FPCN39 CWLW 191341
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 SUNDAY 19 APRIL 1998 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   11     600   4    100   15    2700  10

KAMLOOPS     KEL      14    8     450   4    100   16    2950  10

OKANAGAN     KEL      16    9     500   4    100   15    2900  10

CASTLEGAR    SPOK     24   10     850   4     75   15    2100   6

CRANBROOK    SPOK      9    8     950   6    100   13    3950  11

REVELSTOKE   KEL      77   10    1600   9    100   14    2900  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 SUNDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    VR   5   NW  11   NW  13
CRANBROOK             VR   5   NW  20

           INVERSION HT    BREAKTHRU TEMP
KELOWNA          525 m          8 C
SPOKANE         1080 m         11 C

TODAY'S VENTING: GOOD

VENTING FOR MONDAY: GOOD

VENTING OUTLOOK TUESDAY THRU THURSDAY: GOOD

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    4    2250  31    100   12    3950  29

PR. GEORGE   P.G.    100    6    1950  24    100   12    3700  26

SMITHERS     P.G.    100    7    1600  19    100   13    3500  23

WELLS GRAY   P.G.    100    6    4000  29    100   13    4000  29

FT NLSN      F.N.     37    9     650  11     70   13    1300   9

FT STJOHN    F.N.     48    9    1150  10    100   15    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 SUNDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            W   24   W   30
SMITHERS              SW  26   SW  30

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE      NONE
FT. NELSON       910 m         10 C

TODAY'S VENTING: GOOD

VENTING FOR MONDAY: GOOD

VENTING OUTLOOK TUESDAY THRU THURSDAY: GOOD

COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    HRDY    100    9    1400  14    100   14    3100  15

FRASER VLY   HRDY     99    9    1300  14    100   15    3050  15

SRN VRISL    HRDY     90    9    1100  13    100   14    3000  15

CNTRL VRISL  HRDY     58    8     600  11    100   13    2650  15

NRN VRISL    HRDY     20    7     150   8    100   11    1950  14

TERRACE      ANT      77    6     900  15    100   10    2150  17

STEWART      ANT       9    6       0   7    100   10    1500  14


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

FORECAST UPPER WINDS FOR SUNDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    VR   5   VR   5   VR   5
PORT HARDY   S   13   S   17   S   20
SANDSPIT     S   39   S   37   S   30

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE      MISSING
PORT HARDY        90 m          7 C
ANNETTE         NONE

TODAY'S VENTING: GOOD

VENTING FOR MONDAY: GOOD

VENTING OUTLOOK TUESDAY THRU THURSDAY: GOOD

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


END/PJS