FPCN39 CWLW 161430
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 Wednesday 16 July 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   KEL      40   22    1350   3    100   28    3200   8

KAMLOOPS     KEL      56   21    1600   5    100   28    3350   8

OKANAGAN     KEL      29   20    1200   3    100   29    3350   8

CASTLEGAR    SPOK     39   20     850   9    100   28    2650  16

CRANBROOK    SPOK     23   19    1050  13    100   27    3950  19

REVELSTOKE   KEL      10   18     700   1    100   24    3450   8


*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   VR   5
CRANBROOK             VR   5   SW  15

           INVERSION HT    BREAKTHRU TEMP
KELOWNA          600 m         18 C
SPOKANE         1050 m         22 C

TODAY'S VENTING:
STRONG DAYTIME HEATING WILL OVERCOME THE MORNING INVERSION.
EXPECT GOOD VENTING TO DEVELOP BY MIDDAY.

VENTING FOR THURSDAY: GOOD

VENTING OUTLOOK FRIDAY THRU SUNDAY:
FAIR TO GOOD FRIDAY. GOOD ON THE WEEKEND.

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   15    3950  19    100   21    3950  19

PR. GEORGE   P.G.     93   15    1450  20    100   21    3700  19

SMITHERS     P.G.     41   14     850  12    100   20    3500  17

WELLS GRAY   P.G.    100   16    4000  19    100   22    4000  19

FT NLSN      F.N.     71   15    1000  15    100   17    1500  19

FT STJOHN    F.N.    100   17    2250  20    100   22    3700  21


*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            W   19   W   22
SMITHERS              W   19   W   22

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE       790 m         13 C
FT. NELSON       NIL m         ## C

TODAY'S VENTING:
ONLY SHALLOW INVERSION PRESENT THIS MORNING. LOW LEVEL WINDS AND
SURFACE HEATING WILL HELP GENERATE GOOD VENTING NEAR MIDDAY.

VENTING FOR THURSDAY: GOOD

VENTING OUTLOOK FRIDAY THRU SUNDAY:
GOOD VENTING IN THE AFTERNOON.

COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     63   18     950   8     73   21    1200   8

FRASER VLY   QUIL     53   16     800   7     82   22    1450   8

SRN VRISL    QUIL     57   18     900   7     78   23    1550   7

CNTRL VRISL  QUIL     57   18     950   7     76   23    1550   7

NRN VRISL    HRDY     19   14     100  11     81   18    1050  11

TERRACE      ANT      30   15    1200   2     45   19    2200   2

STEWART      ANT      26   15     550   3     47   19    1750   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 WEDNESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    W    9   VR   5   VR   5
PORT HARDY   NW  33   N   24   NW  17
SANDSPIT     NW  20   W   17   W   20

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE      NR SFC         ## C
PORT HARDY      NR SFC         ## C
ANNETTE         NIL  m         ## C

TODAY'S VENTING:
LITTLE SIGN OF AN INVERSION THIS MORNING. WEAK WINDS IN THE NORTH
MAY PRECLUDE GOOD VENTING ALTHOUGH A SHORT WINDOW IS LIKELY IN THE
AFTERNOON. ELSEWHERE EXPECT GOOD VENTING BUT LOW MIXING HEIGHTS FOR
THE DAY.

VENTING FOR THURSDAY: GOOD

VENTING OUTLOOK FRIDAY THRU SUNDAY:
FAIR TO GOOD.

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

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