SMI South Central (Smoke Management Instructions) (no subject)

[ODF Smoke Management Instructions]

SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY



ISSUED: Tuesday, April 19, 2011       2:40 PM      Jim Little



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

    WEDNESDAY



Upper level charts show a broad trough over the eastern Pacific and the western US for Wednesday.  An upper level jet cuts across the coastline into central California.  This leaves Oregon on the cool side of the jet stream and air mass temperatures will remain well below average for this time of year.  There will be only limited moisture available but showers are likely most areas.  The cold air aloft will help push mixing heights to high values and smoke dispersal conditions should be good.



    OUTLOOK (THURSDAY - SATURDAY)



On Thursday an upper disturbance swings down from the northwest and phases with a disturbance moving westward across the Pacific to carve out a fairly sharp trough over the eastern Pacific and western US.  This should bring rain or snow to most areas.  The snow level will be down to about 3500 feet.  Smoke dispersal conditions will remain good.



The upper disturbances move east on Friday allowing weak ridging over the region.  Weather should be dry.  Mixing heights will be suppressed slightly but smoke dispersal conditions remain fair to good.  Low level flow will be light and from the south. The ridge moves east Saturday and a Pacific front moves in from the west.  Rain reaches western Oregon during the morning and spreads east during the afternoon.  Expect fair to good smoke dispersal conditions Saturday.



2.  DISPERSION



WEDNESDAY

Mixing height 1700 - 2700 ft during the morning.  Mixing height rises to above 5000 ft during the afternoon then lowers to 1200 - 2200 ft during the evening.



Transport wind SSW to SW at 13 - 25 mph during the morning and afternoon.  Transport wind decreases to WSW to WNW at 6 - 12 mph during the evening.



Surface wind SSW to SW at 9 - 15 mph during the morning and afternoon.  Surface wind becomes light and variable and controlled by local terrain during the evening.



OUTLOOK:



THURSDAY

Mixing height 1100 - 2100 ft during the morning rising above 5000 ft during the afternoon.  Transport wind WNW to NNW at 8 - 12 mph.  Surface wind WNW to NNW at 6 - 10 mph.



FRIDAY

Mixing height below 1000 ft early rising to 2100 - 3100 ft by late morning rising above 5000 ft during the afternoon.  Transport wind ESE to SSE at 4 - 8 mph during the morning becoming SSW to WSW at 4 - 8 mph during the afternoon.  Surface wind ESE to SSE at 4 - 8 mph during the morning becoming SW to W at 4 - 8 mph during the afternoon.



SATURDAY

Mixing height below 1000 ft early rising to 2100 - 3100 ft by late morning rising to 4000 - 5000 ft during the afternoon.  Transport wind SSE to SSW at 4 - 8 mph during the morning becoming SSW to WSW at 4 - 8 mph during the afternoon.  Surface wind SSE to SSW at 4 - 8 mph during the morning becoming SSW to WSW 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 Wednesday, April 20, 2011.

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Avoid ignitions within 15 miles to the S through WNW of SSRAs.  For units that will smolder significantly through the night avoid burning within at least 30 miles to the S through NW in or near drainages leading to SSRAs.  Recommend against burning units that will smolder significantly overnight.  Complete ignitions by 4:00pm.



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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



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

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

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