FPCN39 CWLW 281400
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 WEDNESDAY 28 APRIL 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      30   10    1350   2     60   16    3200   5
KAMLOOPS     KEL      30    9    1450   2     60   15    3350   5
OKANAGAN     KEL      19    6     850   2     60   16    3350   5
CASTLEGAR    SPOK     25    7     800   6    100   15    3500   8
CRANBROOK    SPOK      9    6     950  11    100   13    3950   9
REVELSTOKE   KEL      28    8    1450   2     60   14    3450   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 WEDNESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    N    9   N   22   NE  37
CRANBROOK             E   15   E   35

TODAY'S VENTING: GOOD




VENTING FOR THURSDAY: 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.    100    4    1900  19    100   11    3950  17
PR. GEORGE   P.G.     75    5    1500  12    100   11    3700  15
SMITHERS     P.G.     30    4    1000   5    100   12    3500  12
WELLS GRAY   P.G.     70    2    2000  10    100   13    4000  17
FT NLSN      F.N.     50    3     850  11    100    7    2650  11
FT STJOHN    F.N.     71    2    1150  19    100    6    3700  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 WEDNESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            NE  17   NE  17
SMITHERS              SE   9   S   17

TODAY'S VENTING: GOOD




VENTING FOR THURSDAY: GOOD




COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     41    9     600   7    100   14    2400  11
FRASER VLY   QUIL     41    9     600   7    100   16    3050  11
SRN VRISL    QUIL     25    8     300   6    100   15    2450  10
CNTRL VRISL  QUIL     45   10     650   7    100   14    2300  10
NRN VRISL    HRDY     75    9     750  14    100   12    1150  15
TERRACE      ANT      15    7     500   2     78   14    3200   3
STEWART      ANT      11    6     150   1     75   14    3000   3

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

FORECAST UPPER WINDS FOR WEDNESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    N   17   N   20   NE  26
PORT HARDY   N   15   NE  11   NE  11
SANDSPIT     S   20   S   28   S   24

TODAY'S VENTING: GOOD




VENTING FOR THURSDAY: GOOD




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


END/KAW
$$$$^^