FPCN39 CWLW 041431
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 4 FEBRUARY 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      15    3     450   2     35    6     800   5
KAMLOOPS     KEL      12    2     500   2     42    5    1050   6
OKANAGAN     KEL      11    1     450   2     42    5    1050   6
CASTLEGAR    SPOK      9    1     500  18      9    3     500  18
CRANBROOK    SPOK     10    0     950  10     10    1     950  12
REVELSTOKE   KEL      10    1     500   2     11    2     550   2

*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    W   11   W   24   W   50
CRANBROOK             W   22   W   57

TODAY'S VENTING: POOR EXCEPT RISING TO FAIR THIS AFTERNOON OVER THE
OKANAGAN AND THE FRASER CANYON.

VENTING FOR FRIDAY: 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.     20   -1    1700   5     40    2    2350   9
PR. GEORGE   P.G.     10   -2     700  11     10   -2     700  11
SMITHERS     P.G.      9   -7     500   2      9   -3     500   2
WELLS GRAY   P.G.      9   -5    1300   5     50    2    2000  10
FT NLSN      F.N.     19  -18     800   2     19  -18     800   2
FT STJOHN    F.N.     44  -15    1100  10     47  -14    1150  10

*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            W   28   W   41
SMITHERS              SW  22   SW  41

TODAY'S VENTING: POOR EXCEPT RISING TO FAIR THIS AFTERNOON AT
WILLIAMS LAKE WELLS GRAY AND FORT ST JOHN.


VENTING FOR FRIDAY: FAIR

COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     10    5     100  12     70    7     650  15
FRASER VLY   QUIL     10    4      50  10     10    6      50  12
SRN VRISL    QUIL      9    6     250   0     83    8     800  16
CNTRL VRISL  QUIL      9    4      50   0     50    7     500  11
NRN VRISL    HRDY     10    3      50   2     24    5     450   4
TERRACE      ANT      10   -2     200   5     34    0     900   8
STEWART      ANT       9   -5     200   3      9    0       0  10

*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    W   28   W   39   W   44
PORT HARDY   SW  30   SW  37   SW  41
SANDSPIT     S   57   S   57   SW  57

TODAY'S VENTING: POOR EXCEPT RISING TO GOOD THIS AFTERNOON IN THE
VANCOUVER AND SOUTHERN VANCOUVER ISLAND REGIONS. RISING TO FAIR OVER
CENTRAL VANCOUVER ISLAND THIS AFTERNOON.

VENTING FOR FRIDAY: FAIR

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


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