FPCN39 CWLW 031318
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 3 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      16   22     500   2    100   33    2500  10
KAMLOOPS     KEL      12   21     500   2    100   33    3350  11
OKANAGAN     KEL      12   21     500   2    100   33    3350  11
CASTLEGAR    SPOK     36   22     750  11    100   34    2150  12
CRANBROOK    SPOK      9   18     950  10    100   32    2550  13
REVELSTOKE   KEL      10   20     500   2    100   30    2450  10

*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   SW  19   SW  30
CRANBROOK             SW   9   SW  24

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.     77   13    1900  11    100   25    3950  18
PR. GEORGE   P.G.     13   11     800   5    100   22    3700  14
SMITHERS     P.G.     11    9     700   1     82   17    1900   9
WELLS GRAY   P.G.     76   13    1950  11    100   24    4000  18
FT NLSN      F.N.     27   11     500  18    100   20    3400  27
FT STJOHN    F.N.      9   11     700  18    100   23    3700  28

*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              W   13   W

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     24   19     350   6     54   24     800   9
FRASER VLY   QUIL     25   19     350   6     78   28    1400   8
SRN VRISL    QUIL     12   18     250   1     43   24     700   6
CNTRL VRISL  QUIL     12   18     300   1     62   26    1050   7
NRN VRISL    HRDY      9   13       0   7     60   19    1050   6
TERRACE      ANT       9   11     400   7    100   18    2800  14
STEWART      ANT      41   13     400   9    100   18    2450  13

*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   15   SW  26   SW  43
PORT HARDY   NW  22   W   30   W   54
SANDSPIT     W   26   W   28   SW  31

TODAY'S VENTING: GOOD EXCEPT ONLY FAIR IN THE SOUTH

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