Peak Flow Forecasts Methods and Evaluation CBRFC Open House August 17, 2010
CBRFC April 2014 CUWCD Briefing/Meeting
description
Transcript of CBRFC April 2014 CUWCD Briefing/Meeting
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 dataESP 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: [email protected]
Feedback, Questions, Concerns always welcome….