HYDROLOGIC OUTLOOK
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
1106 AM MDT FRI APR 18 2008
...SPRING FLOOD AND WATER RESOURCES OUTLOOK FOR WESTERN COLORADO AND
EASTERN UTAH...
ONLY A FEW SMALL CHANGES IN THE SNOWPACK DURING THE PAST WEEK.
SNOWPACK HAS INCREASED ONE TO TWO PERCENT OVER THE THE NORTHERN AND
SOUTHERN MOUNTAINS OF COLORADO AND SOUTHEASTERN UTAH. THE SNOWPACK
DECREASED BY ONE PERCENT OVER THE WEST CENTRAL MOUNTAINS OF COLORADO.
IN WESTERN COLORADO...
THE POTENTIAL FOR SPRING 2008 FLOODING DUE TO SNOWMELT IS HIGH AT
THIS TIME FOR PORTIONS OF THE YAMPA...GUNNISON...AND UPPER COLORADO
MAINSTEM BASINS...INCLUDING THE ROARING FORK. ELSEWHERE...INCLUDING
BASINS FLOWING FROM THE SAN JUAN MOUNTAINS SHOULD EXPECT ABOVE
NORMAL PEAK FLOWS WITH MANY AREAS REACHING OR EXCEEDING BANKFULL
FLOW.
SNOW WATER EQUIVALENTS IN ALL THE RIVER BASINS OF WESTERN COLORADO
REMAINED ABOVE NORMAL WITH ONLY SLIGHT CHANGES FROM APRIL 11. THE
YAMPA HAD THE LARGEST INCREASE OF 2 PERCENT AND IS CURRENTLY AT 120
PERCENT OF NORMAL. THE GUNNISON AND AND UPPER COLORADO RIVER BASINS
WERE 137 AND 133 PERCENT OF NORMAL RESPECTIVELY AS OF APRIL 18.
OVERALL THE 2007-08 WINTER SEASON SNOWPACK AS OF APRIL 18TH RANGED
FROM 120 PERCENT OF NORMAL IN THE YAMPA AND WHITE RIVER BASINS TO
158 PERCENT OF NORMAL IN THE ROARING FORK RIVER BASIN.
IN EASTERN UTAH...
SNOW WATER EQUIVALENTS HAVE ALSO REMAINED ABOVE AVERAGE IN THE RIVER
BASINS ACROSS EASTERN UTAH WITH THE NORTHEASTERN BASINS DROPPING 3
TO 4 PERCENT AND THE SOUTHEASTERN BASINS INCREASING 2 PERCENT. AS OF
APRIL 18 THE SNOW WATER EQUIVALENTS RANGED FROM 113 OF NORMAL IN THE
DUCHESNE RIVER BASIN AND THE GREEN RIVER BASIN TO 142 PERCENT OF
NORMAL ACROSS THE RIVER BASINS IN SOUTHEAST UTAH.
IT IS STILL TOO EARLY TO ACCURATELY PREDICT THE FLOODING THREAT DUE
TO SNOWMELT RUNOFF. ESSENTIALLY...THE SPRING WEATHER CONDITIONS WILL
SHAPE THIS YEARS RUNOFF SCENARIO. THE PERIOD OF TIME FOR ADDITIONAL
ACCUMULATIONS IS NEARLY OVER, AND THE MID ELEVATION SNOW WILL
GRADUALLY MELT OFF WITH A RETURN TO SEASONAL CONDITIONS.
PRECIPITATION (% OF AVERAGE) AS OF APRIL 1:
SUBBASIN MAR OCT-MAR APR1 MAR
PRECIP PRECIP SNOW STRMFLW
---------------------- ------ ------- ---- --------
UPPER COLORADO 85 125 125 95
GUNNISON 70 140 130 90
DOLORES/SAN MIGUEL 35 115 130 125
SAN JUAN 35 120 125 135
YAMPA/WHITE 70 115 110 50
RESERVOIR STORAGE (KAF) AS OF APRIL 18:
RESERVOIR USABLE USABLE % OF
CAPACITY CONTENTS CAPACITY
---------------------- --------- ---------- ----------
LAKE GRANBY 490.3 267.7 49
WILLIAMS FORK 96.9 82.3 85
DILLON 254.0 230.1 91
GREEN MOUNTAIN 146.9 58.9 38
TAYLOR PARK 106.2 69.4 65
BLUE MESA 829.5 413.4 50
RIDGWAY 83.2 56.3 68
MCPHEE 381.1 314.5 83
VALLECITO 125.4 33.1 26
NAVAJO 1701.3 1330.7 78
LAKE POWELL 24322.0 10933.1 45
STREAMFLOW FORECASTS (PERIOD APR-JUL 2008):
ALL FORECAST VOLUMES REFLECT NATURAL FLOW. ACTUAL OBSERVED FLOW MAY
BE AFFECTED BY UPSTREAM WATER MANAGEMENT. ABBREVIATION KEY AT THE
BOTTOM.
UPPER COLORADO BASIN, ABOVE GUNNISON CONFLUENCE...
MP MP% RMAX RMIN AVG
---- --- ---- ---- ---
COLORADO RIVER
LAKE GRANBY, GRANBY, NR 230 102 285 183 225
WILLOW CK
WILLOW CK RES, GRANBY, NR 60 118 78 45 51
FRASER RIVER
WINTER PARK 22 110 27 16.0 20
WILLIAMS FORK RIVER
WILLIAMS FORK RES, PARSHALL, N 109 115 133 88 95
BLUE RIVER
DILLON RES 200 120 245 161 167
GREEN MTN RES 335 120 415 270 280
MUDDY CK
WOLFORD MTN RES, BLO 68 113 88 51 60
COLORADO RIVER
KREMMLING, NR 990 114 1260 725 870
EAGLE RIVER
GYPSUM, BLO 425 127 535 330 335
COLORADO RIVER
DOTSERO, NR 1700 118 2080 1360 1440
FRYING PAN RIVER
RUEDI RES, BASALT, NR 200 142 250 159 141
ROARING FORK RIVER
GLENWOOD SPRINGS 1050 148 1270 860 710
COLORADO RIVER
GLENWOOD SPRINGS, BLO 2730 126 3320 2140 2160
CAMEO, NR 3120 129 3760 2480 2420
PLATEAU CK
CAMEO, NR 150 130 230 70 115
GUNNISON BASIN...
MP MP% RMAX RMIN AVG
---- --- ---- ---- ---
TAYLOR RIVER
TAYLOR PARK RES 140 136 172 111 103
ALMONT 230 139 275 187 165
EAST RIVER
ALMONT 300 156 350 250 192
GUNNISON RIVER
GUNNISON, NR 600 154 725 485 390
TOMICHI CK
GUNNISON 125 154 184 80 81
LAKE FORK RIVER
GATEVIEW 180 143 215 147 126
GUNNISON RIVER
BLUE MESA RES 1060 147 1370 860 720
MORROW POINT RES 1160 148 1350 975 785
CRYSTAL RES 1350 148 1600 1100 915
MUDDY CK
PAONIA RES, BARDINE, NR 160 157 215 115 102
NF GUNNISON RIVER
SOMERSET, NR 450 148 555 360 305
SURFACE CK
CEDAREDGE 25 146 32 18.9 17.1
UNCOMPAHGRE RIVER
RIDGWAY RES 140 137 180 107 102
COLONA 190 137 260 133 139
DELTA 165 141 235 97 117
GUNNISON RIVER
GRAND JUNCTION, NR 2350 151 2800 1900 1560
DOLORES BASIN...
MP MP% RMAX RMIN AVG
---- --- ---- ---- ---
DOLORES RIVER
DOLORES 370 140 480 280 265
MCPHEE RES 450 141 550 330 320
SAN MIGUEL RIVER
PLACERVILLE, NR 180 136 235 136 132
DOLORES RIVER
CISCO, NR 940 153 1160 725 615
UPPER COLORADO BASIN, BELOW GUNNISON CONFLUENCE...
MP MP% RMAX RMIN AVG
---- --- ---- ---- ---
COLORADO RIVER
CISCO, NR 6500 140 7990 5010 4650
MILL CK
MOAB, NR, SHELEY TUN, AT 4.8 96 7.0 3.1 5.0
COLORADO RIVER
LAKE POWELL, GLEN CYN DAM, AT 9700 122 12400 7010 7930
YAMPA/WHITE BASINS...
MP MP% RMAX RMIN AVG
---- --- ---- ---- ---
YAMPA RIVER
STAGECOACH RSVR, ABV 33 114 50 20 29
STEAMBOAT SPRINGS 295 105 375 225 280
ELK RIVER
MILNER, NR 405 125 500 320 325
ELKHEAD CK
ELKHEAD, NR 50 128 69 34 39
MAYNARD GULCH, BLO 84 142 112 60 59
7.5 YAMPA RIVER
MAYBELL, NR 1150 116 1490 820 990
LITTLE SNAKE RIVER
SLATER, NR 200 126 250 154 159
DIXON, NR 430 130 590 295 330
LILY, NR 470 129 650 320 365
WHITE RIVER
MEEKER, NR 300 103 385 225 290
WATSON, NR 325 107 450 200 305
SAN JUAN BASIN...
MP MP% RMAX RMIN AVG
---- --- ---- ---- ---
SAN JUAN RIVER
PAGOSA SPRINGS 320 142 380 260 225
CARRACAS, NR 620 153 780 485 405
RIO BLANCO RIVER
PAGOSA SPRINGS, NR, BLANCO DAM 83 157 107 66 53
NAVAJO RIVER
CHROMO, NR, OSO DIV DAM, BLO 101 146 129 77 69
PIEDRA RIVER
ARBOLES, NR 345 150 455 275 230
LOS PINOS RIVER
VALLECITO RES, BAYFIELD, NR 255 124 320 200 205
SAN JUAN RIVER
NAVAJO RES, ARCHULETA, NR 1220 155 1590 910 785
FLORIDA RIVER
LEMON RES, DURANGO, NR 70 121 89 54 58
ANIMAS RIVER
DURANGO 610 139 755 485 440
SAN JUAN RIVER
FARMINGTON 1840 152 2260 1420 1210
LA PLATA RIVER
HESPERUS 30 120 39 22 25
SAN JUAN RIVER
BLUFF, NR 1910 155 2410 1410 1230
MANCOS RIVER
MANCOS, NR 48 145 66 30 33
GREEN RIVER BASIN...
MP MP% RMAX RMIN AVG
---- --- ---- ---- ---
BIG BRUSH CK
VERNAL, NR, RED FLEET RES, ABV 23 110 32 15.3 21
ASHLEY CK
VERNAL, NR 55 106 80 35 52
DUCHESNE RIVER
MYTON 280 106 435 158 265
WHITEROCKS RIVER
WHITEROCKS, NR 58 104 82 38 56
DUCHESNE RIVER
RANDLETT, NR 350 108 555 193 325
GREEN RIVER
GREEN RIVER, UT 3200 101 4310 2090 3170
MP MOST PROBABLE VOLUME IN 1000 ACRE-FEET.
MP% MOST PROBABLE VOLUME IN PERCENT OF THE 71-00 AVERAGE.
RMAX VOLUME THAT HAS A 10 PERCENT CHANCE OF BEING EXCEEDED.
RMIN VOLUME THAT HAS A 90 PERCENT CHANCE OF BEING EXCEEDED.
AVG AVERAGE VOLUME FOR THE 71-00 PERIOD.
ALL FORECAST VOLUMES REFLECT NATURAL FLOW. ACTUAL OBSERVED FLOW MAY
BE AFFECTED BY UPSTREAM WATER MANAGEMENT.
THIS SPRINGS WEATHER CONDITIONS WILL SHAPE THE RUNOFF SCENARIO. WE
HAVE SUFFICIENT SNOWPACK TO CAUSE RIVER FLOODS...BUT TEMPERATURE AND
PRECIPITATION RANGES ABOVE NORMAL HAVE THE POTENTIAL TO EXACERBATE
PEAK RUNOFF.
WITH ABUNDANT RUNOFF EXPECTED IN MOST BASINS, THIS YEAR OFFERS THE
BEST CHANCE IN MANY TO REACH NEAR CAPACITY STORAGE FOR MOST AREA
BASINS.
HOWEVER...IT IS IMPORTANT TO REMEMBER THAT THESE FORECASTS ARE BASED
ON CURRENT CONDITIONS. THE LAST PART IN APRIL HOLDS THE POTENTIAL
FOR ADDITIONAL SNOWFALL OR RETAINING SNOWFALL WHICH COULD CHANGE THESE
FORECASTS.
THE LATEST 30 DAY OUTLOOK FOR MAY SHOWS EQUAL CHANGES FOR NEAR
NORMAL TEMPERATURES AND PRECIPITATION FOR EASTERN UTAH AND WESTERN
COLORADO. THE LATEST 90 DAY OUTLOOK FOR THE PERIOD THROUGH JULY
CALLS FOR ABOVE NORMAL TEMPERATURES FOR EASTERN UTAH AND WESTERN
COLORADO AND BELOW NORMAL PRECIPITATION.
AS