474 MONTHLY WEATHER REVIEW. mCH, 1912

RIVERS AND FLOODS, MARCH, 1912

By H. C. FRANKENFIELD,Profeseor in Charge, River and Flood Division.

The month of March was reinarkable :or the wide 6NOW. extent of territory covered by floods. Practically all $0~17~Dakota-The snowfall for the month was about streams east of the Rocky Mountains were in flood, double that of the previous month, and at the end of except those along the immediate, eastern slope of the the month the in the gulches and timber was melt- inountains and in the northern and eastern Great Lakes ing slowly, indicating an ample water supply for irriga- region: The immediate causes were a marked excess of tion and other urposes. precipitation, ranging froin 2 to 4 inches, and a conthiu- Nontana~oldand stormy weather with heavy ance of the low temperatures of the winter, the ground during the first half of the month, followed by remaining frozen to such an extent that the nin-off from warm, sunny days and freezing ni hts, created favorable the precipitation was much greater than the usual conditions for snow storage. T% e increase in de th amount. There were, of course, some floods resulting during the month in the mountain ranges amountecfto from the breaking of the ice, but these were confined to from 20 to 30 per cent, and is now apparent, consid- the northern tier of States and were not of great im or- it tance. The great majority were due to heavy rains roni ering the extremely solid condition of the snow, and the P unusual amount of moisture retained in the soil from five storms of the southwest type, assisted during the the autumn rains, that an abundant flow of water is latter part of the month by scme heavy fresh snows in assured for most of the streams. eastern , Missouri, and portions of . The Wyomin .-Conditions continued to improve exce t later st?rnw were accoiiipanled by high temperatures over the {ig Horn watershed, which will probably e that rapidly melted the snows, and there was also a sixth E southwest storm durin the first two days of April. the only ortion of the State where the water supply The Mississippi and will not ?Ie abundant. Over the remainder of the fower Ohio floods continued at the State the snow is deep and well packed, and the water close of the month with every pros ect that they would should last until late m the season. reach the bighest stages ever recor aed before the decline Colordo.-The month was stormy with unusuall set in. Reports OP these floods will appear later, either heavy snowfall, and at the end of the month the depti in the Monthly Weather Review or in a special bulletin. of snow was considerably greater than in March, 1911. Detailed reports regarding the floods in other rivers will Melting will be rapid. be found in other portions of this Review. The aggre- New) .-An improvement in conditions wm gate losses were large, but they were offset to a consid- noted, although the water supply will be somewhat erable extent by the value of the property saved as a deficient unless there are more good rains to supplement result of the Weather Bureau wa,rnUigs, whch main- those that fell during the month. tained their usual reputation for timeliness and accuracy. Utah.-Although the snow is loose and in poor con- It was difficult to obtain my accurate statements regard- dition for late preservation, an improvement in general ing the losses from t$hefloods. Incomplete reports place conditions wtts noted as the soil is unfrozen, and reported the estimated value of propert destroyed or damaged, to be well saturated with moisture. Over the water- exclusive of that caused by t x e Mississip i and lower shed of Great Salt Lake the water supply is greater than Ohio floods, at $1,945,750, but it wris proi ably nearly usual for this time of the year, but rather less over twice as much. The value of property saved so far as other watersheds. reported was $1,513,000. No estimates were obtained .-Conditiona continue unfavorable with every from a number of districts, but it is probable that the cor- indication of a marked deficiency in the su ply of water. rect vdiies are not far from $2,000,000. Idaho.-Owing to low temperatures t ere was but little snow melting, and more than the usualE quantity ICE. remained in the mountains. The snow is compact with a high water content, indicating slow melting and a The ice moved out of the Mississippi River at Keokuk fair au ply of water. on the 17th, but remained frozen above, except at a few Wasp1 vngton.-While the preci itation for the month places where it moved out during the last few days of was deficient, the total snowfalP for the season is con- the month. The ice at the Wabash Brid e at Hannibal, sidered near or above the average except along the Mo., broke on the 18th, and that from ta e gorge in the Cascades. Des Moines River at Gregory, Mo., reached Hannibal Oregon.-Owing to the comparatively mild winter, early in the morning of the 27th, passing St. Louis on the the snow settled gradually into a compact mass insuring 29th. The Missouri River was generally clear of ice by slow melting and a gradual run-off. The soil is also in the end of the month, although remainirig closed at a good condition, and there are prospects of a late flow few places. The rivers of northern New and of water in excess of the normal amount. northern New York opened about the middle of the ChZifmia.-The season has been of the driest known, month. and at the end of the month there were but 4 feet of

Unauthenticated | Downloaded 10/02/21 04:20 PM UTC &fAFL(IH, 1912. MONTHLY WEATHER REVIEW. 475 snow at the 7,000-foot level. Present indications favor amount, with average depth of 42.5 inches, but the water a deficient water supply, but April snows and rains may equivalent was only 10.1 inches, or 24 per cent, indi- result in some improvement. cating about 12 per cent less water-this year than last. An interesting and valuable feature of snow measure- The total number of measurements made this year was ment was the intensive work carried on for the second 297. Messrs. Thiessen and Alter were the ioneers in season over the watershed of Maple Creek, Utah, under this work. Its practical value has already een recog- the supervision of the official m charge of the local nized throughout tho State of Utah, and itsB extension ofhe of the Weather Bureau at Salt Lake City, ZJtah. to other fields is only a question of time and expense. The actual work durin March of this year was Hydrographs for t ical points on several principal formed by Mr. J. Cecil iter of the Salt Lake City o&zE: rivers are shown oir CYg art I. The stations selected for The entire watershed was thoroughly surveyed during charting are Keokuk, St. Louis, Memphis, Vicksburg, March, 1911, and 2,000 soundings and 277 measure- and New Orleans, on the Mississippi; Cincinnati and ments made with the Marvin density apparatus. There Cairo, on the Ohio; Nashville, on the Cumberland; were about 4,000 acres of snow, about 3 feet in depth, JohnsonviUe, on the Tennessee:; Kansas Cit , on the with a water equivalent of 11.5 inches, or 32 per cent. Missouri; Little Rock, on the Arkansas; and STl reveport, This year there were 4,500 acres of snow in appreciable on the Red.

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