FPCN39 CWLW 191431
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 Saturday 19 July 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      24   23     850   2    100   31    3200   6
KAMLOOPS     KEL      26   23    1000   3    100   32    3350   6
OKANAGAN     KEL      20   21     850   2    100   31    3350   6
CASTLEGAR    SPOK     27   21     850   6    100   31    3500   7
CRANBROOK    SPOK      9   20     950   9    100   28    3950   8
REVELSTOKE   KEL      13   19     700   2    100   28    3450   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 SATURDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    VR   5   VR   5   N   15
CRANBROOK             VR   5   NE  10

           INVERSION HT    BREAKTHRU TEMP
KELOWNA         1530 m         26 C
SPOKANE         1070 m         26 C

TODAY'S VENTING: BECOMING GOOD BY AFTERNOON.

VENTING FOR SUNDAY: FAIR TO GOOD.

VENTING OUTLOOK MONDAY THRU WEDNESDAY: FAIR MONDAY. GOOD
 TUESDAY AND WEDNESDAY.


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.     23   17    1300   4    100   26    3950  11
PR. GEORGE   P.G.     13   17     900   2    100   24    3700   9
SMITHERS     ANT.     11   15     750   1     60   20    1580   8
WELLS GRAY   P.G.      9   17    1000   4    100   27    4000  11
FT NLSN      F.N.      9   19     400  15    100   24    3400  11
FT STJOHN    F.N.     61   18    1150  15    100   23    3700  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 SATURDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            SW  13   SW  20
SMITHERS              S   20   SW  30

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE       920 m         21 C
FT. NELSON       580 m         21 C

TODAY'S VENTING: BECOMING GOOD BY AFTERNOON.


VENTING FOR SUNDAY: FAIR.


VENTING OUTLOOK MONDAY THRU WEDNESDAY: FAIR MONDAY.
 GOOD TUESDAY AND WEDNESDAY.


COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     65   19     700  12     73   23     850  12
FRASER VLY   QUIL     65   18     700  12     90   25    1250  12
SRN VRISL    QUIL      9   18     650   0     37   23     800   5
CNTRL VRISL  QUIL      9   20     700   0     66   26    1300   6
NRN VRISL    HRDY      9   14       0   4     38   20     700   8
TERRACE      ANT     100   15     850  28    100   19    1650  24
STEWART      ANT      23   14     150  10    100   19    1250  22

*SUBTRACT 20 FROM THE VENTILATION INDEX IN VALLEYS IF THE MIXING
HEIGHT IS BELOW THE HEIGHT OF THE LOCAL HILLS.

FORECAST UPPER WINDS FOR SATURDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    VR   5   VR   5   VR   5
PORT HARDY   VR   5   S   17   SW  26
SANDSPIT     S   31   SW  30   SW  35

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE       900 m         25 C
PORT HARDY      1300 m         28 C
ANNETTE          100 m         14 C

TODAY'S VENTING: GOOD EXCEPT FAIR INNER COAST UNTIL LATE AFTERNOON.

VENTING FOR SUNDAY: FAIR SOUTH. GOOD NORTH.

VENTING OUTLOOK MONDAY THRU WEDNESDAY: GOOD.




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

END/KAL