FPCN39 CWLW 141331
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 TUESDAY 14 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      57    8     950   8    100   15    3200   7

KAMLOOPS     KEL      53    7    1000   8    100   14    3350   7

OKANAGAN     KEL      37    5     800   7    100   14    3350   7

CASTLEGAR    SPOK     18    5     800   3    100   13    3500  11

CRANBROOK    SPOK     10    4     950  14    100   11    3950  12

REVELSTOKE   KEL      38    5     900   7    100   12    3450   7


*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   N   11   NE  11
CRANBROOK             VR   5   E   17

           INVERSION HT    BREAKTHRU TEMP
KELOWNA         1700 m         11 C
SPOKANE         1400 m          9 C

TODAY'S VENTING: BECOMING GOOD THIS AFTERNOON.

VENTING FOR WEDNESDAY: GOOD

VENTING OUTLOOK THURSDAY THRU SATURDAY: GOOD DURING THE AFTERNOONS.




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.     59    3    2150   5     93   10    3950   5

PR. GEORGE   P.G.     32    2    1100   6     95   10    3700   5

SMITHERS     P.G.     31    3    1000   5     93   11    3500   5

WELLS GRAY   P.G.     68    4    2700   5     93   11    4000   5

FT NLSN      F.N.      9    3     400  15    100   10    2800  18

FT STJOHN    F.N.      9    2     700  17    100    8    2850  19


*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            VR   5   VR   5
SMITHERS              VR   5   VR   5

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE      1400 m          7 C
FT. NELSON       850 m          8 C

TODAY'S VENTING: BECOMING GOOD THIS AFTERNOON.

VENTING FOR WEDNESDAY: GOOD

VENTING OUTLOOK THURSDAY THRU SATURDAY: GOOD DURING THE AFTERNOONS.




COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     26    9     650   3     88   13    1950   7

FRASER VLY   QUIL     11    8     250   1     96   14    2400   7

SRN VRISL    QUIL     14    9     450   1     88   14    2200   6

CNTRL VRISL  QUIL     35   10     800   4     95   15    2600   6

NRN VRISL    HRDY     69    8     800  11    100   12    1750  13

TERRACE      ANT       9    5     200   4     38   12    2250   2

STEWART      ANT      23    8     350   4     49   12    2050   2


*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    NE  11   E   11   SE  11
PORT HARDY   NE  11   E   19   E   24
SANDSPIT     VR   5   S    9   SE   9

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE       950 m         12 C
PORT HARDY       100 m          7 C
ANNETTE          450 m          8 C

TODAY'S VENTING: BECOMING GOOD THIS AFTENOON EXCEPT REMAINING
FAIR ON THE NORTH COAST DUE TO LIGHT WINDS.

VENTING FOR WEDNESDAY: FAIR TO GOOD

VENTING OUTLOOK THURSDAY THRU SATURDAY: FAIR.




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


END/JDG