FPCN39 CWLW 081321
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 FRIDAY 8 MAY 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      35   18     890   5     57   23    1500   5
KAMLOOPS     KEL      28   18     890   5     56   22    1650   5
OKANAGAN     KEL      28   18     890   5     65   23    2000   5
CASTLEGAR    SPOK     43   17     890   5     84   23    1750  10
CRANBROOK    SPOK     18   17    1000   3    100   23    3950   7
REVELSTOKE   KEL      21   16     690   5     78   23    2600   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 FRIDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    VR   5   W    9   S   13
CRANBROOK             VR   5   S   15

           INVERSION HT    BREAKTHRU TEMP
KELOWNA          700 m         16 C
SPOKANE         1200 m         19 C

TODAY'S VENTING: GOOD

VENTING FOR SATURDAY: GOOD

VENTING OUTLOOK SUNDAY THRU TUESDAY:




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.     90   12    3620   7    100   16    3950   8
PR. GEORGE   P.G.     90   11    1800   6    100   16    3700   8
SMITHERS     P.G.     29   11     700   7     40   14    1100   6
WELLS GRAY   P.G.     80   13    2600   7    100   17    4000   8
FT NLSN      F.N.     75   12    1500   8    100   13    3400   9
FT STJOHN    F.N.     75   12    3700   7    100   14    3700   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 FRIDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            VR   5   S   15
SMITHERS              NW  17   NW  15

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE      1220 m         15 C
FT. NELSON       600 m         10 C

TODAY'S VENTING: GOOD.

VENTING FOR SATURDAY: GOOD

VENTING OUTLOOK SUNDAY THRU TUESDAY: GOOD.


COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     45   13     960  12     58   15    1050   6
FRASER VLY   QUIL     45   12    1010  11     64   16    1250   6
SRN VRISL    QUIL     41   12    1000  12     57   16    1200   5
CNTRL VRISL  QUIL     41   12    1000  12     62   17    1300   5
NRN VRISL    HRDY     29   10     400   9    73   12     900  10
TERRACE      ANT      90    9     100   9    100   15    3000   8
STEWART      ANT      85    8     100  10    100   15    2550   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 FRIDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    W   11   W   11   W   13
PORT HARDY   NW  43   NW  39   NW  33
SANDSPIT     NW  31   NW  35   NW  43

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE      1100 m         14 C
PORT HARDY      1200 m         15 C
ANNETTE         NONE

TODAY'S VENTING: GOOD.

VENTING FOR SATURDAY: GOOD

VENTING OUTLOOK SUNDAY THRU TUESDAY: GOOD.

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


END/MWSO