FPCN39 CWLW 191400
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 MONDAY 19 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       9   12     600   0     19   16    1450   1
KAMLOOPS     KEL       9   11     650   0     48   18    2300   2
OKANAGAN     KEL       9    8     500   0     39   16    2000   2
CASTLEGAR    SPOK     40   12     900   9    100   16    2000  16
CRANBROOK    SPOK    100   11    1850  23    100   17    3950  18
REVELSTOKE   KEL       9   10     650   0     37   15    2000   2


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

FORECAST UPPER WINDS FOR MONDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    VR   5   SW  19   S   33
CRANBROOK             SW  11   W   28

TODAY'S VENTING: FAIR TO GOOD EAST. POOR TO FAIR WEST.

VENTING FOR TUESDAY: 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    7     950   7    100   15    3950  11
PR. GEORGE   P.G.      9    7     700   6    100   15    2750  10
SMITHERS     P.G.     13    7     700   2     47   14    1450   5
WELLS GRAY   P.G.      9    7     950   7    100   15    4000  11
FT NLSN      F.N.      9    8     400   2     35   15     850   6
FT STJOHN    F.N.      9    7     700   4    100   16    3700   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 MONDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            SE  13   S   17
SMITHERS              SE  24   SE  17

TODAY'S VENTING: POOR THIS MORNING. FAIR TO GOOD THIS AFTERNOON
EXCEPT REMAINING POOR FORT NELSON.

VENTING FOR TUESDAY: FAIR

COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     67   11     900  10    100   14    1900  10
FRASER VLY   QUIL     66   11     850  10    100   14    1800  10
SRN VRISL    QUIL     41   10     600   6     89   14    1600   9
CNTRL VRISL  QUIL     54   11     800   7    100   15    2050   9
NRN VRISL    HRDY     11    9     100   3     61   11     750  10
TERRACE      ANT       9    6     200   5    100   12    1550  31
STEWART      ANT       9    7       0   8    100   12    1200  23


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

FORECAST UPPER WINDS FOR MONDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    S   26   SW  37   SW  46
PORT HARDY   S   30   SW  37   SW  30
SANDSPIT     W   15   SW   9   S   22

TODAY'S VENTING: GOOD.

VENTING FOR TUESDAY: FAIR

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


END/TCS/RET
$$$$^^