SLCESPAZ

NATIONAL WEATHER SERVICE
COLORADO BASIN RIVER FORECAST CENTER
SALT LAKE CITY, UTAH
Mar 01, 2018


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

Forecasts include monthly values for March - May and seasonal 
volumes for Mar - July and Apr - July.

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February OBSERVED DATA (est.): (From USGS gage data) 
                       - values in KAF -
Feb observed (Colorado Diamond Ck 811.4 + Muddy River 2.5 
  + Virgin River 7.1 - Powell Release 735.1) ~ 85.9 KAF

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FORECASTS (using the Ensemble Prediction System):

* All Forecasts are the 50% exceedance probability value *

Lake Mead Intervening Flow:

March - May Forecasts

	   March      71  KAF (65% of average)
	   April      47  KAF (45% of average)
	   May        48  KAF (63% of average)

April - July Forecast:     162 KAF (58% of average)

March - July Forecast:     233 KAF (60% of average)

Lake Mead Evaporation Coefficients to Adjust Intervening Flow:

Mar - May CBRFC Evaporation amounts

	  Mar       36.5  KAF
	  Apr       37.9  KAF
	  May       47.3  KAF
       
Equation to use: 

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


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Tributaries:

           Virgin River
           nr Littlefield

	   Mar  5.2 KAF (35% of median or 22% of average)
	   Apr  6.7 KAF (44% of median or 30% of average)
	   May  4.4 KAF (37% of median or 18% of average)
	   
          Little Colorado
           nr Cameron

	   Mar  0.6 KAF (  3% of median or  2% of average) 
	   Apr  1.4 KAF ( 18% of median or  7% of average) 
	   May  2.1 KAF (215% of median or 50% of average) 
 
          Paria Creek
           nr Lees Ferry

	   Mar  0.9 KAF (55% of median or 40% of average)
	   Apr  0.7 KAF (70% of median or 60% of average)
	   May  0.2 KAF (46% of median or 30% of average)

       * All Forecasts are the 50% exceedance probability value * 


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