FPCN39 CWLW 151331
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 WEDNESDAY 15 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      12    8     700   1    100   17    3200   6
KAMLOOPS     KEL      11    7     750   1    100   15    3350   6
OKANAGAN     KEL       9    5     600   0    100   14    3350   6
CASTLEGAR    SPOK     30    7     750   9    100   15    3500  13
CRANBROOK    SPOK     73    6    1500  17    100   11    3950  13
REVELSTOKE   KEL      10    5     650   1     94   12    2950   6

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

FORECAST UPPER WINDS FOR WEDNESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    VR   5   NW  13   N   13
CRANBROOK             VR   5   E   15

           INVERSION HT    BREAKTHRU TEMP
KELOWNA          800 m          7 C
SPOKANE          800 m          6 C

TODAY'S VENTING: GOOD.

VENTING FOR THURSDAY: GOOD

VENTING OUTLOOK FRIDAY THRU SUNDAY: GENERALLY 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    3     950  12    100   13    3950  15
PR. GEORGE   P.G.     22    4     900   7    100   12    3700  13
SMITHERS     P.G.     23    4     800   5    100   12    3000  12
WELLS GRAY   P.G.     19    4    1100  12    100   13    4000  15
FT NLSN      F.N.      9    5     400  13    100   12    2100  12
FT STJOHN    F.N.      9    6     700  14    100   11    2750  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 WEDNESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            W   19   W   24
SMITHERS              SW  13   W   24

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE      1000 m         10 C
FT. NELSON       700 m         11 C

TODAY'S VENTING: GOOD.

VENTING FOR THURSDAY: GOOD.

VENTING OUTLOOK FRIDAY THRU SUNDAY: GENERALLY GOOD.


COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     31    9     500   6     72   14    1550   6
FRASER VLY   QUIL     ##   ##     ###  ##     93   17    3050   5
SRN VRISL    QUIL     27    9     400   5     74   15    1600   6
CNTRL VRISL  QUIL     28    9     450   5     91   17    2850   5
NRN VRISL    HRDY     10    7     100   2     68   14    1500   6
TERRACE      ANT      23    6     600   4     74   14    2050   5
STEWART      ANT      12    7     250   1     60   14    1750   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 WEDNESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    NW   9   NW   9   W    9
PORT HARDY   W   11   SW  11   SW  13
SANDSPIT     S   39   S   37   S   37

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE       800 m         13 C
PORT HARDY      1000 m         12 C
ANNETTE          100 m          6 C

TODAY'S VENTING: GOOD.

VENTING FOR THURSDAY: GOOD

VENTING OUTLOOK FRIDAY THRU SUNDAY: GENERALLY GOOD.


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


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