FPCN39 CWLW 121325
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 12 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      47    7     850   7    100   11    2550  12
KAMLOOPS     KEL      26    5     650   6    100   12    3350  12
OKANAGAN     KEL      14    4     600   2    100   12    3350  12
CASTLEGAR    SPOK    100    6    1350  20    100   10    3500  19
CRANBROOK    SPOK    100    5    2650  21    100    9    3950  20
REVELSTOKE   KEL      50    5    1250   6    100    8    2450  12

*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   W   17   W   24
CRANBROOK             W    9   W   24

           INVERSION HT    BREAKTHRU TEMP
KELOWNA          640 m          6 C
SPOKANE          880 m          3 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.      9    1     950  10     95    7    2950   9
PR. GEORGE   P.G.     28    2     900  10     99    7    2400  10
SMITHERS     P.G.     14    1     650   5     88    9    2600   6
WELLS GRAY   P.G.      9    4    1000  10     90    7    2900   9
FT NLSN      F.N.     27    4     850   4    100    8    2100  12
FT STJOHN    F.N.      9    1     700   6     68    5    1700  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 SUNDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            NW  15   N   13
SMITHERS              W   19   W   13

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE      1010 m          8 C
FT. NELSON       950 m          6 C

TODAY'S VENTING: GOOD.

VENTING FOR MONDAY: FAIR TO GOOD.

VENTING OUTLOOK TUESDAY THRU THURSDAY: FAIR BECOMING POOR THURSDAY.




COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     94    8    1400  11    100   10    2000  12
FRASER VLY   QUIL     63    7     800  10    100   11    2200  11
SRN VRISL    QUIL     73    8    1000   9    100   11    2100  11
CNTRL VRISL  QUIL     36    5     400   8     95    9    1550  10
NRN VRISL    HRDY      9    5     200   0     73   10    2250   4
TERRACE      ANT       9    4     200   3     52   10    1700   4
STEWART      ANT      12    5     100   3     58   10    1700   4

*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    SE  11   S   11   SW  15
PORT HARDY   VR   5   VR   5   VR   5
SANDSPIT     NW  17   NW  17   NW  13

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE       900 m          8 C
PORT HARDY       360 m          5 C
ANNETTE          550 m          5 C

TODAY'S VENTING: GOOD LOCALLY FAIR NORTH.

VENTING FOR MONDAY: GOOD SOUTH. FAIR NORTH.

VENTING OUTLOOK TUESDAY THRU THURSDAY: GOOD BECOMING FAIR THURSDAY.




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


END/MWSO