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Experimental Short-Range Ensemble Forecast (SREF)
Dispersion Forecast for Los Angeles, CA (+0 hours)

 

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Forecast

Probability that concentration exceeds			Number of members	Mean	Variance
1% of maximum value	10% of maximum value	100% of maximum value

Concentration at
5th percentile	10th percentile	25th percentile	50th percentile	75th percentile	90th percentile	95th percentile

Individual member plots
eta_ctl1	eta_ctl2	eta_n1	eta_n2	eta_n3	eta_n4	eta_p1
eta_p2	eta_p3	eta_p4	nmm_ctl	nmm_n1	nmm_p1	rsm_ctl1
rsm_n1	rsm_n2	rsm_p1	rsm_p2	em_ctl	em_n1	em_p1

Model Details:

The 6-hour HYSPLIT dispersion forecasts above are output using 21 members of the National Weather Service (NWS) National Centers for Environmental Prediction (NCEP) Short-range ensemble forecasts (SREF) for a source location of Los Angeles, CA, International Airport (LAX). Members are composed of dispersion output using the following models: Eta, WRF/NMM, WRF/ARW (em), and RSM.

• 10-minute release from the layer 10 - 50 m above ground beginning at 06 UTC
• All output is for the layer 0 to 100 m
• 03 UTC NCEP SREF forecast
• No wet nor dry deposition
• Eruption mass is arbitrarily set to one unit. Concentrations shown are with respect to the one unit source.

Probability that concentration exceeds:

These plots show the probability, in percent, that the concentration exceeds a concentration equal to the given percent of the maximum value. For example, the plot on the left labeled "1% of maximum value", shows the probability of the concentrations exceeding 1E-12 units of mass per cubic meter. This is indicated by the "C-12" label on the line of text above the plot. The center plots shows the probabilities of exceeding the concentration 1E-11 (C-11), and the plot on the right, 1E-10 (C-10).

Concentration at:

These plots show the concentrations at the given percentile. The plots are labeled "PC05", "PC10", "PC25", "PC50", "PC75", "PC90", and "PC95" in the line of text above each of the 5th, 10th, 25th, 50th, 75th, 90th, and 95th percentile plots, respectively. For instance, for each point on the PC75 plot, there is a 75% chance that the concentration is less than that shown.