FPCN39 CWLW 181400
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 18 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   15     600   0     56   19    2750  12
KAMLOOPS     KEL       9   16     650   0     56   18    2850   8
OKANAGAN     KEL       9   13     550   0     56   18    2850   8
CASTLEGAR    SPOK     22   12     750   5     56   19    2950   8
CRANBROOK    SPOK      9   10     950  12     40   18    1600   6
REVELSTOKE   KEL       9   10     500   0     56   16    2750   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 SUNDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    W    9   W   20   W   26
CRANBROOK             S   19   S   46

TODAY'S VENTING: FAIR TO GOOD.

VENTING FOR MONDAY:  FAIR TO 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.     66   12    1450  15    100   15    3950  12
PR. GEORGE   P.G.     52   12    1150  12    100   15    3700  12
SMITHERS     P.G.      9    8     500   1     93   13    1100   7
WELLS GRAY   P.G.     66   12    1450  15    100   15    4000  12
FT NLSN      F.N.      9    6     400   0     49   14     750   5
FT STJOHN    F.N.      9   10     700   5     67   16    1850   7

*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            W   17   W   19
SMITHERS              S   13   S   19

TODAY'S VENTING: FAIR TO GOOD.

VENTING FOR MONDAY:  FAIR TO GOOD.




COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     57   12    1150   6     68   15    1250   7
FRASER VLY   QUIL     58   13    1200   6     75   17    1450   7
SRN VRISL    QUIL     52   12    1150   5     63   15    1250   6
CNTRL VRISL  QUIL     48   11    1050   5     69   17    1400   6
NRN VRISL    HRDY     13    8     150   3     75   13    1000  10
TERRACE      ANT      70    9     750  12    100   14    2150  12
STEWART      ANT      70    9     750  12    100   14    1900  12

*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    SW  19   SW  22   SW  31
PORT HARDY   S   39   S   52   SW  48
SANDSPIT     S   70   S   57   S   57

TODAY'S VENTING: GOOD.

VENTING FOR MONDAY: GOOD.




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


END/
$$$$^^