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

Date:  30-Apr-16 Local Time:  07:24 AM Meteorologist:  Branz
Ag Burn Decision Above 3000 ft:  Permissive Burn Day (Fair)    
A.M. Stability (F) = -7 Wind Speed (mph)  = 22
500 millibar height (decameters) = 564 Average Rainfall (in) = 0
Meteorological (MET) Factor   = 1
Air Quality (AQ) Factor (Basinwide 00-06 PST Average PM2.5) = 5.1
Allocation Equation: = 16044
   
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 6 3 1 0.17 200 4 COL
Sutter 11 11 1 0.17 200 10 YUB
Butte 6 4 1 0.17 200 2 CIC-GRD
Yolo/Solano 11 11 1 0.15 200 6 DAV-WOO
Glenn 4 4 1 0.13 200 0 WLW
Sacramento 10 11 1 0.09 200 5 SAC
Yuba 11 11 1 0.07 200 10 YUB
Placer 7 6 1 0.05 200 4 ROS
Tehama 4 4 1 200 acres
unless reduced
by PM
200 0 WLW
Shasta 7 6 1 200 6 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:
*** PRUNINGS ONLY DAY ***
North winds have increased overnight as the pressure gradient tightens in response to an upper low moving south across the region. These winds will become quite gusty this afternoon, especially for the west side of the Valley. The strength of these winds has triggered a Prunings Only Day. Otherwise...expect sunny skies and warmer temperatures this afternoon.

24hr Outlook
*** Permissive Burn Day ***
The pressure gradient will relax for Sunday as the upper low kicks out into the Desert SW, but elevated north winds will persist through at least the morning hours. High pressure will rebound for Monday, leading to warmer temperatures for early next week. The weather pattern looks dry through Tuesday before another trough pushes into the North State for the Wednesday - Friday timeframe. Some shower and thunderstorm activity is possible with this system, although most of the impacts will be in the higher elevations.
Mixing Height Discussion:
Valley: Mixing heights will reach 2000-2500 feet by afternoon.
Winds:
Valley: North to northwesterly 20-25 mph with gusts to 40 mph this afternoon.
Delta: North to northwesterly 20-25 mph with gusts to 40 mph this afternoon.