[willamette-fcst] Forecast - Monday, October 6th, 2008

[Willamette Valley Ag/Burning Forecast]

Daily Smoke Management Forecast




Oregon Department of Agriculture
Smoke Management Program
Weather Outlook and Field Burning Advisory for Willamette Valley Growers and Fire Districts.

Issued: 
     Monday, October 6th, 2008 at 9:00am.

Burn Advisory:
     Agricultural burning is allowed.  Suggested burn times are from 10:00am until 4:30pm.
     Preparatory burning is not allowed.
     Propane flaming is not allowed.
     Straw stack burning is allowed from 10:00am until 4:30pm.

Weather Discussion:
     Southern Willamette Valley field burning is done for the
     season. South-southwesterly transport winds, ahead of an
     approaching cold front, will make for good ventilation
     conditions over the Willamette Valley this afternoon.
     However, damp field conditions makes burning of north-valley
     fields highly unlikely today. 

     A fairly strong early season storm brought rain and wind to
     Western Oregon over the weekend with high temperatures only
     in the low 60s (about 10 degrees below normal). The north
     valley generally received a total of one-half to one inch of
     rain Friday through Saturday, while the south valley was
     soaked with three-quarters to one and one-half inches of
     rain. Southerly wind gusts up to 30 mph followed the cold
     front Saturday morning across the Willamette Valley with
     gusts to near 50 mph along the northern and central coast.     

     A weak warm front kept skies gray Sunday, with very light
     rain across Western Oregon. Additional rainfall amounts were
     generally less than one-tenth of an inch. Doppler radar was
     showing a decrease in the light rainfall this mornining
     across NW Oregon.  There were even a few patches of blue sky
     showing up over Western Oregon. Clouds kept temperatures
     mild overnight with minimums generally in the mid 50s. 
     Today will be a break day between storms with most of the
     Willamette Valley seeing at least a little sunshine this
     afternoon.  Temperatures will warm close to normal with
     highs in the mid to upper 60s.

     The ODA surface analysis showed light southerly gradients
     over the Willemette Valley this morning, with a weak warm
     front pushing northward across Western Washington. 
     Satellite imagery showed the next cold front about 500 miles
     off the Washington and Northern Oregon Coast.  It is
     forecast to spread more rain onto the coast tonight and
     across the Willamette Valley overnight.  Rainfall amounts
     are expected to be significantly less with this system
     compared with the one that came onshore Friday night.  The
     Willamette Valley is forecast to get between one-tenth and
     one-third of an inch by midday Tuesday.

Surface Winds:
     S 5-15 this morning, S 5-15 this afternoon.
Transport Winds:
     SSW 15 this morning, SSW 18 this afternoon.
Atmospheric Ventilation Conditions:
     Maximum mixing height today will be near 3500 feet.  Ventilation index 63.
High Temperature:
     Salem\'s high temperature today will be near 67.
Humidities:
     Minimum relative humidity will be near 68%.
Sunrise/Sunset:
     Salem sunset tonight: 6:42pm; sunrise tomorrow: 7:18am.

Extended Outlook:
     A westerly flow aloft will keep a lot of clouds and a chance
     of showers across Western Oregon Tuesday afternoon through
     Wednesday, with the best chance for showers in the Western
     Cascade Foothills of the north valley.  High temperatures
     should cool a couple of degrees each day.

     A fairly dry but cool system is forecast to drop, from the
     Gulf of Alaska, into the region Thursday, bringing an increased
     chance of showers and the lowest snow levels so far this autumn.
     All of the loong-range models are forcasting a strong upper-level
     ridge of high pressure to build over the west coast, beginning
     Friday, for what could be several days of dry weather.  That
     would give damp fields a chance to dry and set up a potential
     burning opportunity next week. 

Tomorrow (07 Oct):  Light Rain Turning to Showers with Partial Clearing.  54/63

Wed (08 Oct):  Mostly Cloudy.  Chance of Light Showers...Mainly near the Mountains.  41/61

Thu (09 Oct):  Increasing Chance of Showers.  Snow Level Dropping to 4000 feet.  39/59

Fri (10 Oct):  Partly Sunny.  37/65

Sat (11 Oct):  Areas of AM Fog...Partly Cloudy in the Afternoon.  36/66

Sun (12 Oct):  Areas of AM Fog...Mainly South.  Mostly Sunny.  40/69

Mon (13 Oct):  Patchy AM Fog.  Increasing Clouds Late.  42/66

ODA Meteorologist
weather at oda.state.or.us