FPCN39 CWLW 191434
SMOKE CONTROL FORECAST FOR COASTAL BC AND THE INTERIOR INCLUDING THE
NORTHEAST ISSUED BY THE MOUNTAIN WEATHER SERVICE OFFICE OF
ENVIRONMENT CANADA AT 8:00 AM PDT Monday 19 May 1997 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   P.G.     15   15     400   4    100   19    3200  12
KAMLOOPS     P.G.     15   14     550   4    100   19    3350  12
OKANAGAN     P.G.     15   12     550   4    100   19    3350  12
CASTLEGAR    P.G.     15   13     700   4    100   20    3500  12
CRANBROOK    P.G.     15   10    1100   4    100   16    3950  14
REVELSTOKE   P.G.     15   12     550   4    100   18    3450  12

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

FORECAST UPPER WINDS FOR MONDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    VR   5   W   13   W   19
CRANBROOK             SW  13   SW  31

           INVERSION HT    BREAKTHRU TEMP
KELOWNA          600 m         16 C
SPOKANE          800 m         16 C

TODAY'S VENTING: A COLD FRONT WILL SLIDE SOUTHWARD ACROSS THE
SOUTHERN INTERIOR TODAY. THE AIRMASS WILL BECOME UNSTABLE IN
THE WAKE OF THE FRONT. AS A RESULT VENTING WILL BECOME GOOD.

VENTING FOR TUESDAY: GOOD

VENTING OUTLOOK WEDNESDAY THRU FRIDAY: CONTINUING 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.    100    9    3950  14    100   14    3950  14
PR. GEORGE   P.G.     94    9    1950  12    100   12    3700  13
SMITHERS     P.G.     79   10    1500  11    100   15    3500  12
WELLS GRAY   P.G.    100    8    4000  14    100   15    4000  14
FT NLSN      F.N.     62    9    1000  12    100   12    2400  19
FT STJOHN    F.N.      9    5     700  12     81    7    1500  14

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

FORECAST UPPER WINDS FOR MONDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            NE  54   NE  61
SMITHERS              NE  31   NE  61

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE      NONE m         ## C
FT. NELSON       600 m          9 C

TODAY'S VENTING: AN UNSTABLE AIRMASS WILL GIVE GOOD VENTING.

VENTING FOR TUESDAY: GOOD

VENTING OUTLOOK WEDNESDAY THRU FRIDAY: CONTINUING GOOD.




COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     40   14     300  15     90   17    1200  15
FRASER VLY   QUIL     41   14     300  15     90   20    1200  15
SRN VRISL    QUIL     17   14     300   3     90   20    1200  15
CNTRL VRISL  QUIL     18   15     350   3     90   21    1200  15
NRN VRISL    HRDY    100   12    1200  18    100   15    1350  19
TERRACE      ANT     100   13     900  27    100   22    3200  26
STEWART      ANT     100   15     900  23    100   22    3000  24

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

FORECAST UPPER WINDS FOR MONDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    W   20   W   24   NW  22
PORT HARDY   NW  33   N   37   N   39
SANDSPIT     N   54   NE  41   NE  37

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE       700 m         22 C
PORT HARDY      NONE m         ## C
ANNETTE          850 m         16 C

TODAY'S VENTING: A COLD FRONT WILL SLIDE SOUTHWARD ACROSS THE
SOUTH COAST THIS AFTERNOON. THE AIRMASS WILL BECOME UNSTABLE
NORTH OF THE FRONT. AS A RESULT GOOD VENTING IS FORECAST.

VENTING FOR TUESDAY: GOOD

VENTING OUTLOOK WEDNESDAY THRU FRIDAY: CONTINUING GOOD.




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

END/JDG