FPCN39 CWLW 121431
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 Saturday 12 July 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      48   20    1000   6    100   26    2500  12
KAMLOOPS     KEL      38   18     950   6    100   25    2600  12
OKANAGAN     KEL      48   19    1200   6    100   25    2600  12
CASTLEGAR    SPOK     57   18    1100  10    100   24    3500  11
CRANBROOK    SPOK     73   16    1550  15    100   21    3950  12
REVELSTOKE   KEL       9   13     450   5    100   17    2600  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 SATURDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    W    9   W   19   NW  26
CRANBROOK             W   13   W   37

           INVERSION HT    BREAKTHRU TEMP
KELOWNA          500 m         17 C
SPOKANE         1200 m         19 C

TODAY'S VENTING: generally good.

VENTING FOR SUNDAY: good.

VENTING OUTLOOK MONDAY THRU WEDNESDAY: generally 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.     78   16    1350  26    100   21    2750  24
PR. GEORGE   P.G.     70   17    1150  19    100   20    1600  23
SMITHERS     P.G.      9   15     500   7     91   20    1350  18
WELLS GRAY   P.G.     94   17    1600  26    100   20    2350  24
FT NLSN      F.N.     28   21     550  11    100   27    3400  19
FT STJOHN    F.N.      9   15     700  11    100   21    1950  11

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

FORECAST UPPER WINDS FOR SATURDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            W   35   W   35
SMITHERS              SW  26   W   35

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE      2100 m         26 C
FT. NELSON      1100 m         26 C

TODAY'S VENTING: good.

VENTING FOR SUNDAY: good.

VENTING OUTLOOK MONDAY THRU WEDNESDAY: good.


COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     75   18    1150   9    100   23    2050  10
FRASER VLY   QUIL     75   18    1150   9    100   23    2050  10
SRN VRISL    QUIL     59   18    1100   6     99   23    2000   9
CNTRL VRISL  QUIL     59   18    1100   6     99   23    2000   9
NRN VRISL    HRDY     81   16     950  12     88   19    1150  12
TERRACE      ANT      74   18    1100  11    100   23    1850  13
STEWART      ANT      68   18     850  10     93   23    1450  10

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

FORECAST UPPER WINDS FOR SATURDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    W   19   NW  24   NW  31
PORT HARDY   SW  11   W   26   W   30
SANDSPIT     SW  37   SW  33   SW  39

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE       200 m         15 C
PORT HARDY       200 m         13 C
ANNETTE          none

TODAY'S VENTING: good.

VENTING FOR SUNDAY: good.

VENTING OUTLOOK MONDAY THRU WEDNESDAY: good.


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

END/dsl