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: Thursday, February 10, 2011       2:40 PM      Pete Parsons



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


FRIDAY

The axis of a broad upper-level ridge is forecast to shift east of the Cascades with the flow aloft becoming more westerly.  Skies should remain mostly sunny with some increase in high clouds possible by late in the day.  Transport winds are forecast to increase and turn south-southwesterly during the afternoon.  Maximum mixing heights will rise slightly, compared to Thursday, with smoke dispersal conditions improving to marginal.

OUTLOOK (SATURDAY-MONDAY)
The upper-level ridge will flatten on Saturday, as a Pacific cold front spreads rain and mountain snow across western Washington, with increasing clouds across south-central Oregon.  A chance of light rain will spread into the region Saturday night.  Smoke dispersal conditions will become fair to good, with increasing southwesterly transport winds.

By Sunday, the flattened upper-level ridge axis is forecast to be near the Oregon/Idaho border with westerly flow aloft over Oregon.  A Pacific frontal system will likely stall over northern Oregon, with only a chance of rain across south-central zones.  The flow aloft is forecast to turn southwesterly Sunday afternoon, forcing the Pacific frontal system back to the north.  The snow level should remain above 6000 feet. Expect marginal to fair smoke dispersal conditions with southwesterly transport winds weakening and becoming more southerly in the afternoon.

A strong upper-level trough will approach the coastline Monday with increasing southwesterly flow aloft.  Computer models are showing a fairly impressive surface low-pressure system moving into Vancouver Island, British Columbia late in the day.  The associated cold front should bring increasing southerly surface winds to the region with a chance of rain, spreading from west to east, in the afternoon.  Smoke dispersal conditions should be good, with brisk south to southwesterly transport winds.  The snow level will remain above 5000 feet.  In the wake of the strong cold front, snow levels are expected to drop to the basin floors, on Wednesday, with sticking snow likely.


2.  DISPERSION



FRIDAY

Mixing height below 500 ft early rising to 1000 - 1900 ft by late morning.  Afternoon mixing height rises to 1900 - 2900 ft then lowers below 1000 ft during the evening.



Transport wind SSE to SW at 6 - 10 mph during the morning.  Transport wind increases to S to SW at 10 - 18 mph during the afternoon and evening.



Surface wind light and variable and controlled by local terrain during the morning.  Surface wind increases to SSE to SW at 5 - 9 mph during the afternoon and evening.



OUTLOOK:



SATURDAY

Mixing height below 1000 ft early rising to 1500 - 2500 ft by late morning rising to 3500 - 4500 ft during the afternoon.  Transport wind SSW to SW at 14 - 24 mph during the morning becoming SSW to SW at 20 - 36 mph during the afternoon.  Surface wind SSE to SW at 6 - 12 mph.



SUNDAY

Mixing height below 1000 ft early rising to 2000 - 3000 ft by late morning and through the afternoon.  Transport wind SSW to WSW at 15 - 25 mph.  Surface wind SSE to SW at 6 - 10 mph.



MONDAY

Mixing height below 1000 ft early rising to 2000 - 3000 ft by late morning rising to 4000 - 5000 ft during the afternoon.  Transport wind S to SSW at 22 - 38 mph during the morning becoming S to SSW at 30 - 50 mph during the afternoon.  Surface wind SSE to SSW at 9 - 15 mph during the morning becoming S to SSW at 15 - 25 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 Friday, February 11, 2011.

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



Unfavorable burning situation due to very poor smoke dispersion.  Delay ignitions until 11 a.m.  Avoid ignitions within 20 miles to the SSE through SW of SSRAs.  For units that will smolder significantly through the night avoid burning within at least 35 miles to the SSE through SW in or near drainages leading to SSRAs.  Recommend against burning units that will smolder significantly overnight.  Complete ignitions by 3 p.m.



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

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
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://omls.oregon.gov/pipermail/smi_south_central/attachments/20110210/b911e75d/attachment.html>