FPCN39 CWLW 301530
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 30 OCTOBER 1997 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      45   10     700   8    100   14    1650  12
KAMLOOPS     KEL      90   12    1600  15    100   15    2100  15
OKANAGAN     KEL      40   10     700   8     90   13    1700  10
CASTLEGAR    SPOK     57    8    1000  12     97   11    1100  20
CRANBROOK    SPOK     31    7    1100  15     88   10    1600  20
REVELSTOKE   KEL       9    7     450  15     27    9     600  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 THURSDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    SW  13   W   35   W   74
CRANBROOK             W   26   W   67

           INVERSION HT    BREAKTHRU TEMP
KELOWNA         1700 m         13 C
SPOKANE         1400 m         12 C

TODAY'S VENTING: GOOD

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.    100    7    1450  25    100    9    1900  25
PR. GEORGE   P.G.    100    7    1350  25    100    9    1750  25
SMITHERS     P.G.     22    6     600  18    100    9    1500  20
WELLS GRAY   P.G.    100    8    1450  25    100    9    1900  25
FT NLSN      F.N.     39   -3     800   8     59   -1    1000  10
FT STJOHN    F.N.     49    0    1100  12     66    2    1350  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 THURSDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            SW  52   W   74
SMITHERS              SW  52   SW  74

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE      NONE
FT. NELSON      1400 m          7 C

TODAY'S VENTING: GOOD

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     61   14     350  25     99   15     750  25
FRASER VLY   QUIL     57   13     300  25    100   14     750  25
SRN VRISL    QUIL     62   14     300  25    100   16     850  25
CNTRL VRISL  QUIL     14   10      50  25     91   13     600  25
NRN VRISL    HRDY     16   10      50  25     62   12     200  25
TERRACE      ANT      17    7     300  25     29    8     300  25
STEWART      ANT      49    7     200  25     49    8     200  25

*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  43   SW  61   W   74
PORT HARDY   SW  52   SW  63   SW  67
SANDSPIT     SW  63   SW  63   SW  59

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE      1700 m         21 C
PORT HARDY       300 m         13 C
ANNETTE         1700 m         15 C

TODAY'S VENTING: GOOD

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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