FPCN39 CWLW 211344 AAA
SMOKE CONTROL FORECAST FOR COASTAL BC AND THE INTERIOR INCLUDING THE
NORTHEAST ISSUED BY THE MOUNTAIN WEATHER SERVICE OFFICE OF
ENVIRONMENT CANADA AT 7:00 AM PDT SATURDAY 21 AUGUST 1999 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      15   21     500   2    100   28    2150  15
KAMLOOPS     KEL      12   21     500   2    100   29    2500  10
OKANAGAN     KEL      19   23     700   3    100   32    3350  10
CASTLEGAR    SPOK      9   19     500   5     86   25    3000   8
CRANBROOK    SPOK      9   19     950   5     86   24    3000  10
REVELSTOKE   KEL      10   19     500   2     79   24    3000   7

*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   W   24
CRANBROOK             W   13   W   28

TODAY'S VENTING:BECOMING GOOD BY EARLY MORNING.

VENTING FOR SUNDAY: 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.    100   18    3950  15    100   22    3950  15
PR. GEORGE   P.G.    100   17    3700  16    100   19    3700  16
SMITHERS     P.G.     86   15    1250   8    100   17    3500  12
WELLS GRAY   P.G.     80   10    1500  15    100   22    4000  17
FT NLSN      F.N.      9   15     400   1    100   23    3000   7
FT STJOHN    F.N.      9   14     700  10    100   22    3000  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
PR. GEORGE            W   30   SW  39
SMITHERS              SW  31   SW  39

TODAY'S VENTING:GOOD.


VENTING FOR SUNDAY: GOOD


COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL    100   21    1350  10    100   22    1550  14
FRASER VLY   QUIL    100   23    3050   5    100   24    3050  10
SRN VRISL    QUIL     92   21    1250   7    100   23    2500  10
CNTRL VRISL  QUIL     92   21    1250   2    100   23    3050   5
NRN VRISL    HRDY    100   19    1850  11     97   18    1500  11
TERRACE      ANT     100   16    1450  17    100   18    1750  18
STEWART      ANT      83   15     850  14    100   18    1450  15

*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   11   W   17   W   28
PORT HARDY   SW  13   S   20   SW  33
SANDSPIT     S   57   S   54   SW  56

TODAY'S VENTING:GOOD.


VENTING FOR SUNDAY: GOOD




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



END/lm