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, May 3, 2011       2:40 PM      Jim Little



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



    WEDNESDAY



An upper level ridge drifts eastward across the region on Wednesday.  The axis of the ridge is near the coast early in the morning but by evening lies along a line from eastern Washington to eastern Oregon.  Expect dry weather and high afternoon mixing heights for good smoke dispersal conditions most areas.  Afternoon mixing heights should climb to or above 5000 feet and transport winds will be mostly southeasterly.



    OUTLOOK (THURSDAY - SATURDAY)



The upper ridge shifts to the northern plains on Thursday as a weak upper trough moves across the Pacific Northwest.  Moisture is limited, thus expect just mid and high clouds.  Temperatures will climb to 7 to 10 degrees above average.  Transport winds start out southerly but become northwesterly during the day.  High maximum mixing heights should provide good smoke dispersal conditions.



A generally zonal or west to east flow aloft prevails on Friday.  Low level transport winds will be generally west-southwesterly.  Smoke dispersal conditions will be fair as maximum mixing heights will be a bit lower than on Thursday.



Little change in the broad upper scale flow for Saturday is likely, but a weak impulse in the flow could bring an increase in mid and high clouds to the region.  Temperatures dip to around 3 to 6 degrees below average for the time of year.  However maximum mixing heights are again likely to exceed 5000 feet and with a good west-southwest transport wind smoke dispersal conditions should be good.



2.  DISPERSION



WEDNESDAY

Mixing height 2600 - 3600 ft during the morning.  Mixing height rises above 5000 ft during the afternoon then lowers below 1000 ft during the evening.



Transport wind E to SE at 8 - 12 mph during the morning.  Transport wind shifts to SE to SSW at 6 - 10 mph during the afternoon and evening.



Surface wind E to SE at 6 - 12 mph during the morning.  Surface wind shifts to SE to S at 6 - 10 mph during the afternoon then becomes light and variable and controlled by local terrain during the evening.



OUTLOOK:



THURSDAY

Mixing height below 1000 ft early rising above 5000 ft by late morning and through the afternoon.  Transport wind SW to WSW at 10 - 16 mph during the morning becoming WNW to NW at 13 - 25 mph during the afternoon.  Surface wind SSW to WSW at 8 - 12 mph during the morning becoming W to WNW at 10 - 22 mph during the afternoon.



FRIDAY

Mixing height below 1000 ft early rising to 2500 - 3500 ft by late morning rising above 5000 ft during the afternoon.  Transport wind SW to WNW at 4 - 8 mph.  Surface wind light and variable during the morning becoming WSW to NW at 4 - 8 mph during the afternoon.



SATURDAY

Mixing height below 1000 ft early rising to 3500 - 4500 ft by late morning rising above 5000 ft during the afternoon.  Transport wind SW to W at 4 - 8 mph.  Surface wind light and variable.



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, May 4, 2011.

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Avoid ignitions within 15 miles to the E through SSW of SSRAs.  For units that will smolder significantly through the night avoid burning within at least 30 miles to the E through SW in or near drainages leading to SSRAs.  Watch for shifting transport winds.  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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