SMI Northeast (Smoke Management Instructions) Northeast Oregon Smoke Management Instructions

Sat Apr 30 14:33:35 PDT 2011

SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY

ISSUED: Saturday, April 30, 2011       2:35 PM      Pete Parsons

1.  DISCUSSION AND FORECAST FOR NORTHEAST FORECAST AREA ZONES 630-638

SUNDAY

A drying northwesterly flow aloft will help to clear skies, in the wake of an unseasonably cold upper-level trough.  After a near-record-cold morning, a transitory upper-level ridge is forecast to move onshore and across the state.  Mostly sunny skies will help afternoon temperatures recover close to normal.  The freezing level will climb above 6000 feet, with good afternoon mixing and light transport winds.

OUTLOOK (MONDAY-WEDNESDAY)
The upper-level ridge will push east of the state Monday with an increasing westerly flow aloft directing another cold front onshore.  Ahead of the cold front, surface temperatures should warm to near normal with good mixing and increasing southwest to westerly transport winds.  A chance of rain and snow showers returns, by the late afternoon.  The snow level will drop to near 5000 feet late, with brisk transport winds turning mostly westerly.
A weak upper-level trough will push east of the state Tuesday, with a return to a dry northwesterly flow aloft.  Skies should be partly cloudy with a few lingering mountain showers.  The snow level will start out below 4000 feet and slowly rise to about 5500 feet.  Surface temperatures will be well below normal. Mixing should be good, with locally brisk northwesterly winds.

Another weak and transitory upper-level ridge is forecast to move onshore by Wednesday afternoon.  A drier northwesterly flow will bring a return of mostly sunny and warmer conditions.  After another very chilly morning, high temperatures will recover to near normal.  The freezing level will lift to about 7000 feet.  Warmer surface temperatures will make for good afternoon mixing with light winds.

The upper-air pattern is forecast to remain progressive, with long-range computer models differing on the strength of a weaker weather system forecast to come onshore late Thursday and Friday. That system may bring a few showers, to mainly higher terrain, on Friday. A stronger weather system is forecast to bring back cool and damp conditions Saturday night and Sunday.

2.  DISPERSION

SUNDAY

Zone 630 and 632:

Mixing height below 500 ft early rising to 3000 - 4000 ft by late morning.  Afternoon mixing height rises above 5000 ft then lowers to 1500 - 2500 ft during the evening.

Transport wind SE to SSW at 5 - 9 mph.

Surface wind SE to S at 4 - 8 mph throughout the day.

Zone 633 - 638:

Mixing height below 500 ft early rising to 3000 - 4000 ft by late morning.  Afternoon mixing height rises above 5000 ft then lowers to 1500 - 2500 ft during the evening.

Transport wind light and variable and controlled by local terrain.  Transport wind increases to SSE to SSW at 5 - 9 mph during the evening.

Surface wind light and variable and controlled by local terrain.  Surface wind increases to SE to SSW at 4 - 8 mph during the evening.

OUTLOOK:

MONDAY

In the west mixing height 2200 to 3200 ft during the morning rising above 5000 ft during the afternoon.  In the east mixing height below 1000 ft early rising to 3500 to 4500 ft by late morning rising above 5000 ft during the afternoon.  Transport wind S to SSW at 12 - 24 mph during the morning becoming W to WNW at 16 - 30 mph during the afternoon.  Surface wind SSE to SSW at 8 - 14 mph during the morning becoming WSW to WNW at 10 - 18 mph during the afternoon.

TUESDAY

Mixing height 2200 to 3200 ft during the morning rising above 5000 ft during the afternoon.  Transport wind WNW to NNW at 9 - 15 mph during the morning becoming NW to NNW at 12 - 22 mph during the afternoon.  Surface wind W to NW at 4 - 8 mph.

WEDNESDAY

Mixing height below 1000 ft early rising to 3000 to 4000 ft by late morning rising above 5000 ft during the afternoon.  Transport wind light and variable.  Surface wind light and variable.

3.  BURNING INSTRUCTIONS FOR NORTHEAST OREGON ZONES 630-638

    The following considerations should be adhered to in addition to

    the requirements of the Oregon Smoke Management Plan. These

    Instructions are valid for burning conducted on Sunday, May 1, 2011.

    ==================================================================

Zone 630 and 632:

Avoid ignitions within 15 miles to the SE through SW of SSRAs.  For units that will smolder significantly through the night avoid burning within at least 30 miles to the SE through SW in or near drainages leading to SSRAs.  Verify transport winds away from SSRAs if burning in any other direction.  Recommend against burning units that will smolder significantly overnight.  Complete ignitions by 6 p.m.

Zone 633 - 638:

Avoid ignitions within 15 miles in all directions of SSRAs.  For units that will smolder significantly through the night avoid burning within at least 30 miles in all directions of SSRAs.  Recommend against burning units that will smolder significantly overnight.  Complete ignitions by 6 p.m.

    =========================================================

4.  SPECIAL NOTE:

    The smoke management forecaster is available at (503)-

    945-7401. Please call this number and not individual's

    numbers to discuss daily burning.  For large burns (over

    2000 tons) or burns extending over a considerable period,

    please request a special forecast.  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

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

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

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