May 1, 2019 Spring and Summer Streamflow Forecasts
Upper Missouri Basin
The high elevation snow pack in the Upper Missouri Basin as of May 1
was near to above average. The snow pack above Fort Peck, Montana was
115 percent. The snow pack in the St. Mary Basin was 89 percent, and the
Milk River Basin was 92 percent.
April precipitation across the Upper Missouri Basin was above average.
Basin precipitation summaries for the Missouri Basin include: Milk St. Mary,
111 percent; Milk Canada, 82 percent; Lower Milk, 113 percent; above Toston,
123 percent; Toston to Ft. Peck, 131 percent.
April 2019 Upper Missouri Mean Precip Oct-Apr WY2019 Upper Missouri Mean Precip
Stream flow in the Upper Missouri Basin is forecast to be
near to above average during the upcoming Spring and Summer.
The St. Mary River is forecast to have 81 percent of average
May-September flows. Runoff is expected to range around
122 percent of average for the Missouri Basin above Fort Peck,
Montana.
Upper Missouri May 1, 2019 Spring and Summer Streamflow Forecasts
Of the four major irrigation reservoirs in Montana; Lima
Reservoir had 121 percent average storage, Clark Canyon was
holding 124 percent of average water, Gibson Reservoir had 87
percent of average stored water, and Fresno Reservoir had
111 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; 101 and 125 percent of average water, respectively.
Yellowstone Basin
The high elevation snow pack in the Yellowstone Basin was near to below average
on May 1. The snow pack in the Upper Yellowstone Basin was 103 percent
of average. The snow packs in the Wind, Bighorn, and Shoshone Basins were 108,
81, and 106 percent of average, respectively. The snow packs in the Tongue
and Powder basins were 73 and 76 percent of average, respectively.
Precipitation during April was near to above average. The upper Yellowstone
River Basin received 136 percent of average precipitation while the
Lower Yellowstone River Basin reported 131 percent of average. The
Bighorn Basin received 89 percent of average precipitation while the
Wind River Basin received 135 percent of average. The Little Bighorn -
Upper Tongue Basin received 95 percent of average and the Powder River
had 105 percent of average precipitation.
April 2019 Yellowstone Mean Precip Oct-Apr WY2019 Yellowstone Mean Precip
Forecast stream flow in the Yellowstone Basin is near average
for the upcoming Spring and Summer. Stream flow for the
Yellowstone River above Sidney, Montana is forecast to be about
115 percent of average. Flow in the Tongue Basin is expected to be
80 percent of average. Flows in the Powder River are expected
to be about 93 percent of average.
Monthend storage at Boysen Reservoir was 113 percent of average.
Stored water in Buffalo Bill Reservoir was 118 percent of average.
Monthend storage was 100 percent of average at Bighorn Reservoir.
Yellowstone May 1, 2019 Spring and Summer Streamflow Forecasts
Platte Basin
The high elevation snow pack in the Upper North Platte Basin was
105 percent of average on May 1. The snow pack in the North Platte
Basin below Seminoe Reservoir was 108 percent of average. The snow
pack in the South Platte Basin was 101 percent of average.
Precipitation during April in the Upper North Platte Basin was 115
percent of average. In the Lower North Platte Basin, precipitation
was 94 percent of average. The North Platte Plains below Guernsey
Reservoir had 77 percent. The South Platte Mountains had 75
percent whereas the Plains had 62 percent of average April
precipitation.
April 2019 Platte Mean Precip Oct-Apr WY2019 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 111 percent of average. Streams in the South Platte
Basin above South Platte, Colorado can expect 91 percent
of average flow. For the remainder of the South Platte
basin, flows are expected near 80 percent.
Stored water in the South Platte Basin was 103 percent of average
on May 1.
North Platte Streamflow Fcst South Platte Streamflow Fcst
000
FGUS63 KKRF 012109
ESPKRF
WATER SUPPLY FORECAST
NWS MISSOURI BASIN RIVER FORECAST CENTER
PLEASANT HILL MISSOURI
1610 CDT WEDNESDAY MAY 01 2019
DATA CURRENT AS OF: MAY 01 2019
MISSOURI/YELLOWSTONE/PLATTE RIVER BASIN FORECASTS
50% % 10% 90% AVG
PERIOD (KAF) AVG (KAF) (KAF) (KAF)
-------------------------------------------------------------------
BOYSEN RESERVOIR INFLOW MAY-SEP 745 75% 1169 559 996
SBDW4N
BIGHORN R AT KANE MAY-SEP 1138 73% 1724 858 1569
LVEW4N
GREYBULL R NR MEETEETSE MAY-SEP 137 60% 211 95 228
MEEW4N
BUFFALO BILL RESERVOIR INFLOW MAY-SEP 718 109% 881 590 660
CDYW4N
ST MARY R NR BABB MAY-SEP 323 80% 395 273 404
SMYM8N
ST MARY R AT INT BOUNDARY MAY-SEP 378 81% 470 318 465
SMBM8N
MILK R NR CUTBANK MAY-SEP 12 43% 47 6 28
PDBM8N
MILK R AT EASTERN CROSSING MAY-SEP 50 99% 122 29 50
ERNM8N
NORTH PLATTE R NR NORTHGATE MAY-SEP 278 98% 397 210 283
NGTC2
ENCAMPMENT R NR ENCAMPMENT MAY-SEP 140 103% 167 115 137
ERCW4
ENCAMPMENT R NR ENCAMPMENT MAY-SEP 147 102% 174 122 144
ECRW4N
ROCK CK NR ARLINGTON MAY-SEP 64 131% 72 57 49
KCRW4
ROCK CK NR ARLINGTON MAY-SEP 64 131% 72 57 49
KCRW4N
SEMINOE RESERVOIR INFLOW WY MAY-SEP 855 112% 1097 666 765
SETW4
SEMINOE RESERVOIR INFLOW WY MAY-SEP 1014 110% 1258 834 918
SETW4N
LARAMIE R NR WOODS MAY-SEP 69 111% 112 48 62
WODW4
LARAMIE R NR WOODS MAY-SEP 104 109% 147 83 96
WODW4N
LITTLE LARAMIE R NR FILMORE MAY-SEP 54 109% 69 44 50
SMTW4
LITTLE LARAMIE R NR FILMORE MAY-SEP 56 108% 71 46 52
SMTW4N
ANTERO RESERVOIR INFLOW MAY-SEP 10 69% 14 8 15
ANRC2N
SPINNEY MOUNTAIN RES INFLOW MAY-SEP 40 84% 59 27 47
SPYC2N
ELEVENMILE CANYON RES INFLOW MAY-SEP 44 87% 63 30 51
EVNC2N
CHEESMAN LAKE INFLOW MAY-SEP 76 79% 107 60 96
CHEC2N
SOUTH PLATTE R AT SOUTH PLATTE MAY-SEP 153 91% 210 126 169
SPTC2N
BEAR CK AT MORRISON MAY-SEP 14 84% 19 10 16
MRRC2N
CLEAR CK AT GOLDEN MAY-SEP 91 79% 114 80 116
GLDC2N
ST VRAIN CK AT LYONS MAY-SEP 65 74% 87 56 87
LNSC2N
BOULDER CK NR ORODELL MAY-SEP 38 83% 54 36 46
OROC2N
S BOULDER CK NR ELDORADO SPR MAY-SEP 18 50% 29 14 35
BELC2N
CACHE LA POUDRE AT CANYON MOUTH MAY-SEP 212 112% 284 182 189
FTDC2N
LIMA RESERVOIR INFLOW MAY-SEP 49 97% 77 34 51
LRRM8N
CLARK CANYON RESERVOIR INFLOW MAY-SEP 99 85% 162 77 117
CLKM8N
BEAVERHEAD R AT BARRETTS MAY-SEP 127 89% 198 103 143
BARM8N
RUBY R RESERVOIR INFLOW MAY-SEP 67 86% 85 53 78
ALRM8N
BIG HOLE R NR MELROSE MAY-SEP 590 139% 805 505 425
MLRM8
BIG HOLE R NR MELROSE MAY-SEP 645 135% 860 560 478
MLRM8N
HEBGEN RESERVOIR INFLOW MAY-SEP 462 138% 537 406 335
HBDM8N
ENNIS RESERVOIR INFLOW MAY-SEP 792 132% 915 683 599
ELMM8N
GALLATIN R NR GATEWAY MAY-SEP 406 97% 517 332 418
GLGM8
GALLATIN R NR GATEWAY MAY-SEP 406 97% 517 332 418
GLGM8N
GALLATIN R AT LOGAN MAY-SEP 419 108% 587 323 388
LOGM8
GALLATIN R AT LOGAN MAY-SEP 558 107% 703 480 522
LOGM8N
MISSOURI R AT TOSTON MAY-SEP 2646 125% 3214 284 2116
TOSM8N
MISSOURI R AT FORT BENTON MAY-SEP 4067 123% 4991 557 3317
FBNM8N
MISSOURI R NR VIRGELLE MAY-SEP 4478 121% 5662 951 3696
VRGM8N
MISSOURI R NR LANDUSKY MAY-SEP 4690 119% 6298 144 3928
LDKM8N
MISSOURI R BLW FT PECK DAM MAY-SEP 5322 127% 7153 669 4176
FPKM8N
GIBSON RESERVOIR INFLOW MAY-SEP 400 129% 581 345 310
AGSM8N
MARIAS R NR SHELBY MAY-SEP 250 77% 398 188 324
SHLM8N
MUSSELSHELL R AT HARLOWTON MAY-SEP 93 105% 142 62 89
HLWM8N
YELLOWSTONE R AT YELLOWSTONE LK MAY-SEP 744 119% 825 635 625
YLOW4APR
YELLOWSTONE R AT YELLOWSTONE LK MAY-SEP 919 132% 1008 779 697
YLOW4N
YELLOWSTONE R AT CORWIN SPRINGS MAY-SEP 1696 116% 1956 508 1464
CORM8
YELLOWSTONE R AT CORWIN SPRINGS MAY-SEP 1976 122% 2225 749 1623
CORM8N
YELLOWSTONE R AT LIVINGSTON MAY-SEP 1941 115% 2261 741 1680
LIVM8
YELLOWSTONE R AT LIVINGSTON MAY-SEP 2277 121% 2589 43 1886
LIVM8N
YELLOWSTONE R AT BILLINGS MAY-SEP 3682 127% 4522 167 2909
BILM8
YELLOWSTONE R AT BILLINGS MAY-SEP 4635 122% 5453 109 3801
BILM8N
YELLOWSTONE R AT MILES CITY MAY-SEP 7124 109% 8708 188 6537
MILM8N
YELLOWSTONE R AT SIDNEY MAY-SEP 7360 108% 9299 397 6789
SIDM8N
BOULDER R AT BIG TIMBER MAY-SEP 232 91% 287 193 254
BTMM8
BOULDER R AT BIG TIMBER MAY-SEP 274 93% 328 234 295
BTMM8N
STILLWATER R NR ABSAROKEE MAY-SEP 516 111% 637 439 463
SRAM8
STILLWATER R NR ABSAROKEE MAY-SEP 569 109% 691 495 522
SRAM8N
CLARKS FK YELWSTONE R NR BELFRY MAY-SEP 592 126% 704 522 470
BFYM4
CLARKS FK YELWSTONE R NR BELFRY MAY-SEP 664 123% 776 595 539
BFYM4N
BIGHORN R NR ST XAVIER MAY-SEP 1969 85% 2642 598 2309
STXM8N
LITTLE BIGHORN R NR HARDIN MAY-SEP 108 126% 180 85 86
HRDM8N
TONGUE R NR DAYTON MAY-SEP 64 83% 94 46 77
DAYW4N
TONGUE R NR DECKER MAY-SEP 149 75% 268 108 199
DSLM8N
TONGUE R RESERVOIR INFLOW MAY-SEP 151 75% 275 108 201
DKRM8N
POWDER R NR LOCATE MAY-SEP 160 91% 380 111 175
MHDM8
POWDER R NR LOCATE MAY-SEP 179 95% 490 127 189
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 1981-2010
THE 50%, 10% AND 90% COLUMNS INDICATE THE PROBABILITY THAT THE
ACTUAL VOLUME WILL EXCEED THE FORECAST FOR THE VALID TIME PERIOD
FOR MORE INFORMATION PLEASE VISIT: WWW.WEATHER.GOV/MBRFC/WATER
