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: Sunday, April 24, 2011       2:40 PM      Jim Little



1.  DISCUSSION AND FORECAST FOR SOUTH CENTRAL OREGON ZONES 624 AND 625
    MONDAY
A fairly deep and compact upper level low moves west across the Pacific Ocean toward Vancouver Island on Monday.  The upper trough with this supports an active Pacific cold front.  The polar jet is estimated to exceed 175mph at the 30,000 foot level and cuts into North America over extreme southwest Oregon.  Oregon will be under the left front quadrant of the jet and thus prone to rainy weather.  Rain spreads eastward during the day with amounts generally less than a quarter of an inch.  Mixing heights will exceed 5000 feet and west southwesterly transport winds will be brisk for good smoke dispersal conditions.
    EXTENDED OUTLOOK (TUESDAY - THURSDAY)
Minor ridging develops on Tuesday but the jet stream, while weaker, remains over the state.  Areas of light rain will continue through the day.  Transport winds will be brisk westerly most areas and maximum mixing heights will remain high for good smoke dispersal conditions.
Whatever minor ridging develops Tuesday and Tuesday night flattens Wednesday as another upper low and trough move toward the coastline.  There will be limited moisture but areas of light rain will continue.  High maximum mixing heights will give good smoke dispersal conditions most areas.
The upper trough moves in on Thursday supporting a cold front that reaches northwest Oregon early then spreads rain south and east during the day.  Precipitation will begin as rain but as the cooler air behind the cold front spreads in snow is possible Thursday night and Friday morning.  Smoke dispersal conditions will remain good.

2.  DISPERSION



MONDAY

Mixing height above 5000 ft throughout the day.  Mixing height lowers to 2800 - 3800 ft during the evening.



Transport wind SW to WSW at 34 - 54 mph during the morning.  Transport wind decreases to WSW to WNW at 19 - 33 mph during the afternoon and evening.



Surface wind SSW to WSW at 22 - 38 mph during the morning.  Surface wind decreases to WSW to WNW at 15 - 25 mph during the afternoon and decreases to WSW to WNW at 10 - 22 mph during the evening.



OUTLOOK:



TUESDAY

Mixing height 4400 - 5000 ft during the morning rising above 5000 ft during the afternoon.  Transport wind WSW to WNW at 10 - 20 mph.  Surface wind WSW to WNW at 8 - 12 mph.



WEDNESDAY

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



THURSDAY

Mixing height below 1000 ft early rising to 2800 - 3800 ft by late morning rising above 5000 ft during the afternoon.  Transport wind SW to W at 4 - 8 mph.  Surface wind SW to W at 4 - 8 mph during the morning becoming WSW to NW at 5 - 9 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 Monday, April 25, 2011.

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Avoid ignitions within 10 miles to the SW through WNW of SSRAs.  Care needed in selecting units as smoke will likely fumigate along the ground in wind prone areas.  No additional restrictions necessary.



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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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