not only by the heavy precipitation
<br />of the storm, but also by the melting of the mountain snows. During
<br />April the snowfall had been unusually heavy, about three times its
<br />normal depth for that month, and this late snow, being loose, melted
<br />rapidly under the influence of the rain and the high temperature that
<br />prevailed after the storm. Temperature records are not available for
<br />points at the higher altitudes, but the temperature, although cooler,
<br />varies generally with that on the plains, The temperature records
<br />at Denver are shown in the following table,
<br />
<br />Mazimum and minimum temperatures at Denver, June 1-13. 19S1
<br />
<br />lun' Maximum Minimum lun' Maximum MinlmUD1
<br />(" F.) (" F.) ("E'.) ("P.)
<br />1_..~.~..._ _~___. ~ _n__ '111 .. 8__...__n....__~~~~._ 73 54
<br />2_..__________nn____~ 66 .. {L_________~____n_n_ 77 66
<br />a..__...,_m__.' 73 .. 10_~_~..__.n_~__._.__ 81 ..
<br />._.._~__..n~__ ~ .. ., 11_u._~~.__.nn_~_._ 86 '1
<br />rL._.n~un_._ . .. 55 BL.~_.____~~____~_h. 88 61
<br />6n.u._n.~_~_'__ _~__ 50 53 13._____..__h_n._._~ 66 61
<br />7________,___,_________ .. 54
<br />
<br />
<br />METEOROLOGIC CONDITIONS
<br />
<br />21
<br />
<br />Although precipitation was general throughout the State it was
<br />much less in the Rio Grande and Colorado RiverlBasins as shown in
<br />the following table. '
<br />
<br />RainfaU, in inches, in the Ria Grande, Colorado River, and Gunnison River Basin!
<br />June 8-7. 19131 '
<br />
<br />Station Altl- Total Altl- Total
<br />tude rain, Station tude ,,,In.
<br /> (feet) fell (foot) IAll
<br />Rio Grande BasiIl: Colomdo River Basin-Con.
<br />r~~~~jjjjjjjjjjjjjjjjjjjj 7,576 1.51 Oollbt'a.n~ ~____._.n_n~n~.__ 6,000 O.OS
<br />7,700 1.16 Palisaden.____d._h______n~ ',m .,.
<br />7,868 1.18 Orand Junction~__hh__un_ 4,602 ,50
<br />6,800 1.13 FrultlL_ __ ~ _.._..__nn~~____~ .,... .'6
<br />10.115 .20 Gunnison RIver Basin:
<br />Hermit__~____nn_____ _ 8,.912 .16 Pitkinn_..n~_n..____..__~__ 9,180 1.72
<br />Wagon Wheel Gap Ex-peri:- Gunnison___...._.n___n_... 7,670 1.47
<br />ment StBtion_._~_n_~_.____ 9,610 1.21 Cathedt1l.l_ __~____.__n__n.~_ 8.625 1.06
<br />Colorado River Basin: Crested Butte_nn_n_..nn. 8,861 1.20
<br />bi~:::::::::::::::::::::::: 8,671 1.02 Sapinero_ ~____ __nn__~__n~~ 9,360 1.63
<br />8,800 ... ' OolUIllbine RBncl1._n~__..._ 6,925 ....
<br />Nost_ ._._~._.___~_d.._.~.... 8.800 1.2.'1 ~:~tr(C::::::::::::::::::: ~6" 1.16
<br />~~~~~~~e::::::::::::::::::::: 0,483 2." 6.600 .65
<br />~1" 1.21 Montt'ose~~u_n..__~n__n.._ &,811 1."
<br />Olenwood Sprlngs_n~_nn___ 5,823 1.31 Cedaredge_ _ ~ ~ nn_ n..... ~_~ ~.17S 1.12
<br />RiOe~___dn._'"___n____~u__ 5,310 ... De1ta~~n________nh__~____n ~... 1.02
<br />
<br />In the San :ruan region the rainfall was about 1.5 inches. This
<br />slight increase over the rainfaUin the Rio Grande and Colorado River
<br />Basins was doubtless due to moisture from the Pacific Ocean drawn
<br />in by the low-pressure area over Arizona. In the northwestern part
<br />of the State the recorded rainfall ranged from 0.19 inch at Yampa, in
<br />the mountains, near the head of the Yampa River BSllin, to 1.60 inches
<br />at Lay, farther west in the plateau region.
<br />Immediately west of the Contineutal Divide on the north and the
<br />Sangre de Cristo Range on the south, the April precipitation was more
<br />than twice the normal, but the snowfall decreased westward, being
<br />normal or slightly below normal in tho western part of the State, In
<br />the San Juan region, however, the April snowfall was about 150 per-
<br />cent of normal, except at Telluride, where it was 250 percent. There-
<br />fore, the floods resulting from the precipitation snow cover and rise
<br />. ' ,
<br />10 temperature (the latter being similar to that at Denver), were not
<br />so severe as those in the South Platte and Arkansas River Basins and
<br />,
<br />should be termed more correctly unusually high "June rises." The
<br />causes of the floods in June 1921 have been described at length as
<br />they typify the various factors that in combination cause a majo;ity
<br />of the floods in Colorado.
<br />It will be noted that the general storms causing floods have occurred
<br />most frequently during the later part of May and the early part of
<br />June. According to meteorologists of the Weather Bure_this is
<br />~ue ~rincipally to the fact that it is during that season ove great
<br />mterlOr of the North American continent that the tempera e con-
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