FPCN39 CWLW 081433
SMOKE CONTROL FORECAST FOR COASTAL BC AND THE INTERIOR INCLUDING THE
NORTHEAST ISSUED BY THE MOUNTAIN WEATHER SERVICE OFFICE OF
ENVIRONMENT CANADA AT 8:00 AM PDT THURSDAY 8 MAY 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      15   12     800   1    100   21    2700  11
KAMLOOPS     KEL      24   13    1000   2    100   22    3350  13
OKANAGAN     KEL      17   11     850   2    100   21    3350  13
CASTLEGAR    SPOK     28   12     900   5    100   22    3500  13
CRANBROOK    SPOK      9    9     950  10    100   18    3950  15
REVELSTOKE   KEL      16   10     850   2    100   19    2750  13

*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   17   SW  28
CRANBROOK             SW   9   SW  20

           INVERSION HT    BREAKTHRU TEMP
KELOWNA         1500 m         16 C
SPOKANE          900 m         15 C

TODAY'S VENTING: BECOMING GOOD BY THE AFTERNOON

VENTING FOR FRIDAY: GOOD

VENTING OUTLOOK SATURDAY THRU MONDAY: NORTHWESTERLY FLOW GIVING
UNSTABLE IN LOW LEVELS IN THE AFTERNOON GIVING GOOD VENTING.



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   10    1350  16    100   17    3950  23
PR. GEORGE   P.G.     21    8     800   9    100   17    3700  20
SMITHERS     P.G.     11    7     750   1     89   16    1600  12
WELLS GRAY   P.G.     26    8    1100  16    100   17    4000  23
FT NLSN      F.N.     36    8     600  13    100   15    3400  16
FT STJOHN    F.N.    100   11    2800  16    100   16    3700  16

*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            S   28   SW  39
SMITHERS              S   30   S   39

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE      2300 m         17 C
FT. NELSON       800 m         11 C

TODAY'S VENTING:BECOMING GOOD BY MID


VENTING FOR FRIDAY: GOOD


VENTING OUTLOOK SATURDAY THRU MONDAY: NORTHWESTERLY FLOW GIVING
UNSTABLE IN LOW LEVELS IN THE AFTERNOON GIVING GOOD VENTING.


COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     14   11     150   6     43   16     350  10
FRASER VLY   QUIL     20   14     250   6     92   21    1500  10
SRN VRISL    QUIL     18   11     150   7     49   17     400   9
CNTRL VRISL  QUIL     18   12     200   7     64   20     950   8
NRN VRISL    HRDY     21    9     200   7     42   15     450   9
TERRACE      ANT       9    8     200  12    100   16    2150  15
STEWART      ANT      11   10      50   4    100   16    1700  16

*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    S   17   S   24   SW  35
PORT HARDY   S   33   S   44   S   52
SANDSPIT     S   52   S   54   S   61

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE       550 m         18 C
PORT HARDY       500 m         17 C
ANNETTE          500 m         13 C

TODAY'S VENTING: FAIR ON THE SOUTH COAST AS THE SEABREEZE MODERATES
TEMPERATURES.  GOOD ELSEWHERE.

VENTING FOR FRIDAY: GOOD

VENTING OUTLOOK SATURDAY THRU MONDAY:A RIDGE OF HIGH PRESSURE
WILL PRODUCE STABLE CONDITIONS GIVING POOR TO FAIR VENTING.


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

END/LM.