FPCN39 CWLW 041328
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 TUESDAY 4 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      15   23     450   2    100   34    1200  20
KAMLOOPS     KEL      12   22     500   2    100   36    3350  14
OKANAGAN     KEL      12   24     500   2    100   37    3350  14
CASTLEGAR    SPOK     17   24     750   3    100   35    3500   8
CRANBROOK    SPOK      9   22     950  17    100   32    3950  10
REVELSTOKE   KEL      10   23     500   2    100   34    3450  14


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

FORECAST UPPER WINDS FOR TUESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    S    9   S   26   S   41
CRANBROOK             VR   5   SW  19

TODAY'S VENTING: POOR THIS MORNING BECOMINIG GOOD THIS AFTERNOON.



VENTING FOR WEDNESDAY: 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   14     950   7    100   28    3950  15
PR. GEORGE   P.G.       9  16    1100   6     70   26    1650   9
SMITHERS     P.G.      9   14     550   1     44   23     950  10
WELLS GRAY   P.G.      9   17    1000   7    100   27    4000  15
FT NLSN      F.N.     48   19     600  20    100   27    2450  13
FT STJOHN    F.N.     39   19     800   8    100   25    3700  13


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

FORECAST UPPER WINDS FOR TUESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE
SMITHERS              SW  20   SW

TODAY'S VENTING: BECOMING GOOD THIS AFTERNOON.



VENTING FOR WEDNESDAY: GOOD


COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     38   17     450   9     66   25    1050   8
FRASER VLY   QUIL     50   20     600   9    100   30    3050   9
SRN VRISL    QUIL     24   15     300   6     48   23     800   6
CNTRL VRISL  QUIL     30   17     400   6     65   27    1250   6
NRN VRISL    HRDY      9   12       0   6     40   17     500   8
TERRACE      ANT       9   13     200  11     92   22    1850   9
STEWART      ANT      31   15     250  11     91   22    1550   9


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

FORECAST UPPER WINDS FOR TUESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    W   11   SW  24   S   48
PORT HARDY   VR   5   SW  15   SW  31
SANDSPIT     SW  24   SW  28   SW  30

TODAY'S VENTING: GENERALLY GOOD THIS AFTERNOON.


VENTING FOR WEDNESDAY: GOOD


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


END/GF