FPCN39 CWLW 181348
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 THURSDAY 18 JUNE 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       9   13     200   1     42   18    1350   3
KAMLOOPS     KEL      11   13     550   1     69   19    2250   4
OKANAGAN     KEL      11   13     550   1     49   17    1650   4
CASTLEGAR    SPOK     19   14     750   4     29   17    1050   4
CRANBROOK    SPOK     10   12     950  16     10   16     950  16
REVELSTOKE   KEL      10   12     500   1     27   15    1200   3

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

FORECAST UPPER WINDS FOR THURSDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    VR   5   NW  11   NW  15
CRANBROOK             VR   5   SW  11

           INVERSION HT    BREAKTHRU TEMP
KELOWNA          580 m         14 C
SPOKANE         1460 m         20 C

TODAY'S VENTING: FAIR

VENTING FOR FRIDAY: FAIR


VENTING OUTLOOK SATURDAY THRU MONDAY: FAIR TO GOOD AS THE AIRMASS
REMAINS UNSTABLE IN THE NORTHERLY FLOW.


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.     36   12    1900   3     74   16    3950   3
PR. GEORGE   P.G.     22   12    1100   4     47   15    2100   3
SMITHERS     P.G.     17   13     850   3     57   18    2550   3
WELLS GRAY   P.G.     46   13    2450   3     74   16    4000   3
FT NLSN      F.N.     44   16     950   8    100   22    3400   8
FT STJOHN    F.N.     27   13     950   8    100   19    3700   8

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

FORECAST UPPER WINDS FOR THURSDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            NE  39   E   52
SMITHERS              NE  17   NE  52

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE       700 m         13 C
FT. NELSON       500 m         16 C

TODAY'S VENTING: GOOD

VENTING FOR FRIDAY: FAIR

VENTING OUTLOOK SATURDAY THRU MONDAY:FAIR TO GOOD AS THE AIRMASS
REMAINS UNSTABLE IN THE NORTHERLY FLOW.

COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     76   13    1000  11    100   17    1650  11
FRASER VLY   QUIL     76   13     950  11     99   17    1600  11
SRN VRISL    QUIL     66   13     900   9     99   18    1750  10
CNTRL VRISL  QUIL     75   14    1050  10     92   17    1550  10
NRN VRISL    HRDY     11   11     150   1     55   14    1250   5
TERRACE      ANT      69   16    1300   8    100   24    3200  11
STEWART      ANT      50   16     800   7    100   24    2450   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 THURSDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    W   15   NW  17   N   19
PORT HARDY   NW  35   N   35   N   33
SANDSPIT     NW  54   N   41   N   33

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE       100 m         11 C
PORT HARDY       280 m         12 C
ANNETTE          970 m         15 C

TODAY'S VENTING: GOOD

VENTING FOR FRIDAY: FAIR

VENTING OUTLOOK SATURDAY THRU MONDAY: FAIR TO GOOD
AS A RIDGE BUILDS OF THE COAST.

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


END/LM