[willamette-fcst] Forecast - Tuesday, January 26th, 2010

[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.

            ...No Updates Before Tuesday, February 2nd, 2010 at 9:00am...

Issued: 
     Tuesday, January 26th, 2010 at 12:00pm.

Burn Advisory:
     Agricultural burning is not recommended.
     Stack burning is not allowed.

Weather Discussion:
     A low-pressure system tracked eastward, across extreme southern Oregon, overnight and was
     centered over southern Idaho late this morning.  The counter-clockwise circulation around
     this system was continuing to spin clouds over Oregon, with some areas of light rain and
     snow east of the Cascades, where the snow level is about 3500 feet. Winter weather
     advisories have been cancelled for the Bend/Redmond region, of central Oregon, where the
     snow has tapered off to just a few flurries.

     Light snow fell over the Cascade passes this morning, but the snow had tapered off there
     by late this morning with temperatures climbing above freezing.  ODOT road cameras showed
     the snowy road surfaces, from earlier this morning, were turning into wet pavement.  West
     of the Cascades, skies began to clear by mid-morning, with some sunbreaks locally pushing
     temperatures into the 50s.  Winds continued to be light, with the ODA surface analysis
     showing weak high pressure building over the region, in the wake of the system moving
     into Idaho.

     The low-pressure system over southern Idaho will continue to progress eastward today, with
     a split-flow westerly jet stream pattern over Oregon.  A very weak upper-level disturbance
     was pushing a narrow line of developing showers onto the northern and central Oregon coast
     late this morning.  This disturbance will combine with daytime heating to maintain a threat
     of showers through this afternoon across the Willamette Valley.  Light shower activity may
     provide enough mixing of the air mass to lift surface temperatures into the low to mid 50s
     this afternoon.  Corvallis was already 54 degrees late this morning, with Newport at 50.
     Most of the Willamette Valley was still in the mid 40s.

     Skies should remain mostly cloudy across the state this afternoon, with the best chance
     of sunbreaks over northwestern Oregon.  Areas of rain and snow, east of the Cascades, will
     slowly taper off and move east of the region.  Weak windflow may now allow portions of the
     Willamette Valley to break 50 degrees this afternoon, while other areas climb into the low
     to mid 50s (well above normal).

Surface Winds:
     Var 0-7 this afternoon.
Transport Winds:
     WSW 4 this afternoon.
Atmospheric Ventilation Conditions:
     Maximum mixing height today will be near 2000 feet.  Ventilation index 8.
High Temperature:
     Salem\'s high temperature today will be near 51.
Humidities:
     Minimum relative humidity will be near 63%.
Sunrise/Sunset:
     Salem sunset tonight: 5:12pm; sunrise tomorrow: 7:37am.

Extended Outlook:
     A transitory ridge of high pressure will bring dry weather
     Wednesday and most of Thursday, with rising freezing levels.
     The western valleys should get a good dose of fog overnight
     tonight and Wednesday night with only partial afternoon
     clearing.  Overnight minimums will be cooler, and high
     temperatures will vary, depending on the local duration of
     fog.  The next weather system is forecast to bring rain to
     the coast and the western valleys on Friday, with snow
     levels lowering back down to near pass level in the
     Cascades.  Another mild weather system is forecast to come
     onshore about next Tuesday.

Tomorrow (27 Jan):  Partly Sunny After AM Fog.  Snow Level Rising to 5-6000 Feet.  34/49

Thu (28 Jan):  Increasing Clouds After AM Fog.  Snow Level 6-7000 feet.  35/50

Fri (29 Jan):  Rain Developing.  Mild.  Snow Level Dropping to 4500 Feet.  37/52

Sat (30 Jan):  Chance of Showers.  Snow Level 4000 Feet.  37/49

Sun (31 Jan):  Partly Cloudy.  Snow Level 3500 Feet.  35/50

Mon (01 Feb):  Mostly Cloudy.  Snow Level 4000 Feet.  36/50

Tue (02 Feb):  Mostly Cloudy.  Chance of Rain.  Snow Level 4000 Feet.  38/50

ODA Meteorologist
weather at oda.state.or.us