FPCN39 CWLW 251400
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 25 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       9   12     600   0     79   16    1550   5
KAMLOOPS     KEL       9   10     550   0     84   15    2050   7
OKANAGAN     KEL       9    9     500   0     89   14    1300   2
CASTLEGAR    SPOK      9    9     500  18    100   14    1100  12
CRANBROOK    SPOK     10    9     950  45    100   14    2600  11
REVELSTOKE   KEL       9    7     450   0     54   10    1750   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 SATURDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    W   15   W   31   NW  48
CRANBROOK             W   24   W   57

TODAY'S VENTING: GOOD.


VENTING FOR SUNDAY: 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    9    2750  15    100   11    3950   5
PR. GEORGE   P.G.    100    9    2100  16    100   10    2350   6
SMITHERS     P.G.    100   11    2200  14     80   10    1900   4
WELLS GRAY   P.G.     30    4    1000  15    100   11    4000  15
FT NLSN      F.N.      9    7     400   9    100   13    2050  10
FT STJOHN    F.N.     11    7     700  34    100   12    2900  12

*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            W   39   NW  43
SMITHERS              W   30   NW  43

TODAY'S VENTING:GOOD


VENTING FOR SUNDAY: FAIR




COAST


           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL    100   14    1050  41    100   16    1350  18
FRASER VLY   QUIL    100   14    1000  41    100   16    1300  12
SRN VRISL    QUIL    100   15    1100  37    100   17    1400  19
CNTRL VRISL  QUIL    100   16    1300  39    100   18    1550   8
NRN VRISL    HRDY    100   15    1800  21     98   12     950  10
TERRACE      ANT     100   13    2200  18    100   11    1700  17
STEWART      ANT      93   12    1300  11     17   11     850   1

*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    W   39   NW  44   NW  52
PORT HARDY   NW  31   NW  43   NW  52
SANDSPIT     NW  31   NW  39   NW  44

TODAY'S VENTING:GOOD EXCEPT POOR ON THE NORTH COAST.


VENTING FOR SUNDAY: POOR




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






END/lm
$$$$^^