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

Date:  27-Apr-17 Local Time:  08:08 AM Meteorologist:  Lancero
Ag Burn Decision Above 3000 ft:  Permissive Burn Day (Fair)    
A.M. Stability (F) = -5 Wind Speed (mph)  = 13
500 millibar height (decameters) = 570 Average Rainfall (in) = 0.01
Meteorological (MET) Factor   = 1
Air Quality (AQ) Factor (Basinwide 00-06 PST Average PM2.5) = 4.9
Allocation Equation: = 14499
   
ARB REVISED Basinwide Allocation _________________________________________ = 3000
Revised Allocation _________________________________________ = 3000
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 0 1 1 0.17 370 1 COL
Sutter 3 5 1 0.17 370 2 YUB
Butte 7 5 1 0.17 370 8 CIC-GRD
Yolo/Solano 3 3 1 0.15 350 4 DAV-WOO
Glenn - - 1 0.13 330 - WLW
Sacramento 4 7 1 0.09 290 5 SAC
Yuba 3 5 1 0.07 270 2 YUB
Placer 2 2 1 0.05 250 -1 ROS
Tehama 1 1 1 200 acres
unless reduced
by PM
200 0 RBL
Shasta 14 13 1 200 14 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 ***
*** Northerly winds today will be close to Restricted criteria, so please take caution. ***
High pressure is building over the ePac with NW flow aloft and tighter surface gradients will bring gusty northerly winds and warm temps. This morning, low stratus along the east side valley and foothills, but should burn off early. Expect northerly winds 10-15mph gusting 20-25mph throughout the valley, delta winds W-NW 5-10mph 15mph by aftn, and mixing hgts slightly higher 1,800-2,200ft by aftn. Again, take caution with gusty northerly winds.

24hr Outlook
*** RESTRICTED or Permissive Burn Day ***
The building ePac ridge will set up a north wind pattern that will persist through the weekend and into next week. These winds are expected to be gusty and some restricted days are possible, especially Friday, Saturday, and possibly Tuesday. Expect a gradual warming trend through the next several days, with highs topping out in the mid 80s over the weekend.

Mixing Height Discussion:
Valley: Mixing heights will be limited to 1800-2200 feet.
Winds:
Valley:Northerly 10-15mph gusting 20-25mph by aftn.
Delta: W-NW 5-15 mph.