FPCN39 CWLW 101325
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 FRIDAY 10 APRIL 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      12    8     500   1     32   12    1100   3
KAMLOOPS     KEL      12    7     600   1     84   12    1850   8
OKANAGAN     KEL      15    8     750   2     83   12    1850   8
CASTLEGAR    SPOK      9    5     500   4     50   10    1500   5
CRANBROOK    SPOK      9    3     950   9     48    8    2050   8
REVELSTOKE   KEL       9    5     450   1     24    9    1050   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 FRIDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    VR   5   SW  19   SW  30
CRANBROOK             SW  19   SW  50

           INVERSION HT    BREAKTHRU TEMP
KELOWNA         1250 m         11 C
SPOKANE         1100 m         10 C

TODAY'S VENTING: FAIR TO GOOD.

VENTING FOR SATURDAY: GOOD.

VENTING OUTLOOK SUNDAY THRU 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    2     940   7     92    7    2470   5
PR. GEORGE   P.G.      9    0     700   6     93    7    2470   5
SMITHERS     P.G.     14    0     700   3     76    7    2650   5
WELLS GRAY   P.G.      9    3    1000   5     92    7    3000   5
FT NLSN      F.N.     84    3    1550  10    100    8    2700  10
FT STJOHN    F.N.     81    2    1800  10    100    8    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 FRIDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            N   11   VR   5
SMITHERS              VR   5   VR   5

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE       850 m          4 C
FT. NELSON       400 m          1 C

TODAY'S VENTING: GOOD.

VENTING FOR SATURDAY: POOR NORTHEAST OTHERWISE FAIR.

VENTING OUTLOOK SUNDAY THRU TUESDAY: FAIR.




COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     19    8     400   3     39   10     900   4
FRASER VLY   QUIL     19    8     400   3     37   10     850   4
SRN VRISL    QUIL     37    9     450   7     55   11    1050   6
CNTRL VRISL  QUIL     29    8     350   7     56   11    1100   6
NRN VRISL    HRDY     26    7     200  10    100   10    1650  13
TERRACE      ANT      97    4    1650  11    100    9    2650  11
STEWART      ANT     100    7    1800  10    100    9    2000  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 FRIDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    VR   5   S   13   SW  19
PORT HARDY   NW  28   N   17   N    9
SANDSPIT     N   30   N   35   N   35

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE       480 m          8 C
PORT HARDY       140 m          7 C
ANNETTE          100 m          5 C

TODAY'S VENTING: FAIR SOUTH. GOOD NORTH.

VENTING FOR SATURDAY: GOOD.

VENTING OUTLOOK SUNDAY THRU TUESDAY: FAIR TO GOOD.




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


END/MWSO