FPCN39 CWLW 101353
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 SUNDAY 10 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      13   17     600   1     80   26    2200   6
KAMLOOPS     KEL      19   17     750   3     80   26    2250   6
OKANAGAN     KEL      11   15     600   1     84   23    2250   6
CASTLEGAR    SPOK     45   17    1550   4     92   23    2250   9
CRANBROOK    SPOK      9   13    1030   2     80   23    2950   5
REVELSTOKE   KEL      24   17     850   4     80   24    2450   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 SUNDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    VR   5   VR   5   VR   5
CRANBROOK             VR   5   E   17

           INVERSION HT    BREAKTHRU TEMP
KELOWNA          850 m         17 C
SPOKANE         1800 m         20 C

TODAY'S VENTING:  BECOMING GOOD BY LATE MORNING.

VENTING FOR MONDAY: GOOD

VENTING OUTLOOK TUESDAY THRU THURSDAY:
FAIR TO GOOD IN THE AFTERNOONS AS THE AIR MASS DESTABILIZES WITH
AFTERNOON CONVECTION.

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    9     950   6    100   19    3950   6
PR. GEORGE   P.G.     17    9     800   7     87   19    2650   7
SMITHERS     P.G.     11    9     750   1     84   19    2600   6
WELLS GRAY   P.G.      9   10    1000   6    100   20    4000   6
FT NLSN      F.N.      9   10     400  16    100   20    2550   9
FT STJOHN    F.N.      9   11     700  16    100   18    2750   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 SUNDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            SE   9   S   17
SMITHERS              S   15   S   17

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE      1000 m         16 C
FT. NELSON       790 m         17 C

TODAY'S VENTING: BECOMING GOOD BY THE AFTERNOON.

VENTING FOR MONDAY: GOOD

VENTING OUTLOOK TUESDAY THRU THURSDAY: FAIR

COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     32   15     900   3     40   18    1250   3
FRASER VLY   QUIL     34   16    1000   3     45   20    1450   3
SRN VRISL    QUIL      9   13     800   0     40   18    1250   3
CNTRL VRISL  QUIL      9   15     850   0     29   20    1450   2
NRN VRISL    HRDY      9   10     800   5     65   16     900   9
TERRACE      ANT       9   12     950   5     80   20    2200   6
STEWART      ANT       9    8     950   3     80   20    1850   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 SUNDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    VR   5   VR   5   SE  13
PORT HARDY   VR   5   S   24   S   35
SANDSPIT     SW  19   S   20   S   33

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE      1460 m         20 C
PORT HARDY      1160 m         18 C
ANNETTE          640 m         12 C

TODAY'S VENTING: FAIR EXCEPT FARI TO GOOD OVER THE NORTH.

VENTING FOR MONDAY: GOOD

VENTING OUTLOOK TUESDAY THRU THURSDAY:
FAIR TO POOR BECOMING FAIR TO GOOD BY THURDAY AS A TROF MOVES THROUGH
DESTABILING THE AIRMASS.

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


END/LM