California Air Resources Board - Meteorology Section
Basinwide Ag-Burn Acreage Allocation - Sacramento Valley Air Basin

Date:  31-Jul-14 Local Time:  07:19 AM Meteorologist:  Branz
Ag Burn Decision Above 3000 ft:  No Burn Day    
A.M. Stability (F) = 16 Wind Speed (mph)  = 6
500 millibar height (decameters) = 590 Average Rainfall (in) = 0
Meteorological (MET) Factor   = 0.25
Air Quality (AQ) Factor (Basinwide 00-06 PST Average PM2.5) = 9.6
Allocation Equation: = 4270
   
ARB REVISED Basinwide Allocation _________________________________________ = 2000
Revised Allocation _________________________________________ = 1800
District Yesterday's
24-Hr Avg
PM2.5
Yesterday's
PM2.5
(0-6 PST)
Reduction
Factor
Proration Final
Allocation
(Acres)
Avg PM2.5
(0-6 PST)
Conc Stn
Colusa 14 13 1 0.17 200 13 COL
Sutter 8 11 1 0.17 200 11 YUB
Butte 22 47 1 0.17 200 10 CIC-GRD
Yolo/Solano 9 9 1 0.15 200 9 DAV-WOO
Glenn 8 8 1 0.13 200 7 WLW
Sacramento 5 4 1 0.09 0 3 SAC
Yuba 8 11 1 0.07 200 11 YUB
Placer 9 10 1 0.05 200 11 ROS
Tehama 8 8 1 200 acres
unless reduced
by PM
200 7 WLW
Shasta 13 10 1 200 13 AND
When any district's 0-6 am average PM2.5 is >= 27 ug/m increasing concentrations will result in a reduction
in allocation acres (e.g. 27-28 : 20%, 29-30 : 40%, 31-32 : 60%, 33-34 : 80%)
ARB Comments
Cautionary Comments:
*** Permissive Burn Day***
***Today\'s ozone forecast (106) EXCEEDS 100 AQI . It is a No-Burn day only for the SFONA affected district’s counties and zones.***
Elevated PM readings continue in areas close to the Web Fire. Light winds and high AM stability are present again this morning as a strong ridge remains parked over the Valley. Expect very little change from yesterday, with southerly winds eventually picking up this afternoon. More high-elevation showers/thunderstorms are possible this afternoon as well. ***24 Hour + Outlook****
***Permissive Burn Day****
Little change is expected for Friday, and the ozone forecast remains high so expect the possibility of a no-burn day in the SFONA zones. The ridge will weaken a bit for the weekend, leading to a slight increase in onshore flow, but overall expect little change through at least Monday, if not longer.
Mixing Height Discussion:
Valley: Mixing heights will stay around 2000 feet this afternoon.
Winds:
Valley: Becoming southerly 5-10 mph by afternoon.
Delta: Southwesterly 10-15 mph gusting 25mph this afternoon.