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

Date:  25-Apr-17 Local Time:  07:29 AM Meteorologist:  Branz
Ag Burn Decision Above 3000 ft:  Permissive Burn Day (Fair)    
A.M. Stability (F) = -6 Wind Speed (mph)  = 7
500 millibar height (decameters) = 567 Average Rainfall (in) = 0
Meteorological (MET) Factor   = 0.75
Air Quality (AQ) Factor (Basinwide 00-06 PST Average PM2.5) = 5.4
Allocation Equation: = 14222
   
ARB REVISED Basinwide Allocation _________________________________________ = 4000
Revised Allocation _________________________________________ = 4000
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 2 2 1 0.17 540 3 COL
Sutter 2 2 1 0.17 540 5 YUB
Butte 6 6 1 0.17 540 6 CIC-GRD
Yolo/Solano 4 3 1 0.15 500 5 DAV-WOO
Glenn - - 1 0.13 460 - WLW
Sacramento 4 5 1 0.09 380 8 SAC
Yuba 2 2 1 0.07 340 5 YUB
Placer 2 3 1 0.05 300 -1 ROS
Tehama 1 0 1 200 acres
unless reduced
by PM
200 -2 RBL
Shasta 11 5 1 200 11 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***
Winds will begin to shift to a northerly direction by this afternoon as yesterday's weak trough moves east into the Great Basin. Expect mainly light winds through the late morning before increasing after noon. These winds will remain well below restricted criteria, and in fact may remain on the light side, especially in the north. Otherwise...clouds will scatter out through the day and dispersion will be fair to good with cold air aloft.

24hr Outlook
*** Permissive Burn Day ***
Northwesterly transport flow will bring another weak trough to the North State on Wednesday, although precip chances are small. By late in the week, another trough will pass to our east and a ridge will build over the eastern Pacific, setting up a north wind pattern for the Thursday-Saturday time frame. These winds are expected to be gusty and some restricted days are possible. Expect temps to warm up as well during this time.

Mixing Height Discussion:
Valley: Mixing heights will reach 2500-3000 feet this afternoon.
Winds:
Valley: Light and variable 3-6 mph through late morning, trending northerly 5-10 mph this afternoon.
Delta: West to northwesterly 8-12 mph.