SMI South Central (Smoke Management Instructions) South Central Smoke Management Instructions

[ODF Smoke Management Instructions]

SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY



ISSUED: Wednesday, May 4, 2011       2:40 PM      Pete Parsons



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


THURSDAY


An upper-level ridge is forecast to flatten and shift eastward, to over the northern Rockies, as a weak upper-level trough moves across the Pacific Northwest.  Moisture is limited, so expect only some increase in cloudiness but no precipitation.  The surface thermal trough will also weaken and shift east of the region.  Temperatures will start out warmer than on Wednesday but likely top out at about the same level, as increasing westerly transport winds usher cooler marine air into the region.  Cooling aloft and daytime heating will combine for good afternoon mixing.

OUTLOOK (FRIDAY-SUNDAY)

A westerly flow aloft is forecast for Friday, with the region between storm systems. Low level transport winds will be generally west-southwesterly.  Afternoon smoke dispersal conditions will continue to be good.



A strengthening westerly jet stream will direct another cold front across the Pacific Northwest Friday night, with a cool upper-level trough moving onshore Saturday.  Expect mostly cloudy skies Saturday with a chance of showers by the afternoon.  Temperatures will drop back to near or slightly below normal.  With further cooling aloft, maximum mixing heights are again likely to exceed 5000 feet and with brisk west-southwesterly transport winds.



By Sunday, another unseasonably cold upper-level trough will make camp over the Pacific Northwest.  Rain and snow showers will be widespread with precipitation totals over .10 inches common.  The snow level will drop to 4-5000 feet late. Cold air aloft should make for good mixing with brisk west-northwesterly transport winds.



2.  DISPERSION



THURSDAY

Mixing height below 500 ft early rising to 3500 - 4500 ft by late morning.  Afternoon mixing height rises above 5000 ft then lowers to 1500 - 2500 ft during the evening.



Transport wind WSW to WNW at 10 - 20 mph during the morning.  Transport wind increases to WSW to WNW at 15 - 25 mph during the afternoon and evening.



Surface wind WSW to WNW at 8 - 14 mph during the morning.  Surface wind increases to WSW to WNW at 10 - 20 mph during the afternoon then decreases to W to NW at 8 - 12 mph during the evening.



OUTLOOK:



FRIDAY

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 WNW at 6 - 10 mph during the morning becoming WSW to WNW at 12 - 24 mph during the afternoon.  Surface wind light and variable during the morning becoming WSW to WNW at 8 - 12 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 8 - 12 mph during the morning becoming WSW to WNW at 10 - 22 mph during the afternoon.  Surface wind SW to WNW at 4 - 8 mph.



SUNDAY

Mixing height 2800 - 3800 ft during the morning rising above 5000 ft during the afternoon.  Transport wind W to WNW at 10 - 22 mph.  Surface wind WSW to NW at 6 - 10 mph during the morning becoming WNW to NNW at 10 - 20 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 Thursday, May 5, 2011.

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Avoid ignitions within 12 miles to the WSW through NW of SSRAs.  For units that will smolder significantly through the night avoid burning within at least 20 miles to the WSW through NW in or near drainages leading to SSRAs.  Complete ignitions by 6 p.m.



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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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