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

Fri May 22 14:29:41 PDT 2009

SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS
SALEM FORESTRY WEATHER CENTER
OREGON DEPARTMENT OF FORESTRY

ISSUED: Friday, May 22, 2009       2:35 PM      Jim Trost

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

Weak ridging continues to build slowly.  A minor short-wave crosses the area, weakening the ridge temporarily.  Looks pretty insignificant but the wave could destabilize the upper levels just enough for afternoon heating to trigger a thunderstorm or two.  In the lower levels, enough stability remains that mixing will be slightly limited.  As the trough moves away and the sun sets, a strong surface inversion sets up and mixing height falls.  After some variability in the morning transport, it settles to brisk northwest to north.  Biggest problems will be units that could smolder into the night, and the upcoming Memorial Day weekend.  Recommend backing off from burning near SSRAs or recreation areas for the weekend.

    OUTLOOK (SUNDAY - TUESDAY):

As the short-wave drifts east, the air mass gradually stabilizes.  Heating will provide good mixing during the afternoons but overnight mixing becomes very poor and smoke will tend to flow down drainages.  Light overnight surface winds don't help either.  Chances of thunderstorms decrease but still cannot be totally ruled out.  As mentioned above, recommend holding off burning through the weekend due to both dispersion and the holiday.

2.  DISPERSION

SATURDAY
Mixing height 2500 - 3500 ft during the morning, 3800 - 4800 ft in the afternoon, lowering to 1000 - 1800 ft during the evening and less than 1000 ft overnight.

Transport wind NNW to NNE at 6 - 10 mph during the morning, NNW to N at 10 - 22 mph during the afternoon, and NNW to N at 16 - 28 mph in the evening.

Surface wind NW to N at 4 - 8 mph during the morning and NW to NNW at 9 - 15 mph during the afternoon and evening.

OUTLOOK:

SUNDAY
Mixing height below 1000 ft early, 3100 to 4100 ft by late morning, and 4100 to 5000 ft during the afternoon.  Transport wind NW to N at 7 - 13 mph in the morning and NNW to N at 12 - 24 mph during the afternoon.  Surface wind light and variable, becoming NW to NNW at 9 - 15 mph during the afternoon.

MONDAY
Mixing height below 1000 ft early, 2900 to 3900 ft by late morning, and 4300 to 5000 ft in the afternoon.  Transport wind NW to NNE at 6 - 10 mph.  Surface wind NW to NNE at 5 - 9 mph.

TUESDAY
Mixing height below 1000 ft early, rising to 3000 to 4000 ft by late morning, and 4100 to 5000 ft in the afternoon.  Transport wind W to NW at 4 - 8 mph.  Surface wind light and variable, becoming NW to N at 8 - 12 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 Saturday, May 23, 2009.
    ==================================================================

Wait until the nighttime inversion breaks, then avoid ignitions within 15 miles to the NW through NNE of SSRAs.  Complete ignitions by 4 PM.  For units that will smolder into the night, avoid burning within at least 30 miles to the NW through NNE in or near drainages leading to SSRAs.  Recommend against burning units that will smolder significantly overnight.

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

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://omls.oregon.gov/pipermail/smi_northeast/attachments/20090522/cef442e9/attachment.html>