FPCN39 CWLW 171337
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 THURSDAY 17 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       9   16     200   2     36   25     900   4
KAMLOOPS     KEL       9   15     350   2     36   26    1200   4
OKANAGAN     KEL      12   17     500   2     36   26    1200   4
CASTLEGAR    SPOK     17   19     750   3     26   26     950   4
CRANBROOK    SPOK      9   15     950   7     20   24    1100   7
REVELSTOKE   KEL       9   15     450   2     26   23     950   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 THURSDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    VR   5   VR   5   SW  24
CRANBROOK             S   17   S   43

TODAY'S VENTING: POOR TO FAIR




VENTING FOR FRIDAY: 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.      9   10     950  14    100   21    3950   9
PR. GEORGE   P.G.      9    9     700   1     62   18    1350  11
SMITHERS     P.G.     11   10     750   1     59   17    1200  10
WELLS GRAY   P.G.      9   10    1000  14    100   20    4000   9
FT NLSN      F.N.     34    6     500  22    100   14    2400  19
FT STJOHN    F.N.      9    6     700  16    100   12    2550  19

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

FORECAST UPPER WINDS FOR THURSDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE
SMITHERS              E    9   E

TODAY'S VENTING: FAIR TO GOOD




VENTING FOR FRIDAY: FAIR




COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     34   16     550   6     75   21    1400   8
FRASER VLY   QUIL     25   15     350   6     90   22    1550   9
SRN VRISL    QUIL     13   13     100   4     60   20    1150   6
CNTRL VRISL  QUIL     15   14     150   4     72   21    1300   7
NRN VRISL    HRDY      9   13       0   2     30   16     600   4
TERRACE      ANT      ##   ##     ###  ##     44   19    1150   4
STEWART      ANT      20   14     200   6     44   19     750   6

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

FORECAST UPPER WINDS FOR THURSDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    SW  11   S   19   S   30
PORT HARDY   VR   5   VR   5   E    9
SANDSPIT     N   24   N   19   N   19

TODAY'S VENTING: FAIR TO GOOD EXCEPT POOR NRN VRISL




VENTING FOR FRIDAY: FAIR




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


END/WJW