FPCN39 CWLW 101436
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 THURSDAY 10 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      79    7    1650  18     91    8    1750  25
KAMLOOPS     KEL      76    6    1750  10     88    8    1850  15
OKANAGAN     KEL      35    2     850  10     88    8    1850  15
CASTLEGAR    SPOK     42    3     900   9     81    7    1300  14
CRANBROOK    SPOK     30    0    1250  10     86    6    1700  16
REVELSTOKE   KEL      68    4    1600  25     88    5    1750  30

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

FORECAST UPPER WINDS FOR THURSDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    SW  11   SW  33   W   67
CRANBROOK             W   20   W   70

TODAY'S VENTING: FAIR TO GOOD EXCEPT POOR IN THE SOUTHEAST THIS
MORNING.
VENTING FOR FRIDAY: 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.     41    4     950  15    100    6    1400  22
PR. GEORGE   P.G.     35    5     700  15     71    5    1000  20
SMITHERS     P.G.      9    4     500  18     40    6     500  18
WELLS GRAY   P.G.      9    2     800  12     52    5    1400  20
FT NLSN      F.N.      9    0     400   8      9    0     400  15
FT STJOHN    F.N.     10    4     700  15     34    6    1100  20

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

FORECAST UPPER WINDS FOR THURSDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            SW  67   W   76
SMITHERS              SW  61   SW  76

TODAY'S VENTING: FAIR RISING TO GOOD THIS AFTERNOON OVER THE CENTRAL
INTERIOR. ELSEWHERE POOR RISING TO FAIR EXCEPT REMAINING POOR AT FORT
NELSON.

VENTING FOR FRIDAY: GOOD

COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     89    8     450  18    100    9     550  22
FRASER VLY   QUIL     47    7     200  19    100    9     550  20
SRN VRISL    QUIL     92    9     500  21    100   11     650  25
CNTRL VRISL  QUIL     52    9     500  18    100   10     600  21
NRN VRISL    HRDY     10    8     100   2     45   10     650   7
TERRACE      ANT      11    4     200  15     40    6     200  20
STEWART      ANT      20    1     200  10     36    6     200  21

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

FORECAST UPPER WINDS FOR THURSDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    SW  44   W   63   W   67
PORT HARDY   SW  46   SW  57   SW  59
SANDSPIT     SW  57   SW  67   SW  67

TODAY'S VENTING: FAIR TO GOOD. EXCEPT POOR THIS MORNING RISING TO
FAIR THIS AFTERNOON OVER NRN VRISL AND NEAR TERRACE AND STEWART.

VENTING FOR FRIDAY: GOOD

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


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