FPCN39 CWLW 161400
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 16 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      28   20     600   5     60   25    1150   9
KAMLOOPS     KEL      14   18     600   2     60   26    1600   5
OKANAGAN     KEL      13   16     550   2     56   25    1450   5
CASTLEGAR    SPOK     25   16     750   6     42   24     900   6
CRANBROOK    SPOK     20   11    1200   2     50   23    1500   7
REVELSTOKE   KEL      11   14     500   2     41   19    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 THURSDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    VR   5   NW  11   W   13
CRANBROOK             W    9   W   17

TODAY'S VENTING: GOOD.

VENTING FOR FRIDAY: 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.     36   13    1550   5     78   19    3950  10
PR. GEORGE   P.G.      9   12     700   6     76   17    2250   8
SMITHERS     P.G.     10   11     650   1     47   16    1300   4
WELLS GRAY   P.G.     33    9    1000   6     72   17    4000  10
FT NLSN      F.N.     10   10     500   1     47   15     750  12
FT STJOHN    F.N.     78   13    1150  24    100   17    2400  20

*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            W   24   W   43
SMITHERS              W   19   W   43

TODAY'S VENTING: GOOD.

VENTING FOR FRIDAY: GOOD.




COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     32   15     700   7     72   18    1200  10
FRASER VLY   QUIL     21   16     800   5     68   21    1250  10
SRN VRISL    QUIL     20   15     550   2     68   19    1250   8
CNTRL VRISL  QUIL     23   16     800   2     56   21    1200   7
NRN VRISL    HRDY     27   14     300   7     71   16    1200  12
TERRACE      ANT      80   13    1550   8     85   17    2400  10
STEWART      ANT      44   13     650   7     86   17    2050   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 THURSDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    W   11   NW  15   NW  15
PORT HARDY   NW  24   N   20   NW  20
SANDSPIT     W   13   W   19   W   28

TODAY'S VENTING: GOOD.

VENTING FOR FRIDAY: GOOD




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


END/MWSO
$$$$^^