CBRFCApril 2014

CUWCD Briefing/Meeting

1:30pm April 8, 2014

Ashley Nielson

Outline

• March weather• Precipitation• Current snow conditions• Water supply forecasts• Upcoming weather• Peaks• Discussion

Frequent storms in zonal (east to west) upper air flow pattern

Largest storm impacts:

Bear RiverUpper Green RiverYampa River

Dry again in the south (Duchesne, Virgin River, San Juan, Lower Colorado)

March 2014 Upper Air Pattern

Winter Precipitation

77% 62% 120%

Spring Precipitation

Duchesne = 69%

Past 7 day Observed Precipitation

Observed % of Normal

November 1 Model Soil Moisture

Blue/Green = above average/wet conditions

Red/Orange= below average/dry conditions

2013

Snow

March 10, 2014 April 7, 2014

Snow: Satellite Derived Snow Cover Grids

Snow

107% of median

148% of median

Snow

119% of median 110% of median

Snow

77 % of median

83% of median

April 1st Water Supply Forecasts

91KAF91% 86 KAF

80%

72 KAF64%

36KAF51%

72 KAF97%

193 KAF60%

106 KAF84%

Forecast TrendChange in the forecast % of average between March 1st and April 1st

Forecasts: Daily ESP w/ Forecast

Daily ESP Forecast Official Forecast10%50%

90%

x

Observed data

ESP will be a combination of forecast + observed to date

Forecasts: Provo

April 1 Forecast: 10% - 123 KAF 50% - 100 KAF (91% Average) 90% - 84 KAF

Forecasts:Duchesne

April 1 Forecast: 10% - 55 KAF 50% - 36 KAF (51% Average) 90% - 24 KAF

Forecasts:Duchesne

April 1 Forecast: 10% - 100 KAF 50% - 72 KAF (64% Average) 90% - 55 KAF

Forecasts: Duchesne

April 1 Forecast: 10% - 18 KAF 50% - 14 KAF (73% Average) 90% - 9.7KAF

Forecasts:Duchesne

April 1 Forecast: 10% - 89 KAF 50% - 72 KAF (97% Average) 90% - 58 KAF

Upcoming Weather: Short term warm and dry. Increasing chance of precipitation mid April

5-Day Precipitation Forecast

www.hpc.ncep.noaa.gov

April 8 -13

Long Term Precipitation OutlookClimate Prediction Center

www.cpc.ncep.noaa.gov

April 2014 April-June 2014

Spring Temperature OutlookClimate Prediction Center

www.cpc.ncep.noaa.gov

April 2014 April-June 2014

ENSO Update

Web Reference: iri.columbia.edu/climate/ENSO

60%

• Tend to develop during the period Apr-June• Tend to reach their maximum strength during Dec-Feb • Typically persist for 9-12 months, though occasionally persisting for up to 2 years • Typically recur every 2 to 7 years

• Soil Moisture Impacts– Snow conditions more important at this point– Positive in high elevation basin such as Upper Stillwater, Lake Fork– Negative lower elevation basins (Strawberry, Starvation, Great Basin)

• Snow – Snow near normal (Western Uintas)– Conditions deteriorate moving eastward– Early April storm improved conditions (entire storm not included in

forecasts)

• Forecasts– All forecasts below average – Forecasts better for high elevation basins

• Weather: Warm and Dry for the near future– Better change of precip next week

Summary

Where to Find Peak Flow Forecasts

• Map: – http://www.cbrfc.noaa.gov/gmap/gmapbeta.php?interf

ace=peak

• Special Product (Unreg/Reg)– http://www.cbrfc.noaa.gov/outgoing/cuwcd_peaks/cuwcd_peakf

cst_20140401.txt

• List: – http://www.cbrfc.noaa.gov/rmap/peak/peaklist.php

Green = Low probability of reaching flood flow

Red = High probability of reaching flood flow

Peak Map

Peak List

Special Peak Product

Normal time of peak

Minimum peak of record

Max peak of record

010%

25%50%75%90%

Forecast Probabilities

Flood Flow

Bankfull Flow

Current year observed daily streamflow to date

Forecast Issuance Date

Select to plot min and max year hydrographs

Select to plot all historical peaks

Peaks: Strawberry

10%: 650 cfs50%: 400 cfs (44%)90%: 250 cfs

Peaks: Currant Creek

10%: 330 cfs50%: 240cfs (79% of average)90%: 150 cfs

Peaks: Upper Stillwater

10%: 1400 cfs50%: 1000 cfs (82% of average) 90%: 700 cfs

Peaks: Big Brush

10%: 280 cfs50%: 160 cfs (68% of average)90%: 90 cfs

Discussion

• Forecast discussion• CUWCD Operations discussion• Next briefing date?

– May 7th? Or 8th 1:30 pm

Ashley Nielson

CBRFC HydrologistPhone: 801.524.5130

Email: ashley.nielson@noaa.gov

Feedback, Questions, Concerns always welcome….