FPCN39 CWLW 151444
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 15 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      25   22     650   4    100   29    3200  10
KAMLOOPS     KEL      28   21     950   4     89   28    3350   5
OKANAGAN     KEL      28   21     950   4     89   30    3350   5
CASTLEGAR    SPOK     21   19     800   4     86   28    2150   8
CRANBROOK    SPOK      9   19     950  11    100   27    3950   9
REVELSTOKE   KEL      12   17     550   3     55   23    1450   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 TUESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    VR   5   W   15   W   20
CRANBROOK             W   11   W   30

           INVERSION HT    BREAKTHRU TEMP
KELOWNA         640 m         19 C
SPOKANE        1200 m         26 C

TODAY'S VENTING: Fair to poor this morning becoming good by mid
morning.

VENTING FOR WEDNESDAY: GOOD

VENTING OUTLOOK THURSDAY THRU SATURDAY: Good as a trough of low
pressure swings through on Thursday. A ridge builds onto the
coast on Saturday with only fair to good venting expected.

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   16    1550   5    100   22    3050   7
PR. GEORGE   P.G.     74   15    1350   5    100   20    2850   7
SMITHERS     P.G.     29   15     900   6    100   21    2650  10
WELLS GRAY   P.G.    100   17    2850  19    100   20    3000  10
FT NLSN      F.N.     59   20     650  23    100   25    3400  15
FT STJOHN    F.N.     70   18    1100  23    100   24    3700  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   20   W   24
SMITHERS              W   17   W   24

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE      1700 m         19 C
FT. NELSON       760 m         21 C

TODAY'S VENTING: Fair to good in the Central Interior this morning
becoming good by this afternoon. Poor to fair this morning in the
Peace district becoming good by the afternoon.

VENTING FOR WEDNESDAY: GOOD


VENTING OUTLOOK THURSDAY THRU SATURDAY: Good as a trough of low
pressure swings through on Thursday. A ridge builds onto the coast
by Saturday with only fair to good venting expected.

COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     37   18    1000   4     58   22    1500   4
FRASER VLY   QUIL     40   19    1100   4     78   25    2150   8
SRN VRISL    QUIL     31   19    1050   2     58   21    1500   3
CNTRL VRISL  QUIL     33   20    1150   2     94   25    2150   7
NRN VRISL    HRDY     25   16     500   4     55   18    1500   5
TERRACE      ANT      84   17    1450  10    100   22    2100   9
STEWART      ANT      80   18    1250   9    100   22    2250   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
VANCOUVER    W   13   W   17   W   24
PORT HARDY   NW  17   W   11   W   17
SANDSPIT     W   20   W   15   W   17

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE      none m         none
PORT HARDY      none m         none
ANNETTE         none m         none

TODAY'S VENTING: poor this morning becoming fair this afternoon in
the south. Fair this morning becoming good this afternoon in the
north.

VENTING FOR WEDNESDAY: GOOD

VENTING OUTLOOK THURSDAY THRU SATURDAY: Good as a trough of low
pressure swings through on Thursday. A ridge builds onto the coast
by Saturday with only fair venting expected.

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

END/lm