FPCN39 CWLW 191414
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 PDT FRIDAY 19 SEPTEMBER 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      21   12     650   3     49   20    2300   5
KAMLOOPS     KEL      36   12    1050   4     48   21    2450   5
OKANAGAN     KEL      19   11     750   3     47   20    2350   5
CASTLEGAR    SPOK     33   11    1200   8     48   20    2600   5
CRANBROOK    SPOK     50   12    1850   6     54   17    3950   6
REVELSTOKE   KEL      32   11    1050   4     53   17    2300   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    VR   5   N    9   NE  17
CRANBROOK             VR   5   N   13

           INVERSION HT    BREAKTHRU TEMP
KELOWNA          900 m         11 C
SPOKANE         2200 m         18 C

TODAY'S VENTING: FAIR.

VENTING FOR SATURDAY: POOR.

VENTING OUTLOOK SUNDAY THRU TUESDAY: POOR.




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.     31    8    1150  13     44   17    2250   5
PR. GEORGE   P.G.     43    9    1050  11     50   16    1950   6
SMITHERS     P.G.     44   11    1050   8     54   16    1800   9
WELLS GRAY   P.G.     38    9    1250  13     55   17    2300   9
FT NLSN      P.G.     37   10     900   6     61   18    1850  10
FT STJOHN    P.G.     68   13    1400  12     69   16    1950  11

*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            SW  26   W   48
SMITHERS              SW  46   SW  48

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE      1300 m         13 C
FT. NELSON       800 m         18 C

TODAY'S VENTING: FAIR TO GOOD.

VENTING FOR SATURDAY: FAIR TO POOR.

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     18   15     250   5     31   21    1350   4
FRASER VLY   QUIL     18   15     250   5     31   23    1650   4
SRN VRISL    QUIL      9   15     250   0     35   22    1450   3
CNTRL VRISL  QUIL      9   14     200   0     35   22    1450   3
NRN VRISL    HRDY     18   10     100   9     35   16    1400   5
TERRACE      ANT      11   13     250  28     45   16    2200  15
STEWART      ANT       9   10       0  12     45   16    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 FRIDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    VR   5   NE  11   NE  13
PORT HARDY   S   19   S   22   SW  24
SANDSPIT     S   57   SW  59   SW  69

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE       100 m         14 C
PORT HARDY      3300 m         37 C
ANNETTE         3300 m         34 C

TODAY'S VENTING: POOR TO FAIR.

VENTING FOR SATURDAY:

VENTING OUTLOOK SUNDAY THRU TUESDAY: POOR TO GOOD.


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


END/JMS