FPCN39 CWLW 281430
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 Monday 28 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       9   24     200   0    100   33    3600  10
KAMLOOPS     KEL       9   23     350   0    100   32    3350   8
OKANAGAN     KEL       9   21     350   0    100   31     350   5
CASTLEGAR    SPOK     22   21     900   4     89   31    3500   5
CRANBROOK    SPOK      9   21     950   5     92   29    3950   5
REVELSTOKE   KEL       9   19     450   0     49   28    1550   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 MONDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    VR   5   S    9   S   15
CRANBROOK             VR   5   S   17

           INVERSION HT    BREAKTHRU TEMP
KELOWNA         1680 m         27 C
SPOKANE         1040 m         26 C

TODAY'S VENTING: BECOMING GOOD IN THE MID AFTERNOON. FAIR IN
THE COLUMBIAS THIS AFTERNOON.

VENTING FOR TUESDAY: FAIR

VENTING OUTLOOK WEDNESDAY THRU 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.     40   19    1300  10    100   26    2550   8
PR. GEORGE   P.G.     23   17     850  10    100   24    2000  10
SMITHERS     P.G.     10   16     650   1     55   22    1250   8
WELLS GRAY   P.G.     30   17    1200  10    100   26    4000  10
FT NLSN      F.N.     56   18     650  23    100   24    1850  10
FT STJOHN    F.N.      9   16     700  18    100   22    3700  10

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

FORECAST UPPER WINDS FOR MONDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            S   19   S   31
SMITHERS              S    9   S   31

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE      1300 m         24 C
FT. NELSON       730 m         19 C

TODAY'S VENTING: BECOMING GOOD BY THE LATE AFTERNOON.

VENTING FOR TUESDAY: FAIR

VENTING OUTLOOK WEDNESDAY THRU FRIDAY: FAIR BECOMING GOOD AS
A COLD FRONT DESTABILIZES THE AIRMASS ON THURSDAY.

COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     59   20     800   9     65   24    1150   7
FRASER VLY   QUIL     60   20     800   9     92   28    1900   8
SRN VRISL    QUIL     49   17     700   7     59   24    1100   6
CNTRL VRISL  QUIL     55   22     900   7     93   29    2050   7
NRN VRISL    HRDY     26   16     400   5     59   19    1000   7
TERRACE      ANT      77   17    1250  10    100   22    2700  13
STEWART      ANT      36   17     650   5    100   22    2150  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 MONDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    VR   5   S   15   S   30
PORT HARDY   VR   5   S   24   S   31
SANDSPIT     S   20   S   20   S   28

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE      1200 m         25 C
PORT HARDY      1340 m         21 C
ANNETTE          200 m         15 C

TODAY'S VENTING: BECOMING GOOD IN THE EARLY AFTERNOON.

VENTING FOR TUESDAY: POOR

VENTING OUTLOOK WEDNESDAY THRU FRIDAY: FAIR BECOMING GOOD AS
A COLD FRONT DESTABILIZES THE AIRMASS ON THURSDAY.

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

END/LM