February 1, 2019 Spring and Summer Streamflow Forecasts
Upper Missouri Basin
The high elevation snow pack in the Upper Missouri Basin as of February 1
was near average. The snow pack above Fort Peck, Montana was
100 percent. The snow pack in the St. Mary Basin was 81 percent, and the
Milk River Basin was 147 percent.
January precipitation across the Upper Missouri Basin was near to above average.
Basin precipitation summaries for the Missouri Basin include: Milk St. Mary,
70 percent; Milk Canada, 157 percent; Lower Milk, 85 percent; above Toston,
92 percent; Toston to Ft. Peck, 134 percent.
January 2019 Upper Missouri Mean Precip Oct-Jan WY2019 Upper Missouri Mean Precip
Stream flow in the Upper Missouri Basin is forecast to be
below average during the upcoming Spring and Summer.
The St. Mary River is forecast to have 80 percent of average
April-September flows. Runoff is expected to range around
90 percent of average for the Missouri Basin above Fort Peck,
Montana.

Upper Missouri February 1, 2019 Spring and Summer Streamflow Forecasts
Of the four major irrigation reservoirs in Montana; Lima
Reservoir had 166 percent average storage, Clark Canyon was
holding 127 percent of average water, Gibson Reservoir had 43
percent of average stored water, and Fresno Reservoir had
98 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 119 percent of average water, respectively.
Yellowstone Basin
The high elevation snow pack in the Yellowstone Basin was near average
on February 1. The snow pack in the Upper Yellowstone Basin was 98 percent
of average. The snow packs in the Wind, Bighorn, and Shoshone Basins were 87,
97, and 91 percent of average, respectively. The snow packs in the Tongue
and Powder basins were 88 and 101 percent of average, respectively.
Precipitation during January ranged from below to above average. The Upper
Yellowstone River Basin received 117 percent of average precipitation while
the Lower Yellowstone River Basin reported 113 percent of average. The
Bighorn Basin received 86 percent of average precipitation while the
Wind River Basin received 89 percent of average. The Little Bighorn -
Upper Tongue Basin received 136 percent of average and the Powder River
had 109 percent of average precipitation.
January 2019 Yellowstone Mean Precip Oct-Jan 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
89 percent of average. Flow in the Tongue Basin is expected to be
95 percent of average. Flows in the Powder River are expected
to be about 97 percent of average.
Monthend storage at Boysen Reservoir was 109 percent of average.
Stored water in Buffalo Bill Reservoir was 127 percent of average.
Monthend storage was 100 percent of average at Bighorn Reservoir.

Yellowstone February 1, 2019 Spring and Summer Streamflow Forecasts
Platte Basin
The high elevation snow pack in the Upper North Platte Basin was
106 percent of average on February 1. The snow pack in the North Platte
Basin below Seminoe Reservoir was 137 percent of average. The snow
pack in the South Platte Basin was 104 percent of average.
Precipitation during January in the Upper North Platte Basin was 112
percent of average. In the Lower North Platte Basin, precipitation
was 117 percent of average. The North Platte Plains below Guernsey
Reservoir had 108 percent. The South Platte Mountains had 195
percent whereas the Plains had 110 percent of average January
precipitation.


January 2019 Platte Mean Precip Oct-Jan 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 94 percent of average. Streams in the South Platte
Basin above South Platte, Colorado can expect 90 percent
of average flow. For the remainder of the South Platte
basin, flows are expected near 85 percent.
Stored water in the South Platte Basin was 103 percent of average
on February 1.
North Platte Streamflow Fcst South Platte Streamflow Fcst
WATER SUPPLY FORECAST
NWS MISSOURI BASIN RIVER FORECAST CENTER
PLEASANT HILL MISSOURI
1045 CST MONDAY FEBRUARY 04 2019
DATA CURRENT AS OF: FEBRUARY 03 2019
MISSOURI/YELLOWSTONE/PLATTE RIVER BASIN FORECASTS
50% % 10% 90% AVG
PERIOD (KAF) AVG (KAF) (KAF) (KAF)
-----------------------------------------------------------------
BOYSEN RESERVOIR INFLOW APR-SEP 731 70% 1326 456 1047
SBDW4N
BIGHORN R AT KANE APR-SEP 1179 72% 1959 791 1633
LVEW4N
GREYBULL R NR MEETEETSE APR-SEP 136 58% 251 70 235
MEEW4N
BUFFALO BILL RESERVOIR INFLOW APR-SEP 547 80% 751 416 679
CDYW4N
ST MARY R NR BABB APR-SEP 326 78% 416 273 418
SMYM8N
ST MARY R AT INT BOUNDARY APR-SEP 388 80% 506 322 485
SMBM8N
MILK R NR CUTBANK APR-SEP 20 51% 47 7 39
PDBM8N
MILK R AT EASTERN CROSSING APR-SEP 39 55% 106 15 70
ERNM8N
NORTH PLATTE R NR NORTHGATE APR-SEP 259 84% 432 141 308
NGTC2
ENCAMPMENT R NR ENCAMPMENT APR-SEP 113 76% 159 73 147
ERCW4
ENCAMPMENT R NR ENCAMPMENT APR-SEP 121 77% 167 82 156
ECRW4N
ROCK CK NR ARLINGTON APR-SEP 49 98% 68 37 50
KCRW4
ROCK CK NR ARLINGTON APR-SEP 49 98% 68 37 50
KCRW4N
SEMINOE RESERVOIR INFLOW WY APR-SEP 690 84% 1098 376 826
SETW4
SEMINOE RESERVOIR INFLOW WY APR-SEP 841 86% 1249 507 981
SETW4N
LARAMIE R NR WOODS APR-SEP 39 53% 97 16 73
WODW4
LARAMIE R NR WOODS APR-SEP 74 69% 133 43 108
WODW4N
LITTLE LARAMIE R NR FILMORE APR-SEP 48 90% 79 36 54
SMTW4
LITTLE LARAMIE R NR FILMORE APR-SEP 50 90% 82 38 56
SMTW4N
ANTERO RESERVOIR INFLOW APR-SEP 14 88% 21 9 16
ANRC2N
SPINNEY MOUNTAIN RES INFLOW APR-SEP 42 83% 79 28 51
SPYC2N
ELEVENMILE CANYON RES INFLOW APR-SEP 46 82% 86 30 56
EVNC2N
CHEESMAN LAKE INFLOW APR-SEP 88 84% 166 58 105
CHEC2N
SOUTH PLATTE R AT SOUTH PLATTE APR-SEP 168 89% 294 112 188
SPTC2N
BEAR CK AT MORRISON APR-SEP 15 84% 34 8 18
MRRC2N
CLEAR CK AT GOLDEN APR-SEP 93 75% 145 62 124
GLDC2N
ST VRAIN CK AT LYONS APR-SEP 83 92% 121 59 91
LNSC2N
BOULDER CK NR ORODELL APR-SEP 48 96% 68 36 50
OROC2N
S BOULDER CK NR ELDORADO SPR APR-SEP 28 74% 44 15 38
BELC2N
CACHE LA POUDRE AT CANYON MOUTH APR-SEP 184 92% 309 109 201
FTDC2N
LIMA RESERVOIR INFLOW APR-SEP 47 78% 79 29 60
LRRM8N
CLARK CANYON RESERVOIR INFLOW APR-SEP 115 84% 174 81 137
CLKM8N
BEAVERHEAD R AT BARRETTS APR-SEP 138 81% 198 102 170
BARM8N
RUBY R RESERVOIR INFLOW APR-SEP 75 87% 95 57 86
ALRM8N
BIG HOLE R NR MELROSE APR-SEP 420 83% 613 297 506
MLRM8
BIG HOLE R NR MELROSE APR-SEP 476 85% 669 353 563
MLRM8N
HEBGEN RESERVOIR INFLOW APR-SEP 396 101% 489 330 393
HBDM8N
ENNIS RESERVOIR INFLOW APR-SEP 726 104% 838 596 700
ELMM8N
GALLATIN R NR GATEWAY APR-SEP 329 72% 405 250 459
GLGM8
GALLATIN R NR GATEWAY APR-SEP 329 72% 405 250 459
GLGM8N
GALLATIN R AT LOGAN APR-SEP 310 68% 432 204 454
LOGM8
GALLATIN R AT LOGAN APR-SEP 445 77% 565 331 575
LOGM8N
MISSOURI R AT TOSTON APR-SEP 2191 86% 2843 715 2556
TOSM8N
MISSOURI R AT FORT BENTON APR-SEP 3442 89% 4490 674 3866
FBNM8N
MISSOURI R NR VIRGELLE APR-SEP 3920 90% 5175 999 4348
VRGM8N
MISSOURI R NR LANDUSKY APR-SEP 4108 91% 5525 168 4534
LDKM8N
MISSOURI R BLW FT PECK DAM APR-SEP 4335 90% 5785 308 4817
FPKM8N
GIBSON RESERVOIR INFLOW APR-SEP 273 78% 451 192 351
AGSM8N
MARIAS R NR SHELBY APR-SEP 291 68% 500 207 428
SHLM8N
MUSSELSHELL R AT HARLOWTON APR-SEP 69 63% 110 44 110
HLWM8N
YELLOWSTONE R AT YELLOWSTONE LK APR-SEP 542 82% 683 431 657
YLOW4APR
YELLOWSTONE R AT YELLOWSTONE LK APR-SEP 739 90% 894 584 823
YLOW4N
YELLOWSTONE R AT CORWIN SPRINGS APR-SEP 1405 84% 1709 137 1673
CORM8
YELLOWSTONE R AT CORWIN SPRINGS APR-SEP 1683 88% 2017 322 1912
CORM8N
YELLOWSTONE R AT LIVINGSTON APR-SEP 1699 89% 2017 370 1913
LIVM8
YELLOWSTONE R AT LIVINGSTON APR-SEP 2037 92% 2391 631 2208
LIVM8N
YELLOWSTONE R AT BILLINGS APR-SEP 2871 87% 3380 172 3300
BILM8
YELLOWSTONE R AT BILLINGS APR-SEP 3881 90% 4403 119 4311
BILM8N
YELLOWSTONE R AT MILES CITY APR-SEP 6267 88% 7650 855 7106
MILM8N
YELLOWSTONE R AT SIDNEY APR-SEP 6558 89% 7990 24 7328
SIDM8N
BOULDER R AT BIG TIMBER APR-SEP 222 81% 264 171 273
BTMM8
BOULDER R AT BIG TIMBER APR-SEP 263 84% 304 212 314
BTMM8N
STILLWATER R NR ABSAROKEE APR-SEP 425 86% 494 354 495
SRAM8
STILLWATER R NR ABSAROKEE APR-SEP 482 87% 552 411 552
SRAM8N
CLARKS FK YELWSTONE R NR BELFRY APR-SEP 385 79% 500 298 490
BFYM4
CLARKS FK YELWSTONE R NR BELFRY APR-SEP 458 81% 570 371 562
BFYM4N
BIGHORN R NR ST XAVIER APR-SEP 1859 78% 2823 259 2383
STXM8N
LITTLE BIGHORN R NR HARDIN APR-SEP 105 101% 170 72 104
HRDM8N
TONGUE R NR DAYTON APR-SEP 89 109% 114 64 82
DAYW4N
TONGUE R NR DECKER APR-SEP 202 92% 286 137 220
DSLM8N
TONGUE R RESERVOIR INFLOW APR-SEP 203 92% 293 139 222
DKRM8N
POWDER R NR LOCATE APR-SEP 195 99% 355 116 198
MHDM8
POWDER R NR LOCATE APR-SEP 208 95% 422 122 219
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