FPCN39 CWLW 241339
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 24 JULY 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      30   25     600  10    100   36    2750  15
KAMLOOPS     KEL      12   25     650   1     65   38    3350   3
OKANAGAN     KEL      11   23     550   1     65   38    3350   3
CASTLEGAR    SPOK     15   24     750   2     99   35    3500   6
CRANBROOK    SPOK      9   19     950   7    100   30    3950   6
REVELSTOKE   KEL      10   22     550   1     55   31    2150   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   VR   5   VR   5
CRANBROOK             VR   5   VR   5

TODAY'S VENTING: GOOD THIS AFTERNOON.

VENTING FOR SATURDAY: FAIR




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   20    2300  13    100   31    3950  16
PR. GEORGE   P.G.      9   18     700   5    100   29    3700  15
SMITHERS     P.G.      9   17     500   5    100   26    2650  14
WELLS GRAY   P.G.    100   20    2400  13    100   31    4000  16
FT NLSN      F.N.     31   18     500  23    100   24    1850  21
FT STJOHN    F.N.      9   17     700  20    100   24    3700  21

*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              W   17   W

TODAY'S VENTING: GOOD.

VENTING FOR SATURDAY: FAIR TO GOOD.




COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     74   17     850  13     90   23    1150  13
FRASER VLY   QUIL     77   18     850  13     96   25    1250  13
SRN VRISL    QUIL     63   16     750  10     83   22    1000  12
CNTRL VRISL  QUIL     80   20     950  12    100   28    1650  12
NRN VRISL    HRDY     30   15     550   5     40   19     700   5
TERRACE      ANT      96   16    1000  20    100   23    1950  18
STEWART      ANT      87   17     800  16    100   23    1850  16

*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    W   13   NW  13   NW   9
PORT HARDY   NW   9   NW  11   NW  19
SANDSPIT     SW  17   W   22   W   30

TODAY'S VENTING: FAIR TO GOOD.

VENTING FOR SATURDAY: FAIR TO GOOD.




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


END/MWSO