SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY

ISSUED: Monday, December 9, 2013 2:35 PM Pete Parsons

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

The record-setting cold and dry air mass is slowly moderating. After setting a new all-time record low on Sunday with a minimum of 30 degrees below zero (the previous record was 28 degrees below zero; set in December of 1990 and in February of 1985), Burns had a minimum this morning of a balmy 22 degrees below zero, which fell just shy of the daily record of 26 degrees below zero; set in 1972. Records for Burns go back to 1939.

Baker City set a record Sunday with a minimum temperature of 20 degrees below zero, breaking their old daily record of 13 degrees below zero, set in 1972. This morning, Baker City’s minimum of 11 degrees below zero fell just shy of their daily record of 17 degrees below zero, which was also set in 1972.

An upper-level ridge of high pressure is slowly pushing over Oregon; warming the air aloft and stabilizing the air mass. However, a weak upper-level disturbance is backing the flow aloft to the NW; keeping skies mostly cloudy with a few light snow showers, mainly over the mountains.

Very little change in the weather pattern is forecast for Tuesday, with NW flow aloft continuing to keep skies mostly cloudy with a chance of light snow showers. The air mass will continue to slowly moderate with warming aloft further suppressing daytime mixing. Winds will be generally light.

EXTENDED DISCUSSION

The upper-level ridge is forecast to strengthen over Oregon on Wednesday; shutting off the light snow showers. Surface temperatures will continue to slowly moderate, but additional warming aloft will strengthen low-level inversions and create generally poor ventilation conditions. Light winds should turn mostly southeasterly.

The ridge is forecast to maintain dry and stagnant conditions on Thursday, before weakening and allowing a weak Pacific storm to move onshore late in the day. Increasing south to SE winds will continue to moderate surface temperatures and provide minor improvement to ventilation conditions. Light snow showers are possible Thursday night with possible freezing rain and sleet in the Columbia Basin.

An upper-level ridge will bring a drying and stabilizing NW flow aloft on Friday. Continued moderation of the air mass should marginally improve mixing, but winds will be light.

2. DISPERSION

TUESDAY

Mixing height below 500 ft during the morning rising to 1400 - 2400 ft during the afternoon lowering below 1000 ft during the evening.

Transport wind light and variable and controlled by local terrain.

Surface wind light and variable and controlled by local terrain.

OUTLOOK:

WEDNESDAY

Mixing height below 1000 ft during the morning rising to 1200 to 2200 ft during the afternoon. Transport wind light and variable during the morning becoming SE to SSW at 4 - 8 mph during the afternoon. Surface wind light and variable.

THURSDAY

Mixing height below 1000 ft during the morning rising to 1000 to 2000 ft during the afternoon. Transport wind SE to SSW at 6 - 10 mph. Surface wind SE to S at 4 - 8 mph during the morning becoming light and variable during the afternoon.

FRIDAY

Mixing height 1400 to 2400 ft during the morning rising to 2500 to 3500 ft during the afternoon. Transport wind WSW to WNW at 4 - 8 mph. 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 valid for burning done on Tuesday, December 10, 2013.

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Unfavorable burning situation due to very poor smoke dispersion. Delay ignitions until 11 a.m. Avoid ignitions within 20 miles in all directions of SSRAs. For units that will smolder significantly through the night avoid burning within at least 35 miles in all directions of SSRAs. Recommend against burning units that will smolder significantly overnight. Complete ignitions by 2:30 p.m.

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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_Information

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

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