FPCN39 CWLW 221430
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 Tuesday 22 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      88   21    1600   9    100   25    2700   9
KAMLOOPS     KEL      95   20    2050   9    100   25    2900   9
OKANAGAN     KEL      54   18     850   8    100   25    2900   9
CASTLEGAR    SPOK     54   21    1050  10    100   27    2450  10
CRANBROOK    SPOK     86   20    1550  20    100   25    2650  15
REVELSTOKE   KEL      49   17     650   5     91   19    2000   9

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

FORECAST UPPER WINDS FOR TUESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    W    9   W   19   W   24
CRANBROOK             SW  11   W   28

           INVERSION HT    BREAKTHRU TEMP
KELOWNA          700 m         17 C
SPOKANE         1130 m         22 C

TODAY'S VENTING: GOOD THIS MORNING EXCEPT ONLY FAIR IN SOME VALLEYS
IN THE COLUMBIAS UNTIL MID MORNING.

VENTING FOR WEDNESDAY: GOOD

VENTING OUTLOOK THURSDAY THRU SATURDAY: GOOD TIL FRIDAY AS
THE AIRMASS REMAINS UNSETTLED. FAIR ON SATURDAY AS A RIDGE
BUILDS INTO THE REGION.

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   15    3950  22    100   20    3950  22
PR. GEORGE   P.G.    100   15    1750  21    100   19    3700  21
SMITHERS     P.G.      9   13     500   1    100   17    3500  10
WELLS GRAY   P.G.    100   16    4000  22    100   20    4000  22
FT NLSN      F.N.      9   16     400   3     21   18     800   5
FT STJOHN    F.N.      9   16     700  10     50   21    1750  15

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

FORECAST UPPER WINDS FOR TUESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            W   37   W   50
SMITHERS              W   35   W   50

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE       700 m         16 C
FT. NELSON      2100 m         27 C

TODAY'S VENTING: GOOD EXCEPT POOR IN THE PEACE THIS MORNING BECOMING
FAIR IN THE AFTERNOON.

VENTING FOR WEDNESDAY: GOOD

VENTING OUTLOOK THURSDAY THRU SATURDAY: GOOD TIL FRIDAY AS
THE AIRMASS REMAINS UNSETTLED. FAIR ON SATURDAY AS A RIDGE
BUILDS INTO THE REGION.

COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     34   17     850   4     71   21    1800   5
FRASER VLY   QUIL     29   17     800   3     70   21    1750   5
SRN VRISL    QUIL     23   17     700   2     64   21    1650   5
CNTRL VRISL  QUIL     24   17     700   2     64   21    1650   5
NRN VRISL    HRDY     34   14     350   9     83   17    1000  12
TERRACE      ANT      76   14     850  16    100   16    1400  16
STEWART      ANT      40   14     300  11     80   16     850  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 TUESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    W   19   W   22   W   30
PORT HARDY   W   17   W   20   W   31
SANDSPIT     W   33   W   31   W   35

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE       180 m         10 C
PORT HARDY       340 m         14 C
ANNETTE          120 m         13 C

TODAY'S VENTING: POOR THIS MORNING BECOMING GOOD BY THE AFTERNOON.

VENTING FOR WEDNESDAY: GOOD

VENTING OUTLOOK THURSDAY THRU SATURDAY: GOOD TIL FRIDAY AS
THE AIRMASS REMAINS UNSETTLED. FAIR ON SATURDAY AS A RIDGE
BUILDS INTO THE REGION.

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

END/LM