FPCN39 CWLW 281323
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 FRIDAY 28 AUGUST 1998 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   21     550   0     95   33    2650   6
KAMLOOPS     KEL       9   20     600   0     93   32    2750   6
OKANAGAN     KEL       9   18     500   0     90   31    2600   6
CASTLEGAR    SPOK     21   19     800   4    100   31    3500   8
CRANBROOK    SPOK      9   16     950   5    100   27    3950   9
REVELSTOKE   KEL       9   16     500   0     35   26    1300   3

*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   S    9   SW  22
CRANBROOK             VR   5   W   24

TODAY'S VENTING: GOOD BY THE AFTERNOON.

VENTING FOR SATURDAY: 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.      9   13     950  15    100   24    3950  21
PR. GEORGE   P.G.     16   15     850   4    100   22    3700  16
SMITHERS     P.G.      9   13     550   0     44   19    1200   6
WELLS GRAY   P.G.     73   15    1600  16    100   24    4000  21
FT NLSN      F.N.      9   10     400  27    100   19    2650  27
FT STJOHN    F.N.      9   11     700  28    100   21    3700  25

*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
SMITHERS              SW  41   SW

TODAY'S VENTING: GOOD.

VENTING FOR SATURDAY: GOOD

COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     30   18     300  10     55   25     700   9
FRASER VLY   QUIL     32   19     350  10     77   30    1400   8
SRN VRISL    QUIL     22   17     300   5     51   25     650   8
CNTRL VRISL  QUIL     29   19     300   7     73   30    1350   7
NRN VRISL    HRDY      9   15       0   6     37   20     650   5
TERRACE      ANT       9   11     200  35    100   16     750  36
STEWART      ANT      28   13     100  19     84   16     500  24

*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    VR   5   VR   5   S   20
PORT HARDY   S    9   SW  20   SW  31
SANDSPIT     S   76   SW  80   SW  94

TODAY'S VENTING: FAIR TO GOOD.

VENTING FOR SATURDAY: GOOD

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


END/MWSO