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: Friday, November 5, 2010       2:40 PM      Pete Parsons



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



SATURDAY



The massive upper-level ridge of high pressure responsible for the recent spell of dry, warm and stagnant conditions will continue to weaken and shift eastward.  The ridge axis is forecast to stretch from New Mexico to North Dakota with strengthening southwesterly flow aloft over Oregon.



The second in a series of weather systems will approach the coastline late in the day, with partly to mostly cloudy skies but dry conditions expected over south-central Oregon.  South to southwesterly winds will keep surface temperatures well above normal, and cooling aloft will raise afternoon mixing heights, making for good smoke dispersal conditions.


OUTLOOK (SUNDAY-TUESDAY)


A cold front will likely spread rain across south-central Oregon Sunday morning.  Rain will turn to showers later Sunday afternoon. Rainfall amounts should range from one-tenth to one-quarter of an inch.  Surface temperatures will cool to near normal with continued good smoke dispersal conditions.  Cooler air aloft will drop the snow level to around 5000 feet by evening and 4500 feet overnight.



Showers will taper off Monday, as a flat and transitory upper-level ridge stabilizes the air mass slightly.  Snow levels will remain near 4500 feet and surface temperatures will cool to slightly below normal.  Transport winds will turn mostly westerly with fair to good smoke dispersal conditions.



The next weather system is forecast to move mainly into northern California and southern Oregon on Tuesday.  That would keep snow levels around 4500 feet or lower with rainfall amounts possibly in excess of one-quarter of an inch.  Transport winds will depend on the exact track of the low-pressure center and may switch quickly from southerly to westerly in the afternoon.  Smoke dispersal conditions should remain fair to good.



2.  DISPERSION



SATURDAY

Mixing height below 1500 ft early rising to 3000 - 4000 ft by late morning.  Afternoon mixing height rises to 4000 - 5000 ft then lowers to 2000 - 3000 ft during the evening.



Transport wind S to SW at 15 - 25 mph during the morning.  Transport wind increases to SSW to SW at 18 - 32 mph during the afternoon then decreases to SSW to SW at 15 - 25 mph during the evening.



Surface wind SSE to SSW at 8 - 12 mph during the morning.  Surface wind increases to SSW to WSW at 10 - 20 mph during the afternoon then decreases to SSW to SW at 8 - 12 mph during the evening.



OUTLOOK:



SUNDAY

Mixing height 3000 - 4000 ft during the morning rising to 4000 - 5000 ft during the afternoon.  Transport wind SSW to SW at 19 - 33 mph during the morning becoming W to NW at 18 - 30 mph during the afternoon.  Surface wind S to SW at 10 - 20 mph during the morning becoming W to NW at 9 - 15 mph during the afternoon.



MONDAY

Mixing height 1800 - 2800 ft during the morning rising to 3500 - 4500 ft during the afternoon.  Transport wind WSW to WNW at 8 - 12 mph.  Surface wind WSW to WNW at 4 - 8 mph.



TUESDAY

Mixing height below 1000 ft early rising to 1500 - 2500 ft by late morning rising to 3000 - 4000 ft during the afternoon.  Transport wind SSE to SSW at 9 - 15 mph during the morning becoming WSW to WNW at 8 - 12 mph during the afternoon.  Surface wind SSE to SSW at 5 - 9 mph during the morning becoming light and variable 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 Saturday, November 6, 2010.

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Avoid ignitions within 12 miles to the S through SW of SSRAs.  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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