[willamette-fcst] Forecast - Monday, June 1st, 2009

[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, June 1st, 2009 at 9:00am.

Burn Advisory:
     Agricultural burning is allowed.  Suggested burn times are from 11:00am until 6:30pm.
     Straw stack burning is allowed from 11:00am until 6:30pm.

Weather Discussion:
     An upper-level trough, centered about 900 miles west of the
     northern California Coastline, is continuing to produce a
     warm southerly flow aloft over Oregon.  Moisture is also
     streaming northward, over Oregon, from northern California,
     and will combine with daytime heating to trigger scattered
     afternoon and evening thundershowers over mainly the southern
     two-thirds of the state.  Moisture may shift far enough north
     to bring thundershowers into the Willamette Valley today.

     It was another warm one on Sunday with highs in the 80s
     across the interior valleys of western Oregon.  Coastal
     temperatures were much cooler, with highs in the upper 50s and
     60s. Satellite imagery showed considerable cloudiness over Oregon
     this morning, left over from the showers and thundershowers that
     developed over mainly southern and eastern Oregon on Sunday.
     Doppler radar was indicating that some showers continued overnight
     near the Idaho border and in southwestern Oregon.  Mostly cloudy
     skies held overnight temperatures in the 50s across western Oregon.
     Mid-monring temperatures were near 60 across the Willamette Valley.

     The mid-morning ODA surface analysis showed very weak onshore gradients
     across western Oregon with a weak thermal trough extending from
     northeastern to southwestern Oregon.  Onshore flow was strong enough
     to bring marine clouds into the coast, with little in the way of low
     clouds making into the Willamette Valley this morning.

     Skies will be partly to mostly cloudy today across Oregon
     today.  Daytime heating will act on the moist and unstable
     air mass to produce scattered showers and thunderstorms...possibly
     extending north and west into the Willamette Valley.  Temperatures will
     vary considerably, depending on the extent of local cloud-cover but
     should top out in the 80-85 degree range across the valley.

Surface Winds:
     Var 3-7 this morning, NNW  5-10 this afternoon.
Transport Winds:
     Var 4 this morning, NNW 7 this afternoon.
Atmospheric Ventilation Conditions:
     Maximum mixing height today will be near 3000 feet.  Ventilation index 21.
High Temperature:
     Salem\'s high temperature today will be near 82.
Humidities:
     Minimum relative humidity will be near 37%.
Sunrise/Sunset:
     Salem sunset tonight: 8:52pm; sunrise tomorrow: 5:28am.

Extended Outlook:
     Little change in the weather pattern is forecast Tuesday,
     with an increasing chance of afternoon and evening thundershowers.
     Temperatures may cool a few degrees due to increasing amounts of 
     cloud-cover.  The moist and unstable southerly flow aloft will begin
     to shift further south Wednesday and Thursday, as the parent upper-level
     low-pressure area drifts south to off the southern California Coast.

     A much drier and more stable northerly flow will begin to
     spread south, across Oregon, Friday and Satruday, as the
     upper-level trough moves inland and eventually into Nevada.  Increasing
     onshore flow will begin to cool temperatures across western Oregon.
     A dry northwesterly flow aloft is forecast for early next week, with
     morning clouds and afternoon sunshine, along with seasonal temperatures.

Tomorrow (02 Jun):  Partly to Mostly Cloudy.  Chance of PM T-Storms.  55/79

Wed (03 Jun):  Partly to Mostly Cloudy.  Slight Chance PM T-Storm...Mainly South.  56/83

Thu (04 Jun):  Partly to Mostly Cloudy.  Slight Chance PM T-Storm...Mainly South.  56/82

Fri (05 Jun):  Partly Cloudy and Cooler.  54/77

Sat (06 Jun):  AM Clouds...Mostly Sunny.  51/74

Sun (07 Jun):  AM Clouds...Mostly Sunny.  51/75

Mon (08 Jun):  AM Clouds...Mostly Sunny.  50/74

ODA Meteorologist
weather at oda.state.or.us