FPCN39 CWLW 181400
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 18 SEPTEMBER 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      30   18     650   5     88   28    2450   6
KAMLOOPS     KEL      29   18     750   5     82   26    2300   6
OKANAGAN     KEL      21   16     600   5     80   26    2250   6
CASTLEGAR    SPOK     20   15     700   3     79   25    2200   6
CRANBROOK    SPOK     23   15    1200   4     80   23    2300   6
REVELSTOKE   KEL      16   15     600   5     45   23    1400   4

*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    VR   5   N   19   N   30
CRANBROOK             VR   5   NE  13

TODAY'S VENTING: GOOD.

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.     23   13    1400   3     92   21    2650   8
PR. GEORGE   P.G.     18   13     900   4     69   19    1950   7
SMITHERS     P.G.     17   12     850   3     35   16    1200   3
WELLS GRAY   P.G.     24   12    1100   4     84   20    4000   8
FT NLSN      F.N.     32   11     650   9     50   17    1100   9
FT STJOHN    F.N.      9   10     700   8     71   17    1200   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 SATURDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            SW  13   W   22
SMITHERS              SW  26   SW  22

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     13   16     300   2     34   20     600   7
FRASER VLY   QUIL     19   17     350   4     31   25     600   4
SRN VRISL    QUIL     12   16     250   2     34   22     600   5
CNTRL VRISL  QUIL     17   17     350   3     34   24     550   5
NRN VRISL    HRDY     29   13     500   4     41   17     650   6
TERRACE      ANT      10   13     250  10     77   16     850  10
STEWART      ANT      16   13      50   8     69   16     600   8

*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    N    9   NE  19   N   17
PORT HARDY   VR   5   SW  13   SW  15
SANDSPIT     SW  50   SW  52   SW  63

TODAY'S VENTING: FAIR SOUTH TO GOOD NORTH


VENTING FOR SUNDAY: GOOD




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


END/MWSO
$$$$^^