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

Date:  27-Dec-19 Local Time:  07:29 AM Meteorologist:  Branz
Ag Burn Decision Above 3000 ft:  Permissive Burn Day (Fair)    
A.M. Stability (F) = 9 Wind Speed (mph)  = 14
500 millibar height (decameters) = 560 Average Rainfall (in) = 0
Meteorological (MET) Factor   = 0.7
Air Quality (AQ) Factor (Basinwide 00-06 PST Average PM2.5) = 7.7
Allocation Equation: = 7265
   
ARB REVISED Basinwide Allocation _________________________________________ = 2500
Revised Allocation _________________________________________ = 2500
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 1 1 1 0.17 285 3 COL
Sutter 2 2 1 0.17 285 2 YUB
Butte 5 5 1 0.17 285 13 CIC-GRD
Yolo/Solano 2 2 1 0.15 275 3 DAV-WOO
Glenn 2 2 1 0.13 265 2 WLW
Sacramento 4 3 1 0.09 245 10 SAC
Yuba 2 2 1 0.07 235 2 YUB
Placer 5 6 1 0.05 225 11 ROS
Tehama - - 1 200 acres
unless reduced
by PM
200 - RBL
Shasta 16 16 1 200 16 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 ***
North winds will continue today as high pressure tries to build in from the west behind the pesky upper low that's been hanging around in SoCal for the past few days. Wind speeds should remain just below restricted criteria, but don't be surprised to see some gusts to 25-30 mph in the usual wind-prone areas this afternoon. Otherwise...AM stability is higher today but with clear and sunny conditions, vertical mixing should be fine. Use caution if burning with the north winds.

24hr Outlook
*** Permissive Burn Day ***
Saturday still looks dry at this point, with weaker winds and higher AM stability as high pressure noses in from the west. Rain chances return Sunday with another trough pushing in from the northwest. This system will take a similar track to the last one, so other than a few showers on Sunday, the full effects of the trough will be farther south. Expect another round of gusty north winds on Monday as this system pulls away to the southeast. The first several days of 2020 look dry at this point as a dominant ridge of high pressure takes shape over much of California.
Mixing Height Discussion:
Valley: Mixing heights will reach 1500 feet by afternoon.
Winds:
Valley: North to northwesterly 10-15 mph with gusts to 25 mph in the north and west this afternoon.
Delta: North to northwesterly 10-15 mph with gusts to 25 mph this afternoon.