Flood Potential Outlook Issued by NWS Grand Junction, CO
000
FGUS75 KGJT 121856
ESFGJT
COC007-029-033-037-045-051-053-067-077-081-083-085-091-097-103-
107-111-113-UTC009-019-037-047-191900-
Water Supply Outlook
National Weather Service Grand Junction CO
1256 PM MDT Tue Mar 12 2024
...SPRING FLOOD AND WATER RESOURCES OUTLOOK FOR WESTERN COLORADO
AND EASTERN UTAH AS OF MARCH 12 2024...
Hydrologic Service Area (HSA)
-----------------------------
The Grand Junction HSA falls almost entirely within the Upper
Colorado River Basin, which, ultimately, serves a population of
over 40 million people water across the southwestern US. This
service area encompasses seven basins including; the Upper Green
River Basin and the Duchesne River Basin in eastern Utah, and the
Yampa and White River Basins, Upper Colorado River Mainstem,
Gunnison River Basin, Dolores and San Miguel River Basins, and the
Upper San Juan River Basin in western Colorado. Each river and
their tributaries feed the Colorado River above Lake Powell, and
are primarily fed by snowpack accumulation along the Rocky
Mountains (typically) from November - April. As the snow melts in
the spring, the Upper Colorado River Basin begins to fill lakes,
rivers, streams, reservoirs and trans-basin diversions spread as
far as Denver to Los Angeles. Thus, seasonal water supply outlooks
across the Grand Junction HSA are crucial for water management in
order to support the needs for a vast population through
hydropower, agricultural, municipal and recreational purposes.
Flood & Water Supply Outlook Summary:
-------------------------------------
The potential for spring flooding due to snowmelt is low at this
time, and season water supply volumes remain below to near normal
for the Upper Colorado River Basin.
Currently, the following sites are forecast to have mean daily
peak flows at or above the listed threshold at the given
exceedance level:
Exceedance Value
Segment Threshold (probability)
--------- --------- -------------
Elk-Milner Flood 10
Yampa-Deerlodge Flood 10
Green-Jensen Bankfull 50
Yampa-Maybell Bankfull 50
Eagle-Gypsum Bankfull 25
Yampa-Steamboat Springs Bankfull 10
Colorado-Cameo Bankfull 10
East-Almont Bankfull 10
Gunnison-Grand Junction Bankfull 10
Colorado-CO-UT Stateline Bankfull 10
San Juan-Pagosa Springs Bankfull 10
Forecast volumes, attm, are expected to range near normal due to
average precipitation and snowpack accumulated thus far.
April-July Water Supply Volume Forecasts: March 1
-------------------------------------------------
Green River 75-95%
Duchesne 90-115%
Yampa/White 90-105%
Upper CO Mainstem 85-115%
Gunnison 85-150%
Dolores/San Miguel 60-95%
San Juan 60-75%
NOTE: In normal years, additional snowpack can accumulate in the
mountains through the first half of April. However, it`s worth
noting that precipitation, strong winds and blowing dust, a cold
spring or unseasonably warm spring during the snowmelt season can
greatly affect total runoff volume and timing of peak flow.
Observed Precipitation & Snowpack
---------------------------------
Below normal precipitation in December into early January led to
a slow start to the water year`s total precipitation. Fortunately,
a more active pattern returned to the Western Slope by mid
January. These series of storms brought relief to winter`s
snowpack, and resulted in above average precipitation for the
month of January. Storms continued to accumulated snow into the
beginning of February, rising the total 2024 water year
precipitation to near normal conditions across most high elevation
basins by the end of the month.
Basin snowpack conditions for the period (Percent of Median)
October 1 2023 to March 1 2024:
------------------------------------------------------------
Subbasin Snow Precip
-------- ---- ------
Green River 90 100
Duchesne 110 100
Yampa/White 110 110
Upper CO Mainstem 95 100
Gunnison 84 95
Dolores/San Miguel 85 85
San Juan 85 80
Soil Moisture
-------------
An abnormally high spring runoff in 2023 improved soil moisture
conditions and even removed the entire HSA from the US Drought
Monitor by June. However, a delayed monsoon in the heat of summer
led to increasing evaporation/ evapotrasporation, especially
across southwest Colorado high elevations. As a result, soil
conditions worsened and dropped below normal by Fall (November).
Conditions decrease from north to south, with southwest Colorado
mountains dropping below 50 percent of normal in some areas.
Antecedent soil moisture can impact the efficiency of early
spring runoff, and thus, water supply forecasts such that; basins
with above average soil moisture tend to experience more efficient
runoff from rainfall and snowmelt while basins with below average
antecedent conditions show less efficient runoff until soil
saturation is reached.
Numerical Reservoir & River Outlooks:
-------------------------------------
Table 1:
Status of Reservoir Storage for WFO Grand Junction Reservoirs
Period Ending: February 28, 2024
Figures are in 1000 Acre Feet
================================================================================================
C U R R E N T Y R L A S T Y R 1991-2020
EOM % of % of EOM % of FEB 28 Usable
Storage Average Capacity Storage Average Avg Storage Capacity
------------------------------------------------------------------------------------------------
GUNNISON - BLUE MESA | 561.8| 112| 68|| 296.4| 59|| 499.4| 827.9|
------------------------------------------------------------------------------------------------
GUNNISON - CRYSTAL RE| 10.2| 66| 58|| 16.6| 107|| 15.6| 17.5|
------------------------------------------------------------------------------------------------
CRAWFORD RESERVOIR | 6.7| M| 48|| 2.4| M|| M| 14.1|
------------------------------------------------------------------------------------------------
FRUIT GROWERS DAM - A| 2.3| M| 51|| 2.4| M|| M| 4.5|
------------------------------------------------------------------------------------------------
FLORIDA - LEMON RESER| 15.7| 87| 40|| 17.1| 94|| 18.2| 39.8|
------------------------------------------------------------------------------------------------
DOLORES - MCPHEE RESE| 292.1| 113| 77|| 184.2| 71|| 257.8| 381.1|
------------------------------------------------------------------------------------------------
GUNNISON - MORROW POI| 116.2| 107| 99|| 107.6| 99|| 109.1| 117.0|
------------------------------------------------------------------------------------------------
MUDDY CK - PAONIA RES| 2.9| 96| 17|| 1.1| 38|| 3.0| 16.7|
------------------------------------------------------------------------------------------------
UNCOMPAHGRE - RIDGWAY| 65.5| 96| 79|| 69.9| 103|| 67.9| 83.0|
------------------------------------------------------------------------------------------------
RIFLE CK - RIFLE GAP | 12.6| M| 104|| 4.5| M|| M| 12.2|
------------------------------------------------------------------------------------------------
FRYING PAN - RUEDI RE| 73.2| 109| 72|| 63.3| 94|| 67.4| 102.0|
------------------------------------------------------------------------------------------------
CIMARRON - SILVER JAC| 1.6| 30| 12|| 1.9| 36|| 5.2| 13.0|
------------------------------------------------------------------------------------------------
TAYLOR - TAYLOR PARK | 70.5| 105| 66|| 64.1| 95|| 67.2| 106.2|
------------------------------------------------------------------------------------------------
LOS PINOS - VALLECITO| 66.7| 97| 53|| 74.7| 109|| 68.5| 125.4|
------------------------------------------------------------------------------------------------
GREEN - FLAMING GORGE| 3106.6| 101| 83|| 2457.3| 80|| 3062.9| 3749.0|
------------------------------------------------------------------------------------------------
COLORADO - LAKE POWEL| 7935.1| 56| 33|| 5319.8| 38|| 14153.2| 24322.0|
------------------------------------------------------------------------------------------------
T O T A L S | 12318.2| 67| 41|| 8673.8| 47|| 18395.4| 29931.5|
Table 2:
Mean Daily Peak Flow Forecasts (CFS)
IDLocationFORECAST DATE90% 75% 50% 25% 10%
--------------------------------------------------------------------------------
STMC2Steamboat Spgs2024-03-052501 2988 3311 3977 4568
ENMC2Milner2024-03-0529653360388848316107
MBLC2Maybell2024-03-0578429901113331211016242
LILC2Lily2024-03-0530933314398750226333
YDLC2Deerlodge Park2024-03-051054312472152521683821121
WRMC2Meeker2024-03-0519712174249429343644
WATU1Watson2024-03-0519282220249129073682
SLFC2Slater2024-03-05599 657 729 896 1085
LSRC2Slater2024-03-0514401586191722922952
FISC2Fish Ck-Upper2024-03-05 423 504 627 712 914
ELHC2Hayden2024-03-05 907 1059 1134 1328 1721
WIKC2Hamilton2024-03-051137 1484 1791 2045 2736
WTRU1Whiterocks2024-03-05 325 374 564 671 816
ASHU1Vernal2024-03-05 357 455 616 758 973
SKEC2Montezuma2024-03-05 288 314 357 432 492
RCYC2Redstone2024-03-051159 1270 1447 1585 1885
CSSC2Minturn-Cross Ck2024-03-05303 346 378 457 526
GRVC2Vail2024-03-05650 812 892 1072 1441
PSBC2State Bridge2024-03-05399 488 584 651 814
ALEC2Almont2024-03-051405 1613 1808 2104 2662
ACSC2Anthracite Ck2024-03-051452 1679 1896 2281 3083
SCCC2Cedaredge2024-03-0553 75 102 133 197
TRAC2Taylor Park2024-03-05403 470 544 638 726
OHOC2Gunnison2024-03-05331 389 442 524 642
DCKC2Ridgway2024-03-0536 58 72 89 127
UCRC2Ridgway2024-03-05524 605 681 804 927
LFGC2Gateview2024-03-05875 1029 1178 1381 1556
COWC2Cow Creek2024-03-05250 287 329 458 677
DRRC2Rico2024-03-05443 551 665 733 830
DOLC2Dolores2024-03-051206 1424 1895 2163 2516
SMPC2Placerville2024-03-05625 774 849 961 1094
LCCC2Dolores2024-03-0564 76 112 148 204
PSPC2Pagosa Springs2024-03-051171 1477 1677 2010 2600
LPHC2Hesperus2024-03-05107 132 163 184 237
PIDC2Arboles2024-03-05955 1095 1292 1431 1886
ANBC2Silverton2024-03-0596 1080 1236 1465 1559
VNBC2Bayfield2024-03-05488 619 673 812 905
Table 3:
Special Mean Daily Peak Flow Forecasts (cfs)
LOCATION FLOOD FCST FORECAST FLOWS
FLOW DATE 90% 75% 50% 25% 10%
--------------------------------------------------------------------------------
GREEN - JENSEN, NR 24100 2024-03-01 14300 15800 18400 20000 24000
GREEN - GREEN RIVER, UT 37000 2024-03-01 16000 17500 21500 24500 30000
EAGLE - GYPSUM, BLO 6000 2024-03-01 2000 2450 2800 3500 4400
COLORADO - DOTSERO, NR 17000 2024-03-01 4500 5500 7000 9000 11500
ROARING FORK - GLENWOOD S 13000 2024-03-01 3000 3500 4000 4500 5500
COLORADO - CAMEO, NR 26000 2024-03-01 8500 10500 12500 15500 20000
GUNNISON - GRAND JUNCTION 20524 2024-03-01 5000 7500 8000 8000 10500
COLORADO - CO-UT STATE LI 46000 2024-03-01 11500 16500 19500 23000 31000
COLORADO - CISCO, NR 55000 2024-03-01 13000 18000 21000 25000 33000
SAN JUAN - BLUFF, NR 36000 2024-03-01 2700 3100 3700 4200 4700
COLORADO - CATARACT CANYO -999 2024-03-01 27000 34000 41000 49000 62000
Climatological Outlook and Forecast Conditions
----------------------------------------------
The current ENSO phase remains as El Nino Advisory, however, a La
Nina Watch is now in effect. Above-average sea surface
temperatures (SST) continued through February, though SST
anomalies have weakened. As such El Nino conditions are present
but are expected to transition to ENSO-neutral in the Northern
hemisphere by April - June (79% chance), with La Nina potentially
developing by June - August (55% chance). Based on current trends,
the CPC`s Seasonal Outlook for March - May maintains warmer than
normal temperatures most likely across the PacNW and likely above
normal precip focused over the southeast. Thus, western Colorado
and eastern Utah fall well within the "Equal Chance" sector this
Spring for both temperature and precipitation.
On a shorter-scale timeframe, model guidance indicates a Rex
Block develops over the Western CONUS by the end of the week, and
persisting for several days. If this pattern holds, a low
displaced over the Four Corners region would maintain cooler than
normal temperatures and likely unsettled weather. CPC`s 8-14 Day
Outlook reflects this possibility, with above normal temperatures
hugging the Pacific Coast, less so over the Four Corners region,
and a swath of above normal precipitation from the SoCal coast
into Western Colorado.
--------------------------------------------------------------------
- Visit the Colorado Basin RFC for water supply and river forecasts at:
cbrfc.noaa.gov.
- Visit the Natural Resources Conservation Service for additional
snowpack and reservoir data at:
nrcs.usda.gov/programs-initiatives/sswsf-snow-survey-and-water-
supply-forecasting-program
- Visit our website for local weather, climate and river data at:
weather.gov/gjt
- Visit the Climate Prediction Center for sub-seasonal to seasonal
outlooks, ENSO patterns and additional climate information at:
cpc.ncep.noaa.gov
$$