[willamette-fcst] Forecast - Monday, May 19th, 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, May 19th, 2008 at 9:00am.

Burn Advisory:
     Agricultural burning is allowed.  Suggested burn times are from 12:00pm until 6:30pm.
     Straw stack burning is allowed from 12:00pm until 6:30pm.

Weather Discussion:
     A massive upper-level ridge of high pressure built over the
     Pacific Northwest this past weekend and brought record high
     temperatures to the entire region...including the Oregon
     Coast.  For most of Western Oregon, the warmest day was
     Friday with highs in the 90s from the Coast to the Foothills
     of the Cascades.  Seaside and Astoria hit 98 and 93 degrees
     respectively (both records for the date).  Salem was the
     warm spot in the Willamette Valley with a record high of 99
     degrees.  Eugene was the cool spot but still managed a
     record high with 89.

     Much of Western Oregon saw record warm overnight
     temperatures Friday night ahead of a second record-breaking
     afternoon on Saturday.  Some valley locations were even
     warmer Saturday like Eugene and Portland with 95 degrees
     (both daily records).  The 95 degree reading at Eugene
     Saturday was also the warmest temperature ever recorded
     there during the month of May.  The coastal areas developed
     onshore flow and cooled into the 70s Saturday, while the
     record heat shifted into Central and Eastern Oregon. 
     Redmond and Pendleton had record highs of 97 Saturday, and
     The Dalles had a record 98 degrees.

     Increasing onshore flow brought cooling to all but extreme
     Eastern Oregon Sunday.  The coastal region cooled into the
     mid to upper 60s and the Willamette Valley Cooled into the
     low to mid 80s.  Most of Central and Eastern Oregon also saw
     a few degrees of cooling.

     We will the cooling trend today, as the high pressure ridge
     continues to break down and shift eastward.  High clouds will
     be on the increase across Western Oregon with lots of low clouds
     and fog along the coastal strip.  Light winds in the valley this
     morning will turn onshore this afternoon with high temperatures
     topping out in the low 80s...still more than 10 degrees above
     normal for mid-May.

Surface Winds:
     SE 0-4 this morning, SW 5-10 this afternoon.
Transport Winds:
     SE 5 this morning, SW 10 this afternoon.
Atmospheric Ventilation Conditions:
     Maximum mixing height today will be near 4500 feet.  Ventilation index 45.
High Temperature:
     Salem\'s high temperature today will be near 82.
Humidities:
     Minimum relative humidity will be near 35%.
Sunrise/Sunset:
     Salem sunset tonight: 8:39pm; sunrise tomorrow: 5:38am.

Extended Outlook:
     A fairly strong cold front is forecast to move onshore early
     Tuesday morning and rapidly across the state during the day.
     Rain is likely for most of Western Oregon with numerous
     showers making it east of the Cascades.  The cool-down
     should be significant with high temperatures dropping about
     20 degrees from today across the state.  Temperatures west
     of the Cascades will fall to below normal and the snow level
     should drop to about 5000 feet.  Strong onshore flow will
     make for locally windy conditions east of the Cascades.

     A cold upper-level trough will move over the Pacific
     Northwest Tuesday night and Wednesday for continued cool
     temperatures and the threat of showers.  High pressure will
     slowly push closer to the coastline Thursday and Friday with
     the flow aloft drying out and turning more northerly.  That
     will bring increasing amounts of sunshine and warm
     temperatures back above normal by the holiday weekend, but I
     do not expect record temperatures like we had this past
     weekend.

Tue (20 May):  Rain AM...Showers PM.  Much Cooler.  Snow Level Dropping to 5000 Feet.  54/62

Wed (21 May):  Mostly Cloudy and Cool.  Chance of Showers.  Snow Level 5000 Feet.  46/60

Thu (22 May):  Partly Sunny.  A Little Warmer.  43/66

Fri (23 May):  Partly Cloudy.  Warming to Near Normal.  45/71

Sat (24 May):  Mostly Sunny and Warmer.  45/76

Sun (25 May):  Mostly Sunny.  47/78

Mon (26 May):  Mostly Sunny.  48/76

ODA Meteorologist
weather at oda.state.or.us