FPCN39 CWLW 051358
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 5 APRIL 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      16   10     500   2     60   15    1500   7
KAMLOOPS     KEL      12    9     500   2     59   15    1600   5
OKANAGAN     KEL      14   10     550   2     59   15    1600   5
CASTLEGAR    SPOK     25    9     900   4     75   13    1950   7
CRANBROOK    SPOK     24    6    1200   6     72    9    2050   8
REVELSTOKE   KEL      10    8     500   2     54   12    1150   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 SUNDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    VR   5   VR   5   SE  15
CRANBROOK             VR   5   E   19

           INVERSION HT    BREAKTHRU TEMP
KELOWNA           600m         10 C
SPOKANE           850m          8 C

TODAY'S VENTING: GOOD.

VENTING FOR MONDAY: GOOD.

VENTING OUTLOOK TUESDAY THRU THURSDAY: 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.     23    2     500   5     90   12    2200  13
PR. GEORGE   P.G.     26    2     400   5     85   11    2100  12
SMITHERS     P.G.     40    4     600   8     82   11    1900  15
WELLS GRAY   P.G.     28    3     400   8     60   10    2000  15
FT NLSN      F.N.     23    2     500   5     54   10     800  14
FT STJOHN    F.N.     30    3     700   5     39    9     950  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 SUNDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            S   13   S   22
SMITHERS              S   31   S   22

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE      1100 m         10 C
FT. NELSON      1000 m         10 C

TODAY'S VENTING: GOOD

VENTING FOR MONDAY: GOOD

VENTING OUTLOOK TUESDAY THRU THURSDAY: GOOD

COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     80   10    1350   9     93   12    1650  10
FRASER VLY   QUIL     77   10    1250   9     95   13    1700  10
SRN VRISL    QUIL     63   10    1050   7     95   14    1800   9
CNTRL VRISL  QUIL     64   10    1100   7    100   15    2150   9
NRN VRISL    HRDY     27    8     600   4     69   11    1200   7
TERRACE      ANT     100    9    1900  33    100   12    2750  33
STEWART      ANT      63    8     400  18    100   12    2400  29

*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    SW  13   SW  17   SW  19
PORT HARDY   S   35   S   41   S   39
SANDSPIT     S   56   S   57   S   57

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE       300 m          8 C
PORT HARDY       100 m          7 C
ANNETTE          100 m          7 C

TODAY'S VENTING: GOOD.

VENTING FOR MONDAY: GOOD.

VENTING OUTLOOK TUESDAY THRU THURSDAY: GOOD.

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


END/MWSO