April 1, 2017 Spring and Summer Streamflow Forecasts
Missouri River Basin Mountain Snowpack as of April 1, 2017
Upper Missouri Basin
The high elevation snow pack in the Upper Missouri Basin as of April 1
was below to near average. The snow pack above Fort Peck, Montana was
89 percent. The snow pack in the St. Mary Basin was 108 percent, and the
Milk River Basin was 92 percent.
March precipitation across the Upper Missouri Basin was near to above average.
Basin precipitation summaries for the Missouri Basin include: Milk St. Mary,
174 percent; Milk Canada, 98 percent; Lower Milk, 89 percent; above Toston,
105 percent; Toston to Ft. Peck, 87 percent.
March 2017 Upper Missouri Mean Precip Oct-Mar WY2017 Upper Missouri Mean Precip
Stream flow in the Upper Missouri Basin is forecast to be
near to below average during the upcoming Spring and Summer.
The St. Mary River is forecast to have 66 percent of average
April-September flows. Runoff is expected to range around
105 percent of average for the Missouri Basin above Fort Peck,
Montana.
Upper Missouri April 1, 2017 Spring and Summer Streamflow Forecasts
Of the four major irrigation reservoirs in Montana; Lima
Reservoir had 165 percent average storage, Clark Canyon was
holding 94 percent of average water, Gibson Reservoir had 84
percent of average stored water, and Fresno Reservoir had
148 percent of average stored water.
The major hydroelectric reservoirs in Montana (Canyon Ferry and
Fort Peck), had monthend storage in the average to above
average range; 107 and 119 percent of average water, respectively.
Yellowstone Basin
The high elevation snow pack in the Yellowstone Basin was above average on April 1. The snow pack in the Upper Yellowstone Basin was 118 percent of average. The snow packs in the Wind, Bighorn, and Shoshone Basins were 192, 125, and 146 percent of average, respectively. The snow packs in the Tongue and Powder basins were 111 and 102 percent of average, respectively. Precipitation during March was above average. The upper Yellowstone River Basin received 145 percent of average precipitation while the Lower Yellowstone River Basin reported 141 percent of average. The Bighorn Basin received 158 percent of average precipitation while the Wind River Basin received 330 percent of average. The Little Bighorn - Upper Tongue Basin received 190 percent of average and the Powder River had 133 percent of average precipitation.
March 2017 Yellowstone Mean Precip Oct-Mar WY2017 Yellowstone Mean Precip
Forecast stream flow in the Yellowstone Basin ranged from near
to above average for the upcoming Spring and Summer. Stream flow
for the Yellowstone River above Sidney, Montana is forecast to be
about 140 percent of average. Flow in the Tongue Basin is expected
to be 85 percent of average. Flows in the Powder River are expected
to be about 83 percent of average.
Monthend storage at Boysen Reservoir was 118 percent of average.
Stored water in Buffalo Bill Reservoir was 131 percent of average.
Monthend storage was 95 percent of average at Bighorn Reservoir.
Yellowstone April 1, 2017 Spring and Summer Streamflow Forecasts
Platte Basin
The high elevation snow pack in the Upper North Platte Basin was
98 percent of average on April 1. The snow pack in the North Platte
Basin below Seminoe Reservoir was 95 percent of average. The snow
pack in the South Platte Basin was 96 percent of average.
Precipitation during March in the Upper North Platte Basin was 50
percent of average. In the Lower North Platte Basin, precipitation
was 116 percent of average. The North Platte Plains below Guernsy
Reservoir had 170 percent. The South Platte Mountains had 60
percent whereas the Plains had 111 percent of average March precipitation.
March 2017 Platte Mean Precip Oct-Mar WY2017 Platte Mean Precip
Stream flow in the Platte Basin is forecast to be near
average during the upcoming Spring and Summer. Runoff
for streams above Seminoe Reservoir are expected to be
about 133 percent of average. Streams in the South Platte
Basin above South Platte, Colorado can expect 62 percent
of average flow. For the remainder of the South Platte
basin, flows are expected near 75 percent.
Stored water in the South Platte Basin was 106 percent of average
on April 1.
North Platte Streamflow Fcst South Platte Streamflow Fcst
Water Supply Forecast
NWS Missouri Basin River Forecast Center
Pleasant Hill, Missouri
1200 CST Wednesday April 12 2017
Data current as of: April 11 2017
Missouri/Yellowstone/Platte River Basin Forecasts
50% % 10% 90% AVG
Forecast Point Period (KAF) AVG (KAF)(KAF)(KAF)
-----------------------------------------------------------------
Boysen Reservoir Inflow Apr-Sep 1807 233% 2289 1546 775
SBDW4N
Bighorn R at Kane Apr-Sep 3041 198% 3866 2613 1539
LVEW4N
Greybull R nr Meeteetse Apr-Sep 266 111% 413 207 240
MEEW4N
Buffalo Bill Reservoir Inflow Apr-Sep 1110 140% 1292 970 792
CDYW4N
North Platte R nr Northgate Apr-Sep 434 197% 535 367 220
NGTC2
Encampment R nr Encampment Apr-Sep 189 115% 224 160 164
ERCW4
Encampment R nr Encampment Apr-Sep 197 114% 233 168 172
ECRW4N
Rock Ck nr Arlington Apr-Sep 54 119% 64 44 45
KCRW4
Rock Ck nr Arlington Apr-Sep 55 119% 65 45 46
KCRW4N
Seminoe Reservoir Inflow WY Apr-Sep 985 136% 1254 795 723
SETW4
Seminoe Reservoir Inflow WY Apr-Sep 1131 130% 1403 943 870
SETW4N
Laramie R nr Woods Apr-Sep 73 123% 107 49 59
WODW4
Laramie R nr Woods Apr-Sep 108 114% 142 84 94
WODW4N
Little Laramie R nr Filmore Apr-Sep 62 124% 79 48 50
SMTW4
Little Laramie R nr Filmore Apr-Sep 64 123% 81 50 52
SMTW4N
Antero Reservoir Inflow Apr-Sep 15 93% 20 11 16
ANRC2N
Spinney Mountain Res Inflow Apr-Sep 41 71% 73 30 57
SPYC2N
Elevenmile Canyon Res Inflow Apr-Sep 44 70% 77 31 62
EVNC2N
Cheesman Lake Inflow Apr-Sep 74 62% 147 49 119
CHEC2N
South Platte R at South Platte Apr-Sep 128 62% 258 93 207
SPTC2N
Bear Ck at Morrison Apr-Sep 11 58% 25 7 18
MRRC2N
Clear Ck at Golden Apr-Sep 72 66% 118 49 109
GLDC2N
St Vrain Ck at Lyons Apr-Sep 79 83% 114 65 95
LNSC2N
Boulder Ck nr Orodell Apr-Sep 47 87% 90 37 54
OROC2N
S Boulder Ck nr Eldorado Spr Apr-Sep 21 57% 45 14 37
BELC2N
Cache La Poudre at Canyon Mouth Apr-Sep 193 95% 268 148 202
FTDC2N
Lima Reservoir Inflow Apr-Sep 34 53% 60 23 65
LRRM8N
Clark Canyon Reservoir Inflow Apr-Sep 159 94% 245 114 169
CLKM8N
Beaverhead R at Barretts Apr-Sep 193 96% 286 144 202
BARM8N
Ruby R Reservoir Inflow Apr-Sep 69 79% 78 52 88
ALRM8N
Big Hole R nr Melrose Apr-Sep 826 162% 1116 698 509
MLRM8
Big Hole R nr Melrose Apr-Sep 887 157% 1175 756 567
MLRM8N
Hebgen Reservoir Inflow Apr-Sep 515 128% 566 465 403
HBDM8N
Ennis Reservoir Inflow Apr-Sep 768 108% 858 690 713
ELMM8N
Gallatin R nr Gateway Apr-Sep 451 98% 583 378 459
GLGM8
Gallatin R nr Gateway Apr-Sep 451 103% 583 378 437
GLGM8N
Gallatin R at Logan Apr-Sep 411 96% 604 335 430
LOGM8
Gallatin R at Logan Apr-Sep 544 97% 724 459 563
LOGM8N
Missouri R at Toston Apr-Sep 2697 114% 3487 2333 2361
TOSM8N
Missouri R at Fort Benton Apr-Sep 3832 101% 5108 3366 3810
FBNM8N
Missouri R nr Virgelle Apr-Sep 4374 105% 5891 3842 4156
VRGM8N
Missouri R nr Landusky Apr-Sep 4592 105% 6142 4043 4379
LDKM8N
Missouri R blw Ft Peck Dam Apr-Sep 4821 106% 6313 4154 4537
FPKM8N
Gibson Reservoir Inflow Apr-Sep 618 172% 772 551 359
AGSM8N
Marias R nr Shelby Apr-Sep 407 145% 539 312 281
SHLM8N
Musselshell R at Harlowtown Apr-Sep 37 51% 61 22 72
HLWM8N
Yellowstone R at Yellowstone Lk Apr-Sep 1294 188% 1396 1198 689
YLOW4APR
Yellowstone R at Yellowstone Lk Apr-Sep 1483 174% 1600 1378 851
YLOW4N
Yellowstone R at Corwin Springs Apr-Sep 2588 152% 2886 2383 1702
CORM8
Yellowstone R at Corwin Springs Apr-Sep 2912 147% 3182 2683 1977
CORM8N
Yellowstone R at Livingston Apr-Sep 2791 140% 3156 2567 1997
LIVM8
Yellowstone R at Livingston Apr-Sep 3167 135% 3513 2926 2349
LIVM8N
Yellowstone R at Billings Apr-Sep 4401 129% 5230 3991 3412
BILM8
Yellowstone R at Billings Apr-Sep 5508 123% 6309 5079 4464
BILM8N
Yellowstone R at Miles City Apr-Sep 10383138% 122769309 7513
MILM8N
Yellowstone R at Sidney Apr-Sep 10738134% 127209554 7988
SIDM8N
Boulder R at Big Timber Apr-Sep 200 84% 254 173 239
BTMM8
Boulder R at Big Timber Apr-Sep 300 89% 354 272 336
BTMM8N
Stillwater R nr Absarokee Apr-Sep 599 113% 687 553 528
SRAM8
Stillwater R nr Absarokee Apr-Sep 658 113% 745 612 583
SRAM8N
Clarks Fk Yelwstone R nr Belfry Apr-Sep 820 158% 932 749 519
BFYM4
Clarks Fk Yelwstone R nr Belfry Apr-Sep 892 152% 1002 822 586
BFYM4N
Bighorn R nr St Xavier Apr-Sep 4300 175% 5266 3741 2463
STXM8N
Little Bighorn R nr Hardin Apr-Sep 100 103% 141 77 97
HRDM8N
Tongue R nr Dayton Apr-Sep 94 100% 126 76 94
DAYW4N
Tongue R nr Decker Apr-Sep 190 79% 288 155 240
DSLM8N
Tongue R Reservoir Inflow Apr-Sep 194 81% 293 156 240
DKRM8N
Powder R nr Locate Apr-Sep 248 88% 421 195 281
MHDM8
Powder R nr Locate Apr-Sep 271 83% 465 204 326
LOCM8N
Locations with an "N" suffix indicate natural flows excluding
stream augmentations
KAF: Thousands of acre-feet
%AVG: Current 50%/avg
AVG: Average (50%) seasonal runoff volume as simulated by the river
forecast model considering a continuous simulation of the basin
response to historic climate data (observed precipitation and
temperatures) over the period of 1979-2001
The 50%, 10%, and 90% columns indicate the probablility that the
actual volume will exceed the forecast for the valid time period
