FPCN39 CWLW 181421
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 PST THURSDAY 18 FEBRUARY 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      18    1     500   3     20    4     550   3
KAMLOOPS     KEL      13    0     500   3     26    4     700   5
OKANAGAN     KEL      13    0     500   3     26    4     700   5
CASTLEGAR    SPOK      9    1     500   6     33    3     900   7
CRANBROOK    SPOK      9   -1     950  11     40    4    1100  11
REVELSTOKE   KEL      14    2     600   3     21    3     700   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    SE   9   S   19   SW  48
CRANBROOK             S   11   S   35

TODAY'S VENTING: POOR

VENTING FOR FRIDAY: POOR

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   -2     950   3     20    2    1000   8
PR. GEORGE   P.G.      9   -2     700   5     25    2    1050   9
SMITHERS     P.G.     10   -1     650   5     26    3    1100  10
WELLS GRAY   P.G.     12   -4     700   9     33    2    2000  13
FT NLSN      F.N.     13   -9     900  10     36   -7    2000  10
FT STJOHN    F.N.     25   -6    1000  12     43   -2    1050  14

*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            E   19   SE  20
SMITHERS              E   20   E   20

TODAY'S VENTING: POOR

VENTING FOR FRIDAY: POOR

COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     43    6     350  15     73    8     650  16
FRASER VLY   QUIL     15    4     200   4     37    7     400  10
SRN VRISL    QUIL     32    7     350   7     73    9     850  11
CNTRL VRISL  QUIL     17    5     250   4     40    8     500   7
NRN VRISL    HRDY     23    4     200   9     56    6     550  11
TERRACE      ANT      10    0     250  13     22    2     250  13
STEWART      ANT      12    1     250  12     32    4     400  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    SE  37   S   43   S   41
PORT HARDY   NE  22   NE  22   NE  13
SANDSPIT     N   19   N    9   VR   5

TODAY'S VENTING: FAIR

VENTING FOR FRIDAY: POOR

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

END/MWSO