SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY

 

ISSUED: Thursday, October 30, 2014       2:40 PM      Tom Jenkins

 

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

 

SHORT-TERM DISCUSSION

The atmosphere will become less stable as an upper level trough slowly progresses across western Oregon overnight. Rainfall will impact western zones by sunrise, as a weakening surface cold front approaches the Cascades. Mixing will improve throughout the day, with steady onshore flow.

EXTENDED DISCUSSION

The upper level trough will exit southern Oregon Saturday morning. Significantly-colder air will move in from the northwest behind it, dropping the freezing level to 4,500ft. Mixing will be good in the morning hours, with limited improvement Saturday afternoon. An upper level ridge will build in from the northwest Saturday evening, ushering in a period of stability.

The air aloft will warm rapidly overnight into Sunday morning, forming a surface ridge by sunrise. This will cause winds to become light, and influenced primarily by terrain. Mixing will be restricted as well under the stable conditions. The upper level ridge will slowly push east into the Oregon high desert Sunday evening, weakening slightly. The surface ridge will persist into Monday, with deteriorating mixing conditions as the winds shift to offshore flow. The atmosphere will continue to dry out as a result.

2.  DISPERSION

 

FRIDAY

 

Mixing height above 5000 ft throughout the day.  Mixing height lowers to 1500 - 2500 ft during the evening.

 

Transport wind WSW to WNW at 5 - 9 mph during the morning.  Transport wind shifts to NE to E at 5 - 9 mph during the afternoon and shifts to SE to S at 8 - 12 mph during the evening.

 

Surface wind SW to WNW at 4 - 8 mph during the morning.  Surface wind becomes light and variable and controlled by local terrain during the afternoon then increases to SE to S at 4 - 8 mph during the evening.

 

OUTLOOK:

 

SATURDAY

Mixing height below 1000 ft early rising to 2500 - 3500 ft by late morning rising to 3500 - 4500 ft during the afternoon.  Transport wind NW to N at 4 - 8 mph.  Surface wind light and variable during the morning becoming WNW to NNW at 8 - 12 mph during the afternoon.

 

SUNDAY

Mixing height below 1000 ft early rising to 1500 - 2500 ft by late morning rising to 2500 - 3500 ft during the afternoon.  Transport wind light and variable during the morning becoming WSW to NW at 4 - 8 mph during the afternoon.  Surface wind light and variable.

 

MONDAY

Mixing height below 1000 ft early rising to 1000 - 2000 ft by late morning rising to 2000 - 3000 ft during the afternoon.  Transport wind ESE to S at 4 - 8 mph during the morning becoming S to SW at 4 - 8 mph during the afternoon.  Surface wind ESE to SSE at 4 - 8 mph during the morning becoming SSE to SW at 4 - 8 mph during the afternoon.

 

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

    RANGE PORTION OF ZONE 624

This instruction is valid for burning conducted on Friday, October 31, 2014.

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Avoid ignitions within 12 miles in all directions of SSRAs.  For units that will smolder significantly through the night avoid burning within at least 20 miles in all directions of SSRAs.  Watch for shifting transport winds.  Complete ignitions by 4 p.m. 

 

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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