FPCN39 CWLW 111400
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 SUNDAY 11 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      28    8     850   3     91   16    2550   6

KAMLOOPS     KEL      28    8    1000   3     89   15    2600   6

OKANAGAN     KEL      11    5     550   1     87   14    2500   6

CASTLEGAR    SPOK     25    6     900   4     90   15    3500   5

CRANBROOK    SPOK      9    4     950   9     89   11    3950   5

REVELSTOKE   KEL      10    4     550   1     75   11    2150   6


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

FORECAST UPPER WINDS FOR SUNDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    S    9   S   22   SW  39
CRANBROOK             SW   9   SW  26

TODAY'S VENTING: POOR BECOMING GOOD THIS AFTERNOON.




VENTING FOR MONDAY: 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.      9    4     950  24    100   10    3950  25

PR. GEORGE   P.G.     57    5     950  24    100    9    1850  23

SMITHERS     P.G.     15    5     650   6     66    8    1050  15

WELLS GRAY   P.G.     ##   ##     ###  ##    100   10    4000  25

FT NLSN      F.N.      9    1     400   0      9    6     400   0

FT STJOHN    F.N.      9    3     700  19    100    8    1800  16


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

FORECAST UPPER WINDS FOR SUNDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            SW  54   SW  76
SMITHERS              SW  67   SW  76

TODAY'S VENTING: GENERALLY POOR THIS MORNING BECOMING GOOD THIS
EXCEPT THIS AFTERNOON EXCEPT FORT NELSON




VENTING FOR MONDAY: GOOD




COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     17    8     300   4     88   14    1650   8

FRASER VLY   QUIL     20   10     300   5    100   17    2250   9

SRN VRISL    QUIL     18    8     250   4     82   14    1500   8

CNTRL VRISL  QUIL     18    8     250   4     83   14    1500   8

NRN VRISL    HRDY     13    7     150   4     65   11    1100   7

TERRACE      ANT     100    5     900  38    100    6    1150  39

STEWART      ANT       9    4       0  21     83    6     450  26


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

FORECAST UPPER WINDS FOR SUNDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    S   19   S   33   SW  46
PORT HARDY   S   48   S   70   SW  80
SANDSPIT     SW  67   SW  67   SW  69

TODAY'S VENTING: GENERALLY POOR BECOMING GOOD BY AFTERNOON.




VENTING FOR MONDAY: GOOD




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


END/
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