SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY

 

ISSUED: Sunday, May 3, 2015       2:40 PM      Pete Parsons

 

1.  DISCUSSION AND FORECAST FOR SOUTH CENTRAL OREGON ZONES 624 AND 625

 

SHORT-TERM DISCUSSION

A weak upper-level ridge will give way to increasing SW flow tonight and Monday.  After a risk of an evening thunderstorm, skies should clear overnight through Monday morning.  A mostly dry cold front will bring increasing clouds and onshore flow Monday afternoon and evening, along with the threat of a late-day shower or thunderstorm.  Ventilation should be good ahead of the cold front with mostly SW transport winds.  However, a marine push in the late-afternoon could be problematic for smoldering units to the W-NW of SSRAs.

EXTENDED DISCUSSION

Monday’s mostly dry surface cold front will be followed by a fairly vigorous upper-level trough and much cooler temperatures on Tuesday.  Snow levels should drop to between 6000 and 7000 feet, which will destabilize the air mass and possibly trigger late-day shower and thundershower development.  Expect brisk NW winds and good mixing.

Wednesday through Friday, the upper-level trough is predicted to stall and slowly drift southward across Oregon.  That will keep the air mass cool, moist, and unstable with scattered mainly afternoon and evening showers and thundershowers. Mixing will be good with brisk NW transport winds veering to more northerly later in the week.  Note that transport winds will be erratic near showers and thundershowers, which creates smoke management issues for burns located near SSRAs.

2.  DISPERSION

 

MONDAY

 

Mixing height below 1000 ft early rising to 2500 - 3500 ft by late morning.  Afternoon mixing height rises above 5000 ft then lowers to 3000 - 4000 ft during the evening.

 

Transport wind SSW to WSW at 6 - 10 mph during the morning.  Transport increases to WSW to WNW at 10 - 20 mph during the afternoon then shifts to WNW to NNW and increases to 15 - 25 mph during the evening.

 

Surface wind SSW to WSW at 4 - 8 mph during the morning.  Surface wind shifts to WSW to WNW and increases to 9 - 15 mph during the afternoon then shifts to WNW to NNW at 9 - 15 mph during the evening.

 

OUTLOOK:

 

TUESDAY

Mixing height 3000 - 4000 ft during the morning rising above 5000 ft during the afternoon.  Transport wind WNW to NW at 9 - 15 mph during the morning becoming WNW to NW at 12 - 22 mph during the afternoon.  Surface wind WNW to NNW at 5 - 9 mph during the morning becoming WNW to NW at 9 - 15 mph during the afternoon.

 

WEDNESDAY

Mixing height 3200 - 4200 ft during the morning rising above 5000 ft during the afternoon.  Transport wind NNW to NNE at 9 - 15 mph during the morning becoming NW to N at 12 - 22 mph during the afternoon.  Surface wind NW to NNE at 6 - 10 mph during the morning becoming NW to N at 10 - 18 mph during the afternoon.

 

THURSDAY

Mixing height 3200 - 4200 ft during the morning rising above 5000 ft during the afternoon.  Transport wind NNW to NNE at 10 - 20 mph.  Surface wind NNW to NNE at 8 - 12 mph.

 

3.  BURNING INSTRUCTIONS FOR ZONES 624 AND 625 INCLUDING THE WALKER

    RANGE PORTION OF ZONE 624

This instruction is valid for burning conducted on Monday, May 4, 2015.

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Avoid ignitions within 12 miles to the SSW through NW of SSRAs.  For units that will smolder significantly through the night avoid burning within at least 20 miles to the SW through NNW in or near drainages leading to SSRAs.  Watch for shifting transport winds. 

 

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4.  SPECIAL NOTE:

 

    The smoke management forecaster is available at (503)

    945-7401.  The smoke management forecaster is available

    to discuss specific burns.  The duty forecaster phone

    number is (503) 945-7401. Please call this number and

    not individual's numbers to discuss daily burning. Please

    avoid calling before 8 a.m. and between 2 to 3 p.m.

 

    This forecast is available on the Internet at:

      http://oregon.gov/ODF/FIRE/fire.shtml/#Smoke_Management_Information

 

    Please ensure your units have been planned and accomplished by checking:

      http://oregon.gov/ODF/FIRE/SMP/dailysmoke.shtml