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

[ODF Smoke Management Instructions]

SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY



ISSUED: Thursday, April 28, 2011       2:35 PM      Pete Parsons



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


FRIDAY

The axis of an unseasonably cold upper-level trough is forecast to slowly push east of the state with a continued cool and unstable northwesterly flow aloft. Showers are likely, with a chance of afternoon and evening thunderstorms with small hail.  Minor snow accumulations are likely over higher terrain.  The snow level will start out as low as 1000 feet, before rising to 2500 in the afternoon.  Surface temperatures will also be well below normal. Mixing will be good with brisk northwesterly transport winds.

OUTLOOK (SATURDAY-MONDAY)
An upper-level ridge is forecast to build offshore Saturday with a drier and more stable northwesterly flow aloft over Oregon.  Look for partly cloudy skies.  The air aloft will remain cold enough for daytime heating to possibly trigger a few showers, mainly over higher terrain. After a frosty morning, afternoon temperatures will moderate slightly but remain well below normal.  The snow level will only rise to about 3500 feet.  Mixing should be good with transport winds beginning to veer from northwest to more northerly late in the day.

A weak upper-level ridge axis is forecast to move onshore Sunday, with clearing skies and moderating temperatures.  After a near-record-cold morning, afternoon temperatures will recover close to normal.  The freezing level will climb to about 7000 feet, but the air aloft will stay cool enough for good afternoon mixing with light transport winds.

The transitory upper-level ridge will push east of the state Monday with an increasing westerly flow aloft bringing a weak cold front onshore by the afternoon.  A chance of rain and snow showers returns by the afternoon with the snow level dropping to around 5000 feet. Ahead of the cold front, surface temperatures should warm to near normal with good mixing and increasing onshore transport winds.



2.  DISPERSION



FRIDAY

Mixing height below 2500 ft early rising to 3200 - 4200 ft by late morning.  Afternoon mixing height rises above 5000 ft then lowers to 2500 - 3500 ft during the evening.



Transport wind WNW to NW at 10 - 22 mph during the morning.  Transport wind increases to WNW to NNW at 15 - 27 mph during the afternoon and evening.



Surface wind W to NW at 7 - 11 mph during the morning.  Surface wind increases to WNW to NNW at 10 - 19 mph during the afternoon then decreases to NW to NNW at 8 - 12 mph during the evening.



OUTLOOK:



SATURDAY

Mixing height 2300 to 3300 ft during the morning rising above 5000 ft during the afternoon.  Transport wind WNW to NNW at 5 - 9 mph.  Surface wind WNW to NNW at 4 - 8 mph.



SUNDAY

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.



MONDAY

Mixing height below 1000 ft early rising to 3000 to 4000 ft by late morning rising above 5000 ft during the afternoon.  Transport wind S to SSW at 15 - 29 mph during the morning becoming WSW to W at 15 - 29 mph during the afternoon.  Surface wind SSE to SSW at 8 - 12 mph during the morning becoming WSW to WNW at 9 - 15 mph during the afternoon.



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 Friday, April 29, 2011.

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



Avoid ignitions within 12 miles to the WNW through N of SSRAs.  For units that will smolder significantly through the night avoid burning within at least 20 miles to the WNW through N in or near drainages leading to SSRAs.



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

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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