FPCN39 CWLW 281423
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 PST MONDAY 28 DECEMBER 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       9    0     200   3      9    2     200   3
KAMLOOPS     KEL       9   -1     350   3      9    0     350   3
OKANAGAN     KEL      13    2     450   3     13    2     450   3
CASTLEGAR    SPOK      9    2     500  22      9    2     500  22
CRANBROOK    SPOK      9    0     950  57      9    1     950  57
REVELSTOKE   KEL       9   -1     450   3      9    0     450   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 MONDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    W   17   W   37   W   74
CRANBROOK             W   30   W   78

TODAY'S VENTING: POOR.

VENTING FOR TUESDAY: POOR.

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.     80   -9    1500  20     87   -7    1600  20
PR. GEORGE   P.G.     45  -12     950  15     45  -12     950  15
SMITHERS     P.G.     71   -8    1350  11     71   -8    1350  11
WELLS GRAY   P.G.     60  -10    1150  13     81   -8    1600  20
FT NLSN      F.N.      9  -24     400   0      9  -22     550   0
FT STJOHN    F.N.     50  -21    1250   9     53  -20    1300   9

*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            VR   5   W   31
SMITHERS              SE  19   W   31

TODAY'S VENTING: GOOD.

VENTING FOR TUESDAY: GOOD.


COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     10    9     100  23     10   10     100  23
FRASER VLY   QUIL     10   10      50  11     10   10      50  11
SRN VRISL    QUIL     66   10     550  15     93   11     800  19
CNTRL VRISL  QUIL      9    7      50  11     67   10     550  15
NRN VRISL    HRDY     11    6      50   4     11    6      50   4
TERRACE      ANT       9   -6     200   3      9   -5     200   3
STEWART      ANT       9   -8     150   4     10   -5      50   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 MONDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    SW  41   W   57   W   69
PORT HARDY   SW  35   SW  48   SW  59
SANDSPIT     S   39   SW  41   SW  37

TODAY'S VENTING: GOOD OVER VRISL POOR ELSEWHERE.

VENTING FOR TUESDAY: POOR

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


END/LEC