FPCN39 CWLW 121359
SMOKE CONTROL FORECAST FOR COASTAL BC AND THE INTERIOR INCLUDING THE
NORTHEAST ISSUED BY THE MOUNTAIN WEATHER SERVICE OFFICE OF
ENVIRONMENT CANADA AT 8:00 AM PDT FRIDAY 12 SEPTEMBER 1997 FOR TODAY.

VENTILATION INDICES (TEMPERATURE) AND MIXING HEIGHTS.
MIXING HEIGHTS IN METRES ABOVE SEA LEVEL.
AVERAGE WINDS IN KNOTS.

SPOT INDICES ARE DETERMINED BY THE ASPECT AND ELEVATION OF THE SITES.
COMPARE WINDS, TEMPERATURES AND ELEVATION WITH THE SITES HERE
TO DETERMINE THE INDEX IN ANY OTHER AREA.

SOUTHERN INTERIOR

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
FRSR CANYN   KEL       9   16     450   4     77   19    2200   8
KAMLOOPS     KEL       9   15     550   4     76   19    2200   8
OKANAGAN     KEL       9   15     550   4     76   18    2200   8
CASTLEGAR    SPOK     80   15    1100   7     80   18    2550  10
CRANBROOK    SPOK    100   14    1650  10     80   17    2600  11
REVELSTOKE   KEL       9   14     550   4     79   17    2750   8

*SUBTRACT 20 FROM THE VENTILATION INDEX IN VALLEYS IF THE MIXING
HEIGHT IS BELOW THE HEIGHT OF THE LOCAL HILLS.

FORECAST UPPER WINDS FOR FRIDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    VR   5   SW  15   SW  22
CRANBROOK             SW   9   W   26

           INVERSION HT    BREAKTHRU TEMP
KELOWNA          600 m         15 C
SPOKANE         1400 m         15 C

TODAY'S VENTING: GOOD.

VENTING FOR SATURDAY: GOOD.

VENTING OUTLOOK SUNDAY THRU TUESDAY: GOOD.




CENTRAL INTERIOR/NORTHEAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
WILLIAMS L   P.G.     25    8    1000   6     78   17    2500  10
PR. GEORGE   P.G.     25    7     900   4     78   16    2500  10
SMITHERS     P.G.     12   10     800   1     87   14    2550   8
WELLS GRAY   P.G.     44    7    1400   9     90   12    2800  10
FT NLSN      F.N.     25   10     750   5     70   12    2550   9
FT STJOHN    F.N.     70   10    1750   8     70   12    2550  12

*SUBTRACT 20 FROM THE VENTILATION INDEX IN VALLEYS IF THE MIXING
HEIGHT IS BELOW THE HEIGHT OF THE LOCAL HILLS.

FORECAST UPPER WINDS FOR FRIDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            VR   5   VR   5
SMITHERS              VR   5   VR   5

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE      1400 m         13 C
FT. NELSON       700 m         10 C

TODAY'S VENTING: GOOD.

VENTING FOR SATURDAY: GOOD.

VENTING OUTLOOK SUNDAY THRU TUESDAY: GOOD.




COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     74   16     950  11     90   20    2700  12
FRASER VLY   QUIL     20   13     150  10     90   19    2700  12
SRN VRISL    QUIL      9   14     200   4     90   20    2950  10
CNTRL VRISL  QUIL      9   14     200   4     98   19    2700  10
NRN VRISL    HRDY     12   13     150   2     88   16    2950  11
TERRACE      ANT      15   13     850   4     89   18    2900  12
STEWART      ANT      11   14     550   4     87   18    2900  12

*SUBTRACT 20 FROM THE VENTILATION INDEX IN VALLEYS IF THE MIXING
HEIGHT IS BELOW THE HEIGHT OF THE LOCAL HILLS.

FORECAST UPPER WINDS FOR FRIDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    SW  19   SW  30   SW  35
PORT HARDY   S   17   S   19   SW  19
SANDSPIT     VR   5   VR   5   E    9

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE       300 m         14 C
PORT HARDY       100 m         14 C
ANNETTE         NO INVERSION

TODAY'S VENTING: GOOD.

VENTING FOR SATURDAY: GOOD.

VENTING OUTLOOK SUNDAY THRU TUESDAY: GOOD.




VENTILATION GUIDELINES:
          0-33.....POOR
          34-54.....FAIR
          55-100.....GOOD.
VENTILATION INDICES NORMALLY DROP TO POOR AFTER SUNSET.


END/JMS