FPCN39 CWLW 311510
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 FRIDAY 31 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      35   11     200   25    66   13     450  25
KAMLOOPS     KEL       9    8     350    3    77   14    1600  11
OKANAGAN     KEL       9   10     350    3    50   13     700  10
CASTLEGAR    SPOK     25    8     900   10    59   10    1050  12
CRANBROOK    SPOK     19    7    1250   10    50    9    1600  10
REVELSTOKE   KEL       9    6     450    3    21    7     450   5

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

FORECAST UPPER WINDS FOR FRIDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    W    9   W   26   W   50
CRANBROOK             W   15   W   44

           INVERSION HT    BREAKTHRU TEMP
KELOWNA          550 m         12 C
SPOKANE          900 m          9 C

TODAY'S VENTING: FAIR TO GOOD

VENTING FOR SATURDAY: FAIR

VENTING OUTLOOK SUNDAY THRU TUESDAY: FAIR


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.     10    6     950   5     55    9    1450   8
PR. GEORGE   P.G.     10    7     700   6     55    9     700   8
SMITHERS     P.G.      9    7     500   7     45    8     500   7
WELLS GRAY   P.G.     17    8    1400   7     58    9    1900  12
FT NLSN      F.N.      9   -2     900   4     32    0     950   8
FT STJOHN    P.G.     28    5    1100  12     50    7    1100  15

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

FORECAST UPPER WINDS FOR FRIDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            W   41   W   50
SMITHERS              SW  44   SW  50

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE       600 m          9 C
FT. NELSON      1100 m         13 C

TODAY'S VENTING: FAIR

VENTING FOR SATURDAY: FAIR

VENTING OUTLOOK SUNDAY THRU TUESDAY: FAIR


COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     25   12     300   9     60   14    1100  12
FRASER VLY   QUIL     21   12     200   8     60   14    1050  12
SRN VRISL    QUIL     47   13     450  10     65   15    1300  11
CNTRL VRISL  QUIL      9    9     200  10     58   13     100  10
NRN VRISL    HRDY     16   10      50   6     50   11     250  10
TERRACE      ANT      10    7     200   8     35    8     300  10
STEWART      ANT       9    7      50   2     21    8     150   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 FRIDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    SW  26   SW  35   W   44
PORT HARDY   SW  43   SW  48   SW  50
SANDSPIT     SW  44   SW  48   SW  52

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE       150 m         12 C
PORT HARDY       150 m         11 C
ANNETTE          100 m         12 C

TODAY'S VENTING: GOOD SOUTH FAIR NORTH

VENTING FOR SATURDAY: FAIR

VENTING OUTLOOK SUNDAY THRU TUESDAY: FAIR

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


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