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

Date:  31-Jul-15 Local Time:  07:36 AM Meteorologist:  Mims
Ag Burn Decision Above 3000 ft:  Marginal Burn Day    
A.M. Stability (F) = 21 Wind Speed (mph)  = 5
500 millibar height (decameters) = 593 Average Rainfall (in) = 0.00
Meteorological (MET) Factor   = 0.15
Air Quality (AQ) Factor (Basinwide 00-06 PST Average PM2.5) = 12.7
Allocation Equation: = 2927
   
ARB REVISED Basinwide Allocation _________________________________________ = 2000
Revised Allocation _________________________________________ = 2000
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 17 17 1 0.17 200 17 COL
Sutter 9 7 1 0.17 200 4 YUB
Butte 13 8 1 0.17 200 12 CIC-GRD
Yolo/Solano 0 0 1 0.15 200 0 DAV-WOO
Glenn 11 6 1 0.13 200 10 WLW
Sacramento 14 11 1 0.09 200 12 SAC
Yuba 9 7 1 0.07 200 4 YUB
Placer 12 8 1 0.05 200 12 ROS
Tehama 11 6 1 200 acres
unless reduced
by PM
200 10 WLW
Shasta 23 40 1 200 22 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:
*** Restricted Fields Day ***
High pressure, monsoonal moisture and smoke from the various wildfires will continue affecting our region. Combined these factors make for a less than desirable burning situation today and a restricted field declaration. Lots of clouds and a possible sprinkle or two as a slug of monsoon moisture make its way northward. This will help conditions feel a little more muggy and set the stage for afternoon convection over the higher elevations. Smoke will continue moving into the valley, leading to hazy skies and some AQI issues. Triple digits once again North of the Buttes, but cooler in the south thanks to the delta breeze.

24hr Outlook
***Restricted Field Day***
A weak trough well keep onshore going into the weekend, leading to better dispersion overall. Smoke will continue to be an issue until full containment since the overall flow pattern will allow smoke to enter the valley from several directions.
Mixing Height Discussion:
Valley: Mixing heights over 1800 feet by early afternoon.
Winds:
Valley:Southerly 2-10 mph early, increasing 5-15 mph, especially in the south by afternoon.
Delta: Southwesterly 10-20 mph, gusting to 25 mph