FPCN39 CWLW 161330
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 16 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      29   12     500   6    100   16    2800  11
KAMLOOPS     KEL      18   10     500   6    100   16    3350  11
OKANAGAN     KEL       9    9     350   6    100   16    3350  11
CASTLEGAR    KEL      22    9     550  17    100   16    3500  12
CRANBROOK    KEL      10    5     950  14    100   12    3950   9
REVELSTOKE   KEL       9    8     450   6    100   14    3450  11

*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   W   20   NW  28
CRANBROOK             VR   5   W   19

           INVERSION HT    BREAKTHRU TEMP
KELOWNA          500 m          9 C
SPOKANE        missing         n/a

TODAY'S VENTING: GOOD.



VENTING FOR FRIDAY: GOOD.



VENTING OUTLOOK SATURDAY THRU MONDAY: Generally 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.     99    7    1850  18    100   12    3950  15
PR. GEORGE   P.G.     94    9    1700  15    100   13    3700  14
SMITHERS     P.G.      9    5     500   1    100   12    2300  13
WELLS GRAY   P.G.    100    7    2150  17    100   12    4000  15
FT NLSN      F.N.     30    8     550  13    100   15    2300  11
FT STJOHN    F.N.     30    7     800  10     74   11    1350  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 THURSDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            W   11   NW   9
SMITHERS              S   20   S    9

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE      None            6 C
FT. NELSON      600  m         12 C

TODAY'S VENTING: GOOD.




VENTING FOR FRIDAY: GOOD




VENTING OUTLOOK SATURDAY THRU MONDAY: GENERALLY GOOD.




COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     73    9     850  12    100   13    2000  10
FRASER VLY   QUIL     94   11    1650  10    100   16    3050  11
SRN VRISL    QUIL     76   10    1050  10    100   14    2050   9
CNTRL VRISL  QUIL     77   10    1100  10    100   14    2050   9
NRN VRISL    HRDY     36    8     400   8     90   12    1900   7
TERRACE      ANT     100    9    1400  28    100   13    2100  26
STEWART      ANT     100    9    1050  25    100   13    1750  25

*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   17   W   20   NW  28
PORT HARDY   S   33   S   30   SW  24
SANDSPIT     S   59   S   57   S   56

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE       200 m          7 C
PORT HARDY       150 m          7 C
ANNETTE         None m          7 C

TODAY'S VENTING: GOOD.




VENTING FOR FRIDAY: GOOD




VENTING OUTLOOK SATURDAY THRU MONDAY: GENERALLY GOOD.




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


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