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: Saturday, May 14, 2011       2:40 PM      Pete Parsons



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


SUNDAY

An upper-level low-pressure system is forecast to finally come onshore just south of the Oregon/California border.  Southeasterly flow aloft will continue, with a substantial increase in the amount of moisture circulating into Oregon.  Look for widespread showers and/or areas of steady rain and snow, along with a chance of afternoon thunderstorms.

Significant precipitation is forecast, with more than .25" locally possible.  The snow level will lower to near the basin floor, with local minor snow accumulations.  Maximum temperatures could be as much as 20 degrees below normal.  Cooling aloft will make for fair to good smoke dispersal conditions with brisk southwesterly transport winds.

OUTLOOK (MONDAY-WEDNESDAY)

On Monday, the upper-level low-pressure system is forecast to open into a general trough, with its axis along the coast.  The flow aloft will veer from southeasterly to southwesterly, which is a more stable and drier weather pattern.  Expect showers to decrease with partial clearing allowing for a chance of afternoon thunderstorms.  The snow level will remain near the basin floor with surface temperatures still 10-15 degrees below normal. Maximum mixing heights should climb above 5000 feet with light south to southwesterly transport winds.

Another weather system is forecast to feed into the general trough over the Pacific Northwest, on Tuesday, with the main energy directed into Northern California and southern Oregon.  Clouds will increase with showers likely, and a chance of thunderstorms, by late-afternoon.  The snow level will only rise to 5500 feet, with surface temperatures about 10 degrees below normal.  Cool air aloft will maintain good mixing with transport winds veering to more onshore in the afternoon.

The upper-level trough appears as if it will finally weaken and shift eastward on Wednesday.  A drier northwesterly flow aloft will taper off the shower activity with afternoon clearing.  The snow level will be 5500-6000 feet with surface temperatures recovering to within 5 degrees of normal.  Afternoon mixing heights should rise above 5000 feet with light north-northwesterly transport winds.


2.  DISPERSION



SUNDAY

Mixing height below 2000 ft early rising to 3000 - 4000 ft by late morning.  Afternoon mixing height rises to 4000 - 5000 ft then lowers to 2500 - 3500 ft during the evening.



Transport wind SSW to SW at 10 - 18 mph during the morning.  Transport wind increases to SW to WSW at 15 - 25 mph during the afternoon then decreases to WSW to WNW at 10 - 20 mph during the evening.



Surface wind S to SW at 9 - 15 mph during the morning and afternoon.  Surface wind decreases to SW to W at 6 - 10 mph during the evening.



OUTLOOK:



MONDAY

Mixing height 3000 - 4000 ft during the morning rising above 5000 ft during the afternoon.  Transport wind SSE to SW at 6 - 10 mph.  Surface wind SSE to SSW at 4 - 8 mph.



TUESDAY

Mixing height below 1000 ft early rising to 3500 - 4500 ft by late morning rising above 5000 ft during the afternoon.  Transport wind S to SW at 6 - 10 mph during the morning becoming SW to WNW at 6 - 10 mph during the afternoon.  Surface wind S to SW at 4 - 8 mph during the morning becoming SW to WNW at 4 - 8 mph during the afternoon.



WEDNESDAY

Mixing height below 1000 ft early rising to 3500 - 4500 ft by late morning rising above 5000 ft during the afternoon.  Transport wind NNW to NNE at 6 - 10 mph.  Surface wind NW to NNE at 4 - 8 mph.



3.  BURNING INSTRUCTIONS FOR ZONES 624 AND 625 INCLUDING THE WALKER

    RANGE PORTION OF ZONE 624

This instruction is valid for burning conducted on Sunday, May 15, 2011.

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Avoid ignitions within 12 miles to the SSW through WNW of SSRAs.  No additional restrictions necessary.



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

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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