SLCESPAZ

NATIONAL WEATHER SERVICE
COLORADO BASIN RIVER FORECAST CENTER
SALT LAKE CITY, UTAH
September 16, 2018


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

Forecasts include monthly values for September - November.

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September 1-15 OBSERVED (EST.) DATA: (From USGS gage data) 
                       - values in KAF -

(Colorado Diamond Ck 393.9 + Muddy River 1.1 + 
Virgin River 2.6 - BOR Powell Release 336.0) ~ 61.6 KAF

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FORECASTS (using the Ensemble Prediction System):

* All Forecasts are the 50% exceedance probability value *

Lake Mead Intervening Flow:

September - November Forecasts

	   September  65  KAF (86% of average)
	   October    68  KAF (94% of average)
	   November   60  KAF (90% of average)


Lake Mead Adjusted Intervening Flow:

September - November Forecasts

	  September  60.1  KAF
	  October    50.9  KAF
	  November   48.1  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

	   Sep  6.5 KAF (97% of median or 73% of average)
	   Oct 10.2 KAF (94% of median or 91% of average)
	   Nov 11.0 KAF (94% of median or 91% of average)
	   
          Little Colorado
           nr Cameron

	   Sep 20.0 KAF (182% of median or 143% of average)
	   Oct  5.2 KAF (361% of median or  76% of average)
	   Nov  2.9 KAF (753% of median or  76% of average)
 
          Paria Creek
           nr Lees Ferry

	   Sep  1.3 KAF ( 97% of median or 70% of average)
	   Oct  1.7 KAF (116% of median or 87% of average)
	   Nov  1.3 KAF (101% of median or 95% of average)

       * All Forecasts are the 50% exceedance probability value * 

$$

Finch/CBRFC