[willamette-fcst] Forecast - Thursday, May 1st, 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: 
     Thursday, May 1, 2008 at 4:45 pm.

Burn Advisory Friday, May 2, 2008:
     Agricultural burning is allowed.  Suggested burn times are from 10:00am until 6:30pm.
     Straw stack burning is allowed from 10:00am until 6:30pm.

Weather Discussion:
     A transitory upper-level ridge moved onshore today...drying
     out and warming up the air mass over Oregon.  A weak warm
     front spread mainly middle and high clouds across Western
     Oregon this afternoon with mostly sunny skies east of the
     Cascades.  Doppler radar was showing an area of light rain
     along the Central Oregon Coast, and Newport did report some
     light rain this afternoon.  There is a chance that the light
     rain could make it over the coast range and into the
     Willamette Valley this evening, but amounts would be very light.

     Afternoon temperatures were in the low 50s along the coast
     and upper 50s in the Willamette Valley.  The southwestern
     valleys warmed into the low 60s.  Most of Centra and Eastern
     Oregon was in the 50s.

     The transitory upper-level ridge is forecast to shift east
     of the Cascades tonight with increasing areas of very light
     rain across Western Oregon tonight and Friday.  Cloudy skies
     tonight will combine with a warming air mass to hold minimum
     temperatures near 40 across Western Oregon, so frost should
     not be an issue.  Temperatures should still fall below the
     freezing mark overnight across much of Central and Eastern
     Oregon, but it will not be a cold Friday morning as it was
     this morning.

     A weak upper-level trough may keep a few showers going
     through much of Saturday...especially over Northern Oregon. 
     The snow level will hold near 5000 feet Friday and Saturday.
      Only a few showers are likely to make it east of the
     Cascades late Friday and Saturday.  Temperatures will be
     near normal Friday with western valley highs likely climbing
     into the low 60s.  Ventilation conditions are forecast to
     improve just enough to allow for stack burning Friday.

Surface Winds:
     SE 5-10 Friday morning, S 5-10 Friday afternoon.
Transport Winds:
     SSE  10 Friday morning, W 5-10 Friday afternoon.
Atmospheric Ventilation Conditions:
     Maximum mixing height Friday will be near 3500 feet.  Ventilation index 18.
High Temperature:
     Salem\'s high temperature Friday will be near 61.
Humidities:
     Minimum relative humidity will be near 54%.
Sunrise/Sunset:
     Salem sunset tonight: 8:18pm; sunrise Friday: 5:59am.

Extended Outlook:
     A weak upper-level trough is forecast to maintain a chance
     of showers, mainly from the Cascades eastward, Saturday with
     a ridge of high pressure bringing warmer and dry conditions
     Sunday and Monday.  Another upper-level trough will likely
     bring an cooler and perhaps damp weather to the region
     Tuesday or Wednesday, but it does not appear to be a real
     strong or cold system.

Fri (02 May):  Light Rain at Times.  Snow Level 5000 Feet.  41/61

Sat (03 May):  Mostly Cloudy.  Slight Chance of Showers.  Snow Level 5000 Feet.  43/61

Sun (04 May):  Becoming Mostly Sunny and Warmer.  39/67

Mon (05 May):  Increasing Clouds Late.  42/70

Tue (06 May):  Mostly Cloudy & Cooler.  Chance of Showers.  Snow Level 5-6000 Feet.  43/65

Wed (07 May):  Chance of Showers.  Snow Level 5000 Feet.  42/62

Thu (08 May):  Slight Chance of Showers.  Snow Level 5000 Feet.  39/62

Fri (09 May):  Slight Chance of Showers.  Snow Level 5000 Feet.  39/62

ODA Meteorologist
weather at oda.state.or.us