FPCN39 CWLW 201332
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 SUNDAY 20 SEPTEMBER 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      23   16     750   3    100   22    3200   8
KAMLOOPS     KEL      18   14     700   3    100   23    3350   8
OKANAGAN     KEL      18   14     700   3    100   21    3350   8
CASTLEGAR    SPOK     27   15    1450   2    100   22    3500   8
CRANBROOK    SPOK     82   13    2350   8    100   19    3950   9
REVELSTOKE   KEL       9   12     550   0     81   18    2000   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 SUNDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    VR   5   NE   9   NE  13
CRANBROOK             VR   5   NE  11

TODAY'S VENTING: GOOD

VENTING FOR MONDAY: 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    9     950   5     65   19    2300   6
PR. GEORGE   P.G.     11    9     900   1     16   16    1200   1
SMITHERS     P.G.     13   10     900   1     43   20    1750   3
WELLS GRAY   P.G.      9   12    1000   5     65   20    2400   6
FT NLSN      F.N.     21   11     500  10     69   23    1100   7
FT STJOHN    F.N.      9   10     700  12     51   20    1100   5

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

FORECAST UPPER WINDS FOR SUNDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE
SMITHERS              SW  15   SW

TODAY'S VENTING: FAIR

VENTING FOR MONDAY: FAIR


COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     44   15     750   6     58   19    1050   6
FRASER VLY   QUIL     45   15     750   6     85   23    1550   8
SRN VRISL    QUIL     14   13     250   2     52   19    1000   5
CNTRL VRISL  QUIL     14   13     300   2     67   22    1300   6
NRN VRISL    HRDY      9   13     400   0     18   17     900   1
TERRACE      ANT      38   13     650   8     52   20    1200   5
STEWART      ANT      38   14     600   6     50   20    1000   5

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

FORECAST UPPER WINDS FOR SUNDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    VR   5   NE  17   NE  31
PORT HARDY   N    9   N    9   NE  11
SANDSPIT     W   20   W   19   SW  22

TODAY'S VENTING: FAIR

VENTING FOR MONDAY: FAIR

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

END/MWSO