SLCESPAZ

NATIONAL WEATHER SERVICE
COLORADO BASIN RIVER FORECAST CENTER
SALT LAKE CITY, UTAH
May 1, 2019


The following are updated forecasts for the Lake Mead Local 
(or intervening flow).

Forecasts include monthly values for April - June.

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April 1-30 OBSERVED (EST.) DATA: (From USGS gage data) 
                       - values in KAF -

(Colorado Diamond Ck 817.2 + Muddy River 2.9 + 
Virgin River 20.6 - BOR Powell Release 722.8) ~ 117.9 KAF

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FORECASTS (using the Ensemble Prediction System):

* All Forecasts are the 50% exceedance probability value *

Lake Mead Intervening Flow:

May - July Forecasts

	  May       103  KAF (111% of average)
          June       62  KAF (100% of average)
          July       63  KAF (100% of average)


Lake Mead Adjusted Intervening Flow:

May - July Forecasts

	  May        71.1  KAF
          June       42.0  KAF
          July       65.7  KAF


Equation Used for Adjusted Flow: 

Inflow(BOR) = Inflow(NWS) + Evap(BOR) - Evap(NWS) + BankStorageChange(BOR)

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Tributaries:

           Virgin River
           nr Littlefield

	   May  42.0 KAF (373% of median or 173% of average)
           Jun  10.2 KAF (221% of median or 100% of average)
           Jul   7.1 KAF (122% of median or 100% of average)
	   
          Little Colorado
           nr Cameron

	   May   2.2 KAF (1746% of median or  61% of average)
           Jun   0.2 KAF (1000% of median or 111% of average)
           Jul   6.3 KAF ( 256% of median or 100% of average)
        
          Paria Creek
           nr Lees Ferry

	   May   0.7 KAF (155% of median or 107% of average)
           Jun   0.4 KAF (141% of median or  90% of average)
           Jul   1.0 KAF (151% of median or 101% of average)

       * All Forecasts are the 50% exceedance probability value * 

$$

Finch/CBRFC