FPCN39 CWLW 251419
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 25 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      18    6     450   3     67   10    1700   5
KAMLOOPS     KEL      15    7     550   3     67   11    1700   5
OKANAGAN     KEL      15    7     550   3     67   10    1700   5
CASTLEGAR    SPOK      9    4     500   7      9    6     500   7
CRANBROOK    SPOK     10    4     950  28     90    6    1800   8
REVELSTOKE   KEL       9    2     450   3     10    4     500   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   SW  20   SW  50
CRANBROOK             SW  17   SW  43

TODAY'S VENTING: GOOD 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.     60    2    1200  26    100    6    2050  12
PR. GEORGE   P.G.     16    0     750  11     52    4    1150  10
SMITHERS     P.G.      9    0     700   0     55    3     900   0
FT NLSN      F.N.      9   -8     400   2      9   -7     400   2
FT STJOHN    F.N.     26   -6     950   7     37   -2     900   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 THURSDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            SW  30   SW  41
SMITHERS              W   33   W   41

TODAY'S VENTING: FAIR EXCEPT POOR IN SOME VALLEYS.

VENTING FOR FRIDAY: POOR

COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL    100    9    1100  37    100   10    1550  10
FRASER VLY   QUIL    100    9     950  37    100   10    1450  10
SRN VRISL    QUIL     20    8     150   8    100   11    1650   8
CNTRL VRISL  QUIL     20    8     150   8    100   10    1350  10
NRN VRISL    HRDY     12    5     300   1     35   47     400  12
TERRACE      ANT      10    1     200  25     45    3     400  12
STEWART      ANT      ##   ##     ###  ##     35    3     500   8

*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   39   W   48   W   46
PORT HARDY   W   39   NW  48   W   43
SANDSPIT     W   39   W   44   W   41

TODAY'S VENTING: GOOD SOUTH AND FAIR NORTH.

VENTING FOR FRIDAY: POOR

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

END/KJ