FPCN39 CWLW 201338
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 20 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      30   15     800   4    100   24    3200   9
KAMLOOPS     KEL      38   15     950   5    100   24    3350   9
OKANAGAN     KEL       9   12     600   0    100   22    3350   9
CASTLEGAR    SPOK     22   14     850   4    100   24    3500   7
CRANBROOK    SPOK      9   14     950   9    100   22    3950   8
REVELSTOKE   KEL      38   15    1050   5    100   25    3450   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 WEDNESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    VR   5   VR   5   E   19
CRANBROOK             VR   5   E   20

           INVERSION HT    BREAKTHRU TEMP
KELOWNA         1300 m         17 C
SPOKANE         1100 m         17 C

TODAY'S VENTING: GOOD

VENTING FOR THURSDAY: GOOD

VENTING OUTLOOK FRIDAY THRU SUNDAY: 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   11     950  12    100   20    3950   6
PR. GEORGE   P.G.     39   15    1050   9    100   21    3700   7
SMITHERS     P.G.     11   11     700   1     91   21    2700   7
WELLS GRAY   P.G.     10   13    1000  12    100   20    4000   6
FT NLSN      F.N.     18   16     550   6     99   24    3400   6
FT STJOHN    F.N.      9   15     700   6     99   22    3700   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
PR. GEORGE            VR   5   SE   9
SMITHERS              S   11   S    9

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE      950 m         17 C
FT. NELSON      850 m         20 C

TODAY'S VENTING: GOOD

VENTING FOR THURSDAY: GOOD

VENTING OUTLOOK FRIDAY THRU SUNDAY: GOOD




COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     37   14     400  11     81   19     950  13
FRASER VLY   QUIL     41   15     400  11    100   23    2050  13
SRN VRISL    QUIL     35   14     350   8     83   20    1050  11
CNTRL VRISL  QUIL     36   15     400   8    100   22    1550  13
NRN VRISL    HRDY     52   11     650   9     62   15     900   8
TERRACE      ANT      73   13    1350   8    100   20    3200  13
STEWART      ANT      61   14    1200   6    100   20    1950   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 WEDNESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    VR   5   VR   5   E   15
PORT HARDY   NW   9   VR   5   SE  13
SANDSPIT     S   33   S   43   S   52

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE      450 m          17 C
PORT HARDY      1200 m         20 C
ANNETTE         1600 m         18 C

TODAY'S VENTING: GOOD

VENTING FOR THURSDAY: GOOD

VENTING OUTLOOK FRIDAY THRU SUNDAY: GOOD




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


END/