FPCN39 CWLW 181342
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 18 MARCH 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   SPOK      9    5     200   3     40   10     950   5
KAMLOOPS     SPOK      9    4     350   3     37   10    1000   5
OKANAGAN     SPOK      9    2     350   3     35    9     950   5
CASTLEGAR    SPOK     18    4     800   3     32    9    1050   5
CRANBROOK    SPOK      9    2     950   5     29    8    1550   4
REVELSTOKE   SPOK      9    0     450   3     19    4     750   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 THURSDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    VR   5   S   11   SW  33
CRANBROOK             SW  19   SW  61

TODAY'S VENTING: FAIR WEST TO POOR EAST.

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.    100    2    1400  20    100    7    3950  36
PR. GEORGE   P.G.     58    3    1000  20    100    7    2350  31
SMITHERS     P.G.      9    1     500   6    100    6    1400  20
WELLS GRAY   P.G.     36    1    1150  20    100    7    4000  36
FT NLSN      F.N.      9   -4     400   0     37    3     800   8
FT STJOHN    F.N.      9   -1     700  12    100    3    2250  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  24   W   30
SMITHERS              SW  28   W   30

TODAY'S VENTING: GOOD LOCALLY FAIR IN THE NORTHEAST.

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     47    7     400  15     78   10     950  12
FRASER VLY   QUIL     47    7     350  15     88   11    1250  11
SRN VRISL    QUIL     39    7     350  11     83   11    1100  11
CNTRL VRISL  QUIL     18    5     150   7     54    9     550  11
NRN VRISL    HRDY     10    5     100   1     73    8    1350   7
TERRACE      ANT       9    2     200   9     83    5    1400  10
STEWART      ANT      10    2      20   5     48    5     650   7

*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    VR   5   VR   5   S   20
PORT HARDY   VR   5   VR   5   SW  26
SANDSPIT     SW  20   SW  28   SW  37

TODAY'S VENTING: GOOD LOCALLY FAIR.

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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